Biopsy-verified response of severe lupus nephritis to treatment with rituximab (anti-CD20 monoclonal antibody) plus cyclophosphamide after biopsy-documented failure to respond to cyclophosphamide alone

Tailoring the treatment of inflammatory rheumatic diseases by a better stratification and characterization of the clinical patient heterogeneity. Findings from a systematic literature review and experts' consensus

Inflammatory rheumatic diseases are different pathologic conditions associated with a deregulated immune response, codified along a spectrum of disorders, with autoinflammatory and autoimmune diseases as two-end phenotypes of this continuum. Despite pathogenic differences, inflammatory rheumatic diseases are commonly managed with a limited number of immunosuppressive drugs, sometimes with partial evidence or transferring physicians' knowledge in different patients. In addition, several randomized clinical trials, enrolling these patients, did not meet the primary pre-established outcomes and these findings could be linked to the underlying molecular diversities along the spectrum of inflammatory rheumatic disorders. In fact, the resulting patient heterogeneity may be driven by differences in underlying molecular pathology also resulting in variable responses to immunosuppressive drugs. Thus, the identification of different clinical subsets may possibly overcome the major obstacles that limit the development more effective therapeutic strategies for these patients with inflammatory rheumatic diseases. This clinical heterogeneity could require a diverse therapeutic management to improve patient outcomes and increase the frequency of clinical remission. Therefore, the importance of better patient stratification and characterization is increasingly pointed out according to the precision medicine principles, also suggesting a new approach for disease treatment. In fact, based on a better proposed patient profiling, clinicians could more appropriately balance the therapeutic management. On these bases, we synthetized and discussed the available literature about the patient profiling in regard to therapy in the context of inflammatory rheumatic diseases, mainly focusing on randomized clinical trials. We provided an overview of the importance of a better stratification and characterization of the clinical heterogeneity of patients with inflammatory rheumatic diseases identifying this point as crucial in improving the management of these patients.

Anti-vimentin antibodies: a unique antibody class associated with therapy-resistant lupus nephritis

Background

Tubulointerstitial inflammation (TII) in lupus nephritis is associated with a worse prognosis. Vimentin, a filamental antigen, is commonly targeted by in situ activated B-cells in TII. The prognostic importance of high serum anti-vimentin antibodies (AVAs) in lupus nephritis and their relationship with common lupus autoantibody specificities is unknown. Herein we investigated associations between AVA isotypes, other autoantibodies, and response to mycophenolate mofetil (MMF) in the presence or absence of rituximab.

Methods

The Translational Research Initiative in the Department of Medicine (TRIDOM) cross-sectional cohort of 99 lupus patients was assayed for IgG-, IgA- and IgM- AVAs, lupus-associated and rheumatoid arthritis-associated antibodies, and hierarchically clustered. Serum from baseline, 26 and 52 weeks from 132 Lupus Nephritis Assessment with Rituximab (LUNAR) trial enrolled lupus nephritis patients was also analysed and correlated with renal function up to week 78.

Results

In TRIDOM, AVAs, especially IgM AVAs, clustered with IgG anti-dsDNA and away from anti-Sm and -RNP and rheumatoid arthritis-associated antibodies. In LUNAR at baseline, AVAs correlated weakly with anti-dsDNA and more strongly with anticardiolipin titers. Regardless of treatment, IgG-, but not IgM- or IgA-, AVAs were higher at week 52 than at baseline. In contrast, anti-dsDNA titers declined, regardless of therapeutic regime. High IgG AVA titers at entry predicted less response to therapy.

Conclusion

AVAs, especially IgG AVAs, are unique in distribution and response to therapy compared with other commonly measured autoantibody specificities. Furthermore, high-titer IgG AVAs identify lupus nephritis patients resistant to conventional therapies. These data suggest that AVAs represent an independent class of prognostic autoantibodies.

Management of refractory lupus nephritis: challenges and solutions

Refractory lupus nephritis, broadly defined as failure to attain clinical remission after appropriate induction immunosuppressive therapy, is associated with an increased risk of progression to end-stage kidney disease and mortality. This is a challenging issue in clinical practice, as modern induction therapy despite proven efficacy can still be associated with treatment failure. Moreover, newer therapies have failed in recent years to displace or even match existing protocols for effective induction of remission. Refractory disease is generally assessed on the basis of clinical parameters, which may be unreliable, and renal biopsy, which is often not performed in a standard or timely fashion. Persisting histological inflammation in 30%–50% of patients who have attained clinical remission highlights the disparity between clinical and immunological response to therapy. The lack of an international consensus regarding what constitutes refractory lupus nephritis compounds clinician indecision regarding optimal management for these patients. Moreover, non-adherence to prescribed therapy versus primary treatment failure can be challenging to discriminate, and the time point at which non-response becomes treatment failure is unclear. In this review, we assess the key published evidence for the treatment of refractory lupus nephritis and provide practical recommendations based around the use of adjunctive therapies. These agents include rituximab and calcineurin inhibitors, with evidence consisting largely of observational or uncontrolled studies, as well as some of the biologic therapies currently under investigation through prospective clinical trials. The poor prognosis of refractory lupus nephritis demands regular review of patient response and the flexibility to switch or augment therapy.

Effectiveness and Safety of Rituximab in Systemic Lupus Erythematosus: A Case Series Describing the Experience of 2 Centers

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organs and systems. B cells have a critical role in the pathogenesis of SLE. Rituximab (RTX) is a drug composed of chimeric monoclonal antibodies against the CD20 protein, producing a depletion of B lymphocytes.

