A dose-escalation study of rituximab for treatment of systemic lupus erythematosus and Evans' syndrome: immunological analysis of B cells, T cells and cytokines

Development of New Drugs for Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is a rare disorder characterized by the autoantibody-mediated destruction of red blood cells, and treatments for it still remain challenging. Traditional first-line immunosuppressive therapy, which includes corticosteroids and rituximab, is associated with adverse effects as well as treatment failures, and relapses are common. Subsequent lines of therapy are associated with higher rates of toxicity, and some patients remain refractory to currently available treatments. Novel therapies have become promising for this vulnerable population. In this review, we will discuss the mechanism of action, existing data, and ongoing clinical trials of current novel therapies for AIHA, including B-cell-directed therapy, phagocytosis inhibition, plasma cell-directed therapy, and complement inhibition.

Rituximab Use in Warm and Cold Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia is a rare condition characterized by destruction of red blood cells with and without involvement of complement. It is associated with significant morbidity and mortality. In warm autoimmune hemolytic anemia, less than 50% of patients remain in long-term remission following initial steroid therapy and subsequent therapies are required. Cold agglutinin disease is a clonal hematologic disorder that requires therapy in the majority of patients and responds poorly to steroids and alkylators. Rituximab has a favorable toxicity profile and has demonstrated efficacy in autoimmune hemolytic anemia in first-line as well as relapsed settings. Rituximab is the preferred therapy for steroid refractory warm autoimmune hemolytic anemia (wAIHA) and as part of the first- and second-line treatment of cold agglutinin disease. This article reviews the mechanism of action of rituximab and the current literature on its role in the management of primary and secondary warm autoimmune hemolytic anemia and cold agglutinin disease.

Efficacy and safety of rituximab for systemic lupus erythematosus treatment: a meta-analysis

Background:

Given the inconsistency of previous studies and the newly emerging evidence, we decided to conduct a meta-analysis.

Methods:

The meta-analysis included 2 randomized controlled trials and 13 observational studies 742 patients in total. Qualified studies were properly searched from databases . Data were analyzed by the RevMan 5.3 software. Results were demonstrated as WMD , SMD and RR with 95% CIs, I² and P value.

Results:

we observed that a remarkable increase of complement C3 in the rituximab group than placebo group (WMDfixed= 7.67mg/dL, 95%CIs=−0.16~15.50, I²=0%, P=0.05). A significant increase of complement C4 was observed in the rituximab group than placebo group (WMDfixed=3.14mg/dL, 95%CIs=1.06~5.22, I²=0%, P=0.003). Notably decreased peripheral CD19+B cells in rituximab group than placebo group (WMDfixed=−117.93n/µl, 95%CIs=−172.94~−62.91, I²=0%, P<0.0001) in RCTs. Patients with severe or refractory SLE got more satisfactory efficacy results after receiving rituximab in observational studies, such as British Isles Lupus Assessment Group index score, SLE Disease Activity Index score, complement C3/C4, anti-dsDNA antibodies, peripheral CD19⁺B cells and so on. Safety profiles were no difference between rituximab and placebo groups.

Conclusion:

although the efficacy of rituximab is highly controversial for SLE, our study shows that rituximab presents a satisfying efficacy and safety for SLE.

Rationale for CD40 pathway blockade in autoimmune rheumatic disorders

CD40 and its ligand CD40L (CD154) belong to the tumor necrosis factor receptor superfamily and are expressed by a variety of immune and non-immune cells. CD40L plays a central role in co-stimulation and regulation of the immune response via activation of cells expressing CD40. Imbalance of the CD40-CD40L co-stimulatory pathway has been reported in many autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome, thus supporting its role in the breach of immune tolerance that is typical of these diseases. Targeting CD40-CD40L signalling might represent a novel therapeutic option for several autoimmune disorders.

Non-Antibody-Secreting Functions of B Cells and Their Contribution to Autoimmune Disease

B cells play multiple important roles in the pathophysiology of autoimmune disease. Beyond producing pathogenic autoantibodies, B cells can act as antigen-presenting cells and producers of cytokines, including both proinflammatory and anti-inflammatory cytokines. Here we review our current understanding of the non-antibody-secreting roles that B cells may play during development of autoimmunity, as learned primarily from reductionist preclinical models. Attention is also given to concepts emerging from clinical studies using B cell depletion therapy, which shed light on the roles of these mechanisms in human autoimmune disease.

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".

Rituximab in Minimal Change Disease: Mechanisms of Action and Hypotheses for Future Studies

Treatment with rituximab, a monoclonal antibody against the B-lymphocyte surface protein CD20, leads to the depletion of B cells. Recently, rituximab was reported to effectively prevent relapses of glucocorticoid-dependent or frequently relapsing minimal change disease (MCD). MCD is thought to be T-cell mediated; how rituximab controls MCD is not understood. In this review, we summarize key clinical studies demonstrating the efficacy of rituximab in idiopathic nephrotic syndrome, mainly MCD. We then discuss immunological features of this disease and potential mechanisms of action of rituximab in its treatment based on what is known about the therapeutic action of rituximab in other immune-mediated disorders. We believe that studies aimed at understanding the mechanisms of action of rituximab in MCD will provide a novel approach to resolve the elusive immune pathophysiology of MCD.

The Efficacy of Rituximab Combined with 131I for Ophthalmic Outcomes of Graves' Ophthalmopathy Patients

PURPOSE

The purpose of this study is to examine the effectiveness of introducing both rituximab (RTX) and 131I for active Graves' ophthalmopathy (GO) with hyperthyroidism.

METHODS

In total, 217 patients suffering from active GO with hyperthyroidism were included in this research. All subjects were randomly assigned to 3 groups. Patients in group A solely received 131I treatment; group B1 underwent a methylprednisolone treatment in combination with 131I treatment; and group B2 received an RTX in combination with 131I treatment. Hyperthyroidism treatment outcomes, orbital volumetry, ophthalmic assessments, serum cytokine levels, and adverse effects were measured after treatment.

RESULTS

The orbital volumetry principle was significantly different from 24 weeks after the start of treatment among all 3 groups, and improvements in most ophthalmic parameters were regarded significantly different among 3 groups (all p < 0.05). The expression levels of miR-146a and most serum cytokines were regarded significantly different from 24 weeks after the start of treatment among 3 groups (all p < 0.05).

CONCLUSIONS

In comparison with other therapies, RTX treatment in combination with 131I treatment is considered to be more effective for hyperthyroidism with active GO.

Clinical Features of Systemic Lupus Erythematosus Patients Complicated With Evans Syndrome: A Case-Control, Single Center Study

The aim of the study was to investigate the clinical features of systemic lupus erythematous (SLE) complicated with Evans syndrome (ES). We conducted a retrospective case-control study to compare the clinical and laboratory features of age- and gender-matched lupus patients with and without ES in 1:3 ratios. In 5724 hospitalized SLE patients, we identified 27 (0.47%, 22 women and 5 men, average age 34.2 years) SLE patients complicated with ES. Fifteen patients (55.6%) presented with hematologic abnormalities initially, including 6 (22.2%) cases of isolated ITP, 4 (14.8%) cases of isolated AIHA, and 5 (18.5%) cases of classical ES. The median intervals between hematological presentations the diagnosis of SLE was 36 months (range 0-252). ES developed after the SLE diagnosis in 4 patients (14.8%), and concomitantly with SLE diagnosis in 8 patients (29.6%). Systemic involvements are frequently observed in SLE patients with ES, including fever (55.6%), serositis (51.9%), hair loss (40.7%), lupus nephritis (37%), Raynaud phenomenon (33.3%), neuropsychiatric (33.3%) and pulmonary involvement (25.9%), and photosensitivity (25.9%). The incidence of photosensitivity, hypocomplementemia, elevated serum IgG level, and lupus nephritis in patients with ES or without ES was 25.9% vs 6.2% (P = 0.007), 88.9% vs 67.1% (P = 0.029), 48.1% vs 24.4% (P = 0.021), and 37% vs 64.2% (P = 0.013), respectively. Twenty-five (92.6%) patients achieved improvement following treatment of glucocorticoids and immunosuppressants as well as splenectomy, whereas 6 patients experienced the relapse and 1 patient died from renal failure during the follow-up. ES is a relatively rare complication of SLE. Photosensitivity, hypocomplementemia, and elevated serum IgG level were frequently observed in ES patients, but lupus nephritis was less observed. More than half of patients presented with hematological manifestation at onset, and progress to typical lupus over months to years. Therefore, monitoring with antoantibodies profile as well as nonhematological presentations are necessary for patients with ITP and (or) AIHA.

B cells and progressive multifocal leukoencephalopathy: search for the missing link

Progressive multifocal leukoencephalopathy (PML) is a deadly demyelinating disease due to JC virus (JCV) replication in the brain. PML classically occurs in patients with severe immunodepression, and cases have recently been linked to therapeutic monoclonal antibodies such as natalizumab and also rituximab, which depletes B cells. B cells appear to play a complex role in the pathogenesis of PML. They may act as a viral reservoir and as a vector for viral dissemination in the central nervous system. Anti-JCV antibody responses appear to have a limited effect on JCV replication in the brain. However, accumulating evidence suggests that B cells may considerably influence T cell responses through their cytokine secretion. This immunomodulatory function of B cells may play an important role in the control of JCV infection and in the pathogenesis of PML, including rituximab-induced PML.

Haematological manifestations of lupus

Our purpose was to compile information on the haematological manifestations of systemic lupus erythematosus (SLE), namely leucopenia, lymphopenia, thrombocytopenia, autoimmune haemolytic anaemia (AIHA), thrombotic thrombocytopenic purpura (TTP) and myelofibrosis. During our search of the English-language MEDLINE sources, we did not place a date-of-publication constraint. Hence, we have reviewed previous as well as most recent studies with the subject heading SLE in combination with each manifestation. Neutropenia can lead to morbidity and mortality from increased susceptibility to infection. Severe neutropenia can be successfully treated with granulocyte colony-stimulating factor. While related to disease activity, there is no specific therapy for lymphopenia. Severe lymphopenia may require the use of prophylactic therapy to prevent select opportunistic infections. Isolated idiopathic thrombocytopenic purpura maybe the first manifestation of SLE by months or even years. Some manifestations of lupus occur more frequently in association with low platelet count in these patients, for example, neuropsychiatric manifestation, haemolytic anaemia, the antiphospholipid syndrome and renal disease. Thrombocytopenia can be regarded as an important prognostic indicator of survival in patients with SLE. Medical, surgical and biological treatment modalities are reviewed for this manifestation. First-line therapy remains glucocorticoids. Through our review, we conclude glucocorticoids do produce a response in majority of patients initially, but sustained response to therapy is unlikely. Glucocorticoids are used as first-line therapy in patients with SLE with AIHA, but there is no conclusive evidence to guide second-line therapy. Rituximab is promising in refractory and non-responding AIHA. TTP is not recognised as a criteria for classification of SLE, but there is a considerable overlap between the presenting features of TTP and SLE, and a few patients with SLE have concurrent TTP. Myelofibrosis is an uncommon yet well-documented manifestation of SLE. We have compiled the cases that were reported in MEDLINE sources.

Variability of the impact of adverse events on physicians' decision making

Background

Physicians frequently differ in their treatment recommendations. However, few studies have examined the reasons underlying these differences. The objective of this study was to examine whether physicians vary in the importance they attach to specific adverse events for two treatment options found in recent randomized controlled trials to have equivalent efficacy and overall toxicity.

Methods

A Max-Diff survey was administered to physicians attending a national scientific conference to quantify the influence of 23 specific adverse events on decision making related to two treatment options for vasculitis. This approach was chosen because it results in greater item discrimination compared to rating scales. We used Hierarchical Bayes modeling to generate the relative importance score for each adverse event and examined the association between physicians’ characteristics and the five most influential factors.

Results

118 physicians completed the survey. The mean age (SD) was 48 years (10); 68% were male and 81% reported spending the majority of time in clinical practice. There was significant variability in the ratings of the relative importance of all adverse events, except those that were mild and easily reversible. We found a positive correlation between increasing physician age with ratings of sepsis (r = 0.29, p = 0.002) and opportunistic infection (r = 0.23, p = 0.016), and an inverse association between age with progressive multifocal leukoencephalopathy (r = - 0.28, p = 0.003). Physician sex, work setting, location, and number of patients with vasculitis seen per year were not associated with the influence of specific adverse events on decision making.

Conclusion

Our findings demonstrate that physicians differ substantially in how they perceive the importance of specific adverse events which may help explain observed unwarranted variability in physicians’ recommendations in clinical practice. Further efforts are needed to ensure that the reasons underlying variability in physicians’ recommendations are transparent.

Rheumatoid arthritis synovial tissue harbours dominant B-cell and plasma-cell clones associated with autoreactivity

OBJECTIVE

To identify potential autoreactive B-cell and plasma-cell clones by quantitatively analysing the complete human B-cell receptor (BCR) repertoire in synovium and peripheral blood in early and established rheumatoid arthritis (RA).

METHODS

The BCR repertoire was screened in synovium and blood of six patients with early RA (ERA) (<6 months) and six with established RA (ESRA) (>20 months). In two patients, the repertoires in different joints were compared. Repertoires were analysed by next-generation sequencing from mRNA, generating >10 000 BCR heavy-chain sequence reads per sample. For each clone, the degree of expansion was calculated as the percentage of the total number of reads encoding the specific clonal sequence. Clones with a frequency ≥ 0.5% were considered dominant.

RESULTS

Multiple dominant clones were found in inflamed synovium but hardly any in blood. Within an individual patient, the same dominant clones were detected in different joints. The majority of the synovial clones were class-switched; however, the fraction of clones that expressed IgM was higher in ESRA than ERA patients. Dominant synovial clones showed autoreactive features: in ERA in particular the clones were enriched for immunoglobulin heavy chain gene segment V4-34 (IGHV4-34) and showed longer CDR3 lengths. Dominant synovial clones that did not encode IGHV4-34 also had longer CDR3s than peripheral blood.

CONCLUSIONS

In RA, the synovium forms a niche where expanded--potentially autoreactive--B cells and plasma cells reside. The inflamed target tissue, especially in the earliest phase of disease, seems to be the most promising compartment for studying autoreactive cells.

Emerging role for the killer-cell immunoglobulin-like receptors genotype, in the susceptibility of skin diseases

NK cells are a major group of immune cells responsible for the phenomenon of natural, innate cytotoxicity. One of the better studied receptors of human NK cells are killer cell immunoglobulin-like receptors (KIR) responsible for checking the presence of MHC class I molecules, which serve as their ligands. Although previously treated as specific for NK cells, nowadays these receptors are known to also occur on T cells. Genetics of KIR molecules is very complicated, what create a great variability of haplotypes in various populations world-wide. In addition, some KIR are known to recognize HLA-C (epitopes C1 or C2), HLA-B (Bw4) or HLA-A (A3 and/or A11) molecules. Therefore, this makes a huge diversity of reactions among individuals, depending on the presence or absence of given KIR and their ligands, hence differential susceptibility to several diseases, including various dermatoses. This paper underlines the important role of both KIR genotypes and HLA class I genes with reference to the various skin diseases.

Efficacy and safety of rituximab therapy for systemic lupus erythematosus: a systematic review and meta-analysis

OBJECTIVE

To review the efficacy and safety of rituximab therapy for systemic lupus erythematosus (SLE).

METHODS

We searched for randomized controlled trails and observational studies that evaluated the effect of rituximab based on the systemic lupus erythematosus disease activity index (SLEDAI), British Isles lupus assessment group index (BILAG), urine protein levels, and the prednisolone dose, and had adequate data to calculate the mean, standard deviation (SD), and 95% confidence intervals, and to systematically review and meta-analyze observational studies with fixed effects model or random effects model.

RESULTS

We included 2 randomized controlled studies and 19 observational clinical studies. We summarized the data from the 19 observational studies, analyzed the heterogeneity of the literature, and then used fixed effect model or random effect model for statistical analysis. The SLEDAI, BILAG, and urine protein levels and the prednisolone dosage were decreased after rituximab treatment, and the decreases in the BILAG, urine protein levels, and the prednisolone dose were found to be significant (P<0.05), when compared with baseline level. Rituximab's adverse effects generally could be controlled with an effective dosing regimen.

CONCLUSIONS

Although there are still controversies about rituximab's treatment on SLE, but our study had showed that rituximab had favorable effects on refractory lupus. The long-term efficacy and safety of rituximab require further study.

B-cell depletion in SLE: clinical and trial experience with rituximab and ocrelizumab and implications for study design

B cells are believed to be central to the disease process in systemic lupus erythematosus (SLE), making them a target for new therapeutic intervention. In recent years there have been many publications regarding the experience in SLE of B-cell depletion utilising rituximab, an anti-CD20 mAb that temporarily depletes B cells,reporting promising results in uncontrolled open studies and in routine clinical use. However, the two large randomised controlled trials in extra-renal lupus (EXPLORER study) and lupus nephritis (LUNAR study) failed to achieve their primary endpoints. Based on the clinical experience with rituximab this failure was somewhat unexpected and raised a number of questions and concerns, not only into the true level of benefit of B-cell depletion in a broad population but also how to test the true level of effectiveness of an investigational agent as we seek to improve the design of therapeutic trials in SLE. A better understanding of what went wrong in these trials is essential to elucidate the underlying reasons for the disparate observations noted in open studies and controlled trials. In this review, we focus on various factors that may affect the ability to accurately and confidently establish the level of treatment effect of the investigational agent, in this case rituximab, in the tw studies and explore hurdles faced in the randomised controlled trials investigating the efficacy of ocrelizumab, the humanised anti-CD20 mAb, in SLE. Further, based on the lessons learned from the clinical trials, we make suggestions that could be implemented in future clinical trial design to overcome the hurdles faced.

Anti-CD20 (rituximab) therapy for anti-IFN-γ autoantibody-associated nontuberculous mycobacterial infection

Patients with anti-IFN-γ autoantibodies have impaired IFN-γ signaling, leading to severe disseminated infections with intracellular pathogens, especially nontuberculous mycobacteria. Disease may be severe and progressive, despite aggressive treatment. To address the underlying pathogenic IFN-γ autoantibodies we used the therapeutic monoclonal rituximab (anti-CD20) to target patient B cells. All subjects received between 8 and 12 doses of rituximab within the first year to maintain disease remission. Subsequent doses were given for relapsed infection. We report 4 patients with refractory disease treated with rituximab who had clinical and laboratory evidence of therapeutic response as determined by clearance of infection, resolution of inflammation, reduction of anti-IFN-γ autoantibody levels, and improved IFN-γ signaling.

Rituximab in immunologic glomerular diseases

Experimental data suggest that the B-cell antigen CD20 may play a significant role in the pathogenesis of many diseases including glomerular diseases. These and other findings underpin the central concept of B-cell-depleting therapies that target CD20 antigen as treatments for lupus nephritis, idiopathic membranous nephropathy, focal segmental glomerulosclerosis, cryglobulinemic glomerulonephritis, antibody mediated renal allograft rejection and recurrent glomerulonephritis in renal allograft. Use of rituximab as a B-cell depleting therapy has been associated with clinical improvement and has emerged as a possible adjunct or alternative treatment option in this field of nephrology.

Rituximab therapy in refractory neuropsychiatric lupus: current clinical evidence

OBJECTIVE

To review and summarize published information on the effectiveness and safety of rituximab (RTX) in adult patients with refractory neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

We describe a patient with persistently active NPSLE, despite conventional therapy, who responded dramatically to RTX. Current evidence on the therapeutic use of RTX in this complex situation is also analyzed through a systematic review of the English-language literature, based on a PubMed search.

RESULTS

Available data on the use of RTX in refractory NPSLE come from a large number of case reports and some open-label studies. Including our case, 35 patients have been well documented. A complete or partial therapeutic response was achieved in 85% of patients after 1 cycle of treatment. A positive correlation between serological markers of disease activity and clinical outcome has also been demonstrated in some of these patients. Clinical improvement was accompanied by a significant reduction in the daily dose of oral corticosteroids. Relapse after RTX treatment was noted in 45% of cases (median 9.5 months; range, 4-33 months). Infections were observed in 29% of patients.

CONCLUSION

Evidence for the effectiveness of RTX as induction therapy in NPSLE is based solely on several case reports and noncontrolled trials. Although it is not yet possible to make definite recommendations, the global analysis of these cases supports the off-label use of RTX in cases of severe refractory NPSLE.

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.

Importance of B cell co-stimulation in CD4(+) T cell differentiation: X-linked agammaglobulinaemia, a human model

We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans.

Targeted biological therapies for Graves' disease and thyroid-associated ophthalmopathy. Focus on B-cell depletion with Rituximab

Based on experience from the treatment of other autoimmune diseases and because of the limitations imposed by existing therapeutic options for Graves' disease (GD) and thyroid-associated ophthalmopathy (TAO), rituximab (RTX) was recently proposed as a novel therapy option. Here, we summarize the rationale for using RTX; give an overview of the possible mechanisms of action; and give an account of its effects and side-effects when used in GD and TAO. Scant evidence, originating from only a few methodologically inhomogeneous studies, suggests that RTX may prolong remission for hyperthyroidism over that seen with antithyroid drugs, at least in mild GD. Furthermore, in patients with TAO, who are unresponsive to conventional immunosuppressive therapy, RTX seems efficacious. As we wait for larger-scale randomized studies, RTX, should be considered experimental and reserved for patients who do not respond favourably to conventional therapy. It is the first in what is likely to be a series of new and emerging treatments specifically targeting relevant components of the immune system. Further studies will hopefully lead to improved and better tailored, individualized therapy for GD and especially TAO.

[Use of rituximab in the treatment of lupus patients. The LESIMAB database]

Systemic lupus erythematosus is an autoimmune disease that may involve the function of organs and reduce the survival of patients. Advances in the diagnosis and treatment have improved the short-term prognosis.However, most therapeutic improvements come from progress in other areas of medicine and only in recent years is this trend changing. Unfortunately, the development of new drugs for lupus is facing specific difficulties and the development of rituximab in lupus has been stopped despite good results in the observational studies. This review examines some of the aspects that influence these difficulties from the perspective of the LESIMAB database.

Effector and regulatory B cells: modulators of CD4+ T cell immunity

B cells are essential for humoral immunity, but the role that they have in regulating CD4(+) T cell responses remains controversial. However, new data showing that the transient depletion of B cells potently influences the induction, maintenance and reactivation of CD4(+) T cells, with the recent identification of antibody-independent functions of B cells, have reinvigorated interest in the many roles of B cells in both infectious and autoimmune diseases. In this Review, we discuss recent data showing how effector and regulatory B cells modulate CD4(+) T cell responses to pathogens and autoantigens.

Off-label use of rituximab in systemic lupus erythematosus: a systematic review

Considerable interest in the efficacy of rituximab (a monoclonal CD20 antibody) in patients with systemic lupus erythematosus (SLE) has been generated due to its unique mode of action, culminating in a series of randomized and open trials, and case reports. However, this use is off-license and two significant RCTs have reported negative findings, reopening the debate on clinical benefit. This review of the available data suggests that rituximab induces B-cell depletion in 95% of patients, and a significant reduction in disease activity is achieved with a relatively good safety profile in patients with SLE.

B-cell-depletion therapy in SLE--what are the current prospects for its acceptance?

Analogous to the successful introduction of biologic agents to treat rheumatoid arthritis, it was widely envisaged that similar successful studies would follow in systemic lupus erythematosus (SLE), as much was known about the etiopathogenesis of the disease and appropriate agents to block the key cells and molecules were available. The reality, however, has been different. The failure of rituximab, a monoclonal antibody that induces B-cell depletion, to meet its primary and secondary end points in trials of nonrenal SLE (EXPLORER) and renal (LUNAR) lupus nephritis has been disappointing given the success reported in many open-label studies. Concluding that B-cell-depletion therapy is not effective in SLE seems rather extreme. Further analysis of the as-yet unpublished results and their comparison with data from published studies might provide insight into whether B-cell depletion will eventually be accepted as a useful approach for the treatment of SLE.

Targeting B cells in immune-mediated inflammatory disease: a comprehensive review of mechanisms of action and identification of biomarkers

B cell-depletion therapy, particularly using anti-CD20 treatment, has provided proof of concept that targeting B cells and the humoral response may result in clinical improvements in immune-mediated inflammatory disease. In this review, the mechanisms of action of B cell-targeting drugs are investigated, and potential biomarkers associated with response to treatment in patients with autoimmune diseases are identified. Most available data relate to B cell depletion using anti-CD20 therapy (rituximab) in patients with rheumatoid arthritis (RA). Treatment leads to significant clinical benefit, but apparently fails to deplete long-lived plasma cells, and discontinuation is associated with relapse. Biomarkers commonly used in studies of B cell-targeted therapies include rheumatoid factor, anti-citrullinated peptide antibodies, and immunoglobulin (Ig) levels. More recently, there has been interest in markers such as B cell phenotype analysis, and B lymphocyte stimulator (BLyS)/a proliferation-inducing ligand (APRIL), the latter particularly in studies of the IgG Fc-transmembrane activator and CAML interactor (TACI) fusion protein (atacicept) and anti-BLyS therapy (belimumab). Data from clinical trials of B cell-depleting agents in RA suggest that specific autoantibodies, BLyS, APRIL, and circulating and synovial B lineage cell levels may have potential as biomarkers predictive of response to treatment. Further trials validating these markers against clinical outcomes in RA are required. In patients with systemic lupus erythematosus, Fc receptors and levels of circulating immune cells (including B cells and natural killer cells) may be relevant markers.

Evans' syndrome in pregnancy: a systematic literature review and two new cases

Evans' syndrome, the coexistence of immune thrombocytopenia (ITP) with autoimmune haemolytic anaemia (AIHA), is rare in pregnancy, with a few published cases. Concerns about the teratogenic effect of pharmacological agents used in the management of Evans' syndrome limit the treatment options in pregnancy. In this paper we performed a systematic review of the literature of all published cases with Evans' syndrome in pregnancy and we report two new cases. The review was performed by searching the electronic databases PubMed, EMBASE, Cochrane Library and Google scholar up to the end of December 2008. The selection criteria were Evans' syndrome in pregnancy; autoimmune haemolytic anaemia; immune thrombocytopenia. Thirteen papers reporting 14 pregnancies in women with Evans' syndrome have been published: 7 papers are written in English. Evans' syndrome can be diagnosed with a full blood count, film and Coombs testing. It runs a more benign course in pregnancy than in non-pregnant state (notably neutropenia does not occur) and very often resolves post-delivery. The fetal outcome may be less favourable: a minority of fetuses are affected by transplacental passage of antibody and have a significant morbidity and mortality. With appropriate treatment, women with Evans' syndrome can have successful pregnancies, with a good response to conventional treatment. More detailed studies of Evans' syndrome in pregnancy, especially of fetal outcome, are required.

CD40 and autoimmunity: the dark side of a great activator

CD40 is a tumor necrosis factor receptor superfamily member expressed by immune and non-immune cells. CD40:CD154 interactions mediate T-dependent B cell responses and efficient T cell priming. Thus, CD40 is a likely candidate to play roles in autoimmune diseases in which activated T and B cells cause pathology. Diseases in which CD40 plays a pathogenic role include autoimmune thyroiditis, type 1 diabetes, inflammatory bowel disease, psoriasis, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus. This review discusses the role of CD40:CD154 interaction in human and mouse autoimmunity, human polymorphisms associated with disease incidence, and disrupting CD40:CD154 interactions as an autoimmune therapy.

Anti-CD20 therapy in patients with refractory systemic lupus erythematosus: a longitudinal analysis of 52 Hispanic patients

The objective of this study was to investigate the efficacy and safety of anti-CD20 treatment in Hispanic patients with refractory systemic lupus erythematosus and to determine whether baseline parameters predict disease flare. Fifty-two patients with systemic lupus erythematosus, 13 with active lupus nephritis, eight with thrombocytopenia, three with leukocytopenia, 25 with severe musculoskeletal involvement and three with skin involvement) refractory to conventional therapy were treated with anti-CD20 treatment (rituximab; MabThera, Roche) plus ongoing immunosuppressive treatment. Disease activity was assessed monthly using the SLEDAI validated for the Mexican population with a follow-up period of 6 months. At 6 months of follow-up, significant clinical improvements were detected, with a reduction in the global SLEDAI validated for the Mexican population score. Five of the 13 patients with lupus nephritis (38.4%) had a complete renal response and five (38.4%) had a partial response. Rituximab was also effective in patients with autoimmune thrombocytopenia, inducing a significant increase in platelet counts (p = 0.012). Nineteen of 25 patients with severe musculoskeletal involvement had remission of arthritis. Only one of the three patients with skin involvement had no lesions at 6 months. Rituximab treatment also allowed a reduction of the oral prednisone dose in the majority of patients. No baseline predictors of flare were found. Treatment was discontinued after the first infusion in two patients due to serum sickness and in another due to pulmonary infection. In conclusion, the addition of rituximab to conventional immunosuppressive therapy may be an effective strategy for lupus nephritis, autoimmune thrombocytopenia and inflammatory polyarthritis in patients with refractory systemic lupus erythematosus.

Rituximab in severe lupus nephritis: early B-cell depletion affects long-term renal outcome

BACKGROUND AND OBJECTIVES

Standard treatment for lupus nephritis, including corticosteroids and cyclophosphamide, is efficient but is still associated with refractory or relapsing disease, or severe deleterious effects. Rituximab, a monoclonal chimeric anti-B cell antibody, is increasingly used in patients with lupus nephritis, but reported series were small and had a short follow-up.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The authors analyzed clinical and histologic data of 20 patients who were treated with rituximab for lupus nephritis and followed up for at least 12 mo.

RESULTS

Nineteen women and one man received rituximab as induction treatment for an active class IV (15 cases) or class V (5 cases) lupus nephritis. Rituximab was given for lupus nephritis refractory to standard treatment (12 cases), for relapsing disease (6 cases), or as first-line treatment (2 cases). Three patients received cyclophosphamide concomitantly with rituximab. Ten received new injections of rituximab as maintenance therapy. Side effects included mainly five infections and four moderate neutropenias. After a median follow-up of 22 mo, complete or partial renal remission was obtained in 12 patients (60%). Lupus nephritis relapsed in one patient, who responded to a new course of rituximab. The achievement of B cell depletion 1 mo after rituximab, which negatively correlated with black ethnicity and hypoalbuminemia, was strongly associated with renal response. Rapidly progressive glomerulonephritis did not respond to rituximab.

CONCLUSION

Rituximab is an interesting therapeutic option in relapsing or refractory lupus nephritis when early B cell depletion is obtained.

B-cell-targeted therapy for systemic lupus erythematosus: an update

Systemic lupus erythematosus (SLE) is a classic autoimmune disease characterized by a myriad of immune system aberrations, most likely resulting from pathogenic autoantibody production, immune complex deposition, and subsequent end-organ damage. B cells play a key role in the pathogenesis; therefore, B-cell-targeted therapies, including B-cell depletion and blockage of B-cell survival factors such as B-lymphocyte stimulator (BLyS), are potential therapeutic targets for SLE. In uncontrolled clinical trials from approximately 20 studies, rituximab--a mouse-human chimeric anti-CD20 monoclonal antibody that effectively depletes B cells--has been demonstrated to reduce disease activity and decrease serum autoantibodies, with a clinical response of 86% in a case series of approximately 400 SLE patients with refractory disease, with or without concomitant use of cyclophosphamide. Epratuzumab, a humanized anti-CD22 monoclonal antibody that partially depletes B cells, has also been shown to reduce disease activity but not to decrease autoantibody levels in patients with moderately active SLE. Randomized controlled phase I/II trials in patients with active SLE have documented that belimumab, a humanized anti-BLyS monoclonal antibody, reduces B-cell numbers, inhibits disease activity and decreases anti-double-stranded DNA autoantibody in SLE patients. All these therapies are well tolerated, but accompanying infectious complications have been observed. Other B-cell-targeted therapies such as 'humanized' monoclonal antibodies to CD20 (e.g. ocrelizumab) and agents that interrupt B-cell/T-cell interactions also have potential, and the efficacy of these, along with rituximab, belimumab and epratuzumab, needs to be determined by randomized controlled trials.