Successful long-term treatment of systemic lupus erythematosus with rituximab maintenance therapy

Should Renal Inflammation Be Targeted While Treating Hypertension?

Despite extensive research and a plethora of therapeutic options, hypertension continues to be a global burden. Understanding of the pathological roles of known and underexplored cellular and molecular pathways in the development and maintenance of hypertension is critical to advance the field. Immune system overactivation and inflammation in the kidneys are proposed alternative mechanisms of hypertension, and resistant hypertension. Consideration of the pathophysiology of hypertension in chronic inflammatory conditions such as autoimmune diseases, in which patients present with autoimmune-mediated kidney inflammation as well as hypertension, may reveal possible contributors and novel therapeutic targets. In this review, we 1) summarize current therapies used to control blood pressure and their known effects on inflammation; 2) provide evidence on the need to target renal inflammation, specifically, and especially when first-line and combinatory treatment efforts fail; and 3) discuss the efficacy of therapies used to treat autoimmune diseases with a hypertension/renal component. We aim to elucidate the potential of targeting renal inflammation in certain subsets of patients resistant to current therapies.

JM, Zhang K, Fang D. Inositol-Requiring Enzyme 1α-Mediated Synthesis of Monounsaturated Fatty Acids as a Driver of B Cell Differentiation and Lupus-like Autoimmune Disease

OBJECTIVE

To explore the molecular mechanisms underlying dysregulation of lipid metabolism in the pathogenesis of systemic lupus erythematosus (SLE).

METHODS

B cells in peripheral blood from patients with SLE and healthy controls were stained with BODIPY dye for detection of lipids. Mice with targeted knockout of genes for B cell-specific inositol-requiring enzyme 1α (IRE-1α) and stearoyl-coenzyme A desaturase 1 (SCD-1) were used for studying the influence of the IRE-1α/SCD-1/SCD-2 pathway on B cell differentiation and autoantibody production. The preclinical efficacy of IRE-1α suppression as a treatment for lupus was tested in MRL.Faslpr mice.

RESULTS

In cultures with mouse IRE-1α-null B cells, supplementation with monounsaturated fatty acids largely rescued differentiation of plasma cells from B cells, indicating that the compromised capacity of B cell differentiation in the absence of IRE-1α may be attributable to a defect in monounsaturated fatty acid synthesis. Moreover, activation with IRE-1α/X-box binding protein 1 (XBP-1) was required to facilitate B cell expression of SCD-1 and SCD-2, which are 2 critical enzymes that catalyze monounsaturated fatty acid synthesis. Mice with targeted Scd1 gene deletion displayed a phenotype that was similar to that of IRE-1α-deficient mice, with diminished B cell differentiation into plasma cells. Importantly, in B cells from patients with lupus, both IRE-1α expression and Xbp1 messenger RNA splicing were significantly increased, and this was positively correlated with the expression of both Scd1 and Scd2 as well as with the amount of B cell lipid deposition. In MRL.Faslpr mice, both genetic and pharmacologic suppression of IRE-1α protected against the pathologic development and progression of lupus-like autoimmune disease.

CONCLUSION

The results of this study reveal a molecular link in the dysregulation of lipid metabolism in the pathogenesis of lupus, demonstrating that the IRE-1α/XBP-1 pathway controls plasma cell differentiation through SCD-1/SCD-2-mediated monounsaturated fatty acid synthesis. These findings provide a rationale for targeting IRE-1α and monounsaturated fatty acid synthesis in the treatment of patients with SLE.

Immunosuppressive Treatment in Antiphospholipid Syndrome: Is It Worth It?

The antiphospholipid syndrome (APS) is characterized by the development of venous and/or arterial thrombosis and pregnancy morbidity in patients with persistent antiphospholipid antibodies (aPL). Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening form of APS occurring in about 1% of cases. Lifelong anticoagulation with vitamin K antagonists remains the cornerstone of the therapy for thrombotic APS, but frequently the use of anticoagulation may be problematic due to the increased risk of bleeding, drug interactions, or comorbidities. Immunosuppressant drugs are widely used to treat several autoimmune conditions, in which their safety and effectiveness have been largely demonstrated. Similar evidence in the treatment of primary APS is limited to case reports or case series, and studies on a large scale lack. Immunomodulatory drugs may be an emerging tool in managing such particular situations, like refractory obstetrical complications, CAPS, or so-called APS non-criteria manifestations. In addition, immunomodulatory drugs may be useful in patients experiencing recurrent thromboembolic events despite optimized anticoagulant therapy. We did a comprehensive review of literature analyzing the possible role of immunomodulation in primary APS to provide a broad overview of potentially safe and effective target treatments for managing this devastating disease.