OBJECTIVE

To analyze the effectiveness and safety of RTX in patients with SLE in clinical practice.

METHODS

Collection of retrospective variables of the medical records of 20 patients with SLE treated with RTX in 2hospitals (Hospital de la Santa Creu i Sant Pau, and Hospital del Mar, in Barcelona, Spain). We evaluated demographic, clinical, serological and treatment variables.

RESULTS

There was a statistically significant association in the following variables collected in the study before and after treatment: there was a decrease in the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) (P<.001), erythrocyte sedimentation rate (P=.017), use of glucocorticoids (P=.025) and IgM values (P=.031), as well as an increase in the C4 values (P=.014) after treatment with RTX. A patient with SLE, antiphospholipid syndrome, complex comorbidity and multiorgan lupus involvement died after developing a septic process, months after receiving a single treatment cycle with RTX.

CONCLUSIONS

Although RTX currently has no official indication approved for SLE, our data suggest that it may be effective in reducing the activity of the disease and as a steroid-sparing agent, with an acceptable safety profile. However, larger follow-up periods with a greater number of patients are needed to solve the remaining doubts about the use of RTX in SLE.

Genotypes, phenotypes and treatment with immunomodulators in the rheumatic diseases

The autoimmune rheumatological diseases rheumatoid arthritis (RA), spondyloarthritis (SpA) and systemic lupus erythematosus (SLE) are treated with conventional immunosuppressive agents and with modern biological immunomodulators. The latter group of medications have brought about a major change in our ability to control RA and SpA, with more modest results for SLE. The biologicals are very specific in their mechanisms of action, targeting one specific cytokine or one particular cellular marker. Because of this, their efficacy can readily be linked to a single immunomodulatory mechanism. This observation has fuelled hopes that the efficacy of these agents can be predicted at the individual level based on the patient's genetic predisposition, immunological profile or disease phenotype. Whilst the biologic therapies have improved the prospects for patients with these diseases very significantly, the hope that they could be targeted to the patient in an individualized manner has not completely born fruit. In this review, I will argue that we are witnessing important progress in this field, and that justified hope exists for true advances in precision medicine in the autoimmune diseases in the coming years.

The value of repeat biopsy in lupus nephritis flares

Whether a repeat renal biopsy is helpful during lupus nephritis (LN) flares remains debatable. In order to analyze the clinical utility of repeat renal biopsy in this complex situation, we retrospectively reviewed our series of 54 LN patients who had one or more repeat biopsies performed only on clinical indications. Additionally, we reviewed 686 well-documented similar cases previously reported (PubMed 1990-2015).The analysis of all patients reviewed showed that histological transformations are common during a LN flare, ranging from 40% to 76% of cases. However, the prevalence of transformations and the clinical value of repeat biopsy vary when they are analyzed according to proliferative or nonproliferative lesions.The great majority of patients with class II (78% in our series and 77.5% in the literature review) progressed to a higher grade of nephritis (classes III, IV, or V), resulting in worse renal prognosis. The frequency of pathological conversion in class V is lower (33% and 43%, respectively) but equally clinically relevant, since almost all cases switched to a proliferative class. Therefore, repeat biopsy is highly advisable in patients with nonproliferative LN at baseline biopsy, because these patients have a reasonable likelihood of switch to a proliferative LN that may require more aggressive immunosuppression.In contrast, the majority of patients (82% and 73%) with proliferative classes in the reference biopsy (III, IV or mixed III/IV + V), remained into proliferative classes on repeat biopsy. Although rebiopsy in this group does not seem as necessary, it is still advisable since it will allow us to identify the 18% to 20% of patients that switch to a nonproliferative class. In addition, consistent with the reported clinical experience, repeat biopsy might also be helpful to identify selected cases with clear progression of proliferative lesions despite the initial treatment, for whom it is advisable to intensify inmunosuppression. Thus, our experience and the literature data support that repeat biopsy also brings more advantges than threats in this group.The results of the repeat biopsy led to a change in the immunosuppresive treatment in more than half of the patients on average, intensifying it in the majority of the cases, but also reducing it in 5% to 30%.

Targeted B cell therapies in the treatment of adult and pediatric systemic lupus erythematosus

Belimumab (Benlysta) is a fully-humanized monoclonal antibody that inhibits B-lymphocyte stimulator (also known as B cell activating factor) and was approved by the U.S. Federal Drug Administration and European Medicines Evaluation Agency for treatment in adults with autoantibody-positive systemic lupus erythematosus (SLE). Rituximab (Rituxan) is a chimeric anti-CD20 monoclonal antibody targeting B lymphocytes. This review discusses the key findings of the phase III trials in adults with SLE and of real-world use of belimumab and rituximab in the care of both adult and pediatric SLE patients. It highlights the safety profile of belimumab and rituximab and gives insight into the consideration of these therapies for specific SLE disease states. It concludes with a discussion of the current clinical trials investigating B cell therapies in specific SLE disease states and a look to the future, with ongoing clinical trials.

