Favourable response to therapy with the anti-CD20 monoclonal antibody rituximab in primary chronic cold agglutinin disease

Efficacy of sutimlimab for cold agglutinin disease in a patient on chronic hemodialysis

Reports of cold agglutinin disease (CAD), an autoimmune hemolytic anemia, in dialysis patients are limited. Recently, sutimlimab for CAD was covered by insurance. Herein, we report a case in which sutimlimab was effective in the treatment of CAD in a patient undergoing hemodialysis (HD). The patient was a 73 year-old Japanese man with an 11 year history of HD for diabetic nephropathy. He was admitted to our hospital for examination and treatment of erythropoiesis-stimulating agent (ESA)-induced hyporesponsive anemia and fatigue, which was present in the previous year October to March when temperatures were cooler. The patient was diagnosed with hemolytic anemia based on decreased hemoglobin levels, elevated reticulocyte count, elevated lactate dehydrogenase levels, and decreased haptoglobin levels. Furthermore, he was diagnosed with CAD based on a positive direct antiglobulin test for C3 and cold agglutinin tests. The patient did not respond well to an elevated dialysate temperature or rituximab therapy. After initiating sutimlimab treatment, an increase in the hemoglobin level was observed despite a decrease in temperature, and his fatigue disappeared. Anemia in hemodialysis patients is generally renal; however, some ESA resistance exists, which may be due to hemolytic anemia. In this case, the use of sutimlimab was effective in controlling hemolytic anemia due to CAD.

Monoclonal antibodies for treatment of cold agglutinin disease

INTRODUCTION

Cold agglutinin disease (CAD) is a difficult-to-treat autoimmune hemolytic anemia and B cell lymphoproliferative disorder associated with fatigue, acrocyanosis and a risk of thromboembolic events. Cold-induced binding of autoantibodies agglutinates red blood cells and triggers the classical complement pathway, leading to predominantly extravascular hemolysis.

AREAS COVERED

This review summarizes clinical and experimental antibody-based treatments for CAD and analyzes the risks and benefits of B cell and complement directed therapies, and discusses potential future treatments for CAD.

EXPERT OPINION

Conventional treatment of CAD includes a B cell targeted treatment approach with rituximab, yielding only limited treatment success. Addition of a cytotoxic agent (e.g. bendamustine) increases efficacy but this is accompanied by an increased risk of neutropenia and infection. Novel complement-directed therapies have emerged and were shown to have a good efficacy against hemolysis and safety profile but are expensive and unable to address circulatory symptoms. Complement inhibition with sutimlimab may be used as a bridging strategy until B cell directed therapy with rituximab takes effect or continued indefinitely if needed. Future antibody-based treatment approaches for CAD involve the further development of complement-directed antibodies, combination of rituximab and bortezomib, and daratumumab. Non-antibody based prospective treatments may include the use of Bruton tyrosine kinase inhibitors.

Practical therapy for primary autoimmune hemolytic anemia in adults

BACKGROUND AND AIM

Autoimmune hemolytic anemias (AIHA) constitute a rare and heterogeneous group of diseases whose therapy differs according to the type of antibody involved in the genesis of the disease and the existence or not of an identified cause. With the aim of providing a practical guide for the therapy of AIHA, we summarize the emergency therapy and general measures habitually used in all forms of AIHA, as well as the specific treatment of the most frequent primary forms of AIHA: primary warm AIHA and AIHA from cold agglutinin disease (AIHA from CAD). We discuss the dependence of the treatment of the secondary forms on their underlying causes and the changes in the treatment of the primary forms in recent years.

METHODS

We examined the options available for the treatment of primary warm AIHA and AIHA from CAD.

RESULTS

We found many differences and only one similarity in their treatment.

DISCUSSION

The differences, particularly due to the non-responsiveness of AIHA from CAD to many treatments useful for primary warm AIHA, such as steroids, splenectomy and immunosuppressive agents, must be considered in the face of each, single case of AIHA. Preliminary identification of the type of antibody involved in the genesis of the disease and careful exclusion of a secondary form are particularly important. Rituximab plays a central role in the treatment of primary warm AIHA and AIHA from CAD.

Immunoglobulin M Monoclonal Gammopathies of Clinical Significance

Immunoglobulin M monoclonal gammopathy of undetermined significance (MGUS) comprises 15-20% of all cases of MGUS. IgM MGUS is distinct from other forms of MGUS in that the typical primary progression events include Waldenstrom macroglobulinaemia and light chain amyloidosis. Owing to its large pentameric structure, IgM molecules have high intrinsic viscosity and precipitate more readily than other immunoglobulin subtypes. They are also more commonly associated with autoimmune phenomena, resulting in unique clinical manifestations. Organ damage attributable to the paraprotein, not fulfilling criteria for a lymphoid or plasma cell malignancy has recently been termed monoclonal gammopathy of clinical significance (MGCS) and encompasses an important family of disorders for which diagnostic and treatment algorithms are evolving. IgM related MGCS include unique entities such as cold haemagglutinin disease, IgM related neuropathies, renal manifestations and Schnitzler's syndrome. The diagnostic approach to, and management of these disorders differs significantly from other categories of MGCS. We describe a practical approach to the evaluation of these patients and our approach to their treatment. We will also elaborate on the key unmet needs in IgM MGCS and highlight potential areas for future research.

