Immune Thrombocytopenic Purpura Patient & Family Handbook

Immune Thrombocytopenic Purpura

A Handbook for Patients and Families • Hematology Series

Immune Thrombocytopenic Purpura

A Handbook for Patients and Families

Authors Karyn J. Brundige, MSN RN CPNP Joana R. Duran, MSN PNP CNS Kimberly Jacobson, MSN RN CPNP CPON® Joan O’Brien-Shea, MSN RN CPON® Beth Savage, MSN CPNP CPON®

Content Reviewers APHON Steering Council

Parent and Patient Reviewers Karen Waisnor (parent) Emerson Waisnor (patient)

This handbook is published by the Association of Pediatric Hematology/Oncology Nurses (APHON) for educa- tional purposes only. The material has been developed by sources believed to be reliable. The material is not intended to represent the only acceptable or safe treatment of immune thrombocytopenic purpura. Under cer- tain circumstances or conditions, additional or different treatment may be required. As new research and clinical experience expand the sources of information available concerning the treatment of immune thrombocytopenic purpura, adjustments in treatment and drug therapy may be required. APHON makes no warranty, guarantee, or other representation, express or implied, concerning the validity or sufficiency of the treatments or related information contained in this handbook. APHON Handbooks for Patients and Families have been developed by healthcare providers who have been edu - cated and currently practice primarily in the United States. APHON acknowledges that treatments and practices presented in this handbook, which are commonly or widely recognized as standard in the United States, may differ from those in other countries. APHON encourages users to defer to their governing body’s preferred treat - ment and practice methods and healthcare providers’ advice. APHON provides this handbook for educational use. Users may copy and distribute this material in unadapted form only, for noncommercial use, and with attribution given to APHON.

WHAT IS ITP? ITP stands for immune thrombocytopenic purpura. ITP occurs when the body’s immune system does not work correctly and results in thrombocytopenia , a decrease in the number of platelets. Platelets are cells in our blood that help form clots to prevent or stop bleeding. When the platelet count is low, the risk of bruising and bleeding increases. One may also develop tiny blood spots under the skin or inside the mouth (petechiae). A normal platelet count is between 150,000 and 400,000. In children with ITP, the plate - let count is less than 100,000. Bleeding after

a minor injury may occur when the platelet count is less than 50,000. The most serious risk of bleeding occurs when the platelet count is less than 20,000. When the count is this low, bleeding may occur without any injury. The cause of ITP is not always known, but it often occurs after a viral illness or infection. It can also be associated with some medications and with autoimmune disorders such as lupus. To fight infections, white blood cells make special proteins called antibodies . These antibodies attach to infection-causing agents such as bacteria and viruses that have invaded the body. Anything the antibody attaches to is seen as foreign by the body. The spleen is an organ that filters the antibody-coated viruses or bacteria out of the blood. In ITP, these same antibodies attach themselves to healthy platelets. The antibodies tell the body that these platelets are foreign and the spleen destroys them. As long as antibodies are attached to the platelets, the spleen will continue to remove as many platelets as possible from the body, resulting in a decreased number of platelets in the blood. Platelets are made in the bone marrow by large cells called megakaryocytes. Thrombopoietin, a protein made by the liver, controls how many platelets are made by the megakaryocytes. In some cases of ITP, not enough throm - bopoietin reaches the bone marrow. When this happens, the megakaryocytes do not make enough new platelets to replace those being destroyed. Most cases of ITP are temporary, or acute . More than 80% of ITP cases in children go away in fewer than 6 months. This happens when the body stops making antibodies against the platelets. Depending on the number of platelets and the risk for serious bleeding, your provider may recommend medications to help manage ITP. If ITP lasts more than 6–12 months it is called chronic . Chronic ITP may also need to be managed with medications or just observed to make sure that no serious bleeds occur.

WHO GETS ITP? ITP can occur in children and adults. Newborns can develop ITP shortly after birth if the child’s mother had ITP during pregnancy. Children are more likely to have acute ITP, while teenagers are more likely to have chronic ITP. Boys and girls are affected equally. ITP is not contagious; it cannot be passed from one person to another. ITP is not inherited.

WHAT ARE SOME SYMPTOMS OF ITP? • Bruising, especially if the bruises cannot be explained by injuries, they are located in uncommon places (like the head or chest), or more bruises exist than are expected. • Petechiae (flat, pinpoint-sized red or purple dots) caused by minor bleeding appear under the skin.

• Nose bleeds and mouth bleeding from gums occur. • Heavy menstrual bleeding (heavy periods) occurs. • Blood appears in urine or stool.

• Confusion, seizures, weakness, or loss of consciousness occur. In rare cases, these symptoms may indi - cate intracranial (brain) hemorrhage or other internal bleeding (for example, in the stomach or lungs).

HOW IS ITP DIAGNOSED? Most children are diagnosed with ITP when their platelet count drops very low and they develop symptoms. To diagnose ITP, your healthcare provider will draw a sample of blood from your child to check the number of platelets. A low platelet count (less than 100,000) but a normal number of other blood cells (red cells and white cells) will usually indicate ITP. Your healthcare provider may ask questions about medications that your child is taking and about recent infections, vaccinations, or immune disorders that may be affecting your child. The healthcare pro - vider will also examine your child for signs of a low platelet count (bruising or petechiae) or infection (enlarged lymph nodes, liver, or spleen). The healthcare provider may also do blood tests to determine if antibodies are being made against the platelets or if there is a higher than normal percentage of immature (young) platelets in the blood. Low platelet counts may also be found in children with other conditions that affect the bone marrow. For this reason, the healthcare provider may ask to do a bone marrow aspiration and biopsy. This test will show whether the platelets are still being made as expected and whether any abnormal cells in the bone marrow are causing your child’s symptoms. During a bone marrow aspiration and biopsy, a needle is inserted into the marrow inside the bone. Some of the marrow (biopsy) and the fluid in the marrow (aspirate) are collected. Patients undergoing bone marrow aspirations and biopsies may experience pain, so children often are sedated for this procedure. If your child is uncomfortable after the test, a mild pain medication such as acetaminophen (Tylenol®) may be given, but not ibuprofen (Motrin® or Advil®) or aspirin.