Approaches for estimating minimal clinically important differences in systemic lupus erythematosus

A minimal clinically important difference (MCID) is an important concept used to determine whether a medical intervention improves perceived outcomes in patients. Prior to the introduction of the concept in 1989, studies focused primarily on statistical significance. As most recent clinical trials in systemic lupus erythematosus (SLE) have failed to show significant effects, determining a clinically relevant threshold for outcome scores (that is, the MCID) of existing instruments may be critical for conducting and interpreting meaningful clinical trials as well as for facilitating the establishment of treatment recommendations for patients. To that effect, methods to determine the MCID can be divided into two well-defined categories: distribution-based and anchor-based approaches. Distribution-based approaches are based on statistical characteristics of the obtained samples. There are various methods within the distribution-based approach, including the standard error of measurement, the standard deviation, the effect size, the minimal detectable change, the reliable change index, and the standardized response mean. Anchor-based approaches compare the change in a patient-reported outcome to a second, external measure of change (that is, one that is more clearly understood, such as a global assessment), which serves as the anchor. Finally, the Delphi technique can be applied as an adjunct to defining a clinically important difference. Despite an abundance of methods reported in the literature, little work in MCID estimation has been done in the context of SLE. As the MCID can help determine the effect of a given therapy on a patient and add meaning to statistical inferences made in clinical research, we believe there ought to be renewed focus on this area. Here, we provide an update on the use of MCIDs in clinical research, review some of the work done in this area in SLE, and propose an agenda for future research.

Rituximab and lupus--a promising pair?

Systemic lupus erythematosus (SLE) is a clinically diverse and potentially life-threatening auto-immune disease that can affect almost any organ system. Although much is still unknown regarding its pathogenesis, B cell abnormalities are thought to be central. A high relapse rate along with the toxicity associated with conventional treatments signify the need for more tailored approaches in this very heterogeneous disease. Both its mechanism targeting B cells and a relatively large number of case series and observational studies have suggested that the B cell-depleting agent rituximab could be a potent SLE drug. However, two randomized controlled trials failed to meet efficacy endpoints. Nevertheless, rituximab has continued to be used as an off-label alternative mainly in patients refractory to conventional immunosuppressive treatment. This article will review the current role of rituximab in SLE.

Use of rituximab as a treatment for systemic lupus erythematosus: retrospective review

OBJECTIVE

To report the experience in three Brazilian institutions with the use of rituximab in patients with different clinical forms of lupus erythematosus systemic in activity.

METHODS

The study consisted of a sample of 17 patients with LES, who were already being treated, but that at some stage of the disease showed refractory symptoms. The patients were subdivided into groups according to the clinical manifestation, and the responses for the use of rituximab were rated as complete, partial or no response. Data were collected through a spreadsheet, and used specific parameters for each group. The treatment was carried on by using therapeutic dose of 1g, and repeating the infusion within an interval of 15 days.

RESULTS

The clinical responses to rituximab of the group only hematological and of the group only osteoarticular were complete in all cases. In the renal group there was a clinical complete response, two partial and one absent. In the renal and hematological group complete response, there was one death and a missing response. The pulmonary group presented a complete response and two partial.

CONCLUSION

The present study demonstrated that rituximab can bring benefits to patients with lupus erythematosus systemic, with good tolerability and mild side effects; it presented, however, variable response according to the system affected.

Rituximab vs mycophenolate and vs cyclophosphamide pulses for induction therapy of active lupus nephritis: a clinical observational study

OBJECTIVE

We report the first comparison between rituximab (RTX) and either MMF or CYC pulses in the treatment of active LN.

METHODS

Fifty-four patients with active LN received three methylprednisolone pulses for 3 consecutive days followed by oral prednisone and RTX 1 g at days 3 and 18 (17 patients) or MMF 2-2.5 g/day (17 patients) or six CYC pulses (0.5 g every fortnight) (20 patients). At 4 months MMF, AZA or ciclosporin were associated to prednisone as a consolidation/maintenance therapy in all groups. The outcomes of the three groups were compared at 3 and 12 months.

RESULTS

Patients in the RTX group were older, had a longer duration of SLE and LN, had more renal flares, had higher activity and had higher chronicity indexes at renal biopsy than the other two groups. Four patients in each group had acute renal dysfunction and ∼50% had nephrotic syndrome. At 3 months, proteinuria was reduced by 50% in 58.8% of patients on RTX, in 64.7% on MMF and in 63.1% on CYC. At 12 months, complete remission was present in 70.6% of patients on RTX, in 52.9% on MMF, and in 65% on CYC. Partial remission was reached in 29.4% on RTX, 41.2% on MMF, and 25% on CYC.

CONCLUSION

RTX seems to be at least as effective as MMF and CYC pulses in inducing remission. Considering that patients treated with RTX had more negative renal prognostic factors, this drug should be considered a viable alternative for the treatment of active LN.

