Successful treatment of pure red cell aplasia with rituximab in patients with chronic lymphocytic leukemia

Ibrutinib in combination with rituximab is highly effective in treatment of chronic lymphocytic leukemia patients with steroid refractory and relapsed autoimmune cytopenias

Autoimmune hemolytic anemia (AIHA) and pure red cell aplasia (PRCA) are common complications of CLL. The optimal treatment of steroid refractory AIHA/PRCA is not well established. We conducted a multicenter study of ibrutinib and rituximab in patients with relapsed/refractory to steroids AIHA/PRCA and underlying CLL. Protocol included induction (ibrutinib 420 mg/day and rituximab, 8 weekly and 4 monthly infusions) and maintenance phase with ibrutinib alone until progression or unacceptable toxicity. Fifty patients were recruited (44-warm AIHA, 2-cold AIHA, 4-PRCA). After the induction 34 patients (74%) have achieved complete response, 10 (21.7%) partial response. Median time to hemoglobin normalization was 85 days. With regards to CLL response 9 (19%) patients have achieved CR, 2 (4%) patients-stabilization and 39 (78%)-PR. The median follow-up was 37.56 months. In AIHA group 2 patients had a relapse. Among 4 patients with PRCA 1 patient did not respond, and 1 patient had a relapse after CR, 2 remained in CR. The most common adverse events were neutropenia (62%), infections (72%), gastrointestinal complications (54%). In conclusion ibrutinib in combination with rituximab is an active second-line treatment option for patients with relapsed or refractory AIHA/PRCA and underlying CLL.

CB-LPD, MGUS, T-LGLL, and PRCA: A rare case report of 4 concomitant hematological disorders

RATIONALE

Monoclonal gammopathy of undetermined significance (MGUS) is a clinically asymptomatic clonal plasma cell or lymphoplasmacytic proliferative disorder. Recently, some case reports have described the association of pure red cell aplasia (PRCA) with MGUS, even with a relatively low monoclonal immunoglobulin burden. T large granular lymphocyte leukemia (T-LGLL) is a chronic lymphoproliferative disorder characterized by clonal expansion of T large granular lymphocytes, which is rare in China. There are some reports about T-LGL leukemia in patients with B-cell lymphoma; however, it is very rare that T-LGLL coexists with MGUS and clonal B-cell lymphoproliferative disorders (CB-LPD).

PATIENT CONCERNS

A 77-year-old man was hospitalized because of anemia. He was diagnosed with MGUS, CB-LPD, and PRCA. During the development of the disease, a group of abnormal T lymphocytes was detected by flow cytometry of peripheral blood.

DIAGNOSIS

Combining clinical manifestations with the result of T cell receptor gene rearrangement and immunophenotype, it was consistent with the diagnosis of T large granular lymphocyte leukemia.

INTERVENTIONS

The patient was treat with bortezomib and dexamethasone regimen, Rituximab and sirolimus.

OUTCOMES

The patient was transfusion independent after therapies.

LESSONS

We report a patient with 4 concomitant hematological disorders: T-LGLL, MGUS, CB-LPD, and PRCA, aiming to represent the clinical and flow cytometry characteristics of these concomitant diseases, analyze the mechanism between diseases, and provide a clinical reference.

Induced complete remission faster in adult patients with acquired pure red cell aplasia by combining cyclosporine A with corticosteroids

To evaluate whether the adult patients with acquired pure red cell aplasia (PRCA) could benefit more from cyclosporine A (CsA) combined with corticosteroids (CS) than CsA or CS alone.Seventy-three patients were evaluated in 2 institutions (6 patients lost to follow-up).The induction therapy included CsA (n = 21), CS (n = 21), or CsA combined with CS (n = 31), and remission was achieved in 16/21 (76.2%), 10/21 (47.6%), and 21/31 (71.0%) patients, respectively. Higher complete remission (CR) rate was achieved in CsA combined with CS group than in CS group (61.3% vs 19.0%, P = .003). Patients achieved CR faster in CsA combined with CS group than in CS group or CsA group (median time, 1 month vs 2 month vs 3 month, P = .010). By multivariate analysis, CsA combined with CS therapy and primary PRCA were the influence factors for CR rate. Twenty-seven patients relapsed due to discontinuation or tapering therapy, and 19 patients regained response by increasing the dose of original regimens or changing to other immunosuppressive therapy. Complete remission to induction therapy was a correlative factor for death (P = .035).CsA combined with CS produced faster and higher CR rate in treating adult patients with PRCA than did CsA or CS alone.