HOW IS ITP TREATED? WHAT ARE THE SIDE EFFECTS OF TREATMENT? Most cases of childhood ITP get better without treatment. Simply monitoring the child’s platelet count, known as observation , is one type of treatment. With time, the body usually stops making antibodies against the platelets. Your child’s platelet count may be low for several weeks or months. As the antibody level decreases, the platelets are no longer destroyed, and the platelet count increases.

While waiting for the white blood cells to stop making these antibod - ies, the body is aware of the low platelet count. As a result, the bone marrow (where platelets are made) will work harder to produce young, larger platelets that can do the job of the many older, smaller platelets. Your healthcare provider may order blood tests to monitor your child’s platelet count. As the platelet count improves, these tests will be needed less often. If the platelet count is low because of a medication, then the medication may be stopped or changed. If the low platelet count is caused by an infection or immune system disorder, then that infection or disorder will be treated, if possible. Treatment for ITP will be required only if your child has a very low platelet count, is bleeding, or wants to participate in sports or other activities that require a higher platelet count. Treatments for ITP include medications and surgery. Your doctor or nurse practitioner will talk to you about the possible benefits and risks of different treatments. Together you can decide what treatment, if any, is best for your child.

Medications do not cure ITP. The most common medications used to treat ITP decrease the number of platelets being destroyed by the spleen. This will increase the platelet count to a safe range so the risk of serious bleed - ing is lowered. The body may still be making antibodies against the platelets, and treatments may need to be repeated for several weeks or months until the body stops destroying its own platelets. These medications include intravenous immune globulin (IVIG) and steroids. A newer class of medications, including romiplostim and eltrombopag, work by increasing the number of platelets made in the bone marrow. Intravenous Immune Globulin (IVIG) IVIG is made from the plasma of human blood. Blood is made up of three different types of cells (red cells, white cells, and platelets) and plasma (the liquid part of the blood). Immunoglobulins, or antibodies, are proteins in the plasma that help the body fight infections. Healthy people can donate their blood or plasma. Immunoglobulins are removed from the plasma of thousands of people and pooled together to make one dose of IVIG. The IVIG is treated to make the product pure (free of other blood proteins) and safe (free of viruses that can cause infection). It is not clear how IVIG works to treat ITP. In ITP, the spleen destroys antibody-coated platelets in the blood. The IVIG may bind to antibody receptors in the spleen. If the receptors in the spleen are blocked by IVIG, they cannot attach to the antibodies on the platelets. IVIG does not cure ITP but will usually result in a rapid (24–48 hours) platelet increase in more than 75% of chil - dren with ITP. This increase in platelets may last for several weeks. If the body is still making antibodies against the platelets when the IVIG is gone, the platelet count may start to drop again. IVIG is a liquid that is given into a vein (intravenously). Medicines can be used to numb the skin on your child’s hand or arm before the needle is placed into the vein. The IVIG infusion rate is started slowly and is then

increased if no side effects occur. The infusion may take several hours. IVIG is usually given in the infusion unit or a hospital. A nurse will monitor your child for side effects. Most reactions to IVIG occur during the infusion, and some side effects may occur 1–3 days after the infusion. Your child may be given diphenhydr - amine (Benadryl®) or acetaminophen (Tylenol®) before the IVIG infusion to decrease the chance of side effects. Common side effects of IVIG include • headache • fever or chills • nausea or vomiting • hives or rash

• feeling tired (fatigue) • muscle or joint pain.

There is a small chance that your child may have a severe allergic reaction to IVIG. If this happens, the infusion is stopped and medications to treat the allergic reaction are given immediately. There is a very small risk that the IVIG may contain viruses that cause infection.

IVIG may prevent some live vaccines from being effective. Live vaccines used to immunize children against diseases like measles, mumps, and rubella (MMR) and chickenpox should not be given for several months after a child receives IVIG. Steroids (Glucocorticoid Steroid Hormones) Steroids, which are natural substances made by the body, are important for many body functions. One steroid is cortisone , a chemical made by the adrenal glands (small organs above the kidneys). Prednisone and dexametha- sone are synthetic (man-made) medicines that are similar to cortisone. These types of steroids are different from the anabolic steroids that are used to build muscles. It is not clear how steroids work to treat ITP, but they may decrease the number of antibodies being made against the platelets and may slow the rate at which the antibody-coated platelets are removed by the spleen. Steroids may also make the blood vessels more stable, lowering the risk of bleeding. Steroids do not cure ITP, but they increase the platelet count in more than 75% of children with ITP. If the body is still making antibodies against the platelets when the steroid dose is decreased or stopped, the platelet count may drop again. Typically, steroids are given by mouth as a pill or a liquid. Your child’s healthcare provider will prescribe how much medicine should be taken. Steroids may be given orally (by mouth) in different ways: • in very high doses over a few days • in high doses for several days followed by a special dosing schedule to stop the medication by slowly decreasing the amount taken (a taper) • in low doses for several weeks or months. Make sure that you understand how to give the medicine and what to do if your child refuses the medicine or vomits a dose.

Steroids also can be given into a vein (intravenously) instead of being taken by mouth. IV steroids are usually given in an infusion unit or a hospital, and medicines can be used to briefly numb the skin on your child’s hand or arm before the needle is placed in the vein. The steroid is given over a few minutes. Common side effects of steroids include • heartburn (reflux) • increase in appetite or weight gain • mood changes • puffiness in the face or behind the neck • problems with sleep • acne.

Most of the common side effects of steroids will get better when the medication is stopped. Children who take steroids for weeks or months may have other side effects, including elevated blood pressure, increased sugar in the blood or urine, risk of infection, thinning of the skin, problems with growth, or calcium loss from the bones. Because of these risks, steroids are usually given only for a few weeks or months at a time. Contact your healthcare provider immediately if your child • is exposed to chickenpox and has not yet had chickenpox or received the vaccine • is drinking more or has an increase in the amount of urine • has black, tar-like stools.

Thrombopoietic Agents Thrombopoietic agents are human-made proteins that increase the number of platelets made in the bone marrow. They are typically used only for patients who have chronic ITP or who have ITP that has not responded to medications that decrease platelet destruction such as IVIG or steroids. Romiplostim (Nplate®) and eltrombopag (Promacta®) are two thrombopoietic medications that are used to treat ITP. Romiplostim is given by subcutaneous injection (under the skin) once a week. The amount given is based on the platelet count. Romiplostim must be given in a doctor’s office or by a caregiver who

has been taught how to administer the medication to the child at home. It is important not to miss an injection. The platelet count may drop very low if the medication is not given on a regular basis. Common side effects of romiplostim include

• headache • dizziness • trouble sleeping (insomnia) • abdominal pain • joint or muscle pain • rebound thrombocytopenia • antibody formation.

Less common but serious side effects of romiplostim include blood clots and changes inside the bone marrow. Your healthcare provider will discuss how to watch for these side effects and whether any special tests are needed to monitor for these side effects. People who use romiplostim have an increased risk of developing bone marrow changes. Your doctor may check your child’s bone marrow to monitor for this. Eltrombopag is given by mouth daily. The dose may be adjusted based on platelet count. Liver function tests will also be monitored while taking this medication. People of East Asian descent require a lower starting dose and monitoring for dose adjustment. Eltrombopag should be taken 4 hours before or after antacids and multivita - mins as they may interact with these medications. Common side effects of eltrombopag include • nausea or vomiting • diarrhea • muscle aches, back pain • abnormal results on liver function tests that aren’t associated with liver toxicity • skin rash, itching • runny or stuffy nose.

Less common but serious side effects of eltrombopag include blood clots, flu- like symptoms, and liver problems. Your healthcare provider will discuss how to watch for these side effects.

Transfusions Most children with ITP make enough platelets, but they also make antibodies against their platelets. The spleen quickly destroys platelets that are coated with an antibody. These antibodies can also bind to platelets that are transfused. When transfused platelets are coated with the antibody, the spleen quickly destroys them. For this reason, platelet transfusions are used only if a child has serious bleeding. Other Medical Treatments Some children with ITP do not respond to IVIG or steroids. If your child has a low platelet count or bleeding despite these treatments, your doctor or nurse practitioner may discuss other treatments. Alternative treatments for ITP include chemotherapy (for example, vincristine, cyclophosphamide, or mercaptopurine), drugs that suppress the immune system (such as mycophenolate and cyclosporine), or a medication (like rituximab) that decreases the number of B-lymphocytes, the white blood cells that make antibodies. Complementary Therapies Some families want to try complementary or natural therapies to treat their child’s ITP. Complementary therapies may include the use of supplements, herbs, or vitamins; homeopathy; or a change in diet. These treatments have not been studied in children with ITP, and we do not know if they are helpful. We do know that some complementary therapies may be harmful because they decrease the platelet count or affect how well the platelets work to stop bleeding. Please talk to your child’s healthcare provider if you want to try complementary or natural therapies.

Medicines to Avoid Children with ITP should not take medicines that decrease their platelet count or inhibit the platelets’ work to stop bleeding. These medications include aspirin and ibuprofen (Advil® or Motrin®). It may not be obvious that a product contains aspirin or ibuprofen. You should always check the medication label and call your healthcare provider if you have any concerns. Because some herbs and supplements may be harmful, be sure to tell your child’s healthcare provider all the medicines that your child is taking, including medications that do not require a prescription.

Surgery The spleen is an organ on the upper left side of the abdo - men under the ribs. The spleen cleans the blood and removes old blood cells. The spleen also helps to fight infections. In ITP, white blood cells in the spleen called B-lymphocytes produce antibodies against platelets. Plate- lets that are coated with antibodies are removed from the blood by the spleen. Removing the spleen often helps to increase the platelet count. Surgery to remove the spleen is called a splenectomy . About 75% of children with ITP are cured with a splenec - tomy; however, this is a major surgery with a risk of serious

bleeding during the procedure. After the spleen is removed, your child will have an increased risk of infection for the rest of their life. After a splenectomy, your healthcare provider may recommend that your child take antibiot - ics by mouth once a day to prevent blood infections. Fever in a child who has had a splenectomy is a medical emergency. If your child has had a splenectomy and has a fever, it is important to see your healthcare provider right away. Because of these risks, splenectomy is only used to treat children who have had a low platelet count for more than 1 year or who have serious bleeding that does not respond to medications. HOW CAN I WORK WITH THE HEALTHCARE TEAM? The care of your child requires a team approach. You are a key player on your child’s healthcare team. You know your child better than anyone else, and your input is important. Other members of your child’s healthcare team include doctors, nurses, pharmacists, and social workers. Always communicate openly with the members of your child’s healthcare team. If there is anything you are not sure about, ask the team. Write down your questions as you think of them, so you’ll remember to ask them dur - ing your next meeting with your healthcare team. • Is the ITP chronic or acute, and what does that mean? • What treatment choices are available? • What treatment do you recommend, and why?

• What are the risks or side effects during the treatment? • What are the risks and side effects after the treatment? • How will ITP impact my child’s daily life and future? • What are the chances that the ITP will recur (happen again)?

Use the lines below to write down any other questions you might want answered.

CAN MY CHILD ATTEND SCHOOL AND PARTICIPATE IN ACTIVITIES DURING THERAPY?

Your child’s ability to go to school during therapy will depend on the intensity of the treatment and your child’s response to treatment. There may be periods when your child is unable to go to school because of hospitalizations or treatments. However, it is important that your child keep up with schoolwork, even when unable to attend in person. Federal laws protect children with disabilities or illnesses to ensure that they receive the same education as their peers. Talk with your child’s healthcare team and school staff about these laws. Then work with them in arranging for a tutor or other ways to help your child stay on track with schoolwork.

Discuss with the healthcare team your child’s ability to attend school. Most children are able to attend school between hospitalizations or treatments. Many hospitals and clinics have resource educational liaisons to assist in coordinating school services and educating teachers and classmates to prepare them for your child’s return to school. When your child’s platelet count is low, your healthcare provider may limit the types of physical activities in which your child can participate. For a child who wants to play sports, this can be very frustrating. Explain to your child why this activity is not allowed at this time, and choose other activities that are safe even for someone with a low platelet count.

ARE MY FEELINGS NORMAL? Hearing that your child has a disease can be overwhelming. It is important to know that this is normal and expected. Most families have difficulty processing all the information the healthcare team is providing in the beginning. However, over time, the information will be repeated and can be absorbed. Many families feel somehow responsible for their child’s disease. Feelings of guilt also are common over not being able to protect their child from illness or because of the amount of time it took to diagnose the child. This disease is not caused by anything that you did or did not do. Feelings of sadness, anger, and helplessness about your child’s diagnosis also are common. These feelings are normal. Each member of the family may express these emotions in different ways and at different times. Talking honestly with one other about these feelings, emotions, and reactions will help everyone in the family. Keep in mind that there is no right or wrong way to feel. Each member of the family needs the chance to express their feelings in their own way when they are ready. Talking to friends, family, and members of the healthcare team can be difficult at times—however, sharing your feelings can help you cope. Your child will benefit from family and friends showing their care through communi - cation and support. HOW CAN I HELP MY CHILD? Children often think that something they did caused their disease. You can help your child by reinforcing that this is not the case. Make sure your child understands that your feelings of anger and sadness are directed at the disease, not at them. This will help you keep a close relationship with your child. Your child will need to share their feelings with someone that they trust, and they may choose someone other than a parent to avoid upset - ting the parent, which is OK. Don’t be afraid to ask your child about their feelings—it may be what your child is waiting for. Keep in mind that your child is still a child in spite of the disease. Children going through treatment still have all the needs of a growing child. All children need love, attention, the opportunity to learn and try new skills, and limits. Do not avoid talking to your child about therapy. Use explanations that your child will understand. Children tolerate treatment better if they understand it and are allowed to help make decisions about their care, when appropriate. The things children can imagine on their own are often more frightening than what is actually happening. As a parent, you may find it difficult to watch your child go through treatment. Your child may sometimes seem sicker during treatment than before treatment. Your feelings about what your child is going through must be bal - anced with the knowledge that treatment provides the chance of curing the disease and making it possible for your child to live a full and meaningful life. It’s difficult to accept how treatment may change your child, but most of these changes are temporary. Despite outward changes, your child is still the same person on the inside. Many healthcare centers have a psychosocial team that can support you and your child through this illness.

IS MY CHILD’S DIET IMPORTANT DURING THERAPY? Yes, your child’s diet is important. Research has shown that well-nourished children tolerate treatment better and experience fewer treatment delays. Your child may have difficulty eating normal meals during treatment. Foods that are appealing to your child will be tolerated better. Offer foods that are high in calories, protein, and carbohydrates. Small frequent meals are often better tolerated than three larger meals. When possible, choose more nutri- tious foods. Your child’s nurse or dietitian can help you put together a list of possible food choices. If your child is on steroid medications, such as prednisone or dexamethasone

(Decadron®), are part of the treatment, your child’s appetite will likely be increased. These medicines may make your child feel constantly hungry and crave unusual foods. Your child may want one particular food constantly. Try to keep healthy snacks on hand. Steroids may cause your child to gain weight and develop a round face and puffy appearance, but these side effects are temporary. It is important to offer your child fluids to drink frequently throughout the day so that dehydration is avoided. Signs of dehydration include decreased urine output, dizziness, and a dry mouth. Multivitamins, herbs, and other supplements should be avoided unless approved by your child’s healthcare team because they can interact with your child’s treatment. Please ask your healthcare team if you are considering having your child take any of these types of supplements. A dietitian may be a member of your child’s healthcare team. Dietitians are trained in the calorie and nutritional needs of children. The dietitian can provide you with education regarding your child’s dietary needs and ideas about how to meet these needs during treatment. Your child’s healthcare team will monitor your child’s nutri - tional status, height, and weight during and after treatment to try to prevent problems. When a concern about nutrition arises, your child’s healthcare team will discuss with you the ways to manage and improve your child’s nutrition.