Effects of adjuvants for human use in systemic lupus erythematosus (SLE)-prone (New Zealand black/New Zealand white) F1 mice

The safety of four different adjuvants was assessed in lupus-prone New Zealand black/New Zealand white (BW)F1 mice. Four groups of mice were injected intraperitoneally with incomplete Freund's adjuvant (IFA), complete Freund's adjuvant (CFA), squalene (SQU) or aluminium hydroxide (ALU). An additional group received plain phosphate-buffered saline (PBS) (UNT group). Mice were primed at week 9 and boosted every other week up to week 15. Proteinuria became detectable at weeks 17 (IFA group), 24 (CFA group), 28 (SQU and ALU groups) and 32 (UNT group). Different mean values were obtained among the groups from weeks 17 to 21 [week 17: one-way analysis of variance (anova) P = 0·016; weeks 18 and 19: P = 0·048; weeks 20 and 21: P = 0·013] being higher in the IFA group than the others [Tukey's honestly significant difference (HSD) post-test P < 0·05]. No differences in anti-DNA antibody levels were observed among groups. Anti-RNP/Sm antibody developed at week 19 in only one CFA-treated mouse. Mean mouse weight at week 18 was lower in the ALU group than the IFA (Tukey's HSD post-test P = 0·04), CFA (P = 0·01) and SQU (P < 0·0001) groups, while the mean weight in the SQU group was higher than in the IFA (P = 0·009), CFA (P = 0·013) and UNT (P = 0·005) groups. The ALU group weight decreased by almost half between weeks 29 and 31, indicating some toxic effect of ALU in the late post-immunization period. Thus, SQU was the least toxic adjuvant as it did not (i) accelerate proteinuria onset compared to IFA; (ii) induce toxicity compared to ALU or (iii) elicit anti-RNP/Sm autoantibody, as occurred in the CFA group.

Biologics in SLE: towards new approaches

In recent years the use of biologic therapies in the management of systemic lupus erythematosus (SLE) has increased, and a number of clinical trials have highlighted both the potential and the pitfalls in the development of such agents. Many investigators reported that the off-label use of rituximab seemed promising in patients with refractory disease, but randomised trials with this agent failed. Likewise, the theoretical appeal of the co-stimulation blocker abatacept could not be confirmed in two clinical trials. Various considerations and post hoc analyses nonetheless suggest that these two biologics might have a role in the treatment of SLE. The anti-B-lymphocyte stimulator (anti-Blys) antibody belimumab demonstrated efficacy and safety in two large randomised trials and became the first approved biologic for lupus. Use in clinical practice has increased slowly, in part, due to uncertainty over which patients should be treated with this agent and in what stage of the disease. Finally, several other biologic agents are currently in advanced stages of clinical development for SLE. The overall picture that emerges is one of optimism that advances in SLE therapy will be realised through the targeted use of an increasing number of biologics.

Biomarkers and updates on pediatrics lupus nephritis

Lupus nephritis is a common complication of systemic lupus erythematosus in children and adolescents. This article reviews the clinical relevance of lupus nephritis and its current treatment. The reader is introduced to novel biomarkers that are expected to improve the management of lupus nephritis in the future, and support the testing of novel medication regimens.

Rituximab treatment in lupus nephritis – where do we stand?

Renal involvement in systemic lupus erythematosus (SLE) is a severe disease manifestation in which novel therapeutic strategies are needed, especially in non-responding patients or patients who relapse after conventional treatment. Rituximab has been used as off-label treatment for lupus nephritis (LN) during the last decade, and to date reports on the clinical effects on more than 400 patients, including the randomized controlled LUNAR study population, have been published. Despite promising results obtained from observational studies and registries, with complete or partial renal response after 6–12 months in 67–77% of patients, the LUNAR trial failed to attain the primary endpoint and rituximab is today unlikely to be approved as treatment for LN. Rituximab has mainly been used as induction therapy in combination with standard of care but the optimal treatment protocol is still to be determined. From observational studies, rituximab has been shown to be efficient in both proliferative and membranous LN, and histopathological studies have demonstrated improvement in renal activity. Adverse events mainly include infusion reactions and infections. Although not approved for the treatment of LN, the currently available data support that rituximab may be used in severe, refractory cases of LN.

Enhanced costimulation by CD70+ B cells aggravates experimental autoimmune encephalomyelitis in autoimmune mice

OBJECTIVE

Assess whether CD70+ B cells contribute to EAE.

MATERIALS AND METHODS

MOG-specific TCR transgenic mice (2D2) were crossed with mice with constitutive CD70 expression on B cells. The development of EAE and the phenotype of B-T lymphocytes were studied in 2D2xCD70 animals.

RESULTS

Spontaneous EAE developed in 20% of 2D2xCD70 and 3% of 2D2 mice. EAE was also more severe in 2D2xCD70 versus 2D2 animals upon MOG immunization. The susceptibility of 2D2xCD70 to EAE was associated with fewer FoxP3+ T cells.

CONCLUSIONS

Expression of CD70 by B cells aggravates EAE possibly by reducing the number of regulatory T cells.

Efficacy of rituximab in 164 patients with biopsy-proven lupus nephritis: pooled data from European cohorts

OBJECTIVE

To present a pooled analysis of the efficacy of rituximab from European cohorts diagnosed with biopsy-proven lupus nephropathy (LN) who were treated with rituximab.

METHODS

Consecutive patients with biopsy-proven LN treated with rituximab in European reference centers were included. Complete response (CR) was defined as normal serum creatinine with inactive urinary sediment and 24-hour urinary albumin <0.5 g, and partial response (PR) as a >50% improvement in all renal parameters that were abnormal at baseline, with no deterioration in any parameter.

