Rituximab for immune cytopenia in adults: idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia, and Evans syndrome

Targeting B cells in the pre-phase of systemic autoimmunity globally interferes with autoimmune pathology

Systemic lupus erythematosus (SLE) is characterized by a loss of self-tolerance, systemic inflammation, and multi-organ damage. While a variety of therapeutic interventions are available, it has become clear that an early diagnosis and treatment may be key to achieve long lasting therapeutic responses and to limit irreversible organ damage. Loss of humoral tolerance including the appearance of self-reactive antibodies can be detected years before the actual onset of the clinical autoimmune disease, representing a potential early point of intervention. Not much is known, however, about how and to what extent this pre-phase of disease impacts the onset and development of subsequent autoimmunity. By targeting the B cell compartment in the pre-disease phase of a spontaneous mouse model of SLE we now show, that resetting the humoral immune system during the clinically unapparent phase of the disease globally alters immune homeostasis delaying the downstream development of systemic autoimmunity.

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The clinically unapparent pre-phase of SLE impacts clinical disease

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Autoreactive IgM antibodies represent a biomarker for early therapeutic intervention

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Pre-phase B cells orchestrate clinical disease

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Depleting pre-phase B cells diminishes disease pathology

Expanded utilization of rituximab in paediatric cardiac transplant patients

WHAT IS KNOWN AND OBJECTIVE

Epstein-Barr virus (EBV) viraemia and autoimmune cytopenias (AICs) are significant complications that occur following paediatric solid organ transplantation. A variety of treatment methods have been investigated but limited research has focused on the utilization of rituximab in paediatric cardiac transplant recipients for these indications. Rituximab is a monoclonal antibody that binds the CD20 antigen on the surface of B-type lymphocytes resulting in B-cell cytotoxicity. It is considered a second-line therapy for treatment of autoimmune cytopenias and EBV viraemia following adult solid organ transplant (SOT) and haematopoietic stem cell transplant (HSCT). However, data for its use in the paediatric population for treatment of autoimmune cytopenias are lacking. Dosing is based on adult studies, and the frequency and length of therapy associated with resolution of EVB viraemia and AICs in paediatric cardiac transplant recipients is unknown. The objective of this retrospective study was to describe the dosing and length of therapy of expanded off-label use of rituximab for the management of refractory EBV viraemia and AICs, specifically in paediatric cardiac transplant patients.

METHODS

A retrospective chart review was conducted evaluating children <18 years of age who underwent cardiac transplantation, were diagnosed with EBV viraemia or autoimmune cytopenia, and subsequently received treatment with rituximab between June 1995 and October 2018. Data were analysed descriptively.

RESULTS AND DISCUSSION

Of all (n = 188) paediatric cardiac transplant recipients since 1995, 10 patients met the inclusion/exclusion criteria. Primary diagnoses were EBV viraemia (n = 6), immune haemolytic anaemia (n = 3) and immune thrombocytopenic purpura (n = 1). Complete responses were observed in 83.3% and 100% of patients with EVB viraemia and AICs treated with rituximab, respectively. All patients (n = 10) received rituximab 325 mg/m² at weekly intervals. The number of total doses associated with complete resolution was 4-6 doses for EBV viraemia and 2-4 doses for AICs. The most common adverse events reported were neutropenia (n = 3), thrombocytopenia (n = 4), infusion reactions (n = 1) and significant anaemia (n = 2).

WHAT IS NEW AND CONCLUSION

Although the efficacy of rituximab for treatment of EBV viraemia and autoimmune cytopenia in the paediatric cardiac transplant population remains unclear, our study supported the benefit of rituximab when added to therapy for treatment of EBV viraemia and ACIs.

Alternative management of Covid-19 infection

Cytokine storm is a life-threatening complication of Covid-19 infection. Excessive cytokines are the products of hyperactive immune inflammatory response mounted by the host against the virus. There is no agreed treatment for cytokine storm. Three therapeutic agents with proven immune-modulatory properties in regular use in a wide range of inflammatory disorders (high dose intravenous immunoglobulin, Rituximab and thalidomide) are proposed for the treatment of cytokine storm. Safety and efficacy of the proposed treatment should be assessed by randomised controlled clinical trials. The use of the proposed treatment is expected to reduce the mortality rate and alter the overall management of the pandemic.

Evans syndrome: clinical perspectives, biological insights and treatment modalities