TKI-induced pure red cell aplasia: first case report of pure red cell aplasia with both imatinib and nilotinib

Tyrosine-kinase inhibitors (TKIs) represent the only hopes for long-term survival for patients with chronic myeloid leukaemia (CML) and gastrointestinal stromal tumours. Thus, uninterrupted use of TKIs is of importance in such patients. Pure red cell aplasia (PRCA) is a rare disorder, not previously known to be associated with TKIs. We present, to the best of our knowledge, the first case of a patient with CML who developed PRCA secondary to both imatinib and nilotinib. Although PRCA was controlled on withdrawal of TKI, TKI continuation in the patient with CML is important. So we treated him with prednisone, but his haemoglobin started to drop on resumption of imatinib. He was changed to nilotinib but again developed PRCA, which did not improve with steroids. We treated him with cyclosporine and were able to reintroduce nilotinib at a reduced dose without further complications. This case report makes physicians aware of this rare complication of TKIs and also provides encouragement that PRCA could be controlled and TKI continued.

Anemia of Central Origin

Hypoproliferative anemia results from the inability of bone marrow to produce adequate numbers of red blood cells. The list of conditions that cause hypoproliferative anemia is long, starting from common etiologies as iron deficiency to rarer diagnoses of constitutional bone marrow failure syndromes. There is no perfect diagnostic algorithm, and clinical data may not always clearly distinguish "normal" from "abnormal", yet it is important for practicing clinicians to recognize each condition so that treatment can be initiated promptly. This review describes diagnostic approaches to hypoproliferative anemia, with particular emphasis on bone marrow failure syndromes.

Autoimmune cytopenias in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is frequently complicated by secondary autoimmune cytopenias (AIC) represented by autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), pure red cell aplasia, and autoimmune granulocytopenia. The distinction of immune cytopenias from cytopenias due to bone marrow infiltration, usually associated with a worse outcome and often requiring a different treatment, is mandatory. AIHA and ITP are more frequently found in patients with unfavorable biological risk factors for CLL. AIC secondary to CLL respond less favorably to standard treatments than their primary forms, and treating the underlying CLL with chemotherapy or monoclonal antibodies may ultimately be necessary.

Pure red cell aplasia complicating the course of long-standing mantle cell lymphoma

Pure red cell aplasia (PRCA) is a rare cause of severe hypoplastic anemia characterized by profound depletion of erythroid precursors. Although PRCA may be associated with lymphoproliferative diseases, it has never been described in mantle cell lymphoma (MCL). We report what to our knowledge is the first case of a patient with indolent, non-nodal MCL complicated by PRCA. The patient presented with severe hypoproliferative anemia in the setting of a long-standing diagnosis of B-cell chronic lymphocytic leukemia. Bone marrow studies revealed the complete absence of erythroid progenitors. Cyclin D1 positivity on immunohistochemistry, confirmed by a positive FISH for t(11;14) (q13;q32), established the final diagnosis of MCL in conjunction with PRCA. Rituximab monotherapy led to rapid remission of splenomegaly and the leukemic picture, but the patient achieved transfusion independency only with subsequent administration of cyclosporine-A, and remained so during the subsequent 15 months despite the gradual disease recurrence.

Successful treatment of acquired pure red cell aplasia with oral corticosteroids in a patient with B-cell CLL

We present the case of a 57-year-old male patient diagnosed with chronic lymphoid leukaemia (CLL) B-cell type along with moderate anaemia. On follow-up investigations the aetiology of anaemia turned out to be pure red cell aplasia (PRCA) on trephine bone biopsy with an elevated serum erythropoietin level. The patient received blood transfusion support. He showed remarkable improvement on oral corticosteroids (prednisolone 60 mg/daily dose) with no further requirement of blood transfusion over next 3 months. However, when the dose of steroid was tapered down to 10 mg/day, the anaemia reappeared. An increase in the dose of steroid brought the haemoglobin level back to normal. Anaemia in CLL can be due to many reasons, of which PRCA is an uncommon association occurring in only around 1% of patients with CLL and usually refractory to the conventional treatment with steroids. This PRCA secondary to CLL is considered to be immune in origin and a response to combination of immunosuppressive therapy such as steroids, cyclosporine, rituximab is anticipated. Our case responded completely to oral steroids alone.

Parvovirus B-19 induced acute pure red cell aplasia in patients with chronic lymphocytic leukemia and neurofibromatosis type-1

Parvovirus B19 induced pure red cell aplasia (PRCA) has been previously reported in a variety of settings. We present two cases, an adult patient with chronic lymphocytic leukemia (CLL) and a child with neurofibromatosis type-1 (NF-1), where the abrupt appearance of severe anemia raised ominous clinical suspicions. Evidence of recent parvovirus B19 infection in association with the selective erythroid precursor deficiency in marrow helped exclude other etiologies. We emphasize the importance of bearing this infectious agent in mind, even when there are associated disorders (such as CLL) that may independently cause PRCA. An association of NF-1 with acute PRCA has not been described in indexed English literature in the past.

Immunohematology

We report results of Rituximab therapy in four patients with chronic immune thrombocytopenic purpura (ITP) refractory to 3-8 prior therapeutic regimens. Rituximab was administered at a dose of 375 mg/m2 once weekly for 4-6 weeks. Three out of four patients achieved a complete remission (rise to platelet count above 100,000/microl). Response duration was 4, 16+, and 11+ months. Rituximab was well tolerated but one patient (a 77 year-old male) developed two serious infections, pneumonia and a hepatic abscess, at 2 and 4 months. We conclude that Rituximab is effective in patients with refractory ITP; nevertheless, careful patient selection is mandatory.

The use of monoclonal antibodies in the treatment of autoimmune complications of chronic lymphocytic leukemia

Autoimmune cytopenias are a frequent complication in CLL, occurring in approximately 5-10% of the patients. The most common manifestation is autoimmune haemolytic anaemia, followed by immune thrombocytopenia and only rarely pure red blood cell aplasia or autoimmune granulocytopenia. Initial treatment is as for the idiopathic autoimmune cytopenias, with most patients responding to conventional corticosteroid therapy. Patients, who do not respond to conventional therapy after 4-6 weeks, should be considered for alternative immunosuppression, monoclonal antibody therapy or splenectomy. While randomized trials demonstrating the benefit of rituximab in CLL-related autoimmune diseases are still lacking, there are considerable data in the literature that provide evidence for its effectiveness. The monoclonal antibody alemtuzumab also displays considerable activity against both the malignant disease and the autoimmune complication in patients with CLL, although at the expense of greater toxicity. A number of new monoclonal antibodies, such as ofatumumab, GA-101, lumiliximab, TRU-016, epratuzumab, and galiximab, are currently investigated in CLL and their activity in CLL-related autoimmune cytopenias should be evaluated in future studies.

A case of pure red cell aplasia and immune thrombocytopenia complicating systemic lupus erythematosus: response to rituximab and cyclophosphamide

Pure red cell aplasia (PRCA) is a recognized but rare complication of systemic lupus erythematosus (SLE) and is characterized by the near absence of red blood cell precursors in the bone marrow but with normal megakaryocyte and granulocytes. We report a novel case of acquired PRCA occurring simultaneously with immune thrombocytopenia in the context of active SLE. Both syndromes were refractory to conventional treatment but responded to rituximab and cyclophosphamide.

Anti-CD20 Therapy for Chronic Lymphocytic Leukemia-associated Autoimmune Diseases

Rituximab is active in chronic lymphocytic leukemia (CLL) and may interfere with autoantibodies production in some immune diseases. We report the results of rituximab treatment in 7 patients with CLL-associated symptomatic autoimmune diseases refractory to standard immunosuppressive therapies: warm antibody hemolytic anemia (AHA) 4 patients, cold agglutinin disease (CAD) 1, immune thrombocytopenia (IT) 1, axonal degenerating neuropathy (ADN) 1. Rituximab was given at the dose of 375 mg/m2 per week for 4 weeks. One patient with AHA and one with CAD achieved complete normalization of hemoglobin levels and laboratory signs of haemolysis, with response duration (RD) of 8+ and 38+ months, respectively. In the patient with IT, complete remission was reached after the first week of treatment and RD was 6 months. The patient with ADN achieved a marked neurological improvement after rituximab therapy, with RD of 12 months. Retreatment of both patients with IT and ADN was effective. Rituximab may be an alternative agent for the treatment CLL-associated autoimmune diseases.

The clinical application of monoclonal antibodies in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) represents the most prevalent adult leukemia. Treatment with chemotherapy over the past 3 decades has been palliative. The introduction of therapeutic antibodies has increased the number of treatment options for this disease. Despite this increase, our true understanding of the mechanism of action of antibody therapy in CLL remains limited. Rituximab, a CD20 antibody, is currently widely used in combination-based strategies for both previously untreated symptomatic CLL and as salvage therapy. Recent data suggest that the addition of rituximab to fludarabine with or without cyclophosphamide prolongs survival in younger patients with CLL. Other improved CD20 antibodies with promising clinical activity, including ofatumumab and GA-101, are coming forward. Alemtuzumab, a CD52 antibody, likewise has demonstrated benefit in both symptomatic, previously untreated CLL and in patients with relapsed disease but has less selectivity. Development of other therapeutic antibodies targeting alternative B-cell-specific antigens in CLL has been less successful, although many promising candidate antibodies and/or small modular immune pharmaceuticals (SMIPs) are coming forward. In addition, recent efforts to combine currently applied therapeutic antibodies with other biologic and targeted therapies with efficacy in CLL offers the potential to move toward alternative non-chemotherapy-based treatment approaches.

Pure red cell aplasia caused by parvovirus B19 in two patients without chronic hemolysis

Infection with human parvovirus B19 (PVB19) induces acquired pure red cell aplasia (PRCA). Chronic hemolytic anemia is well known as an underlying condition. However, additional factors have been recognized to accompany parvoviral PRCA; however, there are only limited reports on iron-deficiency anemia (IDA) and rituximab-induced B-cell dysfunction. We report two patients with PVB19-associated PRCA confirmed by positivity of viral DNA. Although they had no chronic hemolysis, patient 1 had IDA, and patient 2 had remitted small-lymphocytic lymphoma treated with rituximab-containing chemotherapy. Absence of reticulocytes in peripheral blood and marked depletion of erythroid precursors in bone marrow were observed both. Whereas patient 1 received only symptomatic therapy because anemia was not severe, patient 2 was treated with steroids, as PRCA etiology was at first uncertain, and immunological PRCA was not excluded. Both showed rapid increase of reticulocyte counts and recovery from anemia. Although immunoglobulin is considered effective for parvoviral PRCA, notable adverse reactions have been reported. When anemic symptom is not severe, reticulocyte observation only is recommended. The effects of steroids should also be re-evaluated. Optimal treatment according to disease severity remains to be established.

Rituximab in chronic lymphocytic leukemia

Rituximab is a class I chimeric anti-CD20 antibody that has shown efficacy in chronic lymphocytic leukemia (CLL), both as a single agent and in combination with traditional chemotherapies. The modest activity demonstrated in early studies evaluating rituximab in relapsed CLL was improved with higher doses or more dose-intensive regimens that overcame the unfavorable pharmacokinetic features commonly found in CLL. These studies led to a variety of combination trials of rituximab with chemotherapy, where both phase II and later phase III studies have shown great promise for the advancement of CLL therapy. Despite the therapeutic success of rituximab in CLL, studies demonstrating the definitive relative mechanism of tumor clearance are still lacking and this requires further investigation. In addition to being used as a therapy for CLL, rituximab is an effective treatment for autoimmune CLL complications such as hemolytic anemia and immune thrombocytopenia (ITP). Patients with CLL may experience early infusion-related side effects that can be diminished with corticosteroid pretreatment and stepped-up dosing. Risk factors for infusion-related toxicity may relate to atypical CLL expressing bright CD20 antigen expression, although several different studies have not clearly implicated elevated white blood cell count as a risk factor. Other adverse events, including delayed cytopenias, reactivation of hepatitis B, and development of progressive multifocal leukoencephalopathy, are rare. Future efforts focusing on novel combination-based strategies will be required to fully appreciate the benefit of this therapy in CLL.

Autoimmune complications in chronic lymphocytic leukaemia (CLL)

Patients with B-chronic lymphocytic leukaemia /small lymphocytic lymphoma (CLL) have a 5-10% risk of developing autoimmune complications, which primarily cause cytopaenia. These autoimmune cytopaenias can occur at any stage of CLL and do not have independent prognostic significance. The most common autoimmune complication is autoimmune haemolytic anaemia with a lower frequency of immune thrombocytopaenia and pure red blood cell aplasia and only rarely, autoimmune granulocytopaenia (AIG). Autoimmune cytopaenia should always be considered in the differential diagnosis of cytopaenia in patients with CLL. Patients with CLL can also have more than one form of autoimmune cytopaenia, which can occur together with bone-marrow failure. Treatment is usually effective but rarely curative for autoimmune cytopaenia complicating CLL. Optimal therapy will depend on a timely and accurate diagnosis of autoimmune cytopaenia and should be individualised according to the severity of the cytopaenia and the presence or absence of concomitant progressive CLL requiring therapy.