Rituximab as Maintenance Treatment for Systemic Lupus Erythematosus: A Multicenter Observational Study of 147 Patients

OBJECTIVE

The efficacy of rituximab (RTX) in systemic lupus erythematosus (SLE) is a subject of debate. This study was undertaken to investigate the outcomes of RTX treatment in a European SLE cohort, with an emphasis on the role of RTX as a maintenance agent.

METHODS

All patients with SLE who were receiving RTX as induction therapy in 4 centers were included. Patients who received a single course of RTX and those who received RTX maintenance treatment (RMT) were followed up after treatment. Disease flares during the follow-up period were defined as an increase in disease activity and the number or dose of immunosuppressive drugs.

RESULTS

Of 147 patients, 27% experienced treatment failure at 6 months. In a multivariate analysis, a low number of previous immunosuppressive therapies (P = 0.034) and low C4 levels (P = 0.008) reduced the risk of treatment failure. Eighty patients received RMT over a median of 24.5 months during which 85 relapses, mainly musculoskeletal, were recorded (1.06 per patient). At the time of the last RTX course, 84% of the patients were in remission. Twenty-eight (35%) of 80 patients never experienced a flare during RMT and had low damage accrual. Active articular disease at the time of the first RTX administration was associated with a risk of flare during RMT (P = 0.011). After RMT, relapse-free survival was similar to that in patients receiving a single RTX course (P = 0.72).

CONCLUSION

RMT is a potential treatment option for patients with difficult-to-treat disease. Relapses occur during RMT and are more likely in those with active articular disease at the time of the first RTX administration. Relapse risk after RMT remains high and apparently comparable to that seen after a single RTX course.

Rituximab usage in systemic lupus erythematosus-associated antiphospholipid syndrome: A single-center experience

OBJECTIVES

Although the data from primary antiphospholipid syndrome (APS) suggests a beneficial effect of rituximab usage, its therapeutic role remains to be defined in systemic lupus erythematosus (SLE)-associated APS, a complex clinical situation with thrombotic events and lupus activity.

METHODS

A single-center retrospective analysis of rituximab usages in APS was performed in 800 hospitalized SLE patients.

RESULTS

There were 63 SLE-associated APS cases with 6 on rituximab therapy, all female aged 37.7 ± 9.0 years with 1 catastrophic and 16 thrombotic episodes. Therapeutic indications included warfarin failure despite the adequate target international normalized ratio with an average duration of 17.3 ± 11.2 months between the thrombotic recurrences. After the rituximab therapy, there was no relapse of thrombosis with a mean follow-up period of 39.3 ± 20.9 months, and a decrease in lupus activity (SLEDAI-2K, 9.7 ± 5.5 to 5.3 ± 2.2). Infection complications were observed, including episodes of bronchitis and urinary tract infection.

CONCLUSIONS

In this single-center study with largest case numbers and a long-term follow-up period, there were no recurrent thrombotic events after the rituximab therapy, implicating further consideration of large-scale trials enrolling more ethnic groups to evaluate its therapeutic role in SLE-associated APS patients.

Epilepsy in systemic autoimmune disorders

Autoimmunity and inflammation have been implicated as causative factors of seizures and epilepsy. Autoimmune disorders can affect the central nervous system as an isolated syndrome or be part of a systemic disease. Examples of systemic autoimmune disorders include systemic lupus erythematosus, antiphospholipid syndrome, rheumatic arthritis, and Sjögren syndrome. Overall, there is a 5-fold increased risk of seizures and epilepsy in children with systemic autoimmune disorders. Various etiologic factors have been implicated in causing the seizures in these patients, including direct inflammation, effect on blood vessels (vasculitis), and production of autoantibodies. Potential treatments for this autoimmune injury include steroids, immunoglobulins, and other immune-modulatory therapies. A better understanding of the mechanisms of epileptogenesis in patients with systemic autoimmune diseases could lead to targeted treatments and better outcomes.

Anti-CD79 antibody induces B cell anergy that protects against autoimmunity

B cells play a major role in the pathogenesis of many autoimmune disorders, including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and type I diabetes mellitus, as indicated by the efficacy of B cell-targeted therapies in these diseases. Therapeutic effects of the most commonly used B cell-targeted therapy, anti-CD20 mAb, are contingent upon long-term depletion of peripheral B cells. In this article, we describe an alternative approach involving the targeting of CD79, the transducer subunit of the B cell AgR. Unlike anti-CD20 mAbs, the protective effects of CD79-targeted mAbs do not require cell depletion; rather, they act by inducing an anergic-like state. Thus, we describe a novel B cell-targeted approach predicated on the induction of B cell anergy.