The Burden of Cold Agglutinin Disease on Patients’ Daily Life: An Online Survey of 50 American Patients (Preprint)

Background

Cold agglutinin disease (CAD) is a rare disorder, affecting 15% of patients with autoimmune hemolytic anemia. Few studies have assessed CAD symptoms and their impact on daily life, but these studies did not address the patients’ perspectives.

Objective

The aims of this study were to increase the knowledge about CAD through a patient-centric survey and to gain a better understanding of the burden of this disease.

Methods

We conducted an internet-based survey in September 2020 among American patients registered on the CAD Unraveled website and members of the Cold Agglutinin Disease Foundation.

Results

A total of 50 respondents were included in this study. Totally, 90% (45/50) of the patients reported having experienced fatigue. Fatigue was mainly reported on a daily basis, and approximately one-third of these patients (13/45, 29%) said that their fatigue was constant throughout the day. It has also been shown that CAD has a great impact on patients’ physical well-being, emotional well-being, social life, and household finances. The disease varies over time, with or without symptoms. A total of 88% (44/50) of the patients reported previous episodes of the increased intensity or sensitivity of their CAD symptoms, with a mean of 4.5 (SD 5.4) episodes reported during the past year. More than half of the patients (27/50, 54%) considered their disease to be moderate or severe, and 42% (21/50) of the study group reported that their symptoms had worsened since the time of diagnosis.

Conclusions

Our study has provided new data on CAD symptoms, particularly data on the importance and type of fatigue and the fluctuation of CAD symptoms.

Immunoglobulin M Paraproteinaemias

Monoclonal paraproteinaemia is an increasingly common reason for referral to haematology services. Paraproteinaemias may be associated with life-threatening haematologic malignancies but can also be an incidental finding requiring only observation. Immunoglobulin M (IgM) paraproteinaemias comprise 15–20% of monoclonal proteins but pose unique clinical challenges. IgM paraproteins are more commonly associated with lymphoplasmacytic lymphoma than multiple myeloma and can occur in a variety of other mature B-cell neoplasms. The large molecular weight of the IgM multimer leads to a spectrum of clinical manifestations more commonly seen with IgM paraproteins than others. The differential diagnosis of B-cell and plasma cell dyscrasias associated with IgM gammopathies can be challenging. Although the discovery of MYD88 L265P and other mutations has shed light on the molecular biology of IgM paraproteinaemias, clinical and histopathologic findings still play a vital role in the diagnostic process. IgM secreting clones are also associated with a number of “monoclonal gammopathy of clinical significance” entities. These disorders pose a novel challenge from both a diagnostic and therapeutic perspective. In this review we provide a clinical overview of IgM paraproteinaemias while discussing the key advances which may affect how we manage these patients in the future.

Cold agglutinin disease: current challenges and future prospects

Cold agglutinin disease (CAD) is a complement-dependent, classical pathway-mediated immune hemolytic disease, accounting for 15–25% of autoimmune hemolytic anemia, and at the same time, a distinct clonal B-cell lymphoproliferative disorder of the bone marrow. The disease burden is often high, but not all patients require pharmacological treatment. Several therapies directed at the pathogenic B-cells are now available. Rituximab plus bendamustine or rituximab monotherapy should be considered first-line treatment, depending on individual patient characteristics. Novel treatment options that target the classical complement pathway are under development and appear very promising, and the C1s inhibitor sutimlimab is currently being investigated in two clinical Phase II and III trials. These achievements have raised new challenges and further prospects, which are discussed. Patients with CAD requiring therapy should be considered for clinical trials.

Nivolumab-induced cold agglutinin syndrome successfully treated with rituximab

Cold agglutinin syndrome is one of the rare immune-related adverse events of nivolumab. Rituximab should be considered for treatment of nivolumab-induced cold agglutinin syndrome.

Successful treatment of cold agglutinin disease with anti-CD20 antibody (rituximab) in a patient with systemic lupus erythematosus

Cold agglutinin disease (CAD) is a rare cause of anaemia in patients with systemic lupus erythematosus (SLE). CAD is usually refractory to glucocorticosteroid, and other immunosuppressive and/or cytotoxic therapies. We report the case of a 55-years old woman with SLE and CAD that did not respond to high-dose methylprednisolone, cyclosporin A, and double filtration plasma pheresis. Because several recent case reports and studies have indicated promising results of rituximab treatment for CAD and for SLE, rituximab was given weekly at 375 mg/m2in two doses. The rituximab was well tolerated, and there were no adverse effects. The hemolysis and SLE improved markedly, and the patient remained disease free eight months later. This is the first report of successful rituximab treatment of CAD in a patient with SLE. We conclude that rituximab is worth trying in such patients if they fail to respond to conventional treatment.