How I treat CLL up front

Although chronic lymphocytic leukemia (CLL) remains incurable, over the past decade there have been major advances in understanding the pathophysiology of CLL and in the treatment of this disease. This has led to greatly increased response rates and durations of response but not yet improved survival. Advances in the use of prognostic factors that identify patients at high risk for progression have led us to the question whether there is still a role for a "watch and wait" approach in asymptomatic high-risk patients or whether they should be treated earlier in their disease course. Questions remain, including, what is the optimal first-line treatment and its timing and is there any role of maintenance therapy or stem cell transplantation in this disease? CLL is a disease of the elderly and not all patients are eligible for aggressive up-front chemoimmunotherapy regimens, so what is the optimal treatment approach for more frail elderly patients? It is highly likely that our treatment approaches will continue to evolve as the results of ongoing clinical trials are released and that further improvements in the outcome of this disease will result from identification of therapies that target the underlying pathophysiology of CLL.

Diagnosis and management of acquired pure red cell aplasia

Pure red cell aplasia is a syndrome characterized by a severe normocytic anemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Although the causes and natural course of this syndrome are variable and although the anemia in some patients can be managed by treatment of an underlying inflammatory or neoplastic disease, the pathogenesis of a large number of cases is autoimmune, including those associated with thymoma, and are best managed with immunosuppressive therapy.

Autoimmune pancytopenia following combination chemotherapy for chronic lymphocytic leukaemia: Figure 1

Autoimmune haemolysis or thrombocytopenia can complicate purine nucleoside monotherapy for chronic lymphocytic leukaemia (CLL), but Evans syndrome is rare. This is a report of the occurrence of pancytopenia secondary to a unique combination of red cell aplasia with autoimmune thrombocytopenia and neutropenia in a patient with CLL following treatment with fludarabine and cyclophosphamide. This case is unusual for the simultaneous targeting of three haemopoietic lineages by immune dysfunction following fludarabine and cyclophosphamide, which is a treatment regimen believed to reduce autoimmune haematological toxicity in CLL.

Chronic Lymphocytic Leukemia-Associated Pure Red Cell Aplasia

Pure red cell aplasia (PRCA) is a well-known marrow failure which may be acquired or constitutional/congenital, as the Diamond-Blackfan syndrome. Acquired PRCA may show as a primary hematological disorder or secondary to an associated disease, infection or drug. PRCA rarely complicates chronic lymphocytic leukemia (CLL), may occur anytime in the course of the disease and, in this context, it is a minority of total PRCA. Anemia due to PRCA in CLL patients must be carefully evaluated and differentiated from other causes (autoimmune hemolytic anemia, neoplastic lymphocyte infiltration of bone marrow, chemotherapy) that require a different therapeutic approach. PRCA is thought to be an immunologically mediated disorder, but there is no uniformity in the setting of the management. Immunosuppressive therapy is frequently given, such as steroids and cyclosporin-A. Recently, anecdotal cases have been published on the effectiveness of monoclonal antibodies rituximab and alemtuzumab.

Acquired pure red cell aplasia: updated review of treatment

Pure red cell aplasia (PRCA) is a syndrome characterized by a severe normocytic anaemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Primary PRCA, or secondary PRCA which has not responded to treatment of the underlying disease, is treated as an immunologically-mediated disease. Although vigorous immunosuppressive treatments induce and maintain remissions in a majority of patients, they carry an increased risk of serious complications. Corticosteroids were used in the treatment of PRCA and this has been considered the treatment of first choice although relapse is not uncommon. Cyclosporine A (CsA) has become established as one of the leading drugs for treatment of PRCA. However, common concerns have been the number of patients treated with CsA who achieve sustained remissions and the number that relapse. This article reviews the current status of CsA therapy and compares it to other treatments for diverse PRCAs.

Disease-Specific Complications of Chronic Lymphocytic Leukemia

The majority of disease-specific complications in chronic lymphocytic leukemia (CLL), notably infection and autoimmunity, relate to the underlying alterations in immune function. Both cellular and humoral immunity are impaired with qualitative and quantitative defects in B cells, T cells, NK cells, neutrophils and the monocyte/macrophage lineage. Virtually all patients have reduced immunoglobulin levels, even in early stages, and this is associated with an increased frequency and severity of infection. Although prophylactic intravenous immunoglobulin may be of clinical benefit in selected patients, it does not reduce mortality and is certainly not cost-effective. Autoimmune complications occur in up to a quarter of CLL patients and predominantly target blood cells. Autoimmune hemolytic anemia (AHA) is the most common manifestation; immune thrombocytopenia, pure red cell aplasia and autoimmune neutropenia are less common, while non-hematological autoimmunity is rare. The UK CLL4 trial is the largest prospective trial in CLL to examine the significance of both a positive direct antiglobulin test (DAT) and AHA. The study confirmed the usefulness of the DAT in predicting the development of AHA or not, demonstrated that AHA occurred more frequently in patients receiving treatment with chlorambucil or fludarabine alone compared with the combination of fludarabine and cyclophosphamide, and showed that a positive DAT and the development of AHA were poor prognostic markers. Management of CLL-associated autoimmunity rests on good supportive care and the use of immunosuppressive therapies such as steroids and cyclosporine. Splenectomy remains useful, and monoclonal antibodies (rituximab and alemtuzumab) have given promising results.

