A retrospective seven-year analysis of the use of B cell depletion therapy in systemic lupus erythematosus at University College London Hospital: the first fifty patients

Disease-modifying therapies in systemic lupus erythematosus for extrarenal manifestations

Our 2022 published working definition of disease modification in systemic lupus erythematosus (SLE) was 'minimising disease activity with the fewest treatment-associated toxicities and slowing or preventing organ damage progression'. The objective of this review was to classify current SLE treatments according to the proposed non-renal disease modification criteria excluding toxicities. Based on a review of select clinical trial (n=32) and observational study (n=54) publications for 14 SLE medications across different therapeutic classes, and the authors' clinical experience, we evaluated disease modification potential as per the proposed framework at three time points. Specific criteria used to determine disease modification potential included a drug's capacity to reduce: (1) non-renal disease activity, (2) severe flares, (3) use of steroids/immunosuppressants and (4) organ damage accrual. Criteria 1-3 were assessed at 1 year and 2-5 years and, when positive, were considered evidence for disease modification potential; criterion 4 was used to confirm disease modification at >5 years. Each treatment received one of four mutually exclusive designations at each time point: (a) criterion met, (b) indications of criterion met despite insufficient evidence in the literature, (c) inconclusive and (d) no available supportive data. This review excludes an assessment of potential toxicities. Eight of the 14 SLE treatments met ≥1 disease modification criteria up to year 5. Hydroxychloroquine improved overall survival at >5 years, suggesting long-term disease modification, but no data on specific organ systems were reported. Belimumab was the only treatment to meet all criteria. Belimumab and hydroxychloroquine met disease modification definitions across three time points. Evidence for other SLE therapies was incomplete, particularly at >5 years. Future studies are warranted for other treatments to meet the disease modification criteria. We discuss challenges to classification and possible updates to our published criteria.

Systemic lupus erythematosus (SLE) associated uveitis in India - A case series

PURPOSE

To report the uveitic manifestations of patients with systemic lupus erythematosus (SLE).

METHODS

This was a retrospective analysis of all SLE cases with ocular manifestations seen by a single ophthalmologist between 2015 and December 2021.

RESULTS

In total, seven patients with a median age of 40 (range 18-50) years were included in the study. Female (85.7%) predominance was noted. Ocular findings were bilateral in 71% (five patients) of cases. Majority (10 eyes, 83%) of the patients had retinal vasculitis as the common finding. Antinuclear antibodies were positive in all the patients. The vision improved in two (16.6%) eyes, was stable in eight (66%) eyes, and worsened in one (8%) eye. All the patients were treated with oral steroids along with immunosuppressive agents.

CONCLUSION

Though SLE is rare cause of uveitis, it can be associated with significant ocular morbidity. Hence, early diagnosis and treatment can salvage vision in many cases.

CD19 Chimeric Antigen Receptor T Cell Treatment: Unraveling the Role of B Cells in Systemic Lupus Erythematosus

B cell generation of autoantibodies is a crucial step in the pathogenesis of systemic lupus erythematosus (SLE). After their differentiation in the bone marrow, B cells populate the secondary lymphatic organs, where they undergo further maturation leading to the development of memory B cells as well as antibody-producing plasmablasts and plasma cells. Targeting B cells is an important strategy to treat autoimmune diseases such as SLE, in which B cell tolerance is disturbed and autoimmune B cells and autoantibodies emerge. This review discusses the functional aspects of antibody- and cell-based B cell-depleting therapy in SLE. It thereby particularly focuses on lessons learned from chimeric antigen receptor (CAR) T cell treatment on the role of B cells in SLE for understanding B cell pathology in SLE. CAR T cells model a deep B cell depletion and thereby allow understanding the role of aberrant B cell activation in the pathogenesis of SLE. Furthermore, the effects of B cell depletion on autoantibody production can be better described, ie, explaining the concept of different cellular sources of (auto-) antibodies in the form of short-lived plasmablasts and long-lived plasma cells, which differ in their susceptibility to B cell depletion and require different targeted therapeutic approaches. Finally, the safety of deep B cell depletion in autoimmune disease is discussed.

Rituximab as add-on therapy in patients with resistant lupus nephritis who have failed induction or maintenance therapy with other agents: A real-world experience from a single center in Mumbai

BACKGROUND

Lupus nephritis (LN) is associated with poor outcomes and a significant risk of progression to end-stage renal disease (ESRD). Some patients with resistant LN do not respond adequately to current treatment options and need alternative strategies or therapies.

