Management of hematological disorders and cancer

Indications for therapeutic apheresis in hematological disorders

The early apheresis devices were developed in 1930s, but therapeutic apheresis only became widely used decades later, when automated cell separators were introduced. Progress in technical development of these devices continues to this day. Initial use of therapeutic apheresis has not been evidence based. Documents such as the Guidelines by the American Society for Apheresis provided hematologist with better tools to assess the role of therapeutic apheresis in daily practice. This review focuses on the use of therapeutic apheresis in patients with hematological disorders. Four separate apheresis modalities most encountered by hematologists are discussed: therapeutic plasma exchange, therapeutic leukocytapheresis, red blood cell exchange, and extracorporeal photopheresis. Examples of indications are provided and discussed. The future of therapeutic apheresis and its role in different diseases is undergoing continuous re-evaluation as disease pathogenesis is better understood and new treatment options become available.

Treatment of autoimmune hemolytic anemias

Autoimmune hemolytic anemia (AIHA) is a relatively uncommon disorder caused by autoantibodies directed against self red blood cells. It can be idiopathic or secondary, and classified as warm, cold (cold hemagglutinin disease (CAD) and paroxysmal cold hemoglobinuria) or mixed, according to the thermal range of the autoantibody. AIHA may develop gradually, or have a fulminant onset with life-threatening anemia. The treatment of AIHA is still not evidence-based. The first-line therapy for warm AIHA are corticosteroids, which are effective in 70-85% of patients and should be slowly tapered over a time period of 6-12 months. For refractory/relapsed cases, the current sequence of second-line therapy is splenectomy (effective approx. in 2 out of 3 cases but with a presumed cure rate of up to 20%), rituximab (effective in approx. 80-90% of cases), and thereafter any of the immunosuppressive drugs (azathioprine, cyclophosphamide, cyclosporin, mycophenolate mofetil). Additional therapies are intravenous immunoglobulins, danazol, plasma-exchange, and alemtuzumab and high-dose cyclophosphamide as last resort option. As the experience with rituximab evolves, it is likely that this drug will be located at an earlier point in therapy of warm AIHA, before more toxic immunosuppressants, and in place of splenectomy in some cases. In CAD, rituximab is now recommended as first-line treatment.

American Society for Apheresis guidelines on the use of apheresis in clinical practice: practical, concise, evidence-based recommendations for the apheresis practitioner

The 6th Guidelines on the use of therapeutic apheresis in clinical practice published by the American Society of Apheresis provide practical, concise, and evidence based guidance for the apheresis medicine practitioner. The overall format of the Guidelines has remained unchanged with the 6th edition, compared to the 5th edition, with enhancements in the committee process of creating the guidelines. Because of changes in the writing committee structure, a number of changes have occurred in the ASFA category and recommendation grade for the use of apheresis in the treatment for a number of previously categorized clinical indications. In addition, eight new indications for apheresis, twenty three new clinical situations for previously categorized diseases, and ten new apheresis treatments for previously categorized disorders have been added. The 6th Guidelines continue to be an invaluable resource for those involved in apheresis medicine.

The effect of volume replacement during therapeutic leukapheresis on white blood cell reduction in patients with extreme leukocytosis

BACKGROUND

Extreme leukocytosis, generally defined as a white blood cell (WBC) count of more than 100 × 10(9) /L consisting largely of blast cells, especially when accompanied by clinical signs and symptoms of leukostasis or hyperviscosity, often predicts a poor clinical outcome in patients with acute leukemia. In this study, we aimed to investigate the effect of volume replacement (VR) during therapeutic leukapheresis (TA) procedure on early mortality rate and WBC reduction.

STUDY DESIGN AND METHODS

We retrospectively analyzed 29 patients who underwent TA from 2007 to 2011. Fifteen of the patients underwent TA procedure with VR and 14 of the patients underwent TA procedure without VR.