Immune anaemias in patients with chronic lymphocytic leukaemia treated with fludarabine, cyclophosphamide and rituximab ? incidence and predictors

Immune anaemias (IA) [auto-immune haemolytic anaemia (AIHA) and pure red cell aplasia (PRCA)] are complications of chronic lymphocytic leukaemia (CLL). Fludarabine has been associated with AIHA, whereas both rituximab and cyclophosphamide have been used to treat this condition. Combining these agents with fludarabine may reduce the likelihood of AIHA. We report on the incidence, outcome and pretreatment predictors of IA in 300 patients treated with fludarabine, cyclophosphamide and rituximab (FCR). Nineteen patients (6.5%) developed IA [AIHA (5.8%), PRCA (0.7%)] on or after treatment with FCR. Most patients (82.4%) with AIHA had a negative direct antiglobulin test (DAT). Additional markers of haemolysis (indirect hyperbilirubinaemia, reticulocytosis, low haptoglobin and elevated lactate dehydrogenase levels) confirmed the presence of AIHA in these patients. The majority of patients responded to therapies including steroids, ciclosporin, i.v. immunoglobulin, etc. High pretreatment levels of beta-2 microglobulin predicted for development of IA. No haemolytic crisis was observed during FCR therapy in eight patients with AIHA prior to FCR. Thus, the incidence of IA among CLL patients treated with FCR was comparable with historical rates. The diagnosis of AIHA can be considered even if the DAT is negative. Pre-existing AIHA need not preclude front-line FCR therapy.

Lack of clinical efficacy of rituximab in the treatment of autoimmune neutropenia and pure red cell aplasia: implications for their pathophysiology

We describe 11 patients with severe refractory autoimmune cytopenias treated with the anti-CD20 monoclonal antibody rituximab. Six patients had autoimmune neutropenia (AIN), two had pure red cell aplasia (PRCA), one had AIN and autoimmune haemolytic anaemia, one had AIN and immune thrombocytopaenia purpura (ITP) and one had PRCA and ITP. Rituximab was administered at a dose of 375 mg/m(2) as an intravenous infusion weekly for 4 weeks. Six of eight patients with AIN and all three patients with PRCA did not respond. Two patients died: one with resistant AIN and autoimmune haemolytic anaemia died of pneumocytis pneumonia infection, and one with PRCA and ITP died of an acute exacerbation of bronchiectasis. Rituximab in AIN and PRCA appears to be less effective than Campath-1H when compared to historical data from our group. This supports the hypothesis that T cells may be important in the pathophysiology of AIN and PRCA.

The successful treatment of refractory autoimmune hemolytic anemia with rituximab in a patient with chronic lymphocytic leukemia

The most frequent autoimmune complication in chronic lymphocytic leukemia (CLL) is autoimmune hemolytic anemia (AIHA). There are various treatment modalities; however, there is not much experience with the use of the chimeric anti-CD20 monoclonal antibody rituximab in the autoimmune complications of CLL. Here, we present our patient with CLL and AIHA whose AIHA was unresponsive to various treatment modalities. The administration of 375 mg/m(2)/day rituximab weekly for four cycles halted hemolysis and resulted in resolution of the patient's anemia. One year after therapy, the patient is well with a normal blood count. Rituximab might be preferred over other treatment modalities in the autoimmune complications of CLL because it is effective and has fewer side effects than other therapies.

Chronic lymphocytic leukemia: diagnosis and treatment

Traditionally, the goal of therapy in chronic lymphocytic leukemia (CLL) has been palliative, with first-line therapy using alkylating agents and/or involved field radiotherapy (depending on the stage of disease and sites of involvement) because of the older age of affected patients and the low rate of complete remissions (CRs) with no improvement in overall survival despite treatment. With increasing knowledge about the biology, molecular genetics, and prognostic factors of the disease, the philosophy of care for patients with CLL has evolved from palliation to aiming for a potential cure, especially in younger patients. Furthermore, multiple treatment options have emerged, including purine analogues, monoclonal antibodies, and potentially stem cell transplantation. These have been associated with higher frequencies of CRs and longer durations of responses compared to conventional chemotherapy. In addition, a subset of patients treated with chemoimmunotherapy can achieve durable CRs and molecular remissions. This may translate into improved disease-free survival and potentially a "cure." Because of the heterogeneous nature of CLL, new prognostic markers are currently being incorporated into clinical trials to determine their role in routine clinical practice. This review summarizes current therapeutic regimens that are being evaluated in patients with CLL and management of disease-related complications.

Monoclonal Antibody Therapy for B-Cell Malignancies

For decades, chemotherapy was the only available approach for patients with advanced lymphoid malignancies. Treatment paradigms were dramatically altered by the availability of novel and active targeted agents, particularly the monoclonal antibodies, alemtuzumab and rituximab. These agents are now playing an increasingly important role in the treatment of lymphoid malignancies. Alemtuzumab is being used earlier in the course of chronic lymphocytic leukemia in patients with a more intact immune system, when it is likely to have its greatest activity. The immunosuppressive properties of monoclonal antibodies are also being explored in the stem cell transplant setting, including in vivo purging and, with alemtuzumab, for the management of graft-versus-host disease. Rituximab has become ubiquitous in the treatment of most B-cell malignancies. Further research with this antibody is focused on optimizing its use and determining its role in each of the relevant disease states. In addition, newer antibodies are in development for treating chronic lymphocytic leukemia and other B-cell malignancies. New treatment regimens, including combinations of monoclonal antibodies, could enhance complete response rates and prolong progression-free survival, perhaps eventually improving our ability to cure patients with lymphoid malignancies.

Pure red cell aplasia in B-cell lymphoproliferative disorder treated with rituximab: Report of two cases and review of the literature

Pure red cell aplasia (PRCA) is an unusual cause of anemia in patients with chronic lymphoproliferative disorders. Here, we present two cases of PRCA, one associated with chronic lymphocytic leukemia (CLL) and the other with splenic marginal zone lymphoma, in which the PRCA responded dramatically to treatment with rituximab. We then review the literature on PRCA in lymphoma and response to rituximab. PRCA associated with CLL or lymphoma may be another indication for rituximab therapy.

Tolerability and safety of rituximab (MabThera)

Rituximab, a human/mouse chimeric anti-CD20 antibody, has become part of standard therapy for patients with CD20-expressing B-cell lymphoma, and is currently under investigation for other indications including autoimmune diseases, in particular rheumatoid arthritis (RA). Its characteristic tolerability profile was established soon after clinical testing began and compares favourably with chemotherapy. The majority of patients experience mild to moderate infusion-related reactions (IRRs) during the first administration of rituximab, but the incidence decreases markedly with subsequent infusions. Current data suggest that the type of adverse events in patients with RA are similar to those in lymphoma, but that adverse events related to the rituximab infusions are less severe and less frequent. Rituximab induces a rapid depletion of normal CD20-expressing B-cells in the peripheral blood, and levels remain low or undetectable for 2-6 months before returning to pretreatment levels, generally within 12 months. Serum immunoglobulin levels remain largely stable, although a reduction in IgM has been described. T-cells are unaffected by rituximab and consequently opportunistic infections rarely occur in association with rituximab therapy. When used in combination with a variety of chemotherapeutic regimens, rituximab does not add to the toxicity of chemotherapy, with the exception of a higher rate of neutropenia. However, this does not translate into a higher infection rate. Over 540,000 patients worldwide have now received rituximab and serious adverse reactions have occurred in a small minority of patients, but for the great majority of patients, rituximab is safe and well tolerated.

Use of rituximab to treat refractory Diamond-Blackfan anemia

We report here the first case with Diamond-Blackfan anemia (DBA) who responded to rituximab. The patient is an 8-yr-old Japanese girl with refractory DBA accompanied by complex congenital heart disease. She received two doses of rituximab, 375 mg/m(2)/wk. She became transfusion independent 6 months after the treatment without any serious side effect. However, after 8 months of transfusion-free period, her condition returned to the pretreatment level with recovery of peripheral B cells. Rituximab may be a successful therapy for refractory DBA where B cells play a crucial role in the pathogenesis of the severe anemia.

A case of pure red cell aplasia complicated with diffuse large B cell lymphoma, T-cell-rich/histiocyte-rich variant: effectiveness of rituximab and implications for a common immunopathogenic role of B lymphocytes

Diffuse large B cell lymphoma, T-cell-rich/histiocyte-rich variant (DLBL-TH), is characterized by the presence of neoplastic B cells set in a background containing numerous non-neoplastic T lymphocytes and histiocytes. We report here the case of a patient with DLBL-TH who developed overt pure red cell aplasia (PRCA) following chemotherapy and autologous peripheral blood stem cell transplantation. Posttransplantation bone marrow biopsies revealed the absence of erythroid precursors associated with lymphoid aggregates composed of B cells mixed with numerous T cells and histiocytes. Administration of rituximab has led to complete recovery of erythropoiesis, which was associated not only with B cell depletion but also with a marked reduction in bone marrow T cells and histiocytes. These observations strongly suggest the particular pathogenetic role of the patient's B cells in inducing PRCA and recruiting T cells and histiocytes in situ.