OBJECTIVE

The objective is to evaluate the efficacy and safety of rituximab as a re-induction therapy (Re-RTX) followed by maintenance therapy for patients with resistant LN.

METHODS

Twenty-four patients with resistant LN (failed initial induction therapy or severe relapse after remission) were analyzed. Re-RTX was co-administered with other immunosuppressants. The primary KDIGO criteria outcomes included renal response (complete and partial), disease progression, relapses, and infections.

RESULTS

The median age was 28 years (IQR 24.5-42), and the female-to-male ratio was 11:1. All patients had active LN, and 91.3% had proliferative LN. Baseline creatinine was 1.075 mg% (IQR 0.7-1.38), and mean urine protein-to-creatinine ratio (UPCR) was 4.9 (IQR 2.8-6.65). Of the patients receiving RTX as re-induction therapy, 66.6% (16/24) had failed initial induction therapy with other immunosuppressants, whereas 33.3% (8/24) had severe relapse during maintenance therapy.Re-RTX had a favorable renal response at 6 months, with 91.7% of the patients responding (20.8% complete response and 70.8% partial response). At 12 months, 58.3% of the patients maintained a renal response (25% complete response and 33.3% partial response). Approximately one-third of patients relapsed within a year.Fourteen patients (58.3%) continued RTX maintenance therapy with two different treatment regimens. At 6 months, Regimen-1 (500 mg every 6 months) resulted in a partial response in 43% (3/7) and relapse in 57% (4/7) of patients. Regimen 2 (1 g dose per year) achieved a complete response in 28.5% (2/7) and a partial response in 71.5% (5/7) with no relapses at 6 months.At a median follow-up of 29 months, adverse renal outcomes were observed in 29.16% of the patients with progression to advanced chronic kidney disease (CKD) or end-stage renal disease (ESRD). The overall use of Re-RTX was considered safe, with a reported infection prevalence of 16%, which is comparable to the existing data.

CONCLUSION

Re-RTX demonstrated efficacy and safety as an induction therapy for resistant LN. However, the response waned after 1 year, underscoring the need for optimized maintenance therapy.

From systemic lupus erythematosus to lupus nephritis: The evolving road to targeted therapies

Systemic lupus erythematosus is a chronic autoimmune disease characterized by loss of tolerance against nuclear and cytoplasmic self-antigens, induction of immunity and tissue inflammation. Lupus nephritis (LN), the most important predictor of morbidity in SLE, develops in almost 30% of SLE patients at disease onset and in up to 50-60% within the first 10 years. Firstly, in this review, we put the pathogenic mechanisms of the disease into a conceptual frame, giving emphasis to the role of the innate immune system in this loss of self-tolerance and the induction of the adaptive immune response. In this aspect, many mechanisms have been described such as dysregulation and acceleration of cell-death pathways, an aberrant clearance and overload of immunogenic acid-nucleic-containing debris and IC, and the involvement of antigen-presenting cells and other innate immune cells in the induction of this adaptive immune response. This result in a clonal expansion of autoreactive lymphocytes with generation of effector T-cells, memory B-cells and plasma cells that produce autoantibodies that will cause kidney damage. Secondly, we review the immunological pathways of damage in the kidney parenchyma, initiated by autoantibody binding and immune complex deposition, and followed by complement-mediated microvascular injury, activation of kidney stromal cells and the recruitment of leukocytes. Finally, we summarize the rationale for the treatment of LN, from conventional to new targeted therapies, focusing on their systemic immunologic effects and the minimization of podocytary damage.

Focal segmental glomerular sclerosis can be effectively treated using an intensive B-cell depletion therapy

Background

Focal segmental glomerular sclerosis (FSGS) is a histologic lesion rather than a specific disease entity and represents a cluster of different conditions affecting both children and adults that includes primary, secondary and genetically mediated forms. These forms can be distinguished by electron microscopy and genetic assessment and show different responsiveness to steroids and immunosuppressants. Despite some promising effects of rituximab in nephrotic syndrome in children, the results in adults with FSGS are disappointing. Our group previously explored the effectiveness of rituximab in eight adult patients with unselected forms of FSGS and achieved a consistent reduction in proteinuria in one case. Following this experience, we developed an alternative therapeutic option intended to enhance the potential of rituximab with the support of other synergic drugs. We herein report the results of this therapeutic protocol (six administrations of rituximab plus two of intravenous cyclophosphamide plus glucocorticoids) in seven prospectively enrolled patients with extensive podocyte effacement and recurrent relapses or steroid dependence.