RESULTS

WBC reduction was significantly higher in patients who underwent TA with VR (p < 0.001). Early mortality rate was significantly lower in leukemia patients who underwent TA with VR than in patients who underwent TA without VR (p < 0.01); early mortality rates were 6.7% for 7-day and 13.8% for 100-day survivals. The mortality rates in the TA without VR group, however, were 42.9 and 71.4% for 7- and 100-day survivals, respectively.

CONCLUSION

Decreased early mortality rate in TA with VR group may be associated with prompt reduction of WBCs achieved with TA with VR and may also be associated with removal of the cytokines related to leukostasis. TA with VR would give more time for induction chemotherapy and increased overall survival rate.

Hyperleukocytosis, leukostasis and leukapheresis: practice management

Hyperleukocytosis, arbitrarily defined in acute leukemia as a white blood cell count greater than 100,000/mL, often is associated with increased morbidity and mortality in patients with leukemic processes. It can induce leukostasis, tumor lysis syndrome and disseminated intravascular coagulopathy and has significant prognostic implications with or without one of these clinical complications. The main sites that tend to be injured from the obstructions are the central nerve system and lungs. Despite characteristic clinical presentations, the diagnosis of leukostasis is rarely made with high confidence. The main goal of the management of hyperleukocytosis and/or leukostasis is to reduce the white blood cell count before starting induction chemotherapy. The cytoreduction can be achieved by either leukapheresis and/or hyroxyurea. The technical aspects, complications and efficacy of leukapheresis are discussed in the current article.

Oncologic emergencies: Pathophysiology, presentation, diagnosis, and treatment

Oncologic emergencies can occur at any time during the course of a malignancy, from the presenting symptom to end-stage disease. Although some of these conditions are related to cancer therapy, they are by no means confined to the period of initial diagnosis and active treatment. In the setting of recurrent malignancy, these events can occur years after the surveillance of a cancer patient has been appropriately transferred from a medical oncologist to a primary care provider. As such, awareness of a patient's cancer history and its possible complications forms an important part of any clinician's knowledge base. Prompt identification of and intervention in these emergencies can prolong survival and improve quality of life, even in the setting of terminal illness. This article reviews hypercalcemia, hyponatremia, hypoglycemia, tumor lysis syndrome, cardiac tamponade, superior vena cava syndrome, neutropenic fever, spinal cord compression, increased intracranial pressure, seizures, hyperviscosity syndrome, leukostasis, and airway obstruction in patients with malignancies. Chemotherapeutic emergencies are also addressed.

Autoimmune hemolytic anemia: classification and therapeutic approaches

Autoimmune hemolytic anemia (AIHA) is a relatively uncommon cause of anemia. Classifications of AIHA include warm AIHA, cold AIHA (including mainly chronic cold agglutinin disease and paroxysmal cold hemoglobinuria), mixed-type AIHA and drug-induced AIHA. AIHA may also be further subdivided on the basis of etiology. Management of AIHA is based mainly on empirical data and on small, retrospective, uncontrolled studies. The therapeutic options for treating AIHA are increasing with monoclonal antibodies and, potentially, complement inhibitory drugs. Based on data available in the literature and our experience, we propose algorithms for the treatment of warm AIHA and cold agglutinin disease in adults. Therapeutic trials are needed in order to better stratify treatment, taking into account the promising efficacy of rituximab.

Evidence based therapeutic apheresis in autoimmune and other hemolytic anemias

PURPOSE OF REVIEW

This article reviews recent publications that bear on the evidential basis for therapeutic apheresis in diseases in which hemolytic anemia is a prominent feature.

RECENT FINDINGS

Therapeutic plasma exchange continues to be reported sporadically in severe autoimmune hemolytic anemia, with inconsistent results. Autoimmune deficiency of ADAMTS13 has provided a compelling rationale for therapeutic plasma exchange in some patients with thrombotic thrombocytopenic purpura; conversely such deficiency is consistently absent in certain clinically similar syndromes for which therapeutic plasma exchange is not or may not be beneficial. Refinements in assays for ADAMTS13 should further clarify its role in idiopathic thrombotic thrombocytopenic purpura. Oral iron chelators have shown promise in recent trials in chronically transfused patients with sickle cell disease and may provide an alternative to red cell exchange to prevent iron overload.

SUMMARY

The proper role of therapeutic plasma exchange in the treatment of autoimmune hemolytic anemia remains uncertain. Therapeutic plasma exchange continues to be indicated for idiopathic thrombotic thrombocytopenic purpura regardless of ADAMTS13 levels, but more accessible and physiological ADAMTS13 assays may raise questions about the rationale for and value of plasma exchange in ADAMTS13 nondeficient patients. Oral iron chelation may obviate the need for red cell exchange as a means to prevent iron overload in chronically transfused patients with sickle cell disease.

Cold antibody autoimmune hemolytic anemias

The cold antibody autoimmune hemolytic anemias (AIHAs) are primarily comprised of cold agglutinin syndrome (CAS) and paroxysmal cold hemoglobinuria (PCH) but, in addition, there are unusual instances in which patients satisfy the serologic criteria of both warm antibody AIHA and CAS ("mixed AIHA"). CAS characteristically occurs in middle-aged or elderly persons, often with signs and symptoms exacerbated by cold. The responsible antibody is of the IgM immunoglobulin class, is maximally reactive in the cold but with reactivity up to at least 30 degrees C. Therapy is often ineffective, but newer agents such as rituximab have been beneficial in some patients. PCH occurs primarily in children, often after an upper respiratory infection. The causative antibody is of the IgG immunoglobulin class and is a biphasic hemolysin that is demonstrated by incubation in the cold followed by incubation at 37 degrees C in the presence of complement. Acute attacks are frequently severe but the illness characteristically resolves spontaneously within a few days to several weeks after onset and rarely recurs. Treatment consists of supportive care, with transfusions frequently being needed.

A Case Report of Therapeutic Leukapheresis in an Adult With Chronic Myelogenous Leukemia Presenting With Hyperleukocytosis and Leukostasis

Hyperleukocytosis (>100 x 10(9)/L) is an uncommon presentation of chronic leukemias. It can present with a variety of symptoms secondary to leukostasis, a syndrome caused by the sludging of circulating leukemic blasts in the microvasculature. The management includes hydration, cytoreduction, prevention of tumor lysis and, rarely, leukapheresis in cases complicated by leukostasis and hyperviscosity syndrome. We present a case of severe leukocytosis complicated by leukostasis in which leukapheresis was utilized to bring about a rapid reversal of microvascular sludging.

Predictive factors of bleeding and thrombosis during induction therapy in acute promyelocytic leukemia—a single center experience in 34 patients

In this retrospective study, the hemorrhagic and thrombotic events are reported at presentation and during induction in 34 consecutive acute promyelocytic leukemia (APL) patients treated in a single referral center. The most consistent hemostatic abnormality was decreased fibrinogen level (<150 mg/dL) found in 21 patients (61%), partial thromboplastin time (PTT) was normal almost in all patients. A mildly prolonged prothrombin time (PT) was observed in 14 patients (44%). Median platelet count was 30.10(9)/L (range 3-191.10(9)/L). Life-threatening bleeding manifestations occurred in 10 patients (29%). By multivariate analysis, severe bleeding complications did not correlate with hemostatic parameters but did correlate with white cell count at presentation. Four patients (12%) had severe thrombotic events, two cerebral sagital sinus thrombosis, one pulmonary embolism, and one subclavian vein thrombosis. Two other patients had pseudotumor cerebri. Three out of six patients with thrombotic events were found to have thrombophilia. These results may suggest an association between thrombophilia and thrombosis in APL patients. Two patients suffered from combined severe bleeding and thrombosis. Hemostatic parameters are not helpful in predicting neither hemorrhage nor thrombosis.

Leukocytoreduction for acute leukemia

Both in children and adults, acute leukemia may present with extremely high blast counts; a phenomenon known as hyperleukocytosis. Respiratory failure, intracranial bleeding, and severe metabolic abnormalities frequently occur in acute hyperleukocytic leukemias (AHLs) and are the primary determinants of the high early mortality (20% to 40%) observed. The process leading to these complications has long been known as leukostasis, but the biological mechanisms underlying its development and progression have remained unclear. Traditionally, leukostasis has been attributed to overcrowding of leukemic blasts in the microcirculation, and its treatment has focused on prompt leukocytoreduction. However, it is becoming increasingly evident that leukostasis results from the adhesive interactions between leukemic blasts and the endothelium; a mechanism that none of the current therapies directly addresses. The endothelial damage associated with leukostasis is likely to be mediated by cytokines released in situ and by subsequent migration of leukemic blasts in the perivascular space. The adhesion molecules displayed by the leukemic blasts and their chemotactic response to the cytokines in the vascular microenvironment are probably more important in causing leukostasis than the cell number. This may explain why leukostasis may develop in some patients with AHL and not in others, and why some patients with acute leukemia without hyperleukocytosis (<50,000 blasts/mm(3)) develop leukostasis and respond to leukocytoreduction. Leukapheresis effectively reduces the blast count in many patients with AHL and is routinely used for immediate leukocytoreduction. However, the most appropriate use of leukapheresis in acute leukemia remains unclear, and the procedure may not prevent early death more efficiently than fluid therapy, hydroxyurea, and prompt induction chemotherapy. The use of cranial irradiation remains very controversial and is not generally recommended. The identification of the adhesion molecules, soluble cytokines, and chemotactic ligand-receptor pairs mediating endothelial cell damage in AHL should become a priority if better outcomes are desired.

Treatment of autoimmune hemolytic anemias

Treatment of autoimmune hemolytic anemias varies depending on whether the patient has autoimmune hemolytic anemia of warm antibody type, cold agglutinin syndrome, paroxysmal cold hemoglobinuria, or autoimmune hemolytic anemia secondary to an underlying disorder. Initial therapy for warm antibody autoimmune hemolytic anemia should be corticosteroids, such as prednisone at conventional doses of 1 to 1.5 mg/kg/d orally. Criteria must be established to determine whether the therapeutic response is adequate, because long-term therapy may lead to significant detrimental side effects. Splenectomy has the advantage over therapeutic options in that it has the potential for complete and long-term remission. The major adverse effect is the syndrome of overwhelming postsplenectomy infection. Other therapeutic options, which are less likely to have long-term benefit, are immunosuppressive drugs, danazol, intravenous immunoglobulin, and plasma exchange. Therapy of cold agglutinin syndrome often is unsatisfactory. All patients should avoid exposure to cold, and if additional therapy is necessary, the therapies used for warm antibody autoimmune hemolytic anemia may be tried with less likelihood of response. Paroxysmal cold hemoglobinuria requires aggressive supportive therapy, generally supplemented by corticosteroids. Hemolysis usually terminates spontaneously. Patients with secondary autoimmune hemolytic anemia may be treated similarly to those with idiopathic autoimmune hemolytic anemia, and additional therapy for the underlying disorder also may result in remission of the hemolysis.

Leukapheresis reduces early mortality in patients with acute myeloid leukemia with high white cell counts but does not improve long- term survival

PURPOSE

Current published data on therapeutic leukapheresis in hyperleucocytic AML does not define the impact on survival from this procedure. Between 1992 and 1999 we saw 146 patients with newly-diagnosed AML (APL excluded) and an initial WBC count > 50 x 10(9)/L of whom 71 underwent leukapheresis at the discretion of their treating doctors. We compared outcome (early mortality, CR, and overall survival) rates in the patients who were and were not pheresed. After accounting for covariates relevant to these outcomes, including age, performance status, and cytogenetics, there was evidence (p = .006) that pheresis reduced 2-week mortality rate and a suggestion (p = .06) that this resulted in a higher CR rate. However there was no evidence that pheresis lengthened longer-term or overall survival; if anything the suggestion was the converse (p = .06). These data may reflect the fact that the patients chosen to have pheresis were prognostically unfavorable as defined by variables that were not captured in our data set, since the alternative explanation i.e. that pheresis per se shortens overall survival seems less likely. Whether the above justifies the use of pheresis in the absence of evidence from a randomized trial is doubtful, but it seems likely that any long-term benefit to be derived from this procedure must await further advances in anti-leukemia therapy.

Hyperleukocytic leukemias and leukostasis: a review of pathophysiology, clinical presentation and management

Acute hyperleukocytic leukemias (AHL) are associated with a very high early mortality rate mostly due to respiratory failure or intracranial bleeding. The pathophysiological process leading to these complications is called leukostasis but the biological mechanisms underlying its development and progression remain unclear. Although traditionally related to "over-crowding" of leukemic blasts in the capillaries of the microcirculation, leukostasis is likely to result from direct endothelial cell damage. This damage is probably mediated by soluble cytokines released during the interaction between leukemic cells and vascular endothelium and by the subsequent migration of leukemic blasts in the perivascular space. Leukemic cell's ability to respond to chemotactic cytokines and their expression of specific adhesion molecules are probably more important in determining whether leukostasis will develop than the number of circulating blasts. This could explain why leukostasis does not develop in all patients with AHL. The identification of the adhesion molecules, cytokines and receptors mediating endothelial cell damage in AHL should become a priority if therapeutic improvements are desired. Leukapheresis is widely used but it is unclear whether it provides additional benefit to a simpler and less invasive intervention with allopurinol, hydroxyurea and intravenous fluids. Cranial irradiation is not generally recommended. Induction chemotherapy should be started without delay. It is hoped that specific pharmacological inhibitors of the interaction between leukemic cells and vascular endothelium will result in an improved outcome for this very high-risk population.

Indications for emergency apheresis procedures

Therapeutic apheresis has gained tremendous popularity worldwide in the last 2 decades. Emergency procedures can be life saving but should be undertaken for limited indications. Our emergency indications and experiences since the 1970s are critically described.

Clinical Applications of Therapeutic Hemapheresis

Therapeutic hemapheresis may be a life-saving treatment for patients with some diseases, such as thrombotic thrombocytopenic purpura (TTF), Goodpasture's syndrome, and leukemia-induced leukocytosis, among others. Although plasma exchange has been applied for treatment of many conditions, during the last decade a consensus has been reached about the specific but limited number of diseases for which it is of definitive benefit. Some patients are severely ill during the course of the disease, and they require prompt treatment in the intensive care unit. Therapy of these patients is discussed in this review in detail, in addition to technical aspects, indications, contraindications, and complications of therapeutic hemapheresis.

Therapeutic cytapheresis: continuous flow versus intermittent flow apheresis systems

In this retrospective study, we compared two systems, continuous flow (CF) (COBE Spectra) versus intermittent flow (IF) (Haemonetics V-50, M-30), in performance of therapeutic plateletapheresis (TP: N = 49 each) and therapeutic leukapheresis (TL: N = 29 each). Pre- and post-procedure cell reductions, specificity of removal, volumes removed, and incidence of adverse reactions were compared. Standard procedures with minor modifications, starch with IF only, and 180 minutes blood processing time were used. The CF system had a significantly lower percent reduction of platelets during TP at 43 +/- 17% than IF at 53 +/- 19%. However, no significant difference was found between CF and IF in percent reduction of white blood cells during TL with 49 +/- 16% and 42 +/- 14%, respectively. The CF system had significantly less hemoglobin reduction (5 +/- 4% vs. 19 +/- 9%, respectively) and white blood cell reduction (13 +/- 15% vs. 27 +/- 17%, respectively) for TP than IF and lower (not significant) hemoglobin reduction (9 +/- 8% vs. 12.4 +/- 8.2%, respectively) as well as platelet reduction (27 +/- 18% vs. 35 +/- 19%, respectively) for TL. CF also had significantly less volume removed than IF during TP (559 +/- 97 vs. 883 +/- 304, respectively) and TL (710 +/- 134 vs. 1405 +/- 421 ml, respectively). Incidence of reactions was lower for CF than IF during TP (8% vs. 10%, respectively) and during TL (14% vs. 21%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)