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III-81. The answer is D. (Chap. 109) The acute myeloid leukemias (AMLs) are a group of hemato-logic malignancies derived from hematologic stem cells that have acquired chromosomal mutations that prevent differentiation into mature myeloid cells. The specific chromosomal abnormalities predict in which stage of differentiation the cell is arrested and are associated with the several subtypes of AML that have been identified. In the United States, more than 16,000 new cases of AML are diagnosed yearly, and the numbers of new cases of AML has increased in the past 10 years. Men are diagnosed with AML more frequently than women (4.6 cases per 100,000 population vs. 3.0 cases per 100,000, respectively). In addition, older age is associated with increased incidence of AML, with an incidence of 18.6 cases per 100,000 population in those older than 65 years of age. AML is uncommon in adolescents. Other known risk factors for the development of AML include hereditary genetic abnormalities, radiation and chemical exposures, and drugs. The most common hereditary abnormality linked to AML is trisomy 21 (Down syndrome). Other hereditary syndromes associated with an increase of AML include diseases associated with defective DNA repair such as Fanconi’s anemia and ataxia telangiectasia. Survivors of the atomic bomb explosions in Japan were found to have a high incidence of AML as have survivors of other high-dose radiation exposures. However, therapeutic radiation is not associated with an increased risk of AML unless the patient was also treated concomitantly with alkylating agents. Anticancer drugs are the most common causes of drug-associated AML. Of the chemotherapeutic agents, alkylating agents and topoisomerase II inhibitors are the drugs

most likely to be associated with AML.

III-82. The answer is C. (Chap. 109) The goal of therapy in chronic myelogenous leukemia (CML) is to achieve prolonged, durable, nonneoplastic, nonclonal hematopoiesis, which entails the eradication of any residual cells containing the BCR-ABL1 transcript. Hence, the goal is complete molecular remission and cure. Therapy of CML has changed in recent years because of the presence of a proven curative treatment (allogeneic transplantation) that has significant toxicity and a targeted treatment (imatinib) with outstanding outcome based on 8-year follow-up data. New tyrosine kinase inhibitors are becoming available, making this a dynamic topic. Many experts currently recommend initiating therapy with a tyro-sine kinase inhibitor and reserving allogeneic transplantation for those who develop drug resistance. Imatinib mesylate is a tyrosine kinase inhibitor that acts to decrease the activity of the bcr-abl fusion protein that results from the reciprocal translocation of chromosomes 9 and 22 (Philadelphia chromosome). It acts as a competitive inhibitor of the abl kinase at its ATP binding site and thus leads to inhibition of tyrosine phosphorylation of proteins in bcr-abl signal transduction. In newly diagnosed CML, imatinib results in a complete hematologic remission in 95% of patients initially and 76% at 18 months. Low-risk patients have a higher durable remission rate. All imatinib-treated patients who achieved major molecular remission (26%), defined as3 log or greater reduction in BCR-ABL1 transcript level at 18 months compared with pretreatment level, were progression free at 5 years. There is a consensus that molecular responses can be used as a treatment goal in CML. Imatinib, taken orally, has limited side effects that include nausea, fluid retention, diarrhea, and skin rash and is usually well tolerated. Interferon-α was previously the first-line chemotherapy if bone marrow transplant was not an option, but it has been replaced by imatinib mesylate. Autologous stem cell transplant is not currently used for treatment of CML because there is no reliable way to select residual normal hematopoietic progenitor cells. Leukopheresis is used for control of leukocyte counts when the patient is experiencing complications such as respiratory failure or cerebral ischemia related to the high white blood cell count.