B lymphocytes in systemic lupus erythematosus: lessons from therapy targeting B cells

Systemic lupus erythematosus (SLE) is a complex disease characterizedby numerous autoantibodies and clinical involvement in multiple organ systems. Autoantibodies are usually present in serum for years before the onset of clinical disease. Autoimmunity begins with a limited number of autoantibodiesand evolves to become progressivelymore diverse. Eventually clinical disease ensues. The immunological events triggering the onset of clinical manifestations have not yet been defined. While undoubtedly T cells and dendritic cells appear to play major roles in SLE, a central role for B cells in the pathogenesis of this disease has been brought to the fore in the last few years by work performed both in mice and humans by multiple laboratories.As a result, there is little doubt about the importance of B cells in the development of SLE. Yet much remains to be learned about their role in the ongoing disease process and the merit of targeting B cells for the treatment of SLE. This article will review the role of B cells in human SLE as well as the currently available data on the treatment of SLE by depleting B cells with anti-CD20 (rituximab).

Rituximab therapy for factor II inhibitor in a patient with antiphospholipid antibody syndrome

Factor II inhibitors have been associated with an increased risk of bleeding. The management of patients with factor II inhibitors has not been adequately described. We describe a patient with an increased bleeding tendency due to factor II inhibitor who was unable to undergo surgery due to her bleeding tendency. The patient was successfully treated with a course of rituximab, which markedly reduced her factor II inhibitor: the factor II level rose from 12 to 61%; prothrombin time decreased from 20 to 14.7 s; and partial thromboplastin time (PTT) decreased from 148 to 38.8 s. She was able to undergo abdominal surgery without any hemorrhagic complications. This case exemplifies the possibility of treating patients with factor II inhibitors with rituximab therapy.

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.

Cold agglutinin disease

Cold agglutinin disease is a rare and poorly understood disorder affecting 15% of patients with autoimmune hemolytic anemia. We reviewed the clinical and pathologic features, prognosis, and management in the literature and describe our institutional experience to improve strategies for accurate diagnosis and treatment. Retrospective analysis identified 89 patients from our institution with cold agglutinin disease from 1970 through 2012. Median age at symptom onset was 65 years (range, 41 to 83 years), whereas the median age at diagnosis was 72 years (range, 43 to 91 years). Median survival of all patients was 10.6 years, and 68 patients (76%) were alive 5 years after the diagnosis. The most common symptom was acrocyanosis (n = 39 [44%]), and many had symptoms triggered by cold (n = 35 [39%]) or other factors (n = 20 [22%]). An underlying hematologic disorder was detected in 69 patients (78%). Thirty-six patients (40%) received transfusions during their disease course, and 82% received drug therapy. Rituximab was associated with the longest response duration (median, 24 months) and the lowest proportion of patients needing further treatment (55%). Our institution’s experience and review of the literature confirms that early diagnostic evaluation and treatment improves outcomes in cold agglutinin disease.

[Efficacity of rituximab in hemolytic anemia with cold autoantibodies case]

INTRODUCTION

Autoimmune hemolytic anemia with cold autoantibodies or cold agglutinin disease is a rare chronic disorder in which no treatment has, until now, evidence of its effectiveness.

CLINICAL CASE

We report a patient who successfully responded to rituximab for a cold agglutinin disease refractory to conventional therapy with very good tolerance and a complete remission.

CONCLUSION

There are only few observations that have been reported in the literature regarding the efficacity of rituximab in the treatment of cold agglutinin disease. This promising therapy could, in the future, constitute a real alternative.

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.

A new approach to comparing anti-CD20 antibodies: importance of the lipid rafts in their lytic efficiency

The view that B lymphocytes are pathogenic in diverse pathological settings is supported by the efficacy of B-cell-ablative therapy in lymphoproliferative disorders, autoimmune diseases and graft rejection. Anti-B-cell antibodies (Abs) directed against CD20 have therefore been generated, and of these, rituximab was the first anti-CD20 monoclonal Ab (mAb) to be applied. Rituximab-mediated apoptosis, complement-dependent cytotoxicity and Ab-dependent cellular cytotoxicity differ from one disease to another, and, for the same disease, from one patient to another. This knowledge has prompted the development of new anti-CD20 mAbs in the hope of improving B-cell depletion. The inclusion of CD20/anti-CD20 complexes in large lipid rafts (LRs) enhances the results of some, but not all, anti-CD20 mAbs, and it may be possible to include smaller LRs. Lipid contents of membrane may be abnormal in malignant B-cells, and could explain resistance to treatment. The function of these mAbs and the importance of LRs warrant further investigation. A detailed understanding of them will increase results for B-cell depletion in lymphoproliferative diseases.

[Rheumatoid arthritis and autoimmune hemolysis: B-cell depletion for remission induction in a patient with rheumatoid arthritis and cold agglutinin disease]

Autoimmune hemolysis is a rare complication of systemic rheumatic diseases. We report on a 68-year-old female patient with established, long-standing rheumatoid arthritis, who complained of progressive weakness and worsening of her arthralgia under therapy with leflunomide. Physical and laboratory examination revealed autoimmune hemolysis due to cold agglutinin disease. As hemolysis and arthritis were refractory to steroid treatment, B-cell depletion with rituximab was performed leading to a marked reduction of hemolytic parameters as well as remission of her rheumatoid arthritis.

Rituximab in chronic cold agglutinin disease: a prospective study of 20 patients

Chronic cold agglutinin disease (CAD) is an acquired autoimmune hemolytic anemia. Previous therapeutic modalities, including alkylating cytostatics, interferon and prednisolone, have been disappointing. However, several case reports and small-scaled studies have demonstrated promising results after treatment with rituximab. We performed a phase II multicentre trial to investigate the effect of rituximab in CAD, including 20 patients studied from October 2002 until April 2003. Thirteen patients had idiopathic CAD and seven patients had CAD associated with a malignant B-cell lymphoproliferative disease. Rituximab was given in doses of 375 mg/m(2) at days 1, 8, 15 and 22. Sixteen patients were followed up for at least 48 weeks. Four patients were excluded after 8, 16, 23 and 28 weeks for reasons unrelated to CAD. Nine patients (45%) responded to the treatment, one with complete response (CR), and eight with partial response. Eight patients relapsed, one patient was still in remission at the end of follow-up. There were no serious rituximab-related side-effects. Our study confirms previous findings of a favourable effect of rituximab in patients with CAD. However, few patients will obtain CR and, in most patients, the effect will be transient.

Catastrophic multiple organ ischemia due to an anti-Pr cold agglutinin developing in a patient with mixed cryoglobulinemia after treatment with rituximab

Cold agglutinin disease occurring with cryoglobulinemia is a rare occurrence. Here, we report a patient with mixed cryoglobulinemia that was treated with rituximab and, after response, developed an anti-Pr cold agglutinin that manifested with hemolysis and microvascular occlusion causing mesenteric ischemia and cerebral infarction. Unlike previous reports of patients with cryoglobulinemia and cold agglutinin disease, our patient did not have a detectable cryoprecipitate when his cold agglutinin manifested.

A review of the current use of rituximab in autoimmune diseases

Rituximab is a human/murine chimeric monoclonal antibody primarily used for treating non-Hodgkin's B-cell lymphoma. Recently it has also been used in the treatment of several autoimmune diseases. A literature review was conducted to determine the efficacy of rituximab in the treatment of some of these autoimmune diseases. Multiple mechanisms proposed for the rituximab mediated B cell depletion are also discussed. The efficacy of rituximab is well-established and it is FDA approved for treatment of Rheumatoid arthritis. In this review, data on the use of rituximab is presented from 92 studies involving 1197 patients with the following diseases: systemic lupus erythematosus, idiopathic thrombocytopenic purpura, anti-neutrophil cytoplasmic antibody associated vasculitis, Grave's disease, autoimmune hemolytic anemia, pemphigus vulgaris, hemophilia A, cold agglutinin disease, Sjogren's syndrome, graft vs. host disease, thrombotic thrombocytopenic purpura, cryoglobulinemia, IgM mediated neuropathy, multiple sclerosis, neuromyelitis optica, idiopathic membranous nephropathy, dermatomyositis, and opsoclonus myoclonus. The efficacy varies among different autoimmune diseases. The cumulative data would suggest that in the vast majority of studies in this review, RTX has a beneficial role in their treatment. While rituximab is very effective in the depletion of B cells, current research suggests it may also influence other cells of the immune system by re-establishing immune homeostasis and tolerance. The safety profile of RTX reveals that most reactions are infusion related. In patients with autoimmune diseases the incidence of serious and severe side effects is low. Systemic infection still remains a major concern and may result in death.

Cost-effectiveness of rituximab in refractory cold agglutinin disease

Cold haemagglutinin disease (CHAD) is an uncommon condition frequently associated with B-cell lymphoproliferative disorders and is refractory to conventional treatments used in autoimmune haemolytic anaemia. Rituximab has been used in this condition with favourable and lasting responses. Cost has been a major limitation to its use in such indication. We present cost-effectiveness analysis of the use of rituximab in two patients with CHAD. Rituximab successfully controlled haemolysis in both cases of CHAD and was found to be cost-effective through reducing transfusion needs.

Primary chronic cold agglutinin disease: an update on pathogenesis, clinical features and therapy

Chronic cold agglutinin disease (CAD) is a subgroup of autoimmune hemolytic anemia. Primary CAD has traditionally been defined by the absence of any underlying or associated disease. The results of therapy with corticosteroids, alkylating agents and interferon-a have been poor. Cold reactive immunoglobulins against erythrocyte surface antigens are essential to pathogenesis of CAD. These cold agglutinins are monoclonal, usually IgMκ auto antibodies with heavy chain variable regions encoded by the V_H4-34 gene segment. By flowcytometric and immunohistochemical assessments, a monoclonal CD20⁺κ⁺B-lymphocyte population has been demonstrated in the bone marrow of 90% of the patients, and lymphoplasmacytic lymphoma is a frequent finding. Novel attempts at treatment for primary CAD have mostly been directed against the clonal B-lymphocytes. Phase 2 studies have shown that therapy with the chimeric anti-CD20 antibody rituximab produced partial response rates of more than 50% and occasional complete responses. Median response duration, however, was only 11 months. In this review, we discuss the clinical and pathogenetic features of primary CAD, emphasizing the more recent data on its close association with clonal lymphoproliferative bone marrow disorders and implications for therapy. We also review the management and outline some perspectives on new therapy modalities.