Results

Patients had a median baseline serum creatinine level of 2.2 mg/dl (range 1-4.7) that decreased to 1.1 mg/dl (range 0.9-2.2) and 1.1 mg/dl (range 0.75-2.21) after 3 and 6 months, respectively, and remained unchanged at 12 months. Three of five patients with renal failure turned to normal function while the other two patients maintained a stable impairment after 18 and 52 months. The median proteinuria decreased from 6.1 g/24 h to 3.5, 3.5 and 1.9 g/24 h at 3, 6 and 12 months, respectively. Specifically, five of seven patients had a partial response at 12 months and became non-nephrotic. One of them had a complete response at 18 months and was still in complete remission at the last follow-up visit at 36 months. Proteinuria persisted unchanged in two of seven patients with a genetic-related disease. No serious late adverse events were observed.

Conclusions

Our results show that intensive B-cell depletion therapy is able to reverse the nephrotic syndrome of steroid-dependent or frequently relapsing adult patients with putatively idiopathic FSGS (i.e. with extensive podocyte effacement).

Off-label use of rituximab in patients with systemic lupus erythematosus with extrarenal disease activity: a retrospective study and literature review

Introduction

Off-label rituximab is commonly used for patients with systemic lupus erythematosus (SLE) with extrarenal disease activity.

Methods

The outcomes and tolerability of rituximab in adult patients with non-renal SLE treated at our hospital from 2013 to 2020 were described. Patients were followed-up until December 2021. Data were retrieved from electronic medical records. Response was classified into complete, partial or no response according to the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI 2 K)-based definitions.

Results

A total of 44 cycles were administered to 33 patients. Median age was 45 years and 97% were female. Median follow-up was 5.9 years (IQR 3.7-7.2). The most frequent symptoms that motivated rituximab use were thrombocytopenia (30.3%), arthritis (30.3%), neurological manifestations (24.2%) and cutaneous lupus (15.2%). After most treatment cycles a partial remission was achieved. The median SLEDAI-2 K score declined from 9 (IQR 5-13) to 1.5 (IQR 0-4) (p < 0.00001). The median number of flares significantly declined after receiving rituximab. Platelet counts significantly improved in patients with thrombocytopenia and patients with skin disorders or neurological manifestations also had a partial or complete response. Only 50% of patients with a predominant joint involvement had either a complete or a partial response. The median time to relapse after the first cycle was 1.6 years (95% CI, 0.6-3.1). Anti-dsDNA levels decreased significantly after rituximab from a median of 64.3 (IQR 12-373.9) to 32.7 (IQR 10-173), p = 0.00338. The most frequent adverse events were infusion-related reactions (18.2%) and infections (57.6%). All patients needed further treatment to maintain remission or to treat new flares.

Conclusion

A partial or complete response was documented after most rituximab cycles in patients with non-renal SLE. Patients with thrombocytopenia, neurolupus, and cutaneous lupus had better response than those with a predominant joint involvement.

Systemic Lupus Erythematosus: New Diagnostic and Therapeutic Approaches

Systemic lupus erythematosus (SLE) is a devastating autoimmune disease that can result in substantial morbidity and mortality. Diagnosis and treatment of SLE are clinical challenges. Patient presentation and response to therapy are heterogeneous because of the complex immune dysregulation that results in SLE disease pathogenesis. An intricate interplay between genetic risk and skewing of adaptive and innate immune system responses leads to overproduction of type I interferons and other cytokines, complement activation, immune-complex deposition, and ultimately inflammation and tissue damage. Here, we review the classification criteria as well as standard and emerging diagnostic tools available to identify patients with SLE. We then focus on medical management, including novel therapeutics, nonpharmacologic interventions, and comorbidity management.

Rituximab in the real-world treatment of lupus nephritis: A retrospective cohort study in Japan

OBJECTIVES

Although recommended in established international guidelines for lupus nephritis (LN), rituximab is not officially approved for LN treatment, making all such use off-label. The Japan College of Rheumatology (JCR) conducted a retrospective observational study on real-world efficacy and safety of rituximab treatment for LN in Japan.

METHODS

Clinical data were collected from 47 hospitals for LN patients treated with rituximab to retrospectively investigate dosing schedule, efficacy, and safety.