III-83 and III-84. The answers are D and E, respectively. (Chap. 109) Treatment of acute promyelocytic leukemia (PML) is an interesting example of how understanding the function of the protein produced by the genetic abnormality can be used to develop a treatment for the disease. The translocation of the long arms of chromosomes 15 and 17, t(15;17), results in the production of a chimeric protein called promyelocytic leukemia (Pml)/retinoic acid receptor α (Rar-α). The Pml-Rar-α fusion protein suppresses gene transcription and arrests differentiation of the cells in an immature state, leading to promyelocytic leukemia. Pharmacologic doses of the ligand of the Rar-α receptor, tretinoin, stimulate the cells to resume differentiation. With use of tretinoin, the leukemic cells differentiate to mature neutrophils and undergo subsequent apoptosis. Tretinoin plus concurrent anthracycline-based chemotherapy appears to be among the most effective treatments for APL, leading to complete remission (CR) rates of 90% to 95%. The primary side effect of tretinoin is the development of retinoic acid syndrome. The onset of retinoic acid syndrome from ATRA (all- trans retinoic acid) is usually within the first 3 weeks of treatment. Typical symptoms are chest pain, fever, and dyspnea. Hypoxia is common, and chest radiography usually shows diffuse alveolar infiltrates with pleural effusions. Pericardial effusions may also occur. The cause of retinoic acid syndrome is possibly related to the adhesion of the differentiated leukemia cells to the pulmonary endothelium or the release of cytokines by these cells to cause vascular leak. The mortality rate for patients with retinoic acid syndrome is 10%. High-dose glucocorticoid therapy is usually effective in the treatment of retinoic acid syndrome.

Arsenic trioxide has antileukemic activity and may be used in tretinoin refractory cases. It is also under investigation for combination chemotherapy. Cyclophosphamide, daunorubicin, vinblastine, and prednisone are the constituents of the combination chemotherapy commonly known as CHOP, which is indicated for the treatment of B-cell lymphomas. Rituximab is most commonly used as a treatment of B-cell non-Hodgkin’s lymphoma and a variety of autoimmune disorders. Rituximab is a monoclonal antibody directed against the CD20 cell-surface molecule of B lymphocytes. It has no current role in the treatment of acute myeloid leukemias. Whole-body irradiation is used primarily before bone marrow transplant to ensure complete eradication of cancerous leukemic cells in the bone marrow.

III-85. The answer is C. (Chap. 109) Patients with acute leukemia frequently present with nonspecific symptoms of fatigue and weight loss. In addition, weight loss and anorexia are also common. About half have had symptoms for more than 3 months at the time of presentation. Fever is present in only about 10% of patients at presentation, and 5% have evidence of abnormal hemostasis. On physical examination, hepatomegaly, splenomegaly, sternal tenderness, and evidence of infection or hemorrhage are common presenting signs. Laboratory studies are confirmatory with evidence of anemia, thrombocytopenia, and leukocytosis often present. The median presenting leukocyte count at presentation is 15,000/μL. About 20% to 40% have presenting leukocyte counts less than 5000/μL, and another 20% have counts greater than 100,000/μL. Review of the peripheral smear confirms leukemia in most cases. If Auer rods are seen, the diagnosis of acute myeloid leukemia (AML) is virtually certain. Thrombocytopenia (platelet count <100,000/μL) is seen in more than 75% of individuals with AML. After the diagnosis of AML has been confirmed, rapid evaluation and treatment should be undertaken. The general health of the cardiovascular, pulmonary, hepatic, and renal systems should be evaluated because chemotherapy has adverse effects that may cause organ dysfunction in any of these systems. Overall, chromosome findings at diagnosis are currently the most important independent prognostic factor. Patients with t(15;17) have a very good prognosis (~85% cured), and those with t(8;21) and inv(16) have a good prognosis (~55% cured), but those with no cytogenetic abnormality have a moderately favorable outcome (~40% cured). Patients with a complex karyotype, t(6;9), inv(3), or –7, have a very poor prognosis. Among the prognostic factors that predict poor outcomes in AML, age at diagnosis is one of the most important because individuals of advanced age tolerate induction chemotherapy poorly. In addition, advanced age is more likely to be associated with multiple chromosomal abnormalities that predict poorer response to chemotherapy, although some chromosomal markers predict a better response to chemotherapy. Poor performance status independent of age also decreases survival in AML. Responsiveness to chemotherapy and survival are also worse if the leukocyte count is greater than 100,000/μL or the antecedent course of symptoms is prolonged. Anemia, leukopenia, or thrombocytopenia present for more than 3 months is a poor prognostic indicator. However, there is no absolute degree of anemia or thrombocytopenia that predicts worse outcomes.

III-86. The answer is E. (Chap. 110) Viscosity testing is typically reserved for cases of multiple myeloma in which paraproteins (particularly immunoglobulin M) can lead to vascular sludging and subsequent tissue ischemia. Acute lymphoid leukemia (ALL) can lead to end-organ abnormalities in kidney and liver; therefore, routine chemistry tests are indicated. A lumbar puncture must be performed in cases of newly diagnosed ALL to rule out spread of disease to the central nervous system. Bone marrow biopsy reveals the degree of marrow infiltration and is often necessary for classification of the tumor. Immunologic cell-surface marker testing often identifies the cell lineage involved and the type of tumor, information that is often impossible to discern from morphologic interpretation alone.