RESOURCES Foundation for Women & Girls with Blood Disorders’ ITP page fwgbd.org/resources/itpresources ITP Support Association (UK) www.itpsupport.org.uk National Heart, Lung, and Blood Institute nhlbi.nih.gov/health/immune-thrombocytopenia Platelet Disorder Support Association pdsa.org

Platelets on the Web ITP page ouhsc.edu/platelets/itp.html

BIBLIOGRAPHY Blanchette, V., Imbach, P., Andrew, M., Adams, M., McMillan, J., & Wang, E., Milner, R., Ali, K., Barnard, D., & Bernstein, M. (1994). Randomised trial of intravenous immunoglobulin G, intravenous anti-D, and oral prednisone in childhood acute immune thrombocytopenic purpura. Lancet , 344 (8924), 703–707. https://doi.org/10.1016/s0140-6736(94)92205-5 Immune thrombocytopenic purpura. (2005). In R. Hillman, K. Ault, & H. Rinder (Eds.), Hematology in clinical practice (4th ed.). McGraw-Hill Companies, Inc. Kuhne, T., Buchanan, G. R., Zimmerman, S., Michaels, L. A., Kohan, R., Berchtold, W., & Imbach, P. (2003). A prospective comparative study of 2540 infants and children with newly diagnosed idiopathic thrombocytopenic purpura (ITP) from the Intercontinental Childhood ITP Study Group. Journal of Pediatrics , 143 (5), 605–608. https://doi.org/10.1067/s0022-3476(03)00535-3 Nathan, D. G., Orkin, S. H., Look, A., & Ginsburg, D. (2003). Hematology of infancy and childhood (6th ed). Saunders. National Heart, Lung, and Blood Institute. (n.d.). Immune thrombocytopenia . https://www.nhlbi.nih.gov/health-topics/immune- thrombocytopenia O’Brien, S. H., Ritchey, A. K., & Smith, K. J. (2007). A cost-utility analysis of treatment for acute childhood idiopathic thrombocytopenic purpura (ITP). Pediatric Blood and Cancer , 48 (2), 173–180. https://doi.org/10.1002/pbc.20830 Orkin, S. H., Nathan, D. G., Ginsburg, D., Look, A. T., Fisher, D. E., & Lux, S. E., IV. (2009). Nathan and Oski’s hematology of infancy and childhood (7th ed., pp. 1157–1565). Saunders Elsevier. Rosenberg, S. (2014) Immune thrombocytopenic purpura. In N. Kline (Ed.), Essentials of pediatric hematology/oncology nursing: A core curriculum (4th ed.). Association of Pediatric Hematology/Oncology Nurses. Shad, A. T., Gonazalez, C. E., & Sandler, S. G. (2005). Treatment of immune thrombocytopenic purpura in children: Current concepts. Pediatric Drugs , 7 (5), 325–336. https://doi.org/10.2165/00148581-200507050-00004

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Púrpura trombocitopénica inmune

Manual para pacientes y familiares • Serie Hematología

Manual para pacientes y familiares Púrpura trombocitopénica inmune

Autores Karyn J. Brundige, MSN RN CPNP Joana R. Duran, MSN PNP CNS Kimberly Jacobson, MSN RN CPNP CPON® Joan O’Brien-Shea, MSN RN CPON® Beth Savage, MSN CPNP CPON®

Revisor de contenido APHON Steering Council

Revisores por parte de padres y pacientes Karen Waisnor (parent) Emerson Waisnor (patient)

La Association of Paediatric Hematology/Oncology Nurses (APHON) publica este manual únicamente con fines educativos. El material ha sido desarrollado por fuentes consideradas confiables. El material no pretende representar el único tratamiento aceptable o seguro del la púrpura trombocitopénica inmune. Bajo ciertas circunstancias o condiciones, se puede requerir un tratamiento adicional o diferente. A medida que las nuevas investigaciones y la experiencia clínica amplíen las fuentes de información disponibles sobre el tratamiento de la púrpura trombocitopénica inmune, es posible que se requieran ajustes en el tratamiento y la farmacoterapia. APHON no ofrece ninguna garantía, seguridad u otra representación, expresa o implícita, con respecto a la vali- dez o suficiencia de los tratamientos o la información relacionada contenida en este manual. Los manuales APHON para pacientes y familiares han sido desarrollados por proveedores de atención médica con formación y que actualmente ejercen en los Estados Unidos, principalmente. APHON reconoce que los tratamientos y prácticas presentados en este manual, comúnmente o ampliamente reconocidos como estándar en los Estados Unidos, pueden diferir de los de otros países. APHON alienta a los usuarios a referirse a los méto- dos de tratamiento y prácticas preferidos de su organismo rector y al consejo de los proveedores de atención médica. APHON proporciona este manual únicamente para uso educativo. Los usuarios pueden copiar y distribuir este material sólo en su forma no adaptada, para uso no comercial y con atribución otorgada a APHON.

¿QUÉ ES LA ITP? ITP significa Púrpura Trombocitopénica Inmune. Ocurre cuando el sistema inmuni- tario del cuerpo no funciona bien y provoca trombocitopenia , la disminución de la canti- dad de plaquetas. Las plaquetas son células que ayudan a formar coágulos para prevenir o detener el sangrado. Cuando el recuento de plaquetas es bajo, aumenta el riesgo de hematomas y sangrado. Se pueden desar- rollar pequeñas manchas de sangre debajo de la piel o dentro de la boca (petequias). Un recuento normal de plaquetas es de 150.000 a 400.000. En niños con ITP, el recuento es inferior a 100.000. Cuando es