Monoclonal antibodies in the treatment of chronic lymphocytic leukemia

Traditional therapy for chronic lymphocytic leukemia (CLL) has consisted of alkylating agents, purine analogs, or a combination of these drugs. These agents are effective at producing remissions but are not curative.Thus, new drugs are still needed to improve the outcome of patients with CLL. The introduction of monoclonal antibodies, such as rituximab and alemtuzumab, provides a novel therapeutic modality.Rituximab is an active agent in CLL. Standard doses of rituximab result in higher response rates in previously untreated than in relapsed patients but low complete response (CR) rates. Rituximab is most effective in combination with chemotherapy, especially fludarabine-based regimens in the first-line and salvage setting. Rituximab is also useful in the treatment of complications of CLL, such as pure red cell aplasia, autoimmune thrombocytopenia, and autoimmune hemolytic anemia. Alemtuzumab has impressive activity in patients with refractory CLL and may play an important role in the consolidation treatment of CLL. Alemtuzumab is most efficacious at clearing disease in the peripheral blood and bone marrow. Bulky lymphadenopathy is less sensitive to therapy. Because of the significant lymphopenia associated with alemtuzumab, antibacterial and antiviral prophylaxis should always be used.

Does B cell depletion have a role to play in the treatment of systemic lupus erythematosus?

B cell dysfunction and pathogenic autoantibody formation are thought to be critical in the pathogenesis of systemic lupus erythematosus (SLE). In this review we will summarize the results of attempts to utilize B cell depletion, based on the use of a chimeric monoclonal antibody (MAb) specific for human CD20, rituximab, for the treatment of patients with SLE.

Successful high-titer immunoglobulin therapy for persistent parvovirus B19 infection in a lymphoma patient treated with rituximab-combined chemotherapy

A 40-year-old female diagnosed with follicular lymphoma was treated with rituximab-combined chemotherapy. Although she achieved complete remission, she developed progressive anemia and reticulocytopenia. Bone marrow examination revealed features of pure red cell aplasia and hemophagocytosis. In addition, the appearance of large pronormoblasts suggested that she was infected with parvovirus B19. Excess viral DNA in her bone marrow confirmed that her illness was caused by persistent parvovirus B19 infection. Serum immunoglobulin levels decreased beyond the lower normal limit, which indicated that her humoral immunity was impaired after rituximab-combined chemotherapy. Although she had been infected with parvovirus B19, she was re-infected and failed to control the viral expansion. High-titer immunoglobulin against parvovirus B19 was intravenously administrated and resulted in remarkable reticulocytosis and improvement of anemia. High-titer immunoglobulin, which contained a sufficient amount of neutralizing antibodies against parvovirus B19, likely inactivated most viruses in vivo. We successfully eradicated the virus after 2 courses of high-dose therapy at 0.5 g/kg/day every week followed by 8 courses of maintenance therapy at 0.1 g/kg/day every other week. It is important to consider that parvovirus B19 infection is a possible cause of progressive anemia in B-cell lymphoma patients treated with rituximab-combined chemotherapy. We propose that the use of high-titer immunoglobulin against parvovirus B19 may enable such immunocompromised patients to eradicate the virus before sufficient immune system reconstruction.

Rituximab for refractory Evans syndrome and other immune-mediated hematologic diseases

The authors describe a 21-year-old man with long-lasting Evans syndrome refractory to corticosteroids and immunosuppressive agents; the patient responded to four weekly infusions of rituximab. The patient relapsed with thrombocytopenia 7 months post-therapy and was successfully re-treated with two weekly doses of the same monoclonal antibody. He remains in remission for 7-plus months after the second treatment. Therapy was well tolerated, and no infectious complications occurred, despite avoiding administration of prophylactic gammaglobulin. Rituximab appears safe and modestly effective in a variety of immune-mediated hematologic diseases, including autoimmune hemolytic anemia, chronic immune thrombocytopenia, Evans syndrome, pure red cell aplasia, mixed type II cryoglobulinemia, cold agglutinin disease, and Waldenstrom's macroglobulinemia. However, as most of the published literature consists of case reports and small case series, international collaboration is essential in order to better define the efficacy and safety of this agent in children and adults with hematologic diseases.