Cytogenetic testing provides prognostic information on the disease natural history. In ALL, prognosis depends on the genetic characteristics of the tumor, the patient’s age, the white cell count, and the patient’s overall clinical status and major organ function.

III-87. The answer is B. (Chap. 110) Hepatitis B and C are both common causes of cirrhosis and are strongly associated with the development of hepatocellular carcinoma. Hepatitis C, but not hepatitis B, can also lead to a lymphoplasmacytic lymphoma, often in the spleen, that resolves with cure of hepatitis C. Epstein-Barr virus has been associated with a large number of lymphoid malignancies, including posttransplant lymphoproliferative disease (PTLD), Hodgkin’s disease, central nervous system lymphoma, and Burkitt’s lymphoma. Helicobacter pylori infection is necessary and sufficient for gastric mucosa-associated lymphoid tissue (MALT) lymphoma development, and cure can be achieved with eradication of the organism in some cases. HHV8 is a known cause of body cavity lymphoma, including primary pleural lymphoma. In addition to those listed, HTLV-1 is associated with adult T-cell lymphoma or leukemia. Other disorders associated with lymphoma include celiac sprue, autoimmune disease, and biologic therapies for autoimmune disease. Celiac sprue has been associated with gastrointestinal tract lymphoma. Many collagen vascular diseases (e.g., Sjogren’s) and anti–tumor necrosis factor therapies have been associated with the development of lymphoma.

III-88. The answer is B. (Chap. 110) Autoimmune hemolytic anemia and thrombocytopenia are common, and a peripheral blood smear and a Coombs test help evaluate their presence. Hypersplenism is also seen in chronic lymphoid leukemia (CLL) as the spleen sequesters large numbers of circulating blood cells and enlarges. Hence, a careful left upper quadrant examination looking for a palpable splenic tip is the standard of care in this situation. This patient is at risk of hepatic decompensation as well, given his hepatitis C that can also cause anemia and thrombocytopenia. Bone marrow infiltration of tumor cells can lead to cytopenias in CLL. However, this is in effect a diagnosis of exclusion. After these three possibilities have been ruled out, a bone marrow biopsy is a reasonable next step. This initial evaluation before presuming spread of CLL is critical for therapy because each possibility requires different therapy (glucocorticoids or rituximab for hemolysis, hepatology referral for liver failure, and splenectomy for symptomatic hypersplenism).

III-89. The answer is C. (Chap. 110) The peripheral smear shows increased numbers of small, well-differentiated, normal-appearing lymphocytes characteristic of chronic lymphocytic leukemia, the most common leukemia or lymphoma in adults. Common presenting complaints typically include fatigue, frequent infections, new lymphadenopathy, and abdominal complaints relating to splenomegaly. Hairy cell leukemia is a rare disease that presents predominantly in older men. Typical presentation involves pancytopenia, although occasional patients will have a leukemic presentation. Splenomegaly is usual. The malignant cells appear to have “hairy” projections on light and electron microscopy. Patients with this disorder are prone to unusual infections, including infection by Mycobacterium avium intracellulare, and to vasculitic syndromes. Hairy cell leukemia is responsive to chemotherapy with cladribine with clinical complete remissions in the majority of patients and frequent long-term disease-free survival.

III-90. The answer is E. (Chap. 110) Classical Hodgkin’s disease carries a better prognosis than all types of non-Hodgkin’s lymphoma. Patients with good prognostic factors can achieve cure with extended field radiation alone, but those with a higher risk disease often achieve cure with high-dose chemotherapy and sometimes radiation. The chance of cure is so high (>90%) that many protocols are

now considering long-term sequelae of current therapy such as carcinomas, hypothyroidism, premature coronary disease, and constrictive pericarditis in those receiving radiation therapy. A variety of chemotherapy regimens are effective with long-term disease-free survival in patients with advanced disease achieved in more than 75% of patients who lack systemic symptoms and in 60% to 70% of patients with systemic symptoms.

TTT-91. The answer is D.(Chap. 110) The large cell with a bilobed nucleus and prominent nucleoli giving an "owl's eyes" appearance near the center of the field is a Reed-Sternberg cell, confirming the diagnosis of Hodgkin's disease. Hodgkin's disease occurs in 8000 patients in the United States each year, and the disease does not appear to be increasing in frequency. Most patients present with palpable lymphadenopathy that is nontender; in most patients, these lymph nodes are in the neck, supraclavicular area, and axilla. More than half the patients have mediastinal adenopathy at diagnosis, and this is sometimes the initial manifestation. Subdiaphragmatic presentation of Hodgkin's disease is unusual and more common in older men. One-third of patients present with fevers, night sweats, or weight loss, which are В symptoms in the Ann Arbor staging classification. Occasionally, Hodgkin's disease can present as a fever of unknown origin. This is more common in older patients who are found to have mixed cellularity Hodgkin's disease in an abdominal site. Rarely, the fevers persist for days to weeks followed by afebrile intervals and then recurrence of the fever (Pel-Ebstein fever). The differential diagnosis of a lymph node biopsy suspicious for Hodgkin's disease includes inflammatory processes, mononucleosis, non-Hodgkin's lymphoma, phenytoin-induced adenopathy, and nonlymphomatous malignancies.

TTT-92. The answer is E.(Chap. e20) A "dry tap" is defined as the inability to aspirate bone marrow and is reported in approximately 5% of attempts. It is rare in the case of normal bone marrow. The differential diagnosis includes metastatic carcinoma infiltration (17%); chronic myeloid leukemia (15%); myelofibrosis (14%); hairy cell leukemia (10%); acute leukemia (10%); and lymphomas, including Hodgkin's disease (9%).

TTT-93. The answer is B.(Chap. e20) The diagnostic criteria for chronic eosinophilic leukemia and the hypereosinophilic syndrome first requires the presence of persistent eosinophilia greater than 1500/uL in blood, increased marrow eosinophils, and less than 20% myelob-lasts in blood or marrow. Additional disorders that must be excluded include all causes of reactive eosinophilia, primary neoplasms associated with eosinophilia (e.g., T-cell lymphoma, Hodgkin's disease, acute lymphoid leukemia, mastocytosis, chronic myelogenous leukemia, acute myeloid leukemia [AML], myelodysplasia, and myeloproliferative syndromes), and T-cell reaction with increased interleukin-5 or cytokine production. If these entities have been excluded and the myeloid cells show a clonal chromosome abnormality and blast cells (>2%) are present in peripheral blood or are increased in marrow (but <20%), then the diagnosis is chronic eosinophilic leukemia. Patients with hypereosinophilic syndrome and chronic eosinophilic leukemia may be asymptomatic (discovered on routine testing) or present with systemic findings such as fever, shortness of breath, new neurologic findings, or rheumatologic findings. The heart, lungs, and central nervous system are most often affected by eosinophil-mediated tissue damage.

TTT-94. The answer is D.(Chap. e21) Mastocytosis is a proliferation and accumulation of mast cells in one or more organ systems. Only the skin is involved in approximately 80% of cases with the other

20% being defined as systemic mastocytosis caused by the involvement of another organ system The most common manifestation of mastocytosis is cutaneous urticaria pigmentosa, a maculopapular pigmented rash involving the papillary dermis. Other cutaneous forms include diffuse cutaneous mastocytosis (almost entirely in children) and mastocytoma. Clinical manifestations of systemic mastocytosis are related to either cellular infiltration of organs or release of histamine, proteases, eicosanoids, or heparin from mast cells. Therefore, signs and symptoms may include constitutional symptoms, skin manifestations (pruritus, dermatographia, rash), mediator-related symptoms (abdominal pain, flushing, syncope, hypertension, diarrhea), and bone related symptoms (fracture, pain, arthralgia). In a recent series, 40% of patients with systemic mastocytosis had an associated myeloid neoplasm, most commonly myeloproliferative syndrome, chronic myelogenous leukemia, and myelodysplastic syndrome. Eosinophilia was present in approximately one-third of patients. Elevated serum tryptase, bone marrow involvement, splenomegaly, skeletal involvement, cytopenia, and malabsorption predict more aggressive disease and a worse prognosis. Many patients with systemic mastocytosis have an activating mutation of c-Kit, a kinase inhibited by imatinib; however, the mutation appears relatively resistant to this agent.