RESULTS

164 patients were included (145 women and 19 men, with a mean age of 32.3 years). Rituximab was administered in combination with corticosteroids (162 patients, 99%) and immunosuppressive agents in 124 (76%) patients (cyclophosphamide in 58 and mycophenolate in 55). At 6- and 12-months, respectively, response rates were 27% and 30% for CR, 40% and 37% for PR and 33% for no response. Significant improvement in 24-h proteinuria (4.41 g. baseline vs 1.31 g. post-therapy, p=0.006), serum albumin (28.55 g. baseline to 36.46 g. post-therapy, p<0.001) and protein/creatinine ratio (from 421.94 g/mmol baseline to 234.98 post-therapy, p<0.001) at 12 months was observed. A better response (CR+PR) was found in patients with type III LN in comparison with those with type IV and type V (p=0.007 and 0.03, respectively). Nephrotic syndrome and renal failure at the time of rituximab administration predicted a worse response (no achievement of CR at 12 months) (p<0.001 and p=0.024, respectively).

CONCLUSION

Rituximab is currently being used to treat refractory systemic autoimmune diseases. Rituximab may be an effective option for patients with lupus nephritis, especially those refractory to standard treatment or who experience a new flare after intensive immunosuppressive treatment.

In situ B cell-mediated immune responses and tubulointerstitial inflammation in human lupus nephritis

The most prevalent severe manifestation of systemic lupus erythematosus is nephritis, which is characterized by immune complex deposition, inflammation, and scarring in glomeruli and the tubulointerstitium. Numerous studies indicated that glomerulonephritis results from a systemic break in B cell tolerance, resulting in the local deposition of immune complexes containing Abs reactive with ubiquitous self-Ags. However, the pathogenesis of systemic lupus erythematosus tubulointerstitial disease is not known. In this article, we demonstrate that in more than half of a cohort of 68 lupus nephritis biopsies, the tubulointerstitial infiltrate was organized into well-circumscribed T:B cell aggregates or germinal centers (GCs) containing follicular dendritic cells. Sampling of the in situ-expressed Ig repertoire revealed that both histological patterns were associated with intrarenal B cell clonal expansion and ongoing somatic hypermutation. However, in the GC histology, the proliferating cells were CD138(-)CD20(+) centroblasts, whereas they were CD138(+)CD20(low/-) plasmablasts in T:B aggregates. The presence of GCs or T:B aggregates was strongly associated with tubular basement membrane immune complexes. These data implicate tertiary lymphoid neogenesis in the pathogenesis of lupus tubulointerstitial inflammation.

Management of systemic lupus erythematosus in Chinese patients

Systemic lupus erythematosus (SLE) is a worldwide disease with prevalence figures ranging from nine to 130 per 100,000 individuals. SLE appears to be more prevalent in certain ethnic groups, such as the African-Americans, African-Caribbeans and Asians. The prevalence of SLE in Hong Kong Chinese was estimated to be 59 out of 100,000 (104/100,000 among women), which is mid-way between that of the Caucasians and African-Americans. Certain organ manifestations, such as lupus nephritis, are more common in Chinese than Caucasians. A recent prospective study reported that the cumulative incidence of renal disease within 5 years of diagnosis of SLE in Chinese patients was 60%. Despite the improvement in survival of SLE in the past few decades, manifestations that are refractory to conventional therapies and treatment related complications are still major challenges in the management of SLE. Novel-therapeutic modalities for SLE should aim at targeting more specifically the immunopathogenetic pathways to achieve higher efficacy and reduce short- and long-term therapy-related toxicities. This review summarizes the management strategies and novel therapeutic modalities in SLE.

Autoantibody-dependent and autoantibody-independent roles for B cells in systemic lupus erythematosus: past, present, and future

It has long been known that B cells produce autoantibodies and, thereby, contribute to the pathogenesis of many autoimmune diseases. Systemic lupus erythematosus (SLE), a prototypic systemic autoimmune disorder, is characterized by high-circulating autoantibody titers and immune-complex deposition that can trigger inflammatory damage in multiple organs/organ systems. Although the interest in B cells in SLE has historically focused on their autoantibody production, we now appreciate that B cells have multiple autoantibody-independent roles in SLE as well. B cells can efficiently present antigen and activate T cells, they can augment T cell activation through co-stimulatory interactions, and they can produce numerous cytokines which affect inflammation, lymphogenesis, and immune regulation. Not surprisingly, B cells have become attractive therapeutic targets in SLE. With these points in mind, this review will focus on the autoantibody-dependent and autoantibody-independent roles for B cells in SLE and on therapeutic approaches that target B cells.

Efficacy and safety of rituximab in moderately-to-severely active systemic lupus erythematosus: the randomized, double-blind, phase II/III systemic lupus erythematosus evaluation of rituximab trial

OBJECTIVE

B cells are likely to contribute to the pathogenesis of systemic lupus erythematosus (SLE), and rituximab induces depletion of B cells. The Exploratory Phase II/III SLE Evaluation of Rituximab (EXPLORER) trial tested the efficacy and safety of rituximab versus placebo in patients with moderately-to-severely active extrarenal SLE.

METHODS

Patients entered with >or=1 British Isles Lupus Assessment Group (BILAG) A score or >or=2 BILAG B scores despite background immunosuppressant therapy, which was continued during the trial. Prednisone was added and subsequently tapered. Patients were randomized at a ratio of 2:1 to receive rituximab (1,000 mg) or placebo on days 1, 15, 168, and 182.

RESULTS

In the intent-to-treat analysis of 257 patients, background treatment was evenly distributed among azathioprine, mycophenolate mofetil, and methotrexate. Fifty-three percent of the patients had >or=1 BILAG A score at entry, and 57% of the patients were categorized as being steroid dependent. No differences were observed between placebo and rituximab in the primary and secondary efficacy end points, including the BILAG-defined response, in terms of both area under the curve and landmark analyses. A beneficial effect of rituximab on the primary end point was observed in the African American and Hispanic subgroups. Safety and tolerability were similar in patients receiving placebo and those receiving rituximab.

CONCLUSION

The EXPLORER trial enrolled patients with moderately-to-severely active SLE and used aggressive background treatment and sensitive cutoffs for nonresponse. No differences were noted between placebo and rituximab in the primary and secondary end points. Further evaluation of patient subsets, biomarkers, and exploratory outcome models may improve the design of future SLE clinical trials.

Current status on B-cell depletion therapy in autoimmune diseases other than rheumatoid arthritis

Since the approval of the chimeric anti-CD20 antibody rituximab for the treatment of adults with severe-to-moderate rheumatoid arthritis after an inadequate response to TNF blockade, B-cell depletion therapy has been used for the treatment of a broad range of refractory autoimmune disorders. Based on current experiences and a literature search, a systematic review and evaluation of the current status of B-cell depletion therapy in autoimmune diseases other than rheumatoid arthritis, including rheumatic, nephrologic, dermatologic and neurologic autoimmune entities, was performed by an international group of experts based at several academic centres. Although important questions remain about the value and place of B-cell depletion in autoimmune diseases other than RA, preliminary data indicate the value of this therapeutic approach in otherwise refractory patients. However, given the lack of robust data from large randomised controlled trials, anti-CD20 therapy should be considered on an individual basis in otherwise refractory patients and its use based on a risk/benefit net calculation.

A perspective on B-cell-targeting therapy for SLE

In recent years, large controlled trials have tested several new agents for systemic lupus erythematosus (SLE). Unfortunately, none of these trials has met its primary outcome. This does not mean progress has not been made. In fact, a great deal has been learned about doing clinical trials in lupus and about the biological and clinical effects of the drugs being tested. Many of these drugs were designed to target B cells directly, e.g., rituximab, belimumab, epratuzumab, and transmembrane activator and calcium modulator and cyclophilin ligand interactor-immunoglobulin (TACI-Ig). The enthusiasm for targeting B cells derives from substantial evidence showing the critical role of B cells in murine models of SLE, as well promising results from multiple open trials with rituximab, a chimeric anti-CD20 monoclonal antibody that specifically depletes B cells (Martin and Chan in Immunity 20(5):517-527, 2004; Sobel et al. in J Exp Med 173:1441-1449, 1991; Silverman and Weisman in Arthritis Rheum 48:1484-1492, 2003; Silverman in Arthritis Rheum 52(4):1342, 2005; Shlomchik et al. in Nat Rev Immunol 1:147-153, 2001; Looney et al. in Arthritis Rheum 50:2580-2589, 2004; Lu et al. in Arthritis Rheum 61(4):482-487, 2009; Saito et al. in Lupus 12(10):798-800, 2003; van Vollenhoven et al. in Scand J Rheumatol 33(6):423-427, 2004; Sfikakis et al. Arthritis Rheum 52(2):501-513, 2005). Why have the controlled trials of B-cell-targeting therapies failed to demonstrate efficacy? Were there flaws in design or execution of these trials? Or, were promising animal studies and open trials misleading, as so often happens? This perspective discusses the current state of B-cell-targeting therapies for human lupus and the future development of these therapies.

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.

Cooperation of B cells and T cells in the pathogenesis of multiple sclerosis

B cells and T cells are two major players in the pathogenesis of multiple sclerosis (MS) and cooperate at various check points. B cells, besides serving as a source for antibody-secreting plasma cells, are efficient antigen presenting cells for processing of intact myelin antigen and subsequent activation and pro-inflammatory differentiation of T cells. This notion is supported by the immediate clinical benefit of therapeutic B cell depletion in MS, presumably abrogating development of encephalitogenic T cells. However, different B cell subsets strongly vary in their respective effect on T cell differentiation which may relate to B cell phenotype, activation status, antigen specificity and the immunological environment where a B cell encounters a naïve T cell in. In this regard, some B cells also have anti-inflammatory properties producing regulatory cytokines and facilitating development and maintenance of other immunomodulatory immune cells, such as regulatory T cells. Reciprocally, differentiated T cells influence T cell polarizing B cell properties establishing a positive feedback loop of joint pro- or anti-inflammatory B and T cell developments. Further, under the control of activated T helper cells, antigen-primed B cells can switch immunoglobulin isotype, terminally commit to the plasma cell pathway or enter the germinal center reaction to memory B Cell development. Taken together, B cells and T cells thus closely support one another to participate in the pathogenesis of MS in an inflammatory but also in a regulatory manner.

A case of Evans syndrome combined with systemic lupus erythematosus successfully treated with rituximab

Evans syndrome is a rare autoimmune disorder with unknown aetiology. Although corticosteroids and/or intravenous immunoglobulin (IVIG) are commonly used in its treatment, no standard strategy has been established. We report here a 44-year-old male with refractory Evans syndrome combined with systemic lupus erythematosus (SLE) who responded well to rituximab. He was admitted to our hospital with severe bleeding caused by worsening of Evans syndrome. Despite treatment with a high-dose corticosteroid and IVIG, his thrombocytopaenia and haemolytic anaemia did not improve. We started rituximab at a dose of 375 mg/m(2) once a week for a total of two doses. There was significant improvement in his thrombocytopaenia and anaemia 1 month after administration of rituximab. Although the total immunoglobulin G (IgG) level did not change, the titres of platelet-associated IgG (PA-IgG) and of an indirect antiglobulin test (IAT) decreased under the treatment with rituximab. It is suggested that rituximab would be a powerful candidate in the treatment of refractory Evans syndrome by depleting abnormal clone-producing autoantibody.