RESULTS

This retrospective analysis included 115 patients: 84 (73%) received 375 mg/m2 weekly up to four doses, and 31 (27%) received 1000 mg/body in one or two doses 2 weeks apart. Rituximab significantly improved findings for urinalysis, systemic lupus erythematosus serology, and systemic lupus erythematosus disease activity and was assessed as 'extremely effective' in 24.8% of patients and 'effective' in 60.2%. The renal response by the JCR-I criteria was 52.5% for overall response rate (ORR) (complete renal response rate 20.8% and partial renal response rate 31.7%) and that by the JCR-II criteria was 49.5% (21.8% and 27.7%, respectively). Corticosteroid dose was significantly reduced. Rituximab was well tolerated, with frequent but manageable adverse events of infusion reaction and infection.

CONCLUSIONS

Rituximab is effective for the treatment of Japanese patients with LN refractory to conventional therapy.

Review of an Anti-CD20 Monoclonal Antibody for the Treatment of Autoimmune Diseases of the Skin

Biologic therapies targeting B-cells are emerging as an effective strategy to treat a variety of immune-mediated diseases. One of the most studied B-cell-targeted therapies is rituximab, an anti-CD20 monoclonal antibody that exemplifies B-cell depletion therapy and has served as the prototype for other anti-CD20 monoclonal antibodies and the development of biosimilars. While there are multiple studies on the use of rituximab in dermatology, a comprehensive review of rituximab therapy in autoimmune skin conditions is lacking. In this literature review, we summarize indications, treatment efficacy, and safety of rituximab among common autoimmune diseases of the skin: pemphigus vulgaris, cutaneous lupus erythematous, dermatomyositis, systemic sclerosis, thyroid dermopathy, autoimmune pemphigoid diseases, and cutaneous vasculitis diseases. Existing data on rituximab support the approach of rituximab, biosimilars, and newer B-cell-targeting therapies in immune-mediated cutaneous diseases. Overall, rituximab, which targets CD20, provides an effective alternative or concomitant option to traditional immunosuppressants in the management of various autoimmune diseases of the skin. Further studies are necessary to expand the understanding and possible utility of B-cell-targeted therapies among autoimmune skin diseases.

Efficacy of belimumab combined with rituximab in severe systemic lupus erythematosus: study protocol for the phase 3, multicenter, randomized, open-label Synbiose 2 trial

Background

Belimumab, an anti-B-cell activating factor antibody, is approved for the treatment of auto-antibody positive systemic lupus erythematosus with a high degree of disease activity. Anti-CD20 B cell depletion with rituximab is used in refractory SLE as well, although with variable responses. We hypothesized that incomplete B cell depletion, related to a surge in BAFF levels following rituximab treatment, can cause ongoing disease activity and flares. The Synbiose 1 study primarily focused on immunological effects and shows the preliminary clinical benefit of combined rituximab and belimumab in SLE. The Synbiose 2 study will evaluate the clinical efficacy of combining belimumab with rituximab in patients with severe SLE, allowing the tapering of prednisolone and mycophenolate.

Methods

Synbiose 2 is a phase 3, multicenter, randomized, controlled, open-label 2-year clinical trial. Seventy adults with severe SLE including lupus nephritis will be randomized 1:1 to receive either standard of care consisting of prednisolone and mycophenolate as induction and maintenance treatment, or belimumab and rituximab combined with standard of care as induction treatment, followed by prednisolone and belimumab as maintenance treatment. The primary objective is to assess whether combined B cell therapy will lead to a reduction of treatment failure. Secondary endpoints are complete and partial clinical and renal response and the improvement of SLE-specific autoimmune phenomena. Safety endpoints include the incidence of adverse events, with a special interest in infections.

Discussion

The Synbiose 2 trial is the first multicenter phase 3 clinical trial investigating combined B cell targeted therapy in SLE, including lupus nephritis. The outcome of this study will provide further evidence for the clinical efficacy of this new treatment strategy in severe SLE.

Trial registration

ClinicalTrials.gov NCT03747159. Registered on 20 November 2018.

Efficacy and safety of an anti-CD20 monoclonal antibody, rituximab, for lupus nephritis: A meta-analysis

BACKGROUND

The efficacy and safety of rituximab (RTX) for lupus nephritis are still a controversial issue.

METHODS

We systematically searched MEDLINE, EMBASE, and the Cochrane Library databases for all clinical controlled studies.