Ш-95. The answer is A.(Chap. Ill) The patient presents with pneumococcal pneumonia and evidence of hypercalcemia, renal failure, and a wide protein gap suggestive of an M protein. These findings are classic for multiple myeloma. Although the patient appears to be making large quantities of immunoglobulins, they are in fact generally monoclonal, and patients actually have functional hypogammaglobulinemia related to both decreased production and increased destruction of normal antibodies. This hypogammaglobulinemia predisposes patients to infections, most commonly pneumonia with pneumococcus or Staphylococcus aureus or gram-negative pyelonephritis. Bone marrow biopsy would confirm the presence of clonal plasma cells and define the quantity, which will help define treatment options. A serum protein electrophoresis would also be indicated to prove the presence of the M protein suspected by the wide protein gap. Although HIV may be associated with kidney injury, both acute and chronic, hypercalcemia would be an unusual feature. There is no clinical history of aspiration, and the location of infiltrate, upper lobe, is unusual for aspiration. Sweat chloride testing is not indicated because there is no suspicion for cystic fibrosis. Because solid organ malignancy is not suspected, computed tomography of the body is unlikely to be helpful.

TTT-96. The answer is A.(Chap. 112) This patient presents with a multisystem illness involving the heart, kidneys, and peripheral nervous system The physical examination is suggestive of amyloidosis with classic waxy papules in the folds of his body. The laboratory test results are remarkable for renal failure of unclear etiology with significant proteinuria but no cellular casts. A possible etiology of the renal failure is suggested by the elevated gamma globulin fraction and low hematocrit, bringing to mind a monoclonal gammopathy perhaps leading to renal failure through amyloid AL deposition. This could also account for the enlarged heart seen on the echocardiography and the peripheral neuropathy. The fat pad biopsy is generally reported to be 60% to 80% sensitive for amyloid; however, it would not allow a diagnosis of this patient's likely myeloma. A right heart catheterization probably would prove that the patient has restrictive cardiomyopathy secondary to amyloid deposition; however, it too would not diagnose the underlying plasma cell dyscrasia. Renal ultrasonography, although warranted to rule out obstructive uropathy, would not be diagnostic. Similarly, the electromyographic and nerve conduction studies would not be diagnostic. The bone marrow biopsy is about 50% to 60% sensitive for amyloid, but it would allow evaluation of the percent of plasma cells in the bone marrow and allow the

diagnosis of multiple myeloma to be made. Multiple myeloma is associated with amyloid AL in approximately 20% of cases. Light chains most commonly deposit systemically in the heart, kidneys, liver, and nervous system, causing organ dysfunction. In these organs, biopsy would show the classic eosinophilic material that, when exposed to Congo red stain, has a characteristic apple-green birefringence.

TTT-97. The answer is C.(Chap. 115) Heparin-induced thrombocytopenia (HIT) is a clinical diagnosis that must not be missed because life-threatening thrombosis can occur if not treated appropriately. The cause of HIT is the formation of antibodies to the complex of heparin and platelet factor 4 (PF4). This complex is able to activate platelets, monocytes, and endothelial cells. Many patients exposed to heparin will develop antibodies to the heparin-PF4 complex, but only a few of these will progress to develop thrombocytopenia or thrombocytopenia with thrombosis (HITT). The typical patient will develop evidence of HIT 5 to 14 days after exposure to heparin, although it can occur within 5 days in individuals exposed to heparin within about the previous 100 days as would be expected in this patient given his recent hospitalization. The nadir platelet count is typically greater than 20,000/uL. When HIT is suspected, one should not delay treatment for laboratory testing because no currently available test has adequate sensitivity or specificity for the diagnosis. The antiheparin/PF4 antibody test result is positive in many individuals who have been exposed to heparin regardless of whether HIT is present. The platelet activation assay is more specific but less sensitive for HIT. As soon as HIT is suspected, heparin should be discontinued and replaced with an alternative form of anticoagulation to protect against development of new thromboses. Low-molecular-weight heparins (LMWHs) such as enoxaparin are not appropriate treatment options in individuals with HIT. Although heparin is 10 times more likely to cause HIT, LMWHs also cause the illness and should not be used. The primary agents used for HIT in the United States are the direct thrombin inhibitors argatroban and lepirudin. Argatroban is the preferred agent for this patient because of his renal failure. The drug is not excreted by the kidneys, and no dosage adjustment is required. In contrast, lepirudin is markedly increased in renal failure, and a significant dosage adjustment is required. Danaparoid has previously been used frequently for HIT and HITT, but this medication is no longer available in the United States. Other anticoagulants that are used for treatment of HITT include bivalirudin and fondaparinux, but these also are not currently approved for use in the United States.