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.

The use of monoclonal antibodies in immune-mediated hematologic disorders

In this article, the evidence on the clinical use of monoclonal antibodies in the treatment of immune-mediated hematologic disorders is described. Insights into pathogenic mechanisms have revealed a major role of both B and T cells. Controlled trials have shown conflicting results, necessitating further research regarding pathogenesis, mechanism of action, and resistance. Although the use of more potent and specific monoclonal antibody therapy, mainly targeting costimulation signals, may improve response rates and long-term outcome, its use should be carefully balanced against potential side effects.

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.

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

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

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.

Refractory subacute cutaneous lupus erythematosus successfully treated with rituximab

A 48-year-old woman presented with pruritic, scaly, annular plaques over her upper back and chest that were clinically, serologically and histologically characteristic of subacute cutaneous lupus erythematosus (SCLE). She failed to respond to conventional treatment, which included high-dose hydroxychloroquine, methotrexate, prednisolone, chloroquine, acitretin, thalidomide, dapsone and azathioprine. Subsequently treated with intravenous rituximab 375 mg/m(2) weekly for 4 weeks, she remained on adjuvant oral hydrochloroquine 600 mg daily and topical clobetasol propionate 0.05% ointment as required. Clearing of annular plaques was noted 8 weeks after the initial course of rituximab. By 12 weeks there were no new lesions and only post-inflammatory hyperpigmentation remained. Both hyper- and hypopigmentation, which is more common, are consistent with SCLE lesion regression. Skin lesions recurred 11 months later; however, no further lesions occurred after re-introduction of rituximab therapy. The treatment was well tolerated. A maintenance regimen of rituximab, 375 mg/m(2) every 8 weeks for 2 years, was commenced 3 months after completing the second course of treatment, with ongoing disease remission. Rituximab appears to have activity in refractory SCLE and clinical trials are required to further assess this potential therapy.

Rituximab: beyond simple B cell depletion

Rituximab, a chimeric anti-CD20 monoclonal antibody, has a proven track record for over a decade in the treatment of lymphomas, where it has been used to eradicate malignant lymphocytes. In appreciation of the putative role of B cells, especially with respect to autoantibody production, in the pathogenesis of autoimmune diseases, successful trials of B-cell depletion therapy in RA, SLE, and other autoimmune diseases have been carried out. In these trials, clinical benefit has generally correlated with the extent and duration of B-cell depletion, but at times imperfectly, and autoantibody reduction only selectively. Additional mechanisms whereby rituximab may assert its clinical benefit in autoimmune diseases have been examined including a look at B-cell functions as T-cell modulator and antigen-presenting cell, T-regulatory cell behavior, NK cell activity, and macrophage activities in immune inflammation. The available data on rituximab's action in autoimmune diseases is reviewed.

Rituximab in systemic lupus erythematosusA systematic review of off-label use in 188 cases

The complexity of the therapeutic approach in systemic lupus erythematosus (SLE) is increased by the large number of patients who do not respond to the first-line therapies and by relapses after initial clinical remission. In these patients, second-line drugs are often prescribed according to individual clinical decisions. The emergence of biological therapies has increased the therapeutic armamentarium available in these complex situations, but their use is limited by the lack of licensing. Available data on the use of rituximab in SLE rely on a large number of case reports and some observational studies. We analyzed current evidence on the therapeutic use of rituximab in adult SLE patients by a systematic review of reports included in the PubMed database between 2002 and 2007. A total of 188 SLE patients treated with rituximab were identified; 171 (91%) patients showed a significant improvement in one or more of the systemic SLE manifestations. There were 103 patients with lupus nephritis, with an overall rate of therapeutic response of renal involvement of 91%. Adverse events were reported in 44 (23%) patients; the most frequent were infections (19%). Although it is not yet possible to make definite recommendations, the global analysis of all cases reported to date support the off-label use of rituximab in severe, refractory SLE cases, whereas its use as a first-line therapy or in patients with a predominantly mild form of the disease is not advised.

Effect of rituximab on clinical and laboratory features of antiphospholipid syndrome: a case report and a review of literature

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by a hypercoagulable state related to persistently elevated levels of antiphospholipid antibodies (aPL). Current treatment for APS is only partially effective and new therapies are strongly needed.

We report on a case of a 50 years old man with APS who suffered from recurrent thromboembolic episodes despite conventional anticoagulant treatment. Eight years after the first thrombotic manifestation he was diagnosed with a large B cell non-Hodgkin lymphoma. Treatment with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) plus rituximab was started with partial clinical remission of lymphoma and normalization of aPL levels with a three years follow-up period free of thrombotic episodes.

A review of the literature revealed that only 12 case reports on the use of rituximab in patients with primary, secondary and catastrophic APS have been published. Current knowledge clearly suggests the need for clinical trials to evaluate the effect of rituximab in the treatment of resistant APS. Lupus (2008) 17, 50—55.

Rituximab treatment for chronic refractory idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is characterized by mucocutaneous bleeding and a low platelet count caused by increased autoantibodies against self-antigens and T-cell mediated cytotoxicity. About 10-30% patients with ITP will become refractory ITP. Most of them will become refractory to corticosteroids and splenectomy, as well as other available agents such as intravenous immunoglobulins, danazol, or chemotherapy. B cells not only are the passive producers of immunoglobulins, but also play an important immunoregulatory role in pathophysiology of ITP. Rituximab, a chimeric anti-CD20 monoclonal antibody that specifically targets the CD20 molecule on the B-cell surface, is useful in the treatment of ITP through B cells depletion. Rituximab has multiple mechanisms of inducing cytotoxicity in vivo, including antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), direct apoptosis signaling, and possible vaccine effects. In most clinical reports, rituximab was given as an intravenous infusion at a dose of 375 mg/m(2) weekly for four doses. A total complete response (CR) of 33.2% and a total response of 52.9% were reported. Most results found that no clinical or laboratory parameters could predict treatment outcome. Though the infusion-related side effects of rituximab were common in ITP, it was well tolerated with rare severe side effects. In general, rituximab appears to be a promising immunotherapeutic agent for the treatment of refractory ITP. More controlled clinical trials are necessary to evaluate both the efficacy and long-term safety of the drug.

Hepatitis C virus infection and rituximab therapy after renal transplantation

BACKGROUND

Rituximab, a chimeric monoclonal antibody, has been successfully given in various diseases including HCV-associated mixed cryoglobulinemia. However, only preliminary data exists on its efficacy and safety after renal transplantation.

METHODS

We report on a renal transplant recipient with chronic hepatitis C who received rituximab therapy for gastric cancer. Four rituximab infusions of 375 mg/m(2) were given.

RESULTS

Rituximab therapy was complicated by cholestatic hepatitis C with very high HCV RNA levels; liver insufficiency occurred. The patient developed bacterial pneumoniae and respiratory insufficiency was the cause of death. Although other mechanisms cannot be excluded, we found that rituximab therapy was implicated in the pathogenesis of cholestatic hepatitis C in our patient.

CONCLUSIONS

We suggest that rituximab therapy may be associated with significant side effects. More experience has to be accumulated before any conclusions on efficacy and safety of rituximab therapy after RT can be drawn.

Histopathologic and clinical outcome of rituximab treatment in patients with cyclophosphamide-resistant proliferative lupus nephritis

OBJECTIVE

Rituximab is a monoclonal antibody directed against the CD20 marker of B cells. Because of its ability to deplete B lymphocytes, it has been suggested that the drug could be of benefit in B cell-dependent diseases, including systemic lupus erythematosus (SLE). The purpose of this study was to investigate the histopathologic and clinical effects of combination treatment with rituximab and cyclophosphamide (CYC) in patients with CYC-resistant proliferative lupus nephritis.

METHODS

Seven female patients with proliferative lupus nephritis were treated with rituximab in combination with CYC. Renal biopsies were performed before treatment and during followup. SLE activity was evaluated by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and the British Isles Lupus Assessment Group index. In 6 of the 7 patients, immunostaining of lymphocyte subpopulations in the renal tissue was performed before treatment and during followup.

RESULTS

At 6 months of followup, significant clinical improvement was noted, with a reduction in SLEDAI scores (from a mean of 15 to 3), anti-double-stranded DNA antibody levels (from a mean of 174 IU/ml to 56 IU/ml), and anti-C1q antibody levels (from a mean of 35 units/ml to 22 units/ml). On repeat renal biopsy, improvement in the histopathologic class of nephritis occurred in a majority of patients, and a decrease in the renal activity index was noted (from 6 to 3). A reduction in the number of CD3, CD4, and CD20 cells in the renal interstitium was noted in 50% of the patients on repeat biopsy.

CONCLUSION

At 6 months of followup, all patients had responded both clinically and histopathologically to combination therapy. For patients with proliferative lupus nephritis who fail to respond to conventional immunosuppressive therapy including CYC, combined treatment with rituximab and CYC may constitute a new treatment option.

Efficacy of rituximab (anti-CD20) for refractory systemic lupus erythematosus involving the central nervous system

AIM

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious treatment-resistant phenotype of systemic lupus erythematosus. A standard treatment for NPSLE is not available. This report describes the clinical and laboratory tests of 10 patients with NPSLE before and after rituximab treatment, including changes in lymphocyte phenotypes.

METHODS

Rituximab was administered at different doses in 10 patients with refractory NPSLE, despite intensive treatment.

RESULTS

Treatment with rituximab resulted in rapid improvement of central nervous system-related manifestations, particularly acute confusional state. Rituximab also improved cognitive dysfunction, psychosis and seizure, and reduced the SLE Disease Activity Index Score at day 28 in all 10 patients. These effects lasted for >1 year in five patients. Flow cytometric analysis showed that rituximab down regulated CD40 and CD80 on B cells and CD40L, CD69 and inducible costimulator on CD4+ T cells.

CONCLUSIONS

Rituximab rapidly improved refractory NPSLE, as evident by resolution of various clinical signs and symptoms and improvement of radiographic findings. The down regulation of functional molecules on B and T cells suggests that rituximab modulates the interaction of activated B and T cells through costimulatory molecules. These results warrant further analysis of rituximab as treatment for NPSLE.

B lymphocytes as therapeutic targets in systemic lupus erythematosus

In recent years, experimental evidence supporting a major role of B cells in the pathogenesis of autoimmune diseases has grown. This includes the discovery of novel mechanisms of autoantibody pathogenicity and the potential of B cells to mediate inflammation and tissue injury. In some instances, engagement of the B cell receptor and other surface receptors is sufficient to stimulate B cells to produce antibody. As a result, B cells have become targets for immunointervention. In lupus, targeting B cell activation factor (BAFF, BLys) indicates that specific blockade of this longevity factor might be sufficient to suppress systemic autoimmunity. Targeting CD20 represents another promising avenue for the treatment of refractory lupus in both adults and children. Although the clinical data add weight to the importance of B cells in the pathogenesis of lupus, new targets for B cell depletion therapy are being investigated. In experimental models, combining CD19 and CD20 antibodies was more effective than either treatment alone.

Long-term comparison of rituximab treatment for refractory systemic lupus erythematosus and vasculitis: Remission, relapse, and re-treatment

OBJECTIVE

Current treatments for systemic lupus erythematosus (SLE) and vasculitis contribute to mortality and incapacity and are only partially effective; thus, newer therapies are clearly needed. Depletion of B cells has led to disease control in patients with autoimmune disorders. We sought to assess the long-term efficacy and safety of a B cell-depleting therapy in patients with SLE and patients with vasculitis.

METHODS

In a prospective study with a median followup of 24 months, 11 patients with active or refractory SLE and 11 patients with active or refractory antineutrophil cytoplasmic antibody-associated vasculitis (AAV) received a course of therapy with rituximab (an anti-CD20 monoclonal antibody) along with a single dose of intravenous cyclophosphamide.

RESULTS

Remission followed rapid B cell depletion, with response rates of 100% among the 11 patients with SLE (6 patients had a complete response, and 5 patients had a partial response) and 91% among the 11 patients with AAV (9 patients had a complete response, and 1 patient had partial remission). A renal response occurred in all 6 patients with lupus nephritis. Clinical improvement was accompanied by significant reductions in the daily dose of prednisolone. Relapse occurred in 64% of the patients with SLE and in 60% of those with AAV. B cell return preceded relapse in the majority of patients, and further treatment with rituximab proved effective. IgG and IgM levels were maintained in the normal range. The incidence of infective complications was low; however, infusion reactions were common, and human antichimeric antibodies developed in 5 of 14 patients.

CONCLUSION

B cell depletion offers the prospect of sustained disease remission and improved disease control combined with low toxicity in patients with active or refractory SLE or AAV. Relapse following treatment is common, but re-treatment is rapidly effective.

Thrice-Weekly Low-Dose Rituximab Decreases CD20 Loss via Shaving and Promotes Enhanced Targeting in Chronic Lymphocytic Leukemia

Treatment of chronic lymphocytic leukemia (CLL) patients with standard dose infusion of rituximab (RTX), 375 mg/m2, induces clearance of malignant cells from peripheral blood after infusion of 30 mg of RTX. After completion of the full RTX infusion, substantial recrudescence of CLL cells occurs, and these cells have lost > 90% of CD20. To gain insight into mechanism(s) of CD20 loss, we investigated the hypothesis that thrice-weekly low-dose RTX (20 or 60 mg/m2) treatment for CLL over 4 wk would preserve CD20 and enhance leukemic cell clearance. During initial infusions in all 12 patients, the first 30 mg of RTX promoted clearance of > 75% leukemic cells. Four of six patients receiving 20 mg/m2 RTX retained > or = 50% CD20, and additional RTX infusions promoted further cell clearance. However, four of six patients receiving 60 mg/m2 had CD20 levels < 20% baseline 2 days after initial infusions, and additional RTX infusions were less effective, presumably due to epitope loss. Our results suggest that when a threshold RTX dose is exceeded, recrudesced RTX-opsonized cells are not cleared, due to saturation of the mononuclear phagocytic system, but instead are shaved of RTX-CD20 complexes by acceptor cells. Thrice-weekly low-dose RTX may promote enhanced clearance of circulating CLL cells by preserving CD20.

Update on the treatment of lupus nephritis

Lupus nephritis (LN) is a major cause of morbidity and mortality in patients with systemic lupus erythematosus. Although the use of aggressive immunosuppression has improved both patient and renal survival over the past several decades, the optimal treatment of LN remains challenging. Improved outcomes have come at the expense of significant adverse effects owing to therapy. Moreover with long-term survival, the chronic adverse effects of effective therapies including risk of malignancy, atherosclerosis, infertility, and bone disease all become more important. Finally, some patients fail to achieve remission with standard cytotoxic therapy and others relapse when therapy is reduced. For these reasons, recent clinical trials have attempted to define alternate treatment protocols that appear to be efficacious in achieving and maintaining remission, but with less toxicity than standard regimens. This paper discusses established and newer treatment options for patients with proliferative and membranous LN, with an emphasis on the results of these recent clinical trials. We also review the experimental and human data regarding some of the novel targeted forms of therapy that are under investigation and in different phases of clinical trials.

Newer therapeutic approaches for systemic lupus erythematosus: immunosuppressive agents

There has been unprecedented growth in new therapeutic approaches for the treatment of systemic lupus erythematosus (SLE). These approaches include re-evaluation of the doses and duration of therapy with traditional agents, including intravenous cyclophosphamide and azathioprine. Drugs that were developed for other uses are being applied to specific SLE manifestations, and have spurred larger scale trials for overall disease activity. In addition, several new agents show promise in clinical trials; many have safer toxicity profiles than do traditional therapies. Some of these agents have multiple immunomodulatory effects, whereas others interfere with a specific immunologic process in one of the pathogenetic pathways of SLE activity.

Clinical and immunological effects of Rituximab in patients with lupus nephritis refractory to conventional therapy: a pilot study

We studied the clinical and immunological effects of Rituximab (anti-CD20) therapy in patients with lupus nephritis. In an open clinical trial, 22 patients with active systemic lupus erythematosis and renal involvement (mainly class III and IV according to the WHO classification) that was refractory to conventional therapy were studied. In all these patients, Rituximab (0.5 to 1.0 g at days 1 and 15) was added to the immunosuppressive therapy and its therapeutic effect was evaluated. In addition, the levels and function of regulatory T lymphocytes and the apoptosis of immune cells were assessed. We found a significant reduction in disease activity (p < 0.05, MEX-SLEDAI index), and proteinuria (p < 0.05) at days 60 and 90 of Rituximab therapy. Although most patients showed improvement in creatinine clearance and erythrocyturia, no significant changes in these parameters were detected. In most patients (20/22), B cell depletion was observed, but no clear-cut effect of Rituximab on complement levels or auto-antibody titers was detected (p > 0.05 in all cases). One patient died at day 70 with invasive histoplasmosis. No important adverse effects of Rituximab therapy were registered in other patients. A significant enhancement in the levels of different CD4+ regulatory cells (TREG, Th3, Tr1), but not CD8+ Ts lymphocytes, was observed at day 30. This increase was sustained for TREG cells at day 90, and accompanied by an improvement in their regulatory function. In addition, we observed an unexpected increase in the apoptosis of T cells at day 30. Interestingly, the enhancement in the suppressive function of TREG cells was not observed in the two patients that showed the poorest clinical response to Rituximab. We conclude that the data obtained in this open clinical trial suggest that Rituximab is a promising candidate for randomized controlled trials in patients with lupus nephritis refractory to the conventional immunosuppressive therapy. The effects of Rituximab on regulatory cells and apoptosis of T lymphocytes are interesting and its possible role in the putative effect of this biological agent in systemic lupus erythematosis deserves additional studies.

Rituximab therapy for childhood-onset systemic lupus erythematosus

OBJECTIVE

To describe the safety and efficacy of rituximab in the treatment of childhood-onset systemic lupus erythematosus (SLE).

STUDY DESIGN

We conducted a French multicenter retrospective study of childhood-onset SLE treated with rituximab.

RESULTS

Eleven girls with severe SLE, including 8 girls with class IV or V lupus nephritis, 2 girls with severe autoimmune cytopenia, and 1 girl with antiprothrombin antibody with severe hemorrhage, were treated with rituximab. The mean age at onset of rituximab treatment was 13.9 years. Patients received 2 to 12 intravenous infusions of rituximab (350-450 mg/m2/infusion), with corticosteroids. Six patients also received different standard immunosuppressive agents, including Cyclophosphamide (2 patients). Remission was achieved in 6 of 8 patients with lupus nephritis and in the 2 patients with autoimmune cytopenia. Steroid therapy was tapered in 5 patients who responded to treatment, and low-dose prednisone treatment was maintained in 1 patient. The mean follow-up period was 13.2 months (range, 6-26 months), and remission lasted in all who patients who responded to treatment, except 1 patient who was successfully retreated with a second course of rituximab. Anti-double-stranded DNA antibody levels decreased in 6 of 11 patients, and anticardiolipin antibody levels decreased in 3 of 4 patients. Severe adverse events developed in 5 patients. Effective depletion of peripheral blood B cells was observed in 7 of 8 patients who were examined, and this paralleled the remission.

CONCLUSION

Rituximab may be an effective co-therapy; however, further investigations are required because severe adverse events occurred in 45% of the patients in this study.

Emergence of targeted immune therapies for systemic lupus

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, characterised by flares of rampant inflammation that can threaten, in an unpredictable manner, almost any organ in the body. Current standard of care is largely empiric, involving the use of corticosteroids and toxic immune suppressive agents that are widely acknowledged to have unacceptable side effects for long-term use. Recently, there have been significant advances in understanding the nature of some fundamental immune imbalances underlying the complicated clinical manifestations of SLE. Nevertheless attempts to develop and test more targeted, and potentially safer immune-modulating drugs for lupus have encountered significant obstacles, due to the lack of validated biological markers for disease flare and remission, and difficulties in the clinical assessment of the heterogeneous patients. In support of renewed interest in drug development for lupus, large collaborative groups have formed, and efforts are underway to develop objective biomarkers for SLE as well as to improve the standardisation and reproducibility of clinical outcome measures in multi-centre trials.

Rituximab treatment for glomerulonephritis in HCV-associated mixed cryoglobulinaemia: efficacy and safety in the absence of steroids

OBJECTIVE

Rituximab, an anti-CD20 monoclonal antibody, has been used in lupus nephritis and membranous idiopathic nephropathy and has proved effective in non-renal manifestations of type II mixed cryoglobulinaemia (MC) syndrome. We investigated the possible efficacy and safety of rituximab in the treatment of cryoglobulinaemic nephritis.

METHODS

Five patients with active, biopsy-proven, glomerulonephritis in hepatitis C virus (HCV)-related type II MC syndrome were treated with four weekly infusions of rituximab (375 mg/m2) in monotherapy, without steroids whenever possible. Rituximab was the first-line therapy in three cases.

RESULTS

A rapid and sustained renal response was observed in all patients, in one of them without retreatment up to the last follow-up (month 21+). Renal biopsy was repeated after 6 months in one patient and histopathological improvement was documented. Three patients relapsed, at months +5, +7 and +12 of follow-up, respectively. Two of them were then retreated with rituximab and again presented a rapid improvement in renal function. Maintenance therapy with rituximab was performed in two patients: nephritis remission was maintained in both. Fc-gamma receptor 3a (FcgammaRIIIa) genotype characterization was consistent with the clinical response observed. Rituximab also proved effective against other active MC manifestations, when present. No major side-effects occurred and steroids were not required in the follow-up.

CONCLUSIONS

Rituximab may provide effective and safe therapy in type II MC-related glomerulonephritis, possibly as first-line therapy, avoiding steroids and hazardous immunosuppressive treatment.