RESULTS

Six studies with 588 patients were included in our meta-analysis. RTX increased total renal remission rates (TR, odds ratio [OR] 2.16, 95% CI 1.31 to 3.55, P = .003) and complete renal remission rate (CR, OR 2.42, 95% CI 1.18 to 4.94, P = .02) compared with the control group. Subgroup analyses showed that rituximab was more effective at increasing the rate of TR and CR for lupus nephritis patients compared with mycophenolate mofetil (TR, OR 4.6, 95% CI 1.29 to 16.47, P = .02; CR, OR 2.56, 95% CI 1.19 to 5.47, P = .02) and cyclophosphamide (TR, OR 2.89, 95% CI 1.31 to 6.40, P = .009; CR, OR 2.75, 95% CI 1.19 to 6.4, P = .02). Rituximab also had advantage in reducing Systemic Lupus Erythematosus Disease Activity Index score (-2.49, 95% CI -3.77 to -1.22, P = .0001). There were no significant differences between the RTX group and control group on the change of proteinuria (-0.36 g/d, 95% CI -0.71 to -0.00 g/d, P = .05) and serum creatinine (0.13 mg/dL, 95% CI -0.15 to 0.42 mg/dL, P = .36). RTX treatment did not increase the risk of adverse events compared to the control group.

CONCLUSIONS

This study provides clear beneficial effects of RTX in patients with lupus nephritis. In addition, RTX therapy did not increase the risk of adverse events compared to the control group.

Assessing outcomes in a lupus nephritis cohort over a 40-year period

OBJECTIVES

To characterize a LN cohort over 40 years, assessing its evolution, analysing two major outcomes: the development of end-stage renal disease and mortality rates in the first 5 years after LN diagnosis.

METHODS

An observational retrospective study of patients with LN, followed up from 1975 at University College Hospital. Patients were divided into four groups, depending on the decade of LN diagnosis: 1975-1985 (D1), 1986-1995 (D2), 1996-2005 (D3) and 2006-2015 (D4). Comparison between groups was performed with respect to demographic, clinical, serological and histological characteristics and outcome.

RESULTS

Two hundred and nineteen patients with LN were studied. There was a change in ethnic distribution, with a decreasing proportion of Caucasians (58.6% in D1 to 31.3% in D4, P = 0.018) and increase in African-ancestry (17.2% in D1 to 39.6% in D4, P = 0.040). Serological and histological patterns changed throughout time, with a reduction in class IV nephritis (51.7% in D1 to 27.1% in D4, P = 0.035), and increase in class II nephritis (10% in D2 to 18.8% in D4, P = 0.01) and anti-extractable nuclear antigen antibody positivity (17.2% in D1 to 83.3% in D4, P = 0.0001). The 5-year mortality rates decreased from D1 (24.1%) to D2 (4%), stabilizing for the next 30 years. The 5-year progression to end-stage renal disease remained stable over the decades.

CONCLUSION

Despite the changes in treatment of LN in the past 20 years, we have reached a plateau in 5-year mortality and progression to end-stage renal disease rates, suggesting that new therapeutic and management approaches, and strategies to enhance adherence, are needed to improve outcomes further in LN patients.

Management of inflammatory neurologic and psychiatric manifestations of systemic lupus erythematosus: A systematic review

BACKGROUND

The neurological and psychiatric manifestations of systemic lupus erythematosus (NPSLE) are a heterogeneous group of conditions with variable clinical presentation and significant morbidity and mortality.

OBJECTIVES

Our aim was to comprehensively assess and present the evidence for treatments used in the management of inflammatory NPSLE.

METHODS

Medline, Embase, CINHAL and Cochrane CENTRAL were searched from 1990 to end of March 2019 using key words that related to NPSLE and treatment. Included studies comprised clinical trials, observational studies or case series with ≥5 patients and sufficient data related to treatment and outcome in NPSLE patients.

RESULTS

There were 7222 studies identified in the search, of which 90 were included in the review. There was a notable paucity of clinical trials, with only two randomised controlled trials and one pilot study. Treatment categories included corticosteroids (14 studies), cyclophosphamide (18 studies), synthetic DMARDs (7 studies), biologic therapies (14 studies), therapeutic plasma exchange (6 studies), intravenous immunoglobulin (2 studies), autologous stem cell transplant (3 studies), other therapies (8 studies), combination therapies (6 studies), studies with grouped outcome data (5 studies) and observational studies with therapy-specific associations (7 studies). Corticosteroids are accepted as first line treatment in NPSLE and there is low-moderate evidence supporting their benefit. Moderate evidence, based on consistent data in numerous studies and some trial data, supports the use of cyclophosphamide in the treatment of NPSLE. Limited data support some synthetic DMARDs such as mycophenolate, azathioprine and intrathecal methotrexate. In refractory disease, low-moderate evidence supports rituximab therapy and limited evidence supports benefit following autologous stem cell transplant. Regarding adjuvant treatments, limited evidence favours addition of plasma exchange, intravenous immunoglobulin and hydroxychloroquine. There exists very limited data for other therapies.