menor a 50.000, puede ocurrir un sangrado después de una lesión menor. El riesgo más grave de hemorragia es cuando el recuento de plaquetas es inferior a 20.000. Con un conteo tan bajo, el sangrado puede ocurrir sin ninguna lesión. No siempre sabemos la causa de la ITP, pero suele darse después de una enfermedad o infección viral. También puede asociarse con algunos medicamentos y con trastornos autoinmunes como el lupus. Para combatir infecciones, los glóbulos blancos producen proteínas especiales llamadas anticuerpos. Estos anti- cuerpos se adhieren a los agentes causantes de infecciones, como bacterias y virus que han invadido el cuerpo. Cualquier cosa a la que se adhiera el anticuerpo es vista como extraña por el cuerpo. El bazo es un órgano que filtra los virus o bacterias recubiertos de anticuerpos. En la ITP, estos mismos anticuerpos se adhieren a las plaquetas sanas. Los anticuerpos le dicen al cuerpo que estas plaquetas son extrañas y el bazo las destruye. Mientras los anticuerpos estén adheridos a las plaquetas, el bazo continuará eliminando la mayor cantidad posible de plaquetas del cuerpo, lo que resultará en una disminución del número de plaquetas en la sangre. Las plaquetas son producidas en la médula ósea por células grandes llamadas megacariocitos. La trombopoyetina, una proteína producida por el hígado, controla la cantidad de plaquetas que producen los megacariocitos. En algunos casos de ITP, no llega suficiente trombopoyetina a la médula ósea. Cuando esto sucede, los megacariocitos no producen suficientes plaquetas nuevas para reemplazar las que se destruyen. La mayoría de los casos de ITP son temporales o agudos. Más del 80% de los casos en niños desaparece en menos de 6 meses. Esto sucede cuando el cuerpo deja de producir anticuerpos contra las plaquetas. Según la cantidad de plaquetas y el riesgo de sangrado grave, se recomendarán medicamentos para ayudar a controlar la ITP. Si ésta dura más de 6 a 12 meses, se denomina crónica y es posible que esta ITP crónica también deba controlarse con medicamentos o simplemente observarse para asegurarse de que no haya hemorragias graves.

¿A QUIÉN LE PUEDE DAR ITP? La ITP puede ocurrir en niños y adultos. Los recién nacidos pueden desarrollar ITP poco después del nacimiento si la madre la tuvo durante el embarazo. Los niños tienen más probabilidades de tener ITP aguda, mientras que los adolescentes tienen más probabilidades de tener ITP crónica. Los niños de ambos sexos se ven afectados por igual. La ITP no es contagiosa; no se puede pasar de una persona a otra y no se hereda.

¿CUÁLES SON ALGUNOS SÍNTOMAS DE LA ITP? • Hematomas, especialmente si no se pueden explicar por lesiones y están ubicados en lugares poco comunes (como la cabeza o el pecho), o hay más hematomas de los esperados. • Petequias (puntos planos rojos o morados del tamaño de una punta de alfiler) causadas por un sangrado menor. • Hemorragias nasales y bucales de las encías. • Sangrado menstrual abundante (períodos abundantes). • Sangre en la orina o las heces. • Confusión, convulsiones, debilidad o pérdida del conocimiento. En casos raros, estos síntomas pueden indi- car hemorragia intracraneal (cerebro) u otra hemorragia interna (p. ej. en el estómago o los pulmones) .

¿CÓMO SE DIAGNOSTICA LA ITP? La mayoría de los niños son diagnosticados con ITP cuando su recuento de plaquetas baja mucho y desarrollan síntomas. Para el diagnóstico, el proveedor de atención médica le extraerá una muestra de sangre para checar la cantidad de plaquetas. Un recuento bajo de plaquetas (menos de 100 000) pero con un número normal de otras

células sanguíneas (glóbulos rojos y glóbulos blancos) generalmente indicará ITP. Te pregun - tarán sobre los medicamentos que tu hijo(a) está tomando y sobre infecciones recientes, vacunas o trastornos inmunitarios que le puedan estar afectando. También examinará a tu hijo(a) en busca de signos de un recuento de plaquetas bajo (moretones o petequias) o alguna infección (ganglios linfáticos agrandados, hígado o bazo). El proveedor de atención médica hará análisis de sangre para ver si se están produciendo anticuerpos contra las plaquetas o si hay un porcentaje más alto de lo normal de plaquetas inmaduras (jóvenes) en la sangre. También puede haber recuentos bajos de plaquetas en niños con otras condiciones que afectan la médula ósea. Se puede solicitar una aspiración y una biopsia de la médula ósea, que mostrará si las plaquetas todavía se están produciendo como se esperaba y si alguna célula anormal en la médula ósea está causando los síntomas de tu hijo(a). Durante una aspiración y biopsia de médula ósea, se inserta una aguja en la médula dentro del hueso. Se recolecta parte de la médula (biopsia) y el líquido de la médula (aspirado). Los pacientes que se someten a aspiraciones y biopsias de médula ósea pueden experimentar dolor, por lo que se suele sedar a los niños para este procedimiento. Si tu hijo(a) se siente mal después de la prueba, se le puede dar un analgésico suave, como acetaminofeno (Tylenol®), pero ni ibuprofeno (Motrin® o Advil®) ni aspirina.

¿CÓMO SE TRATA LA ITP? ¿CUÁLES SON LOS EFECTOS SECUNDARIOS DEL TRATAMIENTO?

La mayoría de los casos de ITP infantil mejoran sin tratamiento. El simple control del recuento de plaquetas, conocido como observación , es un tipo de tratamiento. Por lo general, con el tiempo, el cuerpo deja de producir anticuerpos contra las plaquetas. El recuento de plaquetas puede ser bajo durante varias semanas o meses. A medida que disminuye el nivel de anticuerpos, las plaquetas ya no se destruyen y su recuento aumenta.

Mientras espera que los glóbulos blancos dejen de producir estos anticuer- pos, el cuerpo se percata del bajo recuento de plaquetas. Entonces, la médula ósea (donde se fabrican las plaquetas) trabaja más duro para producir plaquetas jóvenes y más grandes que hagan el trabajo de muchas plaquetas más viejas y más pequeñas. El proveedor de atención médica pedirá análisis de sangre para controlar el recuento de plaquetas. A medida que el recuento de plaquetas mejora, estas pruebas serán menos necesarias. Si el recuento de plaquetas es bajo debido a un medicamento, se puede suspender o cambiar éste; si es causado por una infección o un trastorno del sistema inmunitario, esa infección o trastorno se tratará, si es posible. Sólo se requiere tratamiento para la ITP si tu hijo(a) tiene un recuento de plaquetas muy bajo, está sangrando o quiere participar en deportes u otras actividades que requieran un recuento de plaquetas más alto. Los tratamientos incluyen medicamentos y cirugía. Su médico o enfermera te hablará sobre los posibles beneficios y riesgos de los diferentes trata - mientos. Juntos pueden decidir qué tratamiento, si lo hay, es el mejor.

Los medicamentos no curan la ITP; los más comunes para tratarla reducen el número de plaquetas que son destruidas por el bazo. Esto aumenta el recuento de plaquetas a un rango seguro, reduciendo el riesgo de hemorragia grave. Si el cuerpo aún está produciendo anticuerpos contra las plaquetas será necesario repetir los tratamientos durante varias semanas o meses hasta que el cuerpo deje de destruir sus propias plaquetas. Estos medicamentos incluyen inmunoglobulina intravenosa (IVIG) y esteroides. Una nueva clase de medicamentos, incluidos romiplostim y eltrombopag, aumentan la cantidad de plaquetas que se producen en la médula ósea. Inmunoglobulina intravenosa (IVIG) La IVIG se hace de plasma de sangre humana, la cual se compone de tres tipos diferentes de células (glóbulos rojos, glóbulos blancos y plaquetas) y plasma (la parte líquida de la sangre). Las inmunoglobulinas , o anticuerpos, son proteínas en el plasma que ayudan al cuerpo a combatir infecciones. Las personas sanas pueden donar su sangre o plasma. Las inmunoglobulinas se extraen del plasma de miles de personas y se combinan para formar una dosis de IVIG, la cual se trata para que sea pura (sin otras proteínas de la sangre) y segura (sin virus que causen una infección) . No está claro cómo funciona la IVIG para tratar la ITP. En la ITP, el bazo destruye las plaquetas recubiertas de anticuerpos en la sangre. La IVIG se une a los receptores de anticuerpos en el bazo bloqueándolos, lo que impide que se unan a los anticuerpos de las plaquetas. La IVIG no cura la ITP, pero por lo general produce un aumento rápido de plaquetas (24 a 48 horas) en más del 75% de los niños. Este aumento de plaquetas puede durar varias semanas. Si el cuerpo todavía está pro - duciendo anticuerpos contra las plaquetas cuando se acaba la IVIG, el conteo de plaquetas puede comenzar a disminuir nuevamente. La IVIG es un líquido que se administra en una vena (vía intravenosa). Se pueden usar medicamentos para adormecer la piel de la mano o el brazo de tu hijo(a) antes de colocar la aguja en la vena.

La infusión de la IVIG inicia lentamente y se va aumentando si no hay efectos secundarios. La infusión puede tardar varias horas. La IVIG generalmente se administra en un centro de infusión o en un hospital. Una enfermera controlará que no haya efectos secundarios. La mayoría de las reacciones a la IVIG ocurren durante la infusión y algunos efectos secundarios pueden ocurrir de 1 a 3 días después. Tu hijo(a) recibirá difenhidramina (Benadryl®) o acetaminofén (Tylenol®) antes de la infusión para disminuir la posibilidad de efectos secundarios. Los efectos secundarios comunes de la IVIG incluyen: • dolor de cabeza

• fiebre o escalofríos • náuseas o vómitos • urticaria o sarpullido

• sentirse cansado (fatiga) • dolor muscular o articular.

Hay una pequeña posibilidad de que tu hijo(a) tenga una reac- ción alérgica grave a la IVIG. Si es así, se detendrá la infusión y de inmediato se darán medicamentos para tratar la reacción alérgica. Hay un riesgo muy pequeño de que la IVIG contenga virus que causen una infección. La IVIG puede impedir que algunas vacunas vivas sean efectivas. Las vacunas vivas usadas para inmunizar a los niños contra enfermedades como sarampión, paperas y rubéola (MMR) y varicela no deben administrarse durante varios meses después de haber recibido la IVIG. Esteroides (hormonas esteroides glucocorticoides) Los esteroides, sustancias naturales que produce el cuerpo, son importantes para varias funciones corporales. Una de éstas es la cortisona , una sustancia química producida por las glándulas suprarrenales (pequeños órganos encima de los riñones). La prednisona y la dexametasona son medicamentos sintéticos (hechos por el hombre) similares a la cortisona. Este tipo de esteroides es diferente a los esteroides anabólicos usados para desarrollar músculos . No se sabe cómo funcionan los esteroides para tratar la ITP, pero disminuyen la cantidad de anticuerpos que se producen contra las plaquetas, así como la velocidad a la que el bazo elimina las plaquetas recubiertas de anticu- erpos. También pueden hacer que los vasos sanguíneos sean más estables, lo que reduce el riesgo de sangrado. Los esteroides no curan la ITP, pero aumentan el recuento de plaquetas en más del 75% de los pacientes. Si el cuerpo sigue produciendo anticuerpos contra las plaquetas al reducir o suspender la dosis de esteroides, el recuento de plaquetas puede volver a caer. En general, los esteroides se administran por vía oral, en píldoras o líquido. El proveedor de atención médica recetará la cantidad de medicamento que debe tomar. Se pueden administrar por vía oral (por la boca) de diferentes maneras: • en dosis muy altas durante unos días • en dosis altas durante varios días, seguido de un programa de dosificación especial para suspender el medicamento al disminuir lentamente la cantidad que se toma (reducción gradual) • en dosis bajas durante varias semanas o meses. Asegúrate de entender cómo administrar el medicamento y qué hacer si tu hijo(a) lo rechaza o vomita una dosis.

También se pueden administrar en una vena (vía intravenosa) en lugar de por vía oral. Los esteroides intravenosos en general se administran en un centro de infusión o en un hospital; se pueden usar medicamentos para adormecer la piel de la mano o el brazo antes pinchar la vena con la aguja. El esteroide se administra durante unos minutos . Los efectos secundarios más comunes de los esteroides incluyen: • acidez estomacal (reflujo) • aumento del apetito o aumento de peso • cambios de humor • hinchazón en la cara o detrás del cuello • problemas para dormir • acné. La mayoría de estos efectos secundarios mejora al suspender el medicamento. Cuando se toman esteroides durante semanas o meses hay otros efectos secundarios, como presión arterial alta, aumento de azúcar en la sangre u orina, riesgo de infección, adelgazamiento de la piel, problemas de crecimiento o pérdida de calcio de los huesos. Por esto, los esteroides generalmente se administran sólo durante algunas semanas o meses a la vez.

Comunícate con el proveedor de atención médica inmediatamente si tu hijo(a) • está expuesto a la varicela y aún no ha tenido varicela ni ha recibido la vacuna • está bebiendo más o aumenta la cantidad de orina • tiene heces negras, parecidas al alquitrán.

Agentes trombopoyéticos Los agentes trombopoyéticos son proteínas fabricadas por el hombre que aumentan la cantidad de plaquetas producidas en la médula ósea. En general, se usan sólo en pacientes con ITP crónica o una ITP que no ha respondido a medicamentos que reducen la destrucción de plaquetas, como la IVIG o los esteroides. Romiplostim (Nplate®) y eltrombopag (Pro- macta®) son medicamentos trombopoyéticos que se usan para tratar la ITP . Romiplostim se administra por inyección subcutánea (bajo la piel) una vez a la semana. La cantidad administrada se basa en el recuento de plaquetas. Debe administrarse en el consultorio de un médico o por un cuidador capacitado en cómo administrar el medicamento en casa. Es importante no saltarse ninguna inyección. El recuento de plaquetas puede descender mucho si el medicamento no se administra con regularidad. Los efectos secundarios más comunes de romiplostim incluyen • dolor de cabeza • mareos • dificultad para dormir (insomnio) • dolor abdominal

• dolor articular o muscular • trombocitopenia de rebote • formación de anticuerpos.

Los efectos secundarios menos comunes pero graves del romiplostim son coágulos de sangre y cambios dentro de la médula ósea. El proveedor de atención médica te explicará cómo estar atento a estos efectos secundarios y si hay que hacer pruebas especiales para controlarlos. Las personas que usan romiplostim tienen un mayor riesgo de desarrollar cambios en la médula ósea. El médico examinará la médula ósea de tu hijo(a) para controlar esto. Eltrombopag se toma diario por vía oral. La dosis se ajusta en función del recuento de plaquetas. También se controlan las pruebas de función hepática mientras se toma el medicamento. Las personas de ascendencia asiática oriental requieren una dosis inicial más baja y un control para ajustar la dosis. Eltrombopag debe tomarse 4 horas antes o después de los antiácidos y multivitaminas, ya que pueden interferir con estos medicamentos. Los efectos secundarios comunes de eltrombopag incluyen: • náuseas o vómitos • diarrea • dolores musculares, dolor de espalda • resultados anormales en las pruebas de la función hepática que no están asociadas con toxicidad hepática • erupción cutánea, picazón • nariz mocosa o congestionada.

Los efectos secundarios menos comunes pero graves del eltrombopag incluyen coágulos de sangre, síntomas similares a los de la gripe y problemas hepáticos. El proveedor de atención médica te explicará cómo estar atento a estos efectos secundarios.

Transfusiones La mayoría de los niños con ITP producen suficientes plaquetas, pero también anticuerpos contra sus plaquetas. El bazo destruye rápidamente las plaquetas que están cubiertas con un anticuerpo. Estos anticuerpos pueden unirse a las plaquetas que se transfunden y cuando éstas se recubren con el anticuerpo, el bazo las destruye rápidamente. Por esto, las transfusiones de plaquetas se usan sólo si hay un sangrado grave. Otros tratamientos médicos Algunos niños con ITP no responden a la IVIG ni a los esteroides. Si tu hijo(a) tiene un recuento de plaquetas bajo o sangrado a pesar de estos tratamientos, su médico o enfermera puede considerar otros tratamientos. Los tratamientos alternativos para la ITP incluyen quimioterapia (p. ej. vincristina, ciclofosfamida o mercaptopu - rina), medicamentos que inhiben el sistema inmunitario (como micofenolato y ciclosporina) o un medicamento (como rituximab) que disminuye la cantidad de linfocitos B, los glóbulos blancos que producen anticuerpos. Terapias complementarias Algunas familias quieren probar terapias complementarias o naturales para tratar la ITP de su hijo(a). Las terapias complementarias pueden incluir el uso de suplementos, hierbas o vitaminas; homeopatía; o un cambio en la dieta. Estos tratamientos no se han estudiado en niños con ITP y no sabemos si son útiles. Sabemos que algunas terapias complementarias pueden ser dañinas porque disminuyen el conteo de plaquetas o afectan el funcionamiento de las plaquetas para detener el sangrado. Habla con el proveedor de atención médica de tu hijo(a) si deseas probar terapias complementarias o naturales.

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