Rituximab: A promising therapy in systemic lupus erythematosus

Several trials of new immunologic agents in systemic lupus erythematosus (SLE) have recently been undertaken. Rituximab, a chimeric antibody directed against CD20 on B lymphocytes, has emerged as a promising therapy. Based upon preliminary data, clinical efficacy of rituximab has been documented in both pediatric and adult-onset SLE patients. The specific manifestations reported to be beneficially affected include lupus nephritis, arthralgia/arthritis, serositis, cutaneous vasculitis, mucositis, rashes, fatigue and neurologic symptoms. Although rituximab's mechanisms of action are incompletely understood, the effects of rituximab are likely mediated by antibody-dependent cell-mediated cytotoxicity and the induction of apoptosis. The resultant repopulation of B cells, alteration of abnormal B cell homeostasis and down-regulation of co-stimulatory molecules on both B and T cells all likely contribute to clinical efficacy. Good tolerability of rituximab is reported with rare serious side effects. The positive response to rituximab verifies a central role for B cells in SLE. This article highlights the clinical experience of rituximab therapy in both pediatric and adult-onset SLE. These data suggest a promising role for rituximab in the treatment of SLE. Further controlled trials and long-term outcome studies are imperative to further define its clinical application and to improve the care of patients.

Rituximab anti-B-cell therapy in systemic lupus erythematosus: pointing to the future

PURPOSE OF REVIEW

To discuss the clinical effects and the immunologic consequences of transient B-cell depletion using the anti-CD20 monoclonal antibody rituximab in systemic lupus erythematosus.

RECENT FINDINGS

A total of 100 rituximab-treated patients with severe disease, refractory to major immunosuppressive treatment, have been reported so far. Within a median follow-up period of 12 months rituximab was well tolerated, which is compatible with the experience accumulated from its use in more than 500 000 lymphoma patients. About 80% of patients achieved marked and rapid reductions in global disease activity. Because of the clinical heterogeneity, dosing differences, and concomitant treatments, including cyclophosphamide in 35% of patients, a proper evaluation of the clinical efficacy or rituximab is difficult. Variable degrees of clinical benefit have been reported for all clinical systemic lupus erythematosus manifestations, including active proliferative nephritis. Whereas 4-weekly infusions of 375 mg/m of rituximab result in complete B-cell depletion lasting most often from 3 to 8 months, a prolonged depletion does not always correlate with a more favorable clinical response. Total immunoglobulin levels and protective antibodies are preserved, but anti-dsDNA antibody titers decrease, often independently of the clinical response.

SUMMARY

The findings reviewed point to a growing optimism for targeting B cells in the treatment of systemic lupus erythematosus; therefore double-blind studies comparing rituximab with existing immunosuppressive therapies are needed. Moreover, careful assessments of the effects of transient B-cell depletion on distinct autoimmune pathogenetic processes will enable optimization of therapeutic single or combined therapeutic schemes.

Repeated B cell depletion in treatment of refractory systemic lupus erythematosus

OBJECTIVES

To report the clinical outcome and safety profile of repeated B cell depletion in seven patients with refractory systemic lupus erythematosus (SLE).

METHODS

Since June 2000, seven patients with refractory SLE had repeated cycles of B cell depletion (18 cycles in total, up to three cycles per patient) because of disease relapse. The clinical response (assessed by the British Isles Lupus Activity Guide (BILAG) activity index), duration of B cell depletion, and adverse events in these patients was reviewed.

RESULTS

Four patients (Nos 1, 2, 3, 6) had three cycles of treatment and three (Nos 4, 5, 7) had two cycles. Four of the seven patients (Nos 1, 3, 5, 6) improved. The mean global BILAG scores dropped from 15 to 6 at 5-7 months. The median duration of clinical response and B cell depletion was 13 months and 6 months, respectively. After the third cycle, 2/4 patients (Nos 1 and 2) improved. The median duration of clinical benefit was 12 months. Most patients tolerate re-treatment very well.

CONCLUSION

Re-treatment with B cell depletion of patients with severe SLE is safe and may be effective for 6-12 months on average.

CD20: A target antigen for immunotherapy of autoimmune diseases

This article reviews the role of CD20 antigen in B cell function and the effectiveness and limits of passive immunotherapy with anti-CD20 monoclonal antibody (Rituximab) in the treatment of autoimmune (or immune-mediated) diseases. Active immunotherapy is a more feasible way to control these chronic diseases. A peptide that mimics the CD20 epitope recognized by Rituximab is employed to stimulate the host immune response against CD20.

Infective endocarditis complicating rituximab (anti-CD20 monoclonal antibody) treatment in an SLE patient with a past history of Libman–Sacks endocarditis: a case for antibiotic prophylaxis?

We report a 54 year old female whose successful treatment of cerebral lupus with rituximab was complicated by the development of streptococcus intermedius, on valves damaged by Libman-Sacks endocarditis more than 20 years previously.