Evans syndrome (ES) is a rare and chronic autoimmune disease characterized by autoimmune hemolytic anemia and immune thrombocytopenic purpura with a positive direct anti-human globulin test. It is classified as primary and secondary, with the frequency in patients with autoimmune hemolytic anemia being 37%–73%. It predominates in children, mainly due to primary immunodeficiencies or autoimmune lymphoproliferative syndrome. ES during pregnancy is associated with high fetal morbidity, including severe hemolysis and intracranial bleeding with neurological sequelae and death. The clinical presentation can include fatigue, pallor, jaundice and mucosal bleeding, with remissions and exacerbations during the person’s lifetime, and acute manifestations as catastrophic bleeding and massive hemolysis. Recent molecular theories explaining the physiopathology of ES include deficiencies of CTLA-4, LRBA, TPP2 and a decreased CD4/CD8 ratio. As in other autoimmune cytopenias, there is no established evidence-based treatment and steroids are the first-line therapy, with intravenous immunoglobulin administered as a life-saving resource in cases of severe immune thrombocytopenic purpura manifestations. Second-line treatment for refractory ES includes rituximab, mofetil mycophenolate, cyclosporine, vincristine, azathioprine, sirolimus and thrombopoietin receptor agonists. In cases unresponsive to immunosuppressive agents, hematopoietic stem cell transplantation has been successful, although it is necessary to consider its potential serious adverse effects. In conclusion, ES is a disease with a heterogeneous course that remains challenging to patients and physicians, with prospective clinical trials needed to explore potential targeted therapy to achieve an improved long-term response or even a cure.

Natural History, Pathogenesis, and Treatment of Evans Syndrome in Children

Primary Evans syndrome (ES) is defined by the concurrent or sequential occurrence of immune thrombocytopenia and autoimmune hemolytic anemia in the absence of an underlying etiology. The syndrome is characterized by a chronic, relapsing, and potentially fatal course requiring long-term immunosuppressive therapy. Treatment of ES is hardly evidence-based. Corticosteroids are the mainstay of therapy. Rituximab has emerged as the most widely used second-line treatment, as it can safely achieve high response rates and postpone splenectomy. An increasing number of new genetic defects involving critical pathways of immune regulation identify specific disorders, which explain cases of ES previously reported as "idiopathic".

Warm Autoimmune Hemolytic Anemia: Clinical Profile and Management

Background

Autoimmune hemolytic anemia (AIHA) is a rare autoimmune disease in which autoantibodies target red blood cells leading to marked decrease in their lifespan. The classification of AIHA is based on the immunochemical properties of the RBC autoantibody. Warm antibody AIHA (wAIHA) accounts for 75-80% of all adult AIHA cases. The treatment of wAIHA is mainly corticosteroids. Our retrospective study aimed to study the clinical profile and management of wAIHA.

Methods

Data of 75 patients admitted with wAIHA or presented to outpatient department (previous medical records) with wAIHA between January 2003 and January 2016 were analyzed.

Results

In our study, females constituted 12 and 26 patients of primary and secondary wAIHA, while males constituted 17 and 20 patients of primary and secondary wAIHA, respectively. Mean hemoglobin level at AIHA onset was found to be 7.1 ± 1.7 g/dL in primary wAIHA group and 6.3 ± 1.2 g/dL in secondary wAIHA group, which is statistically significant. Splenectomy was used as mode of treatment in one (3.4%) patient of primary wAIHA group and 15 (32.60%) patients of secondary wAIHA group, which is statistically significant. Mean age of wAIHA onset was 69.7 ± 21.5 years in wAIHA group secondary to lymphoma and 54.3 ± 25.7 years in other wAIHA group, which is statistically significant.

Conclusion

The most common causes of secondary wAIHA are B-cell lymphoma, systemic lupus erythematosus, rheumatoid arthritis, chronic lymphocytic leukemia (CLL), common variable immune deficiency, renal cell carcinoma and secondary to drug usage (alpha methyldopa and carbamazepine), respectively. Reducing the cumulative dose of corticosteroids with second line treatment whenever possible and therefore reducing the risk of sepsis, specifically in older patients with comorbidities will reduce morbidity and mortality.

The Effect of Histological CD20-Positive B Cell Infiltration in Acute Cellular Rejection on Kidney Transplant Allograft Survival

Background. It is controversial whether lymphocyte infiltration exhibited in biopsy specimens is associated with transplant outcomes. This study focused on the effect of CD20-positive B cell infiltration in biopsy specimens from allografts with acute cellular rejection (ACR) in a Chinese population. Methods. Altogether, 216 patients transplanted from Sep. 2001 to Dec. 2014 with biopsy-proved ACR (Banff I or Banff II) were included in the analysis. Biopsies were immunostained for CD20 and C4d. Baseline information, serum creatinine and GFR before and after treatment, steroid resistance, response to treatment, graft loss, and survival were analyzed. Results. Eighty-three patients were classified into CD20-negative group, and 133 patients were classified into CD20-positive group. Significantly more CD20-negative patients (49/83, 59.0%) received steroid plus antibody therapy compared with the CD20-positive group (52/133, 39.1%) (P = 0.004). The response to treatment for ACR did not differ between these two groups. The CD20-positive group had less graft loss (18.8% versus 32.5%, P = 0.022) and a better graft survival rate. Further exploration of the infiltration degree suggested that it tended to be positively related to graft survival, but this did not reach statistical significance. Conclusion. CD20-positive B cell infiltration in renal allograft biopsies with ACR is associated with less steroid resistance and better graft survival. The presence of CD20-positive B cells is protective for renal allografts.

Bortezomib-based antibody depletion for refractory autoimmune hematological diseases

Certain patients with antibody-mediated autoimmune disease exhibit poor responses to conventional immunosuppression, including B-cell depletion with rituximab. Proteasome inhibitors such as bortezomib demonstrate pleiotropic immunomodulatory effects, including direct toxicity to antibody-producing cells. Here, we report preliminary evidence for the efficacy of bortezomib as salvage therapy for refractory autoimmune hematological disease. Thirteen treatment episodes in 10 patients with autoimmune hematological phenomena (autoimmune hemolytic anemia [AIHA; n = 8], acquired hemophilia (n = 1), immune thrombocytopenia (n = 1), and thrombotic thrombocytopenic purpura [TTP; n = 3]) and a median of 5 (range, 3-12) prior lines of therapy demonstrated an overall response rate of 77% (10 of 13) including 38% (5 of 13) complete remissions. The majority of clinical improvements were rapid, correlated with biomarkers of autoantibody reduction, and were associated with an acceptable safety profile. Responses appeared durable following treatment of TTP and acquired hemophilia; AIHA responses were more limited with a pattern of relapse following bortezomib cessation. These data provide proof of concept for the utility of proteasome inhibition as antibody depletion therapy in autoimmune disease.

Evans Syndrome Secondary to Common Variable Immune Deficiency

Evans syndrome is an underdiagnosed condition consisting of simultaneous or sequential combination of autoimmune hemolytic anemia and immune-mediated thrombocytopenia. We report a case of severe Evans syndrome presenting as altered mental status, a rare presenting sign of the disease. This case highlights the difficulty in diagnosing Evans syndrome and provides a review of the literature and management strategies for treating the disorder.

A molecular perspective on rituximab: A monoclonal antibody for B cell non Hodgkin lymphoma and other affections

Rituximab (a chimeric anti-CD20 monoclonal antibody) is the first Food and Drug Administration approved anti-tumor antibody. Immunotherapy by rituximab, especially in combination-therapy, is a mainstay for a vast variety of B-cell malignancies therapy. Its therapeutic value is unquestionable, yet the mechanisms of action responsible for anti-tumor activity of rituximab and rituximab resistance mechanisms are not completely understood. Investigation of the mechanisms of action that contribute to the rituximab activity have eventually directed to a suite of novel combinations and novel treatment schedules, and also have resulted new generations of antibodies with more desired effects. Although, further investigations are needed to define the mechanisms of rituximab resistance and prominent effector activity of the altered next generation anti-CD20 to improve their efficacies and develop new anti-CD20 monoclonal antibodies in NHL treatment. This article focuses on the properties of CD20 which led scientists to select it as an effective therapeutic target and the molecular details of mechanisms of rituximab action and resistance. We also discuss about the impact of rituximab in monotherapy and in combination with chemotherapy regimens. Finally, we comparatively summarize the next generations of anti CD20 monoclonal antibodies to highlight their advantages relative to their ancestor: Rituximab.

The role of rituximab in adults with warm antibody autoimmune hemolytic anemia

Warm antibody hemolytic anemia is the most common form of autoimmune hemolytic anemia. When therapy is needed, corticosteroids remain the cornerstone of initial treatment but are able to cure only a minority of patients (<20%). Splenectomy is usually proposed when a second-line therapy is needed. This classical approach is now challenged by the use of rituximab both as second-line and as first-line therapy. Second-line treatment with rituximab leads to response rates similar to splenectomy (∼70%), but rituximab-induced responses seem less sustained. However, additional courses of rituximab are most often followed by responses, at the price of reasonable toxicity. In some major European centers, rituximab is now the preferred second-line therapy of warm antibody hemolytic anemia in adults, although no prospective study convincingly supports this attitude. A recent randomized study strongly suggests that in first-line treatment, rituximab combined with steroids is superior to monotherapy with steroids. If this finding is confirmed, rituximab will emerge as a major component of the management of warm antibody hemolytic anemia not only after relapse but as soon as treatment is needed.

B2 cells suppress experimental abdominal aortic aneurysms

Recent reports of rupture in patients with abdominal aortic aneurysm (AAA) receiving B-cell depletion therapy highlight the importance of understanding the role of B cells (B1 and B2 subsets) in the development of AAA. We hypothesized that B2 cells aggravate experimental aneurysm formation. The IHC staining revealed infiltration of B cells in the aorta of wild-type (C57BL/6) mice at day 7 after elastase perfusion and persisted through day 21. Quantification of immune cell types using flow cytometry at day 14 showed significantly greater infiltration of mononuclear cells, including B cells (B2: 93% of total B cells) and T cells in elastase-perfused aortas compared with saline-perfused or normal aortas. muMT (mature B-cell deficient) mice were prone to AAA formation similar to wild-type mice in two different experimental AAA models. Contradicting our hypothesis, adoptive transfer of B2 cells suppressed AAA formation (102.0% ± 7.3% versus 75.2% ± 5.5%; P < 0.05) with concomitant increase in the splenic regulatory T cell (0.24% ± 0.03% versus 0.92% ± 0.23%; P < 0.05) and decrease in aortic infiltration of mononuclear cells. Our data suggest that B2 cells constitute the largest population of B cells in experimental AAA. Furthermore, B2 cells, in the absence of other B-cell subsets, increase splenic regulatory T-cell population and suppress AAA formation.

Resolution of alloimmunization and refractory autoimmune hemolytic anemia in a multi-transfused beta-thalassemia major patient

Beta-thalassemia is one of the most prevalent autosomal disorders, which affect more than 400,000 newborn per year worldwide. In India, the carrier rate of beta-thalassemia varies from 3-17%. The overall rate of alloimmunization in thalassemia patients has been reported to be 5-30% in the world, which is mostly contributed by the alloimmunization to minor blood group antigen. Among Asians, the incidence of red cell alloimmunization is 22%. The recommended treatment for beta-thalassemia major is regular blood transfusion every 3 to 4 weeks. The development of anti-red cell antibodies (alloantibodies and/or autoantibodies) can significantly complicate transfusion therapy. Alloantibodies are commonly associated with red cell hemolysis. Red cell autoantibodies appear less frequently, but they can result in clinical hemolysis called autoimmune hemolytic anemia (AIHA), and in difficulty in cross-matching blood. Patients with autoantibodies may have a higher transfusion rate and often require immunosuppressive drugs or alternative treatments including intravenous immunoglobulin (IVIg) and rituximab (anti-CD20 monoclonal antibody).

Severe refractory autoimmune hemolytic anemia with five-year complete hematologic response to third course of treatment with rituximab: a case report

Introduction

Rituximab is an emerging treatment for autoimmune hemolytic anemia. We report the case of a patient with a five-year complete hematologic response to a third course of treatment with rituximab. Cases of response to rituximab re-treatments have been reported, but none to our knowledge that failed multiple prior treatments and achieved as durable a response.

Case presentation

A 45-year-old Hispanic man presented at age 26 with darkening urine and cold intolerance. His blood tests revealed elevated lactic dehydrogenase and bilirubin, a hemoglobin level of 7.4g/dL, and a positive Coombs test for complement C3 and immunoglobulin G antibody. A diagnosis of autoimmune hemolytic anemia was made. After failing multiple therapies including prednisone, splenectomy, immunoglobulin, cyclosporine, danocrine and azathioprine, our patient was treated with a four-week course of rituximab at a dose of 375mg/m² weekly, 10 years following initial presentation. He achieved a rapid and complete hematologic response that lasted 25 months. Re-treatment with the same course of rituximab prompted a second response that lasted 18 months. A third re-treatment has achieved an ongoing five-year complete hematologic response.

Conclusions

This is an unusual case of a durable five-year remission of autoimmune hemolytic anemia with rituximab re-treatment following relapse after two prior courses of rituximab and despite the persistence of immunoglobulin G and complement-coated red blood cells. No mechanistic explanations for improved response to rituximab re-treatment in autoimmune hemolytic anemia have been reported in the literature. Future studies of rituximab or other B cell-targeting antibodies in the treatment of autoimmune hemolytic anemia should explore autoantibody immunoglobulin G subclass switching and alterations in complement inhibitory proteins on red blood cell membranes as potential correlates of hematologic response.

B-cell depletion in immune thrombocytopenia

B cells play an important role in the immune response and can lead to the development of autoimmune diseases and particularly immune thrombocytopenia (ITP). A rational approach to ITP treatment could involve B-cell depletion such as with rituximab. Rituximab is a chimeric monoclonal antibody directed against CD20 molecule. It has direct effects on antibody production and indirect effects on cellular immunity. Rituximab demonstrated an overall response rate of 62.5% that lasted from 2-48 months. The ability of rituximab as an effective splenectomy-avoiding option was recently confirmed in a meta-analysis of randomized clinical trials and observational studies including 368 patients with an overall response rate of 57%. However, the estimated 5- year response is only 21% in adults. Rituximab appears to be well tolerated, but we lack studies of long-term tolerance. The optimal time to administer rituximab for ITP remains unclear. There is consensus to administer corticosteroids or intravenous immunoglobulin (IVIg) as first-line therapy in ITP. A panel of experts was unable to formulate a clear strategy for the respective place of splenectomy, thrombopoietin-receptor agonists, and rituximab as second-line treatment. Among new-generation CD20-targeted therapy, only veltuzumab has been tested for ITP. Preliminary study suggests that it could have similar efficacy to rituximab. Options other than anti-CD20 treatment may modulate and/or inhibit the B-cell compartment. Several monoclonal antibodies (MoAbs) directed against different B-lymphocyte receptors or structures implicated in the cooperation between B and T lymphocytes have been successfully tested in various autoimmune diseases. Testing these options in ITP will be an exciting challenge.

Barriers to the Access and Use of Rituximab in Patients with Non-Hodgkin's Lymphoma and Chronic Lymphocytic Leukemia: A Physician Survey

Biologics such as rituximab are an important component of oncology treatment strategies, although access to such therapies is challenging in countries with limited resources. This study examined access to rituximab and identified potential barriers to its use in the United States, Mexico, Turkey, Russia, and Brazil. The study also examined whether availability of a biosimilar to rituximab would improve access to, and use of, rituximab. Overall, 450 hematologists and oncologists completed a survey examining their use of rituximab in patients with non-Hodgkin’s lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Less than 40% of physicians considered rituximab as easy to access from a cost perspective. Furthermore, many physicians chose not to treat, were unable to treat, or had to modify treatment with rituximab despite guidelines recommending its use in NHL and CLL patients. Insurance coverage, reimbursement, and cost to patient were commonly reported as barriers to the use of rituximab. Across all markets, over half of physicians reported that they would increase use of rituximab if a biosimilar was available. We conclude that rituximab use would increase across all therapy types and markets if a biosimilar was available, although a biosimilar would have the greatest impact in Brazil, Mexico, and Russia.

B-Cell Targeted Therapies in Autoimmune Cytopenias and Thrombosis

Ever since the advent of Rituximab and subsequently the emergence of other compounds targeting B cells, a cornucopia of medical applications have been found for this family of compounds. After their establishment as standard of care in many conditions such as rituximab in lymphoma and rheumatoid arthritis, they have been progressively found to aid in the treatment of many other conditions. This area constituted a fertile area of research in the past 12 years. Physicians have investigated the B-cell depleting agents use in cases of autoimmune hematologic cytopenias such as immune thrombocytopenia, Evans syndrome, cold and warm autoimmune hemolytic anemia, and other thrombophilic disorders such as the antiphospholipid syndrome and thrombocytopenic purpura. This chapter presents a historical perspective reviewing the various studies that have been published in this field. In addition, it offers a current assessment of the evidence regarding the use of B-cell depleting agents in the aforementioned conditions.

Immunotherapy treatments of warm autoimmune hemolytic anemia

Warm autoimmune hemolytic anemia (WAIHA) is one of four clinical types of autoimmune hemolytic anemia (AIHA), with the characteristics of autoantibodies maximally active at body temperature. It produces a variable anemia—sometimes mild and sometimes severe. With respect to the absence or presence of an underlying condition, WAIHA is either idiopathic (primary) or secondary, which determines the treatment strategies in practice. Conventional treatments include immune suppression with corticosteroids and, in some cases, splenectomy. In recent years, the number of clinical studies with monoclonal antibodies and immunosuppressants in the treatment of WAIHA increased as the knowledge of autoimmunity mechanisms extended. This thread of developing new tools of treating WAIHA is well exemplified with the success in using anti-CD20 monoclonal antibody, Rituximab. Following this success, other treatment methods based on the immune mechanisms of WAIHA have emerged. We reviewed these newly developed immunotherapy treatments here in order to provide the clinicians with more options in selecting the best therapy for patients with WAIHA, hoping to stimulate researchers to find more novel immunotherapy strategies.

A New Kid on the Block: IL-10+ Regulatory B Cells and a Possible Role In Psoriasis

The pivotal role of T cells in the etiology of psoriasis has been elucidated; however, the mechanisms that regulate these T cells are unclear. Recently, it has been shown that an IL-10 producing B cell population may downregulate T cell function and it has been hypothesized that depletion of this B cell population may lead to exacerbation of T-cell mediated autoimmune disease. We present the case of an adolescent male with autoimmune lymphoproliferative syndrome (ALPS) being treated with the anti-CD20 chimeric monoclonal antibody rituximab in addition to intravenous immune globulin (IVIG) for immune thrombocytopenia (ITP) who developed a psoriasiform rash on his hands following mechanical trauma with concomitant severely decreased B cell count. We propose that depletion of the patient's B cells due to rituximab treatment may have led to abrogation of IL-10+ B-cell regulation of T cells. The development of a psoriasiform rash in this predisposed individual may have been triggered by mechanical trauma to his hands (koebnerization). In addition, we believe the patient's rash may have been tempered by concomitant treatment with IVIG, which has been used as treatment in cases of psoriasis. We discuss the immunologic mechanism of psoriasis and the role that a recently described IL-10+ B cell may play in preventing the pathologic process. Further studies are needed to more clearly elucidate this process.

Rituximab: current status as therapy for malignant and benign hematologic disorders

Rituximab is a chimeric monoclonal antibody targeting the pan-B-cell antigen CD20 and was the first monoclonal antibody approved for clinical use in the treatment of cancer. Since its first approval by the FDA in 1997, investigators have continued to explore a variety of clinical conditions in which rituximab has proven effective with minimal toxicity. Rituximab, as monotherapy or in combination with chemotherapy, has been studied extensively in untreated and relapsed/refractory settings as both induction and maintenance therapy for the treatment of CD20-positive lymphomas and chronic lymphocytic leukemia, in addition to non-malignant hematologic disorders including autoimmune hemolytic anemia and immune thrombocytopenic purpura. Here we discuss the clinical development of rituximab with a review of the efficacy data from clinical trials and its current status in the practice of hematology and oncology.

Successful treatment of refractory idiopathic thrombocytopenic purpura and neutropenia with the monoclonal antibody, rituximab

We describe a 22-year-old male with idiopathic autoimmune thrombocytopenia whose diagnosis was made at age of eight. He underwent splenectomy at age ten and ITP recurred at age 21 with episodes of infection and severe neutropenia (absolute count around 170/μl). He showed no response to immunoglobulin, corticosteroids, danazol, cyclosporine and azathioprine. Anti-CD20 antibody was administered at a dose of 375 mg/m(2) once a week for 2 weeks. After the second infusion of rituximab, the platelet count increased from 4,000 to 516,000/mm(3) and neutrophils count raised from 180 to 545/mm(3). The response improvement persisted during follow up for 9 months (neutrophil count 4,390/mm(3)). This observation indicates that B-cells may play a central role in the pathogenesis of ITN. Anti-CD20 antibody therapy may be an efficient treatment for the patients with chronic or recurrent ITN.

Outcomes 5 years after response to rituximab therapy in children and adults with immune thrombocytopenia

Treatments for immune thrombocytopenic purpura (ITP) providing durable platelet responses without continued dosing are limited. Whereas complete responses (CRs) to B-cell depletion in ITP usually last for 1 year in adults, partial responses (PRs) are less durable. Comparable data do not exist for children and 5-year outcomes are unavailable. Patients with ITP treated with rituximab who achieved CRs and PRs (platelets > 150 × 10(9)/L or 50-150 × 10(9)/L, respectively) were selected to be assessed for duration of their response; 72 adults whose response lasted at least 1 year and 66 children with response of any duration were included. Patients had baseline platelet counts < 30 × 10(9)/L; 95% had ITP of > 6 months in duration. Adults and children each had initial overall response rates of 57% and similar 5-year estimates of persisting response (21% and 26%, respectively). Children did not relapse after 2 years from initial treatment whereas adults did. Initial CR and prolonged B-cell depletion predicted sustained responses whereas prior splenectomy, age, sex, and duration of ITP did not. No novel or substantial long-term clinical toxicity was observed. In summary, 21% to 26% of adults and children with chronic ITP treated with standard-dose rituximab maintained a treatment-free response for at least 5 years without major toxicity. These results can inform clinical decision-making.

Monoclonal antibodies and recombinant immunoglobulins for the treatment of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory and degenerative disease leading to demyelination and axonal damage in the CNS. Autoimmunity plays a central role in MS pathogenesis. Per definition, monoclonal antibodies are recombinant biological compounds with a well defined target, thus carrying the promise of targeting pathogenic cells or molecules with high specificity, avoiding undesired off-target effects. Natalizumab was the first monoclonal antibody to be approved for the treatment of MS. Several other monoclonal antibodies are in development and have demonstrated promising efficacy in phase II studies. They can be categorized according to their mode of action into compounds targeting (i) leukocyte migration into the CNS (natalizumab); (ii) cytolytic antibodies (rituximab, ocrelizumab, ofatumumab, alemtuzumab); or (iii) antibodies and recombinant proteins targeting cytokines and chemokines and their receptors (daclizumab, ustekinumab, atacicept, tabalumab [Ly-2127399], secukinumab [AIN457]). In this review, we discuss the specific molecular targets, clinical efficacy and safety of these compounds and discuss criteria to anticipate the position of monoclonal antibodies in the diversifying armamentarium of MS therapy in the coming years.

Immune thrombocytopenia: no longer 'idiopathic'

Immune thrombocytopenia (ITP) is a common hematologic disorder. Its pathogenesis involves both accelerated platelet destruction and impaired platelet production. First-line agents are usually effective initially but do not provide long-term responses. Splenectomy remains an effective long-term therapy, as does rituximab (Rituxan) in a subset of patients. Thrombopoietic agents offer a new alternative, although their place in the overall management of ITP remains uncertain.

Rituximab therapy for autoimmune haematological diseases

Autoimmune haematological diseases are characterized by the production of antibodies against blood proteins or cells, and comprise primary immune thrombocytopenia, autoimmune haemolytic anaemia, acquired haemophilia, and thrombotic thrombocytopenic purpura. Current treatments for these disorders include corticosteroids, cytotoxic drugs and splenectomy, which may be associated with significant systemic toxicity and/or morbility. B cells play a key role in both the development and perpetuation of autoimmunity, since they produce autoantibodies but also function as antigen-presenting cells, and release immunomodulatory cytokines. Rituximab, an anti-CD20 monoclonal antibody that specifically depletes B cells, may be an effective treatment strategy for patients with autoimmune disorders. This article reviews data of the literature, showing that patients with autoimmune haematological diseases can respond to rituximab irrespective of age and number or type of prior treatments. These data suggest that rituximab provides an effective and well-tolerated treatment option for these conditions.

Severe refractory autoimmune hemolytic anemia with both warm and cold autoantibodies that responded completely to a single cycle of rituximab: a case report

Introduction

Mixed warm and cold autoimmune hemolytic anemia runs a chronic course with severe intermittent exacerbations. Therapeutic options for the treatment of hemolysis associated with autoimmune hemolytic anemia are limited. There have been only two reported cases of the effective use of rituximab in the treatment of patients with mixed autoimmune hemolytic anemia. We report a case of severe mixed autoimmune hemolytic anemia that did not respond to steroids and responded to four weekly doses of rituximab (one cycle).

Case presentation

A 62-year-old Caucasian man presented with dyspnea, jaundice and splenomegaly. His blood work revealed severe anemia (hemoglobin, 4.9 g/dL) with biochemical evidence of hemolysis. Exposure to cold led to worsening of the patient's hemolysis and hemoglobinuria. A direct antiglobulin test was positive for immunoglobulin G and complement C3d, and cold agglutinins of immunoglobulin M type were detected. A bone marrow biopsy revealed erythroid hyperplasia. A positron emission tomographic scan showed no sites of pathologic uptake. There was no other evidence of a lymphoid or myeloid disorder. Initial therapy consisted of avoidance of cold, intravenous methylprednisolone and a trial of plasmapheresis. However, there was no clinically significant response, and the patient continued to be transfusion-dependent. He was then started on 375 mg/m²/week intravenous rituximab therapy. After two treatments, his hemoglobin stabilized and the transfusion requirement diminished. Rituximab was continued for a total of four weeks and led to the complete resolution of his hemolytic anemia and associated symptoms. At the patient's last visit, about two years after the initial rituximab treatment, he continued to be in complete remission.

Conclusion

To the best of our knowledge, this is the first reported case of mixed-type autoimmune hemolytic anemia that did not respond to steroid therapy but responded completely to only one cycle of rituximab. The previous two reports of rituximab use in mixed autoimmune hemolytic anemia described an initial brief response to steroids and the use of rituximab at the time of relapse. In both of these case reports, the response to one cycle of rituximab was short-lived and a second cycle of rituximab was required. Our case report demonstrates that severe hemolysis associated with mixed autoimmune hemolytic anemia can be unresponsive to steroid therapy and that a single cycle of rituximab may lead to prompt and durable complete remission.

Autoimmune hemolytic anemia: classification and therapeutic approaches

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

[Autoimmune haemolytic anemia: diagnosis strategy and new treatments]

The pattern of autoimmune hemolytic anemia has changed significantly these last 15 years. With regard to the diagnosis strategy, the use of gel filtration technique to perform the direct antiglobulin test (DAT) has decreased the number of autoimmune haemolytic anemias with negative tests results. In recent years, autoimmune haemolytic anemia increased in patients receiving purine nucleoside analogues, blood transfusions, solid organ transplantation or hematopoietic stem cells transplantation. These difficult autoimmune haemolytic anemia cases need to use new kinds of treatments. With regard to the treatment, very little progress was made this latter 50 years. The discovery of the efficacy of anti-CD20 antibody in this disease represents a breakthrough. Nowdays, the second-line treatment includes rituximab or splenectomy. Sometimes, the anti-CD20 treatment could be proposed in first-line but some clinical trials are needed.

Anti-CD20 monoclonal antibodies and their use in adult autoimmune hematological disorders

Autoimmune hematological disorders encompass a broad group of hematological conditions characterized by the loss of self-tolerance to a variety of antigens. Despite good response to first-line therapy in the majority of patients, relapses are common, necessitating new and safe therapeutic options. The anti-CD20 monoclonal antibody rituximab has led to substantial improvement in the treatment of malignant and immune-mediated disorders involving B cells. Although experience with rituximab in immune-mediated hematological disorders is rarely supported by randomized trials, there is now substantial experience with rituximab suggesting that anti-CD20 therapy is an effective and well-tolerated alternative to immunosuppressive therapy in these disorders. However, caution is needed based on recent reports describing-sometimes severe-rituximab-related complications.

Use of Rituximab in Autoimmune Hemolytic Anemia Associated with Non-Hodgkin Lymphomas

The association between non-Hodgkin lymphomas and autoimmune disorders is a well-known event. Also autoimmune hemolytic anemia (AHA), although much more frequent in patients with chronic lymphocytic leukemia (CLL), has been described in this group of patients. In recent years, among the more traditional therapeutic options, rituximab, an anti-CD20 monoclonal antibody, has shown interesting results in the treatment of primary AHA. Although this drug has been frequently used for AHA in patients with CLL, much less data are available on its use in NHL patients. However, considering that the main pathogenetic mechanism of AHA in course of lymphoproliferative disorders seems to be an antibody production directly or indirectly mediated by the neoplastic clone, this monoclonal antibody represents an ideal therapeutic approach. In this paper we will briefly describe some biological and clinical features of NHL-patients with AHA. We will then analyze some studies focusing on rituximab in primary AHA, finally reviewing the available literature on the use of this drug in NHL related AHA.

Low-dose rituximab and alemtuzumab combination therapy for patients with steroid-refractory autoimmune cytopenias

Treatment of autoimmune cytopenias remains unsatisfactory for patients refractory to first-line management. We evaluated the safety and efficacy of low-dose rituximab plus alemtuzumab in patients with steroid-refractory autoimmune hemolytic anemia and immune thrombocytopenic purpura. Nineteen of 21 included patients were assessable for response (11 with immune thrombocytopenic purpura, 8 with autoimmune hemolytic anemia). Treatment with 10 mg of alemtuzumab subcutaneously on days 1 to 3, plus 100 mg of rituximab intravenously weekly in 4 doses, was administered. The overall response rate was 100%, with complete response in 58%. The median response duration was 46 weeks (range, 16-89 weeks). Median follow-up was 70 weeks (range, 37-104 weeks). Most toxicity was grade 1 fever related to the first dose. Six patients developed infections. The combination of rituximab and alemtuzumab is feasible and has an acceptable safety profile and remarkable clinical activity in this group of patients. This study is registered at www.clinicaltrials.gov as #NCT00749112.

Rituximab in autoimmune hematologic diseases: not just a matter of B cells

Rituximab, a chimeric monoclonal antibody that depletes B cells by binding to the CD20 cell-surface antigen, has been investigated extensively in autoimmune disorders. Following the encouraging results in immune thrombocytopenia (ITP), the use of this agent was explored in other autoimmune hematologic diseases, most notably autoimmune hemolytic anemia (AIHA) and thrombotic thrombocytopenic purpura (TTP), characterized by the presence of pathogenetic autoantibodies. Although randomized clinical trials are lacking, the cumulative data would suggest that rituximab has a beneficial role in their treatment. Response to B-cell-depleting therapy is actually associated with a significant decrease of circulating autoantibodies. However, several lines of evidence indicate that the T-cell compartment may also be modulated by these interventions. The doses and the duration of rituximab treatment in patients with autoimmune diseases are still unclear. The incidence of severe side effects is low but not insignificant. In particular, the risk of systemic infections and viral reactivation is a major concern.

Stem cell transplantation for patients with Evans syndrome

Evans syndrome (ES) is a chronic hematological disorder characterized by autoimmune hemolytic anemia and immune-mediated thrombocytopenia that often requires profound and long-term immunosuppression. Only a few small case series or single case studies of autologous and allogeneic hematopoietic stem cell transplantation (HSCT) in patients with ES have been reported in the literature, with long-term remissions being observed after both autologous and allogeneic HSCT. Patients with ES suffering from refractory disease, multiple relapses and serious disease-related complications should be offered allogeneic HSCT, which is the only treatment with curative potential. Autologous HSCT might be preferable in patients with serious pre-existing comorbidities lacking an HLA-identical donor. Owing to the rarity of this disease and the small number of patients receiving HSCT for ES, prospective controlled studies on this approach are not available. A prospective registration of patients transplanted for ES would allow the development of optimal transplant strategies.

How I treat autoimmune hemolytic anemias in adults

Autoimmune hemolytic anemia is a heterogeneous disease with respect to the type of the antibody involved and the absence or presence of an underlying condition. Treatment decisions should be based on careful diagnostic evaluation. Primary warm antibody autoimmune hemolytic anemias respond well to steroids, but most patients remain steroid-dependent, and many require second-line treatment. Currently, splenectomy can be regarded as the most effective and best-evaluated second-line therapy, but there are still only limited data on long-term efficacy and adverse effects. The monoclonal anti-CD20 antibody rituximab is another second-line therapy with documented short-term efficacy, but there is limited information on long-term efficacy and side effects. The efficacy of immunosuppressants is poorly evaluated. Primary cold antibody autoimmune hemolytic anemias respond well to rituximab but are resistant to steroids and splenectomy. The most common causes of secondary autoimmune hemolytic anemias are malignancies, immune diseases, or drugs. They may be treated in a way similar to primary autoimmune hemolytic anemias, by immunosuppressants or by treatment of the underlying disease.

Rituximab is an effective and safe therapeutic alternative in adults with refractory and severe autoimmune hemolytic anemia

Rituximab-induced B-cell depletion has been proven to be a useful therapy for autoimmune hemolytic anemia (AIHA). The aim of this retrospective study was to evaluate the effectiveness of rituximab in the treatment of 36 patients with AIHA refractory to several treatments. These patients had received a median of four (one to eight) previous treatments, and 13 patients had undergone splenectomy. Rituximab was administered by intravenous infusion at a dose of 375 mg/m(2) once weekly for four doses in 29 patients, and 7 patients received one to six doses. Overall, 28 (77%) of 36 patients achieved response. Twenty-two patients (61%) reached a complete response (CR), and 6 patients (16%) obtained a partial response. All patients that reached CR (61%) were able to maintain the response during more than 6 months, with a median follow-up of 14 months (1-86 months). Sixteen patients maintained response for more than 1 year. The predictors of maintained response were achievement of CR and negative Coombs test result. Splenectomized patients showed a better response rate than those nonsplenectomized. Rituximab was well tolerated, and only one patient presented a transitory rash during infusion. Rituximab induced clinical responses in multitreated severe refractory both warm and cold AIHA patients with little toxicity, and consequently, this therapy should be considered as an early therapeutic option in this setting.

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.

CD20-depleting therapy in autoimmune diseases: from basic research to the clinic

The B lymphocyte-associated antigen CD20 is becoming an important immunotherapy target for autoimmune diseases, although its biological function has not been defined. Besides rheumatoid arthritis, growing experience with B cell-depleting therapy indicates that it may be effective in Sjögren's syndrome, dermatomyositis-polymyositis, systemic lupus erythematosus and some types of vasculitides. However, controlled clinical trials are still lacking for some of these indications. Infection has not been seen as a major limitation to this therapy, but reports of progressive multifocal leukoencephalopathy in an extremely small number of patients are of concern. Here, we review the therapeutic actions of anti-CD20 antibodies, and the recent and ongoing clinical trials with CD20-depleting therapy in autoimmune diseases.