Present and future drug treatments for chronic kidney diseases: evolving targets in renoprotection

At present, there are no specific cures for most of the acquired chronic kidney diseases, and renal transplantation is limited by organ shortage, therefore present efforts are concentrated on the prevention of progression of renal diseases. There is robust experimental and clinical evidence that progression of chronic nephropathies is multifactorial; however, intraglomerular haemodynamic changes and proteinuria play a key role in this process. With a focus on renoprotection, we first examine more established therapies--such as those that modulate the renin-angiotensin-aldosterone system--that can be used for the treatment of proteinuric renal diseases. We then discuss examples of novel drugs and biologics that might be used to target the inflammatory and profibrotic process, and glomerular injury, highlighting results from recent clinical trials.

Pharmacotherapy of lupus nephritis: time for a consensus?

BACKGROUND

The optimal therapy for lupus nephritis has been the subject of considerable debate.

OBJECTIVE

To provide evidence- and expert-based recommendations.

METHODS

To review the literature and the European League Against Rheumatism recommendations.

RESULTS

Risk stratification based on histological, demographical, clinical and laboratory characteristics allows the identification of patients at high risk for loss of renal function, and thus more likely to benefit from more aggressive therapy. Achieving remission within the first months of treatment, irrespective of the agent used, correlates with good long-term renal outcomes; maintenance of remission can be achieved with less toxic therapies. Aggressive management of atherosclerosis risk factors and renoprotective therapy for those patients with chronic renal disease improve long-term survival and prognosis.

The Janus of lupus – benefits and risks with B-cell therapy

Janus was the Roman god of doorways and beginnings. Thus, if B-cell directed therapy is indeed the beginning of a new era in SLE therapy, his would be an appropriate face to regard in this context. But there is a problem: he is a two-faced god. Janus faces in two different directions: past and future, youth and adulthood, barbarism and civility. With respect to biological treatments, perhaps Janus’ faces are the efficacy and the safety dimensions of therapy. In this review, I will consider Janus’ second face, the safety side of B-cell therapy. I will argue that, while safety data have been rather reassuring so far, vigilance is required; and I will point out three specific mistaken assumptions regarding the safety of B-cell directed therapy in SLE.

New treatment strategies for proliferative lupus nephritis: keep children in mind!

Renal involvement is frequent in children with systemic lupus erythematosus (SLE) and carries significant short and long-term morbidity. Treatment strategy in proliferative glomerulonephritis relies mainly on studies in adult patients where conventional treatment regimens including high doses of cyclophosphamide (CYC) and steroids may cause severe side effects. New strategies including sequential therapies of various combinations of low dose CYC, calcineurine inhibitors (cyclosporine or tacrolimus), mycophenolate mofetil, azathioprine, rituximab are now under investigation in adult patients with very few data in children. Organization of international registries and controlled trials in children with lupus nephritis is mandatory to determine long term prognosis and to validate less toxic therapy regimens in childhood.

Targeting of the immune system in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex immune disorder in which loss of tolerance to nucleic acid antigens and other crossreactive antigens is associated with the development of pathogenic autoantibodies that damage target organs, including the skin, joints, brain and kidney. New drugs based on modulation of the immune system are currently being developed for the treatment of SLE. Many of these new therapies do not globally suppress the immune system but target specific activation pathways relevant to SLE pathogenesis. Immune modulation in SLE is complicated by differences in the immune defects between patients and at different disease stages. Since both deficiency and hyperactivity of the immune system can give rise to SLE, the ultimate goal for SLE therapy is to restore homeostasis without affecting protective immune responses to pathogens. Here we review recent immunological advances that have enhanced our understanding of SLE pathogenesis and discuss how they may lead to the development of new treatment regimens.

The biology behind the new therapies for SLE

BACKGROUND

Systemic lupus erythematosus (SLE) is a heterogenous disease with complex pathogenesis.

AIM

In this review, we summarise recent progress in the understanding of SLE pathogenesis and discuss implications for the treatment of SLE patients using standard and experimental medications.

CONCLUSIONS

The discovery that Toll-like receptor signalling and interferon-alpha abundance are central elements of the disease process has led to a new appreciation for hydroxychloroquine as an essential baseline medication. Although much needs to be learned, modulation of the immune system via B-cell depletion is entering clinical practice. Mycophenolate mofetil is an effective and safer alternative to cyclophosphamide for many patients with lupus nephritis. Several other therapeutic approaches are at various stages of preclinical and clinical development. These include anticytokine therapies, co-stimulatory blockade, antigen-specific immune modulation and haematopoietic stem cell transplantation.