TTT-98. The answer is E.(Chap. 115) This patient presents with symptoms of thrombocytopenia, including bleeding gums and easy bruising. The only finding on physical examination may be petechiae at points of increased venous pressure, especially in the feet and ankles. The laboratory findings confirm thrombocytopenia but show no abnormalities in other cell lines. When evaluating isolated thrombocytopenia, one must initially consider whether an underlying infection or medication is causing the platelet count to fall. There is a long list of medications that are implicated in thrombocytopenia, including aspirin, acetaminophen, penicillins, H₂ blockers, heparin, and many others. This patient

discontinued all medications over 6 weeks previously, and the platelet count would be expected to recover if a medication reaction were the cause. She gives no signs of any acute infection. Thus, the most likely diagnosis is immune thrombocytopenia purpura (ITP). This disorder is also known as idiopathic thrombocytopenia purpura and refers to an immune-mediated destruction of platelets and possible inhibition of platelet release from megakaryocytes. ITP can truly be idiopathic, or it can be secondary to an underlying disorder, including systemic lupus erythematosus (SLE), Hiy or chronic hepatitis С virus (HCV) infection. The platelet count can be quite low (<5000/uL) in patients with ITP

and usually presents with mucocutaneous bleeding. Laboratory testing for ITP should include a peripheral smear that typically demonstrates large platelets with otherwise normal morphology. Initial testing should evaluate for secondary causes of ITP, including HIV antibodies, HCV antibodies, serologic testing for SLE, serum protein electrophoresis, and immunoglobulins. If anemia is also present, a direct Coombs test is indicated to assess whether there is a combined autoimmune hemolytic anemia with ITP (Evans syndrome). Antiplatelet antibody testing is not recommended because these tests have low sensitivity and specificity for ITP. In addition, bone marrow biopsy is typically not performed unless there are other abnormalities that are not explained by ITP or the patient has failed to respond to usual therapy.

TTT-99 and Ш-100. The answers are A and E, respectively.(Chap. 115) This patient presents with the classic pentad of thrombotic thrombocytopenic purpura (TTP), which is fever, neurologic symptoms, acute renal failure, thrombocytopenia, and microscopic angiopathic hemolytic anemia (MAHA). Although this is the classic presentation, it is not necessary to have all five characteristics for an individual to be diagnosed with TTP. In recent years, the pathogenesis of inherited and idiopathic TTP has been discovered to be attributable to a deficiency of or antibodies directed against the ADAMTS-13 protein. The ADAMTS-13 protein is a metalloproteinase that cleaves von Willebrand factor (VWF). In the absence of ADAMTS-13, ultra-large VWF multimers circulate in the blood and can cause pathogenic platelet adhesion and activation, resulting in microvascular ischemia and microangiopathic hemolytic anemia. However, it appears as if there is a necessary inciting event because not all individuals with an inherited deficiency of ADAMTS-13 develop TTP. Some drugs have been implicated as causative agents in TTP. Ticlopidine and possibly clopidogrel cause TTP by inducing antibody formation. Other drugs, including mitomycin C, cyclosporine, and quinine, can cause TTP by causing direct endothelial toxicity.

A dziagnosis of TTP can be made based on clinical factors. It should be differentiated from disseminated intravascular coagulation, which causes MAHA but has a predominant coagulopathy Hemolytic uremic syndrome also causes MAHA and appears very similar to TTP in clinical presentation, although neurologic symptoms are less prominent. Often a preceding diarrheal illness alerts one to hemolytic syndrome as the cause of MAHA. It is important to make a prompt and correct diagnosis because the mortality rate for patients with TTP without treatment is 85% to 100%, decreasing to 10% to 30% with treatment. The primary treatment for TTP remains plasma exchange. Plasma exchange should be continued until the platelet count returns to the normal range and there is no further evidence of hemolysis for at least 2 days. Glucocorticoids can be used as adjunctive treatment in TTP but are not effective as the sole therapy. Recent research suggests that rituximab may be useful in primary treatment of TTP. However, relapse is common with rituximab.

Date: 2016-04-22; view: 864