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.

B-cell depletion in the treatment of mixed cryoglobulinemia

A controlled study has been carried out to assess the efficacy of rituximab (RTX), a chimeric antibody that binds to the B-cell surface antigen CD20, in twenty patients with mixed cryoglobulinemia (MC) and HCV-positive chronic active liver disease, resistant to interferon-alpha (IFN-alpha) therapy. They received an intravenous infusion of 375 mg/m(2) RTX once a week for 4 consecutive weeks. Infusion of RTX had a good safety profile, and no severe side-effects were reported. Sixteen patients (80%) had a complete response (CR), characterized by rapid improvement of clinical signs (disappearance of purpura, weakness, arthralgias and improvement of peripheral neuropathy), and decreased cryocrit. CR was associated with a significant reduction in rheumatoid factor (RF) activity and anti-HCV antibody titers. Decline of IgG anti-HCV titers in the cryoprecipitates was usually associated with a favorable response (r= 0.81; p <0.005). No differences in the dynamics of B-cell depletion and recovery were found between responders and non-responders. Molecular monitoring of the B-cell response revealed disappearance/deletion of peripheral clones in the responders and great stability in the non-responders. RTX had a deep impact on hepatitis C viremia: HCV RNA increased to approximately twice the baseline level in the responders, whereas it remained much the same in the non-responders. Twelve out of 16 responders (75%) remained in remission throughout the follow-up. The results indicate that RTX has clinical and biological activity in HCV-positive MC patients. However, in view of the increased viremia in the responders, additional modes of application and combination of RTX with other agents need to be investigated.

Management of cold haemolytic syndrome

Most haemolytic disease is mediated by immunoglobulin G (IgG) antibodies and leads to red blood cell destruction outside of the circulatory system. However, rare syndromes, such as paroxysmal cold haemoglobinuria, show IgG antibodies causing intravascular destruction. Haemolysis may also occur because of immunoglobulin M antibodies. Historically, these antibodies have been termed 'cold agglutinins' because they cause agglutination of red blood cells at 3 degrees C. Cold agglutinin haemolytic anaemia has been associated with a number of autoimmune and lymphoproliferative disorders, and its management differs substantially from warm antibody-mediated haemolytic anaemia. This review of cold haemolytic syndromes describes new therapies and clinical strategies to determine a correct diagnosis.

Rituximab in the treatment of adult acquired hemophilia A: A systematic review

Rituximab is a monoclonal chimeric antibody to the CD20 antigen, which has proven to be effective in the treatment of non-Hodgkin lymphomas. Recently, rituximab has also been employed in many non-malignant autoimmune disorders (i.e., idiopathic thrombocytopenic purpura, thrombotic thrombocytopenic purpura, connective tissue disorders and autoimmune hemolytic anemia) in which it has been used with the aim of interfering with the production of pathologic antibodies. Moreover, this agent has also shown to be effective in the treatment of acquired antibodies against factor VIII. Through a careful literature search, the current knowledge on rituximab therapy in adult acquired hemophilia A is presented in this review. Although mostly based on uncontrolled studies, the literature data suggest that this drug can be useful in the treatment of disorders of acquired inhibitors to factor VIII. However, large, prospective, randomized trials are needed to confirm these positive preliminary results.

Rituximab for the treatment of childhood chronic idiopathic thrombocytopenic purpura and hemophilia with inhibitors

Rituximab, a monoclonal chimeric antibody to the CD20 antigen, is an effective treatment for non-Hodgkin lymphomas. Moreover, rituximab has also shown efficacy in various autoimmune disorders. In this review, we will focus on the use of rituximab in childhood disorders of hemostasis associated with inhibitor formation. Although the results presented suggest that rituximab can be useful in the treatment of this subset of pediatric patients, most of the data come from isolated case reports or descriptions of small, uncontrolled series. Therefore, large, prospective, and randomized trials are needed to confirm the positive, preliminary results.

Anti-CD20 antibody in thrombotic thrombocytopenic purpura refractory to plasma exchange

Thrombotic thrombocytopenic purpura is a rare condition characterized by microangiopathic haemolytic anaemia, thrombocytopenia, altered neurology, renal impairment and fever. While plasma exchange has reduced mortality from more than 90% to between 10 and 30%, a proportion of cases fail to respond. Rituximab may be efficacious in the management of refractory cases of thrombotic thrombocytopenic purpura. We present two cases in which rituximab was used with successful outcomes. Treatment resulted in resolution of severe clinical and haematological abnormalities in both patients. There has been no relapse after 16 months follow up. Our experience supports the use of rituximab in difficult cases of TTP. Ongoing evaluation of its use is in progress at our institution.

Treatment of refractory fludarabine induced autoimmune haemolytic with the anti-cd20 monoclonal antibody rituximab

A patient with cold-type autoimmune haemolytic anaemia for 8 years developed progressive B cell chronic lymphocytic leukaemia (CLL). Despite the risk of fludarabine induced exacerbation of haemolysis, he was given aggressive anti-CLL therapy with six courses of FCR (fludarabine 25 mg/m2 D1-3, cyclophosphamide 250 mg/m2 D2-4 and rituximab 375 mg/m2 D1) every 4 weeks. This resulted in a marked acute increase in haemolysis shortly after completing each course of fludarabine. However, haemolysis had settled to its baseline level by the time of subsequent courses of FCR. FCR resulted in complete clinical remission of CLL but residual haemolysis persisted. The patient was then given four weekly infusions of single agent rituximab, resulting in ongoing remission of haemolysis. In this patient, rituximab appears to have controlled fludarabine induced exacerbation of autoimmune haemolysis. In addition, subsequent single agent rituximab therapy resulted in prolonged remission of cold-type autoimmune haemolytic anaemia. It remains to be seen if the addition of rituximab will allow other patients with a positive direct Coomb's test and/or autoimmune haemolysis to receive fludarabine containing chemotherapy without undue risk of life-threatening haemolytic anaemia.

Cold Hemolytic Syndrome

In most cases, immune-mediated hemolysis occurs extravascularly and is associated with IgG antibodies on the surface of red cells. Rare syndromes include IgG antibodies that cause direct intravascular hemolysis, such as paroxysmal cold hemoglobinuria. Also rare are extravascular hemolytic syndromes caused by IgM polyclonal or monoclonal antibodies that demonstrate red cell agglutination at 3°C, so-called cold antibodies. Because cold agglutinin disease has a high association with several lymphoproliferative disorders and IgM monoclonal gammopathies, its management differs significantly from that associated with warm autoimmune hemolytic anemia. This case-based presentation is designed to guide the reader to the diagnosis and to the initiation of prompt, effective therapy.

Aplastic anemia successfully treated with rituximab

An otherwise healthy 73-year-old female was admitted to our department in 1997 because of easy bruising and a platelet count of 12 x 10(9)/L. The patient was taking no medications. Bone marrow examination revealed erythroid hyperplasia, megakaryocytic hypoplasia, and no sign of malignancy. Chromosome analysis showed a normal karyotype. There was serological evidence of previous infection with parvovirus B19. No antibodies to HBV, HCV, CMV, or EBV were found. ANA and cardiolipin antibodies were not detected. Treatment with prednisolone was without effect, but 3 weeks after i.v. gamma-globulin therapy, the platelet count was normal, 233 x 10(9)/L. Two years later, the patient was readmitted with a platelet count of 11 x 10(9)/L. At this time, treatment with corticosteroids, azathioprine, and gamma-globulin had only a temporary effect, and further therapy was stopped because of side effects. During the next 3 years, the patient developed transfusion-dependent anemia, and her white blood cell count decreased to 1.8 x 10(9)/L. A new bone marrow examination showed aplastic anemia with bone marrow cellularity about 10%. After an intracerebral hemorrhage, the patient accepted treatment with rituximab and received 4 weekly doses of 375 mg/m2. This therapy was followed by an increase in the platelet count to 232 x 10(9)/L, white blood cell count to 6.8 x 10(9)/L, and no more need for blood transfusions. A bone marrow examination 5 months after treatment with rituximab showed hyperplastic myelopoiesis, normoblastic erythropoiesis, and slightly reduced megakaryopoiesis. The use of anti-CD20 monoclonal antibody in aplastic anemia warrants further investigation.

The therapeutic potential of anti-CD20 "what do B-cells do?"

B-cells play a major role in the immunopathogenesis of autoimmune diseases. Not only do they produce autoantibodies, but they regulate other cell types, secrete cytokines, and present antigens. They are thus potential targets for therapeutic intervention. CD20 is a B-cell specific cell surface molecule of uncertain function. An anti-CD20 chimeric mAb (rituximab) has been FDA approved for treatment of B-cell lymphomas since 1997. Rituximab also depletes normal B-cells by several mechanisms, including ADCC. Over the past seven years, it has shown promise in a number of autoimmune diseases in phase I trials and anecdotal reports. Efficacy in rheumatoid arthritis has already been demonstrated in randomized control trials (RCTs), and RCTs in SLE, inflammatory myositis, and ANCA associated vasculitis are under way. Safety does not appear to be a major problem, but continued vigilance is warranted. The increased use of rituximab, other anti-CD20 agents, and other B-cell targeting therapies holds great promise for substantial clinical benefits, as well as providing special opportunities to understand better disease pathogenesis.

B cells as a therapeutic target in autoimmune diseases

Historically, the pathogenic role of B cells in autoimmune disease has been attributed to the formation of autoantibodies which, as soluble immunoglobulins or immunocomplexes, can trigger cellular damage and initiate the inflammatory cascade. Recent results from clinical trials applying B cell-directed therapeutics in rheumatoid arthritis and systemic lupus erythematosus have challenged such traditional views and encouraged novel ideas about the disease involvement of B cells. Suppression of disease activity, often disconnected from effects on autoantibody titers, has supported the notion that B cells may promote autoimmune disease by serving as antigen-presenting cells that sustain T cell activation. Likewise, B cells have been implicated in supporting the process of ectopic lymphoid neogenesis, a mechanism that stabilises pathogenic immune responses in target tissues and thus contributes to disease chronicity. As a general rule, clinical effects of B cell-directed therapeutics have often been unanticipated and unpredicted by experimental models, emphasis-ing the need to explore and verify disease principles in the patient.

Anti-CD20 monoclonal antibody (Rituximab) for life-threatening hemolytic-uremic syndrome

Rituximab is a chimaeric monoclonal antibody directed against the CD20 antigen. It has been successfully used in B-cell malignancy and its efficacy in the treatment of in autoimmune hemolytic anemia and other autoimmune diseases is being investigated. There are also few case reports of its success in thrombotic thrombocytopenic purpura, but no reports of its use in hemolytic-uremic syndrome (HUS). We report a 36-year-old patient who had lost the function of her native kidneys secondary to HUS. After more than 1 year in clinical remission, she received a living unrelated kidney transplant. This immediately precipitated a severe relapse of HUS. The process was abrogated but not completely inactivated, despite over 40 plasma exchange treatments. Consequently, she was given Rituximab in courses of two to three doses, each dose 375 mg/m(2), at weekly intervals with remarkable stabilization of her disease for approximately 6 months.

Nine patients with anti-neutrophil cytoplasmic antibody-positive vasculitis successfully treated with rituximab

OBJECTIVES

Rituximab (RIT) is a monoclonal anti-CD20 antibody, which depletes B-lymphocytes but not plasma cells. RIT is used for treatment of B-cell lymphomas, but has also shown beneficial effects in autoimmune diseases. In this case series RIT was used in anti-neutrophil cytoplasmic antibody (ANCA)-positive vasculitis.

DESIGN

Case series with a structured follow-up of treated patients.

SETTING

Departments of Nephrology and Rheumatology of a university hospital.

SUBJECTS

Two women with myeloperoxidase-ANCA-positive microscopic polyangiitis and seven patients (five men and two women) with proteinase 3-ANCA-positive Wegener's granulomatosis. All patients were resistant to conventional therapy or had relapsed repeatedly after cessation of cyclophosphamide (Cyc).

INTERVENTIONS

The cases were treated with intravenous infusions of RIT once a week two times (three cases) or four times (six cases). To prevent formation of antibodies to RIT, mycophenolate mofetil (five patients), azathioprine (one patient), or a short course of Cyc (two patients) were added or allowed to continue.

MAIN OUTCOME MEASURES

Remission at 6 months assessed with Birmingham vasculitis activity score. The cases were followed 6-24 months and relapse rate was also noted.

RESULTS

Eight of nine patients responded completely and one case responded partially. Pulmonary X-ray improved (four cases), progress of lower extremity gangrene stopped (one case), remission of neuropathy was stable (one patient), renal vasculitis went into remission (two cases), and severe musculoskeletal pain improved (one case). Minor relapse in the nose occurred in two cases. No adverse events or major infections were noted.

CONCLUSION

RIT seems promising and safe in ANCA-positive vasculitis, and controlled studies should be conducted.

Beneficial Effect of Rituximab in Combination with Oral Cyclophosphamide in Primary Chronic Cold Agglutinin Disease

Cold agglutinin disease (CAD) is an uncommon autoimmune hemolytic anemia characterized by B-cell proliferation. Conventional therapies for primary CAD such as corticosteroids, oral alkylating agents, splenectomy, interferon alpha, and plasma exchange are often ineffective at controlling the disease. The anti-CD20 monoclonal antibody rituximab (MabThera) depletes B-lymphocytes and thereby interferes with the production of cold agglutinin. We describe an elderly patient with primary (idiopathic) chronic CAD refractory to steroids who was successfully treated with 4 weekly infusions (375 mg/m2) of rituximab and 6 months of oral cyclophosphamide at a dosage of 60 mg/m2 per day. The increase in hemoglobin level and the decline in the plasma cold agglutinin titer were rapid (from the second rituximab infusion). The hematologic remission persisted for at least 8 months after treatment start, with no adverse effects. Rituximab and cyclophosphamide may be supplementary therapeutic modalities whose combination warrants further clinical investigation.

Rituximab chimeric anti-CD20 monoclonal antibody treatment for adult refractory idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura is an autoimmune disease which involves opsonization of platelets by autoantibodies directed against different surface glycoproteins, leading to their premature destruction by the reticuloendothelial system. Management of patients with refractory ITP is difficult. Recent studies have shown that rituximab, a chimeric anti-CD20 monoclonal antibody, is useful in the treatment of these patients, with overall response rates of about 50%. Most published reports have included a small number patients including case reports. The present study reports the results of a retrospective Danish multicenter study of rituximab in the treatment of adult patients with refractory ITP. Thirty-five patients (median age 52 years, range 17-82 years, 17 males) were included. One patient had immune thrombocytopenia and neutropenia. All patients had received prednisolone (Pred). Next to Pred, 25 patients had been treated with high-dose IgG, and in 16 patients a splenectomy had been performed. Sixteen patients had been treated with azathioprine. Other treatments included, e.g., cyclosporine, danazol, cyclophosphamide, vincristine, interferon, and dexamethasone. The patients were treated with a dose regimen of 375 mg/m2 i.v. approximately once weekly for 4 consecutive weeks. Six patients received a fixed dose of 500 mg disregarding their weight supplemented by 100 mg of methylprednisone i.v. or 50-100 mg of Pred given as premedication together with an antihistamine just before infusion of rituximab. The large majority of patients also received Pred and, in some cases, other concomitant immunosuppressive treatment during part of their rituximab treatment. A complete response (CR) was defined as a rise in the platelet count > 100 x 10(9)/L, a partial response (PR) as a rise in the platelet count > 50 x 10(9)/L, and a minor response (MR) as a rise in the platelet count < 50 x 10(9)/L. No response (NR) was defined as no increase in the platelet count. Because 4 patients were treated twice, a total of 39 outcomes of rituximab treatment were evaluated. Rituximab proved to be effective in 17 of 39 treatments [overall response 44% with 7 CR (18%) (1 patient showed a CR twice), 6 PR (15%), and 4 MR (10%)]. In 9/13 cases of CR or PR, the response (platelet level > 50 x 10(9)/L) was prompt, 1-2 weeks after the first infusion. The remaining patients responded 3-8 weeks later. Patients with CR and PR have been in remission for a median of 47 weeks. In general the side effects were few. In 2 cases, the treatment was stopped because of side effects either during or after the first infusion. Two fatal outcomes were recorded. A 71-year-old female with severe lung disease died 6 days after the first infusion of respiratory failure. The other patient, a 73-year-old man also with severe chronic obstructive lung disease, died of pneumonia approximately 13 weeks following the last rituximab treatment. It is concluded that rituximab may be a useful alternative therapy in patients with severe and symptomatic ITP refractory to conventional treatment.

[Rituximab: a original biotherapy in auto-immune disorders]

SUBJECT

After several decades of hegemony of the T lymphocyte, recent work has suggested the importance of the B lymphocyte in auto-immune diseases. As a consequence, there has emerged over the last few years the idea of using anti-B lymphocyte therapy, in particular rituximab (a chimeric anti-CD20 monoclonal antibody).

CURRENT TOPICS AND IMPORTANT RESULTS

This review addresses various current topics: a) the role of B lymphocytes in auto-immune diseases, notably their capacity to be antigen presenting cells and to be activated by original systems like Blys/Baff; b) the mechanism of action of rituximab (apoptosis, complement-dependent cytotoxicity and antibody-dependent cell cytotoxicity) and the phenomena explaining failures and cases escaping treatment, in particular among lymphoproliferations; c) The results include efficacy and tolerance data for the principal auto-immune affections. Among these, the most promising indications would seem to be for rheumatoid polyarthritis and systemic lupus erythematosis, although some preliminary open studies point to an effect in Goujerot-Sjögren's syndrome, neuropathies, auto-immune cytopenia, idiopathic thrombocytopenic purpura, cryoagglutinins, blistering cutaneous affections...

PERSPECTIVES AND PROJECTS

Controlled studies will be required to determine the true efficacy and tolerance of this molecule, as it is imperative to validate these new immunotherapeutic strategies, above all when they concern innovative and expensive therapy. Nevertheless, these different observations arouse great hopes and at the same time exciting questions, notably as to the role of B lymphocytes in auto-immune diseases.

Two cases of refractory warm autoimmune hemolytic anemia treated with rituximab

Autoimmune hemolytic anemia is thought to be mediated via auto-antibodies produced by lymphoid B cells. This may be an idiopathic process or secondary to an underlying infection or lymphoproliferative disorder. Conventional treatment comprises immunosuppression with corticosteroids and, in some cases, splenectomy. A proportion of patients require lifelong immunosuppression to maintain disease remission. Monoclonal antibody rituximab has gained widespread acceptance in the management of B-cell malignancies. Additionally, it has been used to treat disorders associated with auto-antibody production, such as cold hemagglutinin disease, immune thrombocytopenia, and Evans syndrome. Its use in the treatment of patients with autoimmune hemolytic anemia in the setting of allogeneic bone marrow transplantation as well as in patients with an underlying lymphoproliferative disease has also been reported. We report herein the successful use of rituximab in the treatment of two patients with idiopathic refractory warm autoimmune hemolytic anemia, who are still in remission at 15 and 9 months following treatment.

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.

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.

Treatment of refractory autoimmune diseases with ablative immunotherapy

Immunological manipulations are the basis of modern therapy for refractory autoimmune diseases (AID). Ablative chemotherapy with stem cell support (autotransplant) as well as targeted immunotherapy using specific monoclonal antibodies, such as rituximab and campath 1-H have become acceptable second line therapy for severe refractory AID. Until now, more than 500 autotransplants have been performed worldwide for various autoimmune disorders, including multiple sclerosis (MS), systemic sclerosis (SSc), systemic lupus erythematosis (SLE) and rheumatoid arthritis (RA) with encouraging results, although transplant related mortality (TRM) in the range between 2 and 17% still remains one of the major limitations of the procedure. Immunotherapy is a relatively safe approach associating with sustained remissions in a considerable proportion of treated patients. Better selection of patients and earlier immunotherapy, preceded an irreversible organ damage might further improve the clinical outcome of patients with AID.