B-cell depletion with rituximab in the treatment of autoimmune diseases

In this review, the authors summarise the clinical results obtained after therapy with rituximab in autoimmune diseases, including Graves' disease and Graves' ophthalmopathy. On the basis of qualitative and quantitative analyses of B- and T-cell subsets, and autoantibody levels obtained in other diseases before and after rituximab therapy, the authors interpret the results of the only two clinical investigations of the efficacy of rituximab in the treatment of Graves' disease and Graves' opthalmopathy reported so far. No significant effect on autoantibody levels was observed. Nonetheless, 4 out of 10 Graves' disease patients remained in remission 400 days after rituximab treatment versus none in the control group, and remarkable improvements in the eye symptoms of patients with Graves' ophthalmopathy were observed. This supports a role for B cells in the pathogenesis of Graves' ophthalmopathy, and the authors suggest that abrogation of antigen presentation by B cells accounts for the effect of rituximab. In the authors' opinion, the use of rituximab in severe Graves' ophthalmopathy could be contemplated.

[Lupus membranous nephropathy]

The systemic lupus erythematosus associated renal hystopathological complexity and its clinical translation, are still a diagnostic challenge with therapeutical implications which, however, include new options in the last few years within the immunosupression compass. The new insights elicited by research work attempt to give some light on renal biopsy performance, its relationship with the arrogated clinical spectrum, its prognosis and on the lupus nephropathy new treatments currently under ongoing clinical trials, some of them showing encouraging results. The lupus membranous nephropathy, recognized as an anatomopathological entity more than 4 decades ago, means a specific pattern in the whole renal lupus histologycal range and, in many aspects, an etiopathogenic enigma.

Rituximab in the treatment of anti-neutrophil cytoplasm antibody associated vasculitis and systemic lupus erythematosus: past, present and future

Nephritis is the most frequent severe manifestation of anti-neutrophil cytoplasm antibody associated (ANCA) systemic vasculitis (AASV) and systemic lupus erythematosus (SLE) and carries substantial morbidity. Although immunosuppressive medications and glucocorticoids are effective at inducing remission, patients still suffer from high relapse rates and experience significant treatment-related toxicity. Rituximab (RTX), a chimeric antibody directed against CD20, found on B lymphocytes, shows potential as a treatment for both AASV and SLE. Although direct comparisons with standard therapies are currently unavailable, patients in several studies of refractory and relapsing disease have achieved a remission despite the failure of standard therapies. These reports are supported by several lines of experimental evidence that underlie the rationale for using targeted B-cell therapies and have improved our understanding of the pathogenesis of these complex diseases. Future randomized control trials and long-term follow-up studies are required to confirm the role of RTX and other B-cell targeting therapies in AASV and SLE.

A multicenter phase I/II trial of rituximab for refractory systemic lupus erythematosus

Although corticosteroids and immunosuppressants are widely used for the treatments of systemic lupus erythematosus (SLE), safer and more effective therapies are prerequisite. We and others have reported that anti-CD20 antibody rituximab targeting B cells are effective for refractory SLE and, therefore, safety and clinical efficacy of rituximab in SLE was evaluated by a multicenter phase I/II clinical trial. An open-label, multicenter study of 15 patients with active and refractory SLE (total British Isles Lupus Assessment Group [BILAG] score 8 to 17) was conducted. Rituximab was administered to 5 SLE patients as 4 infusions of 500 mg/body every week and to 10 SLE patients as 2 infusions of 1000 mg/body every other week. Assessment of safety, infusion reactions and adverse effects was used as the primary outcome for clinical tolerability and was evaluated by 28 weeks. Rituximab was well tolerated, with most experiencing no significant adverse effects. B cells rapidly reduced in all patients and remained low until 6 months post-treatment. Four patients developed human antichimeric antibodies without affecting efficacy of rituximab. Changes in routine safety laboratory tests clearly related to rituximab were not observed. Nine among 14 evaluable patients achieved the major or partial clinical response of BILAG score and prednisolone dose significantly decreased at the 28 weeks. Rituximab therapy appears to be safe for the treatment of active SLE patients and holds significant therapeutic promise, at least for the majority of patients experiencing profound B-cell depletion.

Utilidad del rituximab en el tratamiento de pacientes con enfermedades sistémicas autoinmunitarias

BACKGROUND AND OBJECTIVE

To assess the value of rituximab in systemic autoimmune diseases which are refractory to others treatments.

PATIENTS AND METHOD

Prospective study on 12 patients -7 with systemic lupus erythematosus (SLE), 4 with Wegener's granulomatosis (WG), and 1 with overlapping connective disease and autoimmune thrombocytopenia-, controlled in a specialized unit of a tertiary hospital. Four weekly doses of rituximab, 2 biweekly doses of cyclophosphamide, and glucocorticoids were administered to all patients, and other immunosuppressants were also administered as considered necessary in each case.

RESULTS

Mean follow up after treatment with rituximab was 12.8 moths for SLE patients and 12.3 for WG patients. In SLE patients, proteinuria was reduced below 1 g daily in 5 cases (83%), with a clear parallel improvement in the urinary sediment. Serositis was resolved in both cases. One patient required 3 treatment cycles to obtain an adequate response and another required a second cycle for relapse. Only one patient with WG had a favorable response. The patient treated for autoimmune thrombocytopenia had a favorable response, with no relapses, and creatine-kinase levels also tended to return to normal. There were 2 serious adverse events (terminal renal failure and serious colitis in a patient with SLE, and death of one patient with WG), that were not adjudicated directly to rituximab. Immunoglobulin levels did not change substantially. There were no infusion reactions or associated infections.

CONCLUSIONS

Rituximab was useful in patients with SLE refractory to other immunosuppressants. On the contrary, its efficacy in WG was limited. The response of thrombocytopenia was complete and maintained.