CONCLUSION

There are multiple therapeutic options for the management of inflammatory NPSLE including systemic, biologic and interventional therapies; however, currently there is a paucity of high-quality trial data to guide firm recommendations. In order to better understand the optimal treatment of NPSLE and its different subtypes, further well-designed clinical trials are needed.

Low-dose rituximab therapy in steroid-refractory thrombocytopenia due to systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease, characterized by multi-organ symptomatology. 16% of the patients with autoimmune thrombocytopenia have SLE and are associated with high mortality. Intravenous methylprednisolone or high-dose steroids are the first-line treatments in those patients who experienced life-threatening bleeding or have a severely low platelet count, whereas a second line includes splenectomy, as well as other immunosuppressive agents as monotherapy or combined therapy, including azathioprine, cyclophosphamide, cyclosporine, and mycophenolate mofetil. However, response rates of these therapies vary considerably. Rituximab (RTX) became a useful tool in the treatment of autoimmune diseases, due to the decrease of autoantibodies production. In addition, there is evidence that low doses of RTX (100 mg IV per week for 4 weeks) can have a similar effect compared to the standard dose. The objective of this study was to describe the response to low doses of RTX in patients with lupus-induced thrombocytopenia. We present a report of four female patients with newly diagnosed SLE, accompanied by purpuric syndrome and severe thrombocytopenia (< 30 × 109/L) as the clinical debut that was refractory to glucocorticoids (GC) therapy and treated with low doses of RTX. By week 5, complete response (> 100 × 109/L) was achieved in two patients, partial response (> 50 × 109/L) in 1 patient, and no response in one patient. There is little information on the treatment of SLE-associated autoimmune thrombocytopenia. The most extensive study found at the time of our search was the study of 10 Asian patients. They found that 80% of the patients responded by week four and maintained until week 24 of follow-up. At week 36, a follow-up for two patients showed relapse; this occurred on patients with the most disease duration (> 5 years) and was associated with a lower response rate. In contrast, our study with four patients found that half of them presented a complete response: one patient added concomitant therapy with azathioprine (AZA) and another patient without the concomitant therapy. A third patient with a partial improvement, this was seen by week five of treatment. Moreover, a fourth patient who did not have a response by week five of treatment presented a clinical response in subsequent appointments with a count of > 100 at week 24. Those patients who required concomitant use of AZA were patients who had positive antiphospholipid serology. The use of low-dose RTX for the management of severe thrombocytopenia refractory to GC in patients with SLE has a good response. It could be a safe, economical, and effective therapy.

Effects of AS2819899, a novel selective PI3Kδ inhibitor, in a NZB/W F1 mouse lupus-like nephritis model

Phosphoinositide 3-kinases generate lipid-based second messengers that control an array of intracellular signaling pathways. In particular, phosphoinositide 3-kinases delta (PI3Kδ) is expressed primarily in hematopoietic cells and plays an important role in B-cell development and function. B cells play a critical role in autoimmune diseases by producing autoantibodies. Studies have therefore increasingly focused on PI3Kδ as a therapeutic target for the treatment of inflammatory and autoimmune diseases. One such autoimmune disease is systemic lupus erythematosus (SLE). SLE is a chronic systemic autoimmune disease with repeated recurrence and remission, and autoantibodies play an important role in its pathogenesis. Here, we examined the pharmacological profile of the novel PI3Kδ selective inhibitor AS2819899 and investigated its therapeutic potential against SLE in a NZB/W F1 mouse lupus-like nephritis model, a widely-used SLE mouse model. AS2819899 prevented B and T cell activation in vitro, and inhibited antibody production in a T-cell independent de novo antibody production mouse model. In the spontaneous NZB/W F1 mouse model, AS2819899 treatment significantly reduced anti-dsDNA antibody titers and improved kidney dysfunction. Further, AS2819899 inhibited the memory recall reaction in a T-cell dependent antibody production mouse model, suggesting that AS2819899 can potentially maintain remission of SLE. Moreover, we identified a pharmacodynamics marker for AS2819899 that may be useful in clinical studies. These results indicate that AS2819899 may be an attractive therapeutic candidate for SLