Rituximab for the treatment of autoimmune cytopenias in children with immune deficiency

Targeted treatment of autoimmune cytopenias in primary immunodeficiencies

Primary Immunodeficiencies (PID) are a group of rare congenital disorders of the immune system. Autoimmune cytopenia (AIC) represents the most common autoimmune manifestation in PID patients. Treatment of AIC in PID patients can be really challenging, since they are often chronic, relapsing and refractory to first line therapies, thus requiring a broad variety of alternative therapeutic options. Moreover, immunosuppression should be fine balanced considering the increased susceptibility to infections in these patients. Specific therapeutic guidelines for AIC in PID patients are lacking. Treatment choice should be guided by the underlying disease. The study of the pathogenic mechanisms involved in the genesis of AIC in PID and our growing ability to define the molecular underpinnings of immune dysregulation has paved the way for the development of novel targeted treatments. Ideally, targeted therapy is directed against an overexpressed or overactive gene product or substitutes a defective protein, restoring the impaired pathway. Actually, the molecular diagnosis or a specific drug is not always available. However, defining the category of PID or the immunological phenotype can help to choose a semi-targeted therapy directed towards the suspected pathogenic mechanism. In this review we overview all the therapeutic interventions available for AIC in PID patients, according to different immunologic targets. In particular, we focus on T and/or B cells targeting therapies. To support decision making in the future, prospective studies to define treatment response and predicting/stratifying biomarkers for patients with AIC and PID are needed.

A rare case of combined immunodeficiency with cytopenia whose symptoms were controlled by cyclosporine

Combined Immunodeficiency (CID) is a group of inborn error of Immunity (IEI) that may present with both infectious and non-infectious complications. Autoimmunity is an unusual presentation of CID and can be presented as cytopenia. The initial management of cytopenia is corticosteroids and IVIG. The role of other cytotoxic and immunosuppressive drugs in management of cytopenia is not fully understood. The objective of this clinical case report is to highlight the possibly beneficial role of cyclosporine in controlling cytopenia in CID patients. A 26-month-old child with generalized ecchymosis was referred to Mofid Children's Hospital in Tehran, Iran. Physical examination revealed no substantial findings other than ecchymosis, and complete blood count (CBC) revealed thrombocytopenia. Diagnosis of CID and cytopenia followed. The patient was treated by 5 times prednisolone and 4 times Rituximab. Finally, his ecchymosis was controlled by Cellcept, which was then tempered and substituted by cyclosporine.

Treatment and management of primary antibody deficiency: German interdisciplinary evidence-based consensus guideline

This evidence-based clinical guideline provides consensus-recommendations for the treatment and care of patients with primary antibody deficiencies (PADs). The guideline group comprised 20 clinical and scientific expert associations of the German, Swiss, and Austrian healthcare system and representatives of patients. Recommendations were based on results of a systematic literature search, data extraction, and evaluation of methodology and study quality in combination with the clinical expertise of the respective representatives. Consensus-based recommendations were determined via nominal group technique. PADs are the largest clinically relevant group of primary immunodeficiencies. Most patients with PADs present with increased susceptibility to infections, however immune dysregulation, autoimmunity, and cancer affect a significant number of patients and may precede infections. This guideline therefore covers interdisciplinary clinical and therapeutic aspects of infectious (e.g., antibiotic prophylaxis, management of bronchiectasis) and non-infectious manifestations (e.g., management of granulomatous disease, immune cytopenia). PADs are grouped into disease entities with definitive, probable, possible, or unlikely benefit of IgG-replacement therapy. Summary and consensus-recommendations are provided for treatment indication, dosing, routes of administration, and adverse events of IgG-replacement therapy. Special aspects of concomitant impaired T-cell function are highlighted as well as clinical data on selected monogenetic inborn errors of immunity formerly classified into PADs (APDS, CTLA-4-, and LRBA-deficiency).

[Treatment of ITP and AIHA in CVID: A systematic literature review]

INTRODUCTION

Ten to 15% of common variable immunodeficiencies (CVID) develop auto-immune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). Treatment is based on immunosuppressants, which produce blocking effects in the CVID. Our objective was to assess their risk-benefit ratio in these immunocompromised patients.

METHODS

We identified 17 articles detailing the treatment of AIHA and/or ITP in patients suffering from CVID through a systematic review of the MEDLINE database.

RESULTS

The increased infectious risk with corticosteroids does not call into question their place in the first line of treatment of ITP and AIHA in CVID. High-doses immunoglobulin therapy remain reserved for ITP with a high risk of bleeding. In second-line treatment, rituximab appears to be effective, with a lower infectious risk than the splenectomy. Immunosuppressants (azathioprine, methotrexate, mycophenolate, cyclophosphamide, vincristine, ciclosporine) are moderately effective and often lead to severe infections, meaning that their use is justified only in resistant cases and steroid-sparing. Dapsone, danazol and anti-D immunoglobulins have an unfavorable risk-benefit ratio. The place of TPO receptor agonists is still to be defined. The establishment of immunoglobulin replacement in the place of immunosuppressants (except for short-term corticotherapy) or splenectomy appears to be essential to limit the risk of infections, including in the absence of previous infections.

CONCLUSION

The presence of CVID does not mean that it is necessary to give up on corticosteroids as a first-line treatment and rituximab as a second-line treatment for AIHA and ITP, but it should be in addition to immunoglobulin replacement. A splenectomy should be reserved as a third-line treatment.

Immunosuppressive therapy with rituximab in common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary antibody deficiency in adulthood and is characterized by the marked reduction of IgG and IgA serum levels. Thanks to the successful use of polyvalent immunoglobulin replacement therapy to treat and prevent recurrent infections, non-infectious complications, including autoimmunity, polyclonal lymphoproliferation and malignancies, have progressively become the major cause of morbidity and mortality in CVID patients. The management of these complications is particularly challenging, often requiring multiple lines of immunosuppressive treatments. Over the last 5–10 years, the anti-CD20 monoclonal antibody (i.e., rituximab) has been increasingly used for the treatment of both autoimmune and non-malignant lymphoproliferative manifestations associated with CVID. This review illustrates the evidence on the use of rituximab in CVID. For this purpose, first we discuss the mechanisms proposed for the rituximab mediated B-cell depletion; then, we analyze the literature data regarding the CVID-related complications for which rituximab has been used, focusing on autoimmune cytopenias, granulomatous lymphocytic interstitial lung disease (GLILD) and non-malignant lymphoproliferative syndromes. The cumulative data suggest that in the vast majority of the studies, rituximab has proven to be an effective and relatively safe therapeutic option. However, there are currently no data on the long-term efficacy and side effects of rituximab and other second-line therapeutic options. Further randomized controlled trials are needed to optimize the management strategies of non-infectious complications of CVID.

Outcomes and Treatment Strategies for Autoimmunity and Hyperinflammation in Patients with RAG Deficiency

BACKGROUND

Although autoimmunity and hyperinflammation secondary to recombination activating gene (RAG) deficiency have been associated with delayed diagnosis and even death, our current understanding is limited primarily to small case series.

OBJECTIVE

Understand the frequency, severity, and treatment responsiveness of autoimmunity and hyperinflammation in RAG deficiency.

METHODS

In reviewing the literature and our own database, we identified 85 patients with RAG deficiency, reported between 2001 and 2016, and compiled the largest case series to date of 63 patients with prominent autoimmune and/or hyperinflammatory pathology.

RESULTS

Diagnosis of RAG deficiency was delayed a median of 5 years from the first clinical signs of immune dysregulation. Most patients (55.6%) presented with more than 1 autoimmune or hyperinflammatory complication, with the most common etiologies being cytopenias (84.1%), granulomas (23.8%), and inflammatory skin disorders (19.0%). Infections, including live viral vaccinations, closely preceded the onset of autoimmunity in 28.6% of cases. Autoimmune cytopenias had early onset (median, 1.9, 2.1, and 2.6 years for autoimmune hemolytic anemia, immune thrombocytopenia, and autoimmune neutropenia, respectively) and were refractory to intravenous immunoglobulin, steroids, and rituximab in most cases (64.7%, 73.7%, and 71.4% for autoimmune hemolytic anemia, immune thrombocytopenia, and autoimmune neutropenia, respectively). Evans syndrome specifically was associated with lack of response to first-line therapy. Treatment-refractory autoimmunity/hyperinflammation prompted hematopoietic stem cell transplantation in 20 patients.

CONCLUSIONS

Autoimmunity/hyperinflammation can be a presenting sign of RAG deficiency and should prompt further evaluation. Multilineage cytopenias are often refractory to immunosuppressive treatment and may require hematopoietic cell transplantation for definitive management.

Anti-CD20 Treatment of Autoimmune Hemolytic Anemia Refractory to Corticosteroids and Azathioprine: A Pediatric Case Report and Mini Review

Autoimmune hemolytic anemia (AIHA) is a relatively uncommon hematological entity in children and sometimes is characterized by a severe course requiring more than one line course therapy. Treatment decisions depend on the severity and chronicity of the anemia and the characteristics of the autoantibodies. Immunosuppression with corticosteroids is the first-line treatment, especially in warm-reactive AIHA. Refractory cases are treated with immunosuppressive drugs, cytotoxic agents, androgens, or splenectomy, with various side effects and questionable efficacy. Another second-line option is rituximab, an anti-CD20 monoclonal antibody, which has been used as an off-label agent with encouraging results from small limited studies or case reports. Herein, we add our experience on the safety and clinical efficacy of rituximab by presenting the case of a boy with warm-type AIHA resistant to corticosteroids and azathioprine, successfully treated with rituximab. We also offer a review of the relevant literature.

Infectious diseases and immunological markers associated with patients with non-Hodgkin lymphoma treated with rituximab

BACKGROUND

The use of rituximab (RTX) is increasing, even in developing countries. It has become the first-line therapy or adjuvant to chemotherapy (CHOP; cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone) for various diseases, including B cell lymphoma and autoimmune diseases.

AIM

We describe the infectious diseases and immunological markers associated with RTX treatment of patients with non-Hodgkin lymphoma (NHL).

METHODS

Serum immunoglobulins were determined before and after intravenous immunoglobulin (IVIg) administration. Pneumo-23IgG-specific anti-pneumococcal antibodies were evaluated before and after vaccination. Immunophenotyping and lymphocyte proliferation were determined in the course of the treatment.

RESULTS

Seven patients were followed and median age was 56.0 ± 5.0 years (range, 41.9-71.6 years). At baseline, the mean level of IgG was 333.7 ± 40.8 and IgM 40.9 ± 11.3 mg/dL, respectively; immunoglobulin A and E (IgA and IgE) were under the limit of detection. Two patients had reduced or absent B cells and T cell subsets were at normal levels in five patients. All patients failed to mount an efficient post-vaccination immune response against hepatitis B virus, tetanus, diphtheria and against the 23-valent pneumococcal polysaccharide vaccine. During RTX/CHOP treatment, human-IgG-immunoglobulin (IVIg) therapy was introduced in six patients after recurrent infections, including community-acquired pneumonia (85.7%), chronic sinusitis (85.7%) and gastroenteritis (42.9%).

CONCLUSION

Poor response against pneumococcal vaccines increases the susceptibility of respiratory diseases in these patients. In patients with NHL treated with RTX, the benefits achieved with IVIg replacement for the control of recurrent infectious diseases is of paramount importance. Clinicians dealing with monoclonal antibodies against cancer therapy, especially RTX, should be aware of the increasing risks for symptomatic induced hypogammaglobulinemia and respiratory infections.

Clinical Manifestations and Pathophysiological Mechanisms of the Wiskott-Aldrich Syndrome

The Wiskott-Aldrich syndrome (WAS) is a rare X-linked disorder originally described by Dr. Alfred Wiskott in 1937 and Dr. Robert Aldrich in 1954 as a familial disease characterized by infections, bleeding tendency, and eczema. Today, it is well recognized that the syndrome has a wide clinical spectrum ranging from mild, isolated thrombocytopenia to full-blown presentation that can be complicated by life-threatening hemorrhages, immunodeficiency, atopy, autoimmunity, and cancer. The pathophysiology of classic and emerging features is being elucidated by clinical studies, but remains incompletely defined, which hinders the application of targeted therapies. At the same time, progress of hematopoietic stem cell transplantation and gene therapy offer optimistic prospects for treatment options aimed at the replacement of the defective lymphohematopoietic system that have the potential to provide a cure for this rare and polymorphic disease.

An Update on the Use of Immunomodulators in Primary Immunodeficiencies

The genomic revolution in the past decade fuelled by breathtaking advances in sequencing technologies has defined several new genetic diseases of the immune system. Many of these newly characterized diseases are a result of defects in genes involved in immune regulation. The discovery of these diseases has opened a vista of new therapeutic possibilities. Immunomodulatory agents, a hitherto unexplored therapeutic option in primary immunodeficiency diseases have been tried in a host of these newly described maladies. These agents have been shown conclusively to favorably modulate immune responses, resulting in abatement of clinical manifestations both in experimental models and patients. While some of the treatment options have been approved for therapeutic use or have been shown to be of merit in open-label trials, others have been shown to be efficacious in a handful of clinical cases, animal models, and cell lines. Interferon γ is approved for use in chronic granulomatous disease (CGD) to reduce the burden of infection and and has a good long-term efficacy. Recombinant human IL7 therapy has been shown increase the peripheral CD4 and CD8 T cell counts in patients with idiopathic CD4. Anti-IL1 agents are approved for the management of cryopyrin-related autoinflammatory syndrome, and their therapeutic efficacy is being increasingly recognized in other autoinflammatory syndromes and CGD. Mammalian target of rapamycin (mTOR) inhibitors have been proven useful in autoimmune lymphoproliferative syndrome (ALPS) and in IPEX syndrome. Therapies reported to be potential use in case reports include abatacept in CTLA4 haploinsufficiency and LRBA deficiency, ruxolitinib in gain-of-function STAT1, tocilizumab in gain-of-function STAT3 defect, mTOR inhibitors in PIK3CD activation, magnesium in XMEN syndrome, and pioglitazone in CGD. Treatment options of merit in human cell lines include interferon α and interferon β in TLR3 and UNC-93B deficiencies, anti-interferon therapy in SAVI, and Rho-kinase inhibitors in TTC7A deficiency. Anti-IL17 agents have show efficacy in animal models of leukocyte adhesion defect (LAD) and ALPS. This topical review explores the use of various immunomodulators and other biological agents in the context of primary immunodeficiency and autoinflammatory diseases.

The clinical features of autoimmunity in 53 patients with Wiskott-Aldrich syndrome in China: a single-center study

Autoimmune disease (AD) is common in patients with Wiskott-Aldrich syndrome (WAS) and patients with WAS who has an AD usually constitute a high-risk group with poor outcome. However, knowledge of AD in WAS is limited in China. In this study, medical records of 53 patients with WAS at Children´s Hospital of Chongqing Medical University from April 2004 to January 2014 were evaluated retrospectively and 14 patients (26%) had at least one AD. Autoimmune hemolytic anemia (AIHA) was the most common and detected in 12 patients (23%), other complications included immune thrombocytopenia (n = 1), immune neutropenia (n = 1), autoimmune arthritis (n = 1), and renal injury (n = 1). No significant differences were found in the level of serum immunoglobulins and lymphocyte subsets between the AD group and non-AD group. Although eight patients with AD received hematopoietic stem cell transplantation (HSCT), three patients died of pulmonary infection after HSCT.

CONCLUSIONS

AD is frequent in Chinese patients with WAS and AIHA was the most common. AD is a poor prognosis factor for WAS and should be treated as early as possible by HSCT.

WHAT IS KNOWN

• Autoimmune disease is common in patients with WAS. • Manifestations, follow-up finding, and treatment approaches of autoimmune disease in Chinese patients with WAS have received less attention in the literature. What is New: • This study is firstly intended for evaluation of the clinical and immune characteristics of autoimmune disease in a large series Chinese patients with WAS. • AD is frequent in Chinese patients with WAS and AIHA is the most common.

Common variable immunodeficiency

Common variable immunodeficiency (CVID) is a common primary immunodeficiency characterized by a failure in B-cell differentiation with defective immunoglobulin production. Affected patients are uniquely susceptible to recurrent infection with encapsulated organisms and have an increased propensity for the development of inflammatory and autoimmune manifestations. The diagnosis of CVID is commonly delayed and the underlying cause of the disorder is not understood. Replacement antibody therapy reduces the risk of serious infections. However, optimal treatment regimens for the uncommon manifestations associated with this disease, such as granulomatous lymphocytic interstitial lung disease, require further research.

Transient effect of anti-CD20 therapy in a child with 22q11.2 deletion syndrome and severe steroid refractory cytopenias: a case report

We report on the development of steroid-refractory recurrent cytopenias in a child with 22q11.2 deletion syndrome. His first hematological complication was autoimmune hemolytic anemia at 3 months of age. Thereafter, he developed severe autoimmune cytopenias of all 3 hematological lineages with poor response to steroids and intravenous immunoglobulin. At the age of 2½ years, a course of anti-CD20 therapy (Rituximab) was given with transient hematological recovery. Because of persistent symptoms, bone marrow transplantation from a matched unrelated donor was performed. Although the data in the use of anti-CD20 therapy in children with 22q11.2 deletion syndrome and autoimmune cytopenias are limited, our experience suggests its potential benefit.

Lymphoproliferative disorders in immunocompromised individuals and therapeutic antibodies for treatment

The incidence of lymphoproliferative disease (LPD) is significantly higher in individuals who have congenital, acquired or iatrogenically induced immunodeficiency. Although there are a wide range of LPDs including lymphoma and leukemia, this article only covers LPDs in patients with impaired immune function, which are called immunodeficiency-associated LPDs (ID-LPDs). Three of the four ID-LPD categories recognized by WHO have been selected for discussion: LPD in primary immune disorders, post-transplant LPD and LPD in HIV infection. Because of the high incidence and mortality of ID-LPDs, careful evaluation of the morphology, immunophenotype, genotype, viral status and clinical history is required for accurate diagnosis and treatment. Recently, treatment with monoclonal antibodies (mAbs) has been widely used and developed because of its potential benefits. The aim of this review is to describe new information concerning mAb treatment in LPDs and to draw physicians’ attention to mAb therapy, which should be effective for some types of LPD.

Autoimmunity in wiskott-Aldrich syndrome: an unsolved enigma

Wiskott-Aldrich Syndrome (WAS) is a severe X-linked Primary Immunodeficiency that affects 1-10 out of 1 million male individuals. WAS is caused by mutations in the WAS Protein (WASP) expressing gene that leads to the absent or reduced expression of the protein. WASP is a cytoplasmic protein that regulates the formation of actin filaments in hematopoietic cells. WASP deficiency causes many immune cell defects both in humans and in the WAS murine model, the Was(-/-) mouse. Both cellular and humoral immune defects in WAS patients contribute to the onset of severe clinical manifestations, in particular microthrombocytopenia, eczema, recurrent infections, and a high susceptibility to develop autoimmunity and malignancies. Autoimmune diseases affect from 22 to 72% of WAS patients and the most common manifestation is autoimmune hemolytic anemia, followed by vasculitis, arthritis, neutropenia, inflammatory bowel disease, and IgA nephropathy. Many groups have widely explored immune cell functionality in WAS partially explaining how cellular defects may lead to pathology. However, the mechanisms underlying the occurrence of autoimmune manifestations have not been clearly described yet. In the present review, we report the most recent progresses in the study of immune cell function in WAS that have started to unveil the mechanisms contributing to autoimmune complications in WAS patients.

[Primary immunodeficiencies presenting with autoimmune cytopenias in adults]

Although primary immunodeficiencies (PID) are typically marked by increased susceptibility to infections, autoimmune manifestations have increasingly been recognized as an important component of several forms of PID. Here, we discuss two forms of PID in which autoimmune cytopenias are particularly common and may be the first manifestation of the disease in adults: autoimmune lymphoproliferative syndrome (ALPS) and common variable immunodeficiency (CVID). Approximately one fifth of patients with CVID develop autoimmune diseases, and immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AHA) are the most common. Since autoimmune cytopenias frequently precede the diagnosis of CVID, testing for immunoglobulin levels should be performed in patients diagnosed with AITP and AHA. Patients with CVID in association with autoimmune cytopenias have a "particular phenotype" with lower susceptibility to infection and higher susceptibility to autoimmune manifestations and, for patients with AHA, a more frequent development of splenomegaly and lymphoma. Corticosteroids and high doses of intravenous immunoglobulins (IVIg) seem to have the same efficacy as in idiopathic AITP and AHA. Splenectomy and rituximab are as effective as in idiopathic autoimmune cytopenias but are associated with an increased risk of severe infection and should, in our opinion, be considered only for those rare patients with "refractory diseases". The course and outcome of autoimmune cytopenias is not affected by supportive IVIg therapy. Autoimmune destruction of blood cells affects over 70% of ALPS patients. The median age of first presentation is 24 months of age, but with increasing awareness of this condition, adults with autoimmune cytopenias are now being diagnosed more frequently. Testing for ALPS should therefore be considered in young adults with unexplained Evan's syndrome. Patients usually respond to immunosuppressive medications, including corticosteroids. Unlike many patients with idiopathic autoimmune cytopenias, the cytopenias in patients with ALPS typically do not respond to IVIg. After corticosteroids, the immunosuppressive drug that is the most studied in ALPS patients is mycophenolate mofetyl. Rituximab and splenectomy are relatively contraindicated in ALPS because of an increase risk of severe infection and should be reserved for patients who fail all other therapies.

Rituximab for children with immune thrombocytopenia: a systematic review

Background

Rituximab has been widely used off-label as a second line treatment for children with immune thrombocytopenia (ITP). However, its role in the management of pediatric ITP requires clarification. To understand and interpret the available evidence, we conducted a systematic review to assess the efficacy and safety of rituximab for children with ITP.

Methodology/Principal Findings

We searched MEDLINE, EMBASE, Cochrane Library, CBM, CNKI, abstract databases of American Society of Hematology, American Society of Clinical Oncology and Pediatric Academic Society. Clinical studies published in full text or abstract only in any language that met predefined inclusion criteria were eligible. Efficacy analysis was restricted to studies enrolling 5 or more patients. Safety was evaluated from all studies that reported data of toxicity. 14 studies (323 patients) were included for efficacy assessment in children with primary ITP. The pooled complete response (platelet count ≥100×10⁹/L) and response (platelet count ≥30×10⁹/L) rate after rituximab treatment were 39% (95% CI, 30% to 49%) and 68% (95%CI, 58% to 77%), respectively, with median response duration of 12.8 month. 4 studies (29 patients) were included for efficacy assessment in children with secondary ITP. 11 (64.7%) of 17 patients associated with Evans syndrome achieved response. All 6 patients with systemic lupus erythematosus associated ITP and all 6 patients with autoimmune lymphoproliferative syndrome associated ITP achieved response. 91 patients experienced 108 adverse events associated with rituximab, among that, 91 (84.3%) were mild to moderate, and no death was reported.

Conclusions/Significance

Randomized controlled studies on effect of rituximab for children with ITP are urgently needed, although a series of uncontrolled studies found that rituximab resulted in a good platelet count response both in children with primary and children secondary ITP. Most adverse events associated with rituximab were mild to moderate, and no death was reported.

Efficacy and safety of rituximab in common variable immunodeficiency-associated immune cytopenias: a retrospective multicentre study on 33 patients

Patients with common variable immunodeficiency (CVID) are at high risk of developing immune thrombocytopenia (ITP) and/or autoimmune haemolytic anaemia (AHA). Given their underlying immunodeficiency, immunosuppressive treatment of these manifestations may increase the risk of infection. To assess efficacy and safety of rituximab in patients with CVID-associated ITP/AHA, a multicentre retrospective study was performed. Thirty-three patients, 29 adults and four children, were included. Patients received an average of 2·6 treatments prior to rituximab including steroids, intravenous immunoglobulin and splenectomy (21%). The median ITP/AHA duration at time of first rituximab administration was 12 months [range 1-324] and the indication for using rituximab was ITP (22 cases), AHA (n = 5) or both (n = 7); 1 patient was treated sequentially for ITP and then AHA. The overall initial response rate to rituximab was 85% including 74% complete responses. After a mean follow-up of 39 ± 30 months after rituximab first administration, 10 of the initial responders relapsed and re-treatment with rituximab was successful in 7/9. Severe infections occurred after rituximab in eight adults (24%), four of whom were not on immunoglobulin replacement therapy. In conclusion, rituximab appears to be highly effective and relatively safe for the management of CVID-associated severe immune cytopenias.

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.

The autophilic anti-CD20 antibody DXL625 displays enhanced potency due to lipid raft-dependent induction of apoptosis

Despite widespread use of anti-CD20 antibodies as therapeutic agents for oncologic and autoimmune indications, precise descriptions of killing mechanisms remain incomplete. Complement-dependent cytolysis and antibody-dependent cell-mediated cytotoxicity are indicated as modes of target cell depletion; however, the importance of apoptosis induction is controversial. Studies showing that the therapeutic anti-CD20 antibody rituximab (Rituxan) mediates apoptosis of tumor cell targets in vitro after cross-linking by anti-Fc reagents suggest that enhancement strategies applied to Fc-independent activities for anti-CD20 antibodies could improve therapeutic efficacy. An anti-CD20 antibody designated DXL625, with autophilic properties such as increased binding avidity, is shown here to independently induce caspase-mediated apoptosis of an established B-cell lymphoma line in vitro. Depletion of membrane cholesterol or chelation of extracellular calcium abrogated the pro-apoptotic activity of DXL625, indicating that intact lipid rafts and calcium are required for this activity. The Fc-mediated complement-dependent and antibody-dependent cellular killing mechanisms are maintained by DXL625 despite conjugation of the parental Rituxan antibody to the autophilic DXL peptide sequence. This study shows a strategy for improving anti-CD20 immunotherapy by endowing therapeutic antibodies with self-interacting properties.

Autoimmune hemolytic anemia and common variable immunodeficiency: a case-control study of 18 patients

To describe the main characteristics and treatment of autoimmune hemolytic anemia (AHA) in patients with common variable immunodeficiency (CVID), we analyzed data from 18 patients, 4 from an earlier study and 14 from the French DEF-I cohort on adult patients with primary hypogammaglobulinemia. To be included, patients had to have CVID and a previous history of AHA with a hemoglobin level < or =90 g/L at onset. To determine whether AHA is associated with a particular clinical phenotype of CVID, we conducted a case-control study from the DEF-I cohort. The estimated frequency of AHA in CVID patients from the DEF-I cohort was 5.5% (14/252). Median age at AHA diagnosis was 26 years (range, 1-57 yr), and 27.5 years (range, 5-61 yr) at CVID diagnosis. CVID was diagnosed before the onset of AHA in only 2 patients (11%). CVID was diagnosed more than 6 months after AHA in 10 cases (55.5%), and the 2 conditions were diagnosed concomitantly in 6 cases. The 14 patients included in the DEF-I cohort were compared with 238 control patients with CVID but without AHA. Corticosteroids were used as initial treatment for all patients in the current study. An initial response was obtained in 15 of 18 (83%) patients. Overall, 9 of these (60%) achieved a lasting response with steroids alone (7 patients) or in combination with intravenous immunoglobulin (2 patients). Seven patients underwent splenectomy, and 5 additional splenectomies were performed for associated autoimmune thrombocytopenic purpura. After splenectomy, a lasting response was obtained in 3 of the 7 patients with AHA. However, 5 of the 12 splenectomized patients experienced life-threatening infection. Severe infection occurred in 2 of 4 patients receiving immunosuppressive drugs. At the end of follow-up, 13 of 18 (72%) patients were in treatment-free remission (13 complete responses), and 4 of 18 (22%) were in remission while on prednisone < or =20 mg/d. One patient had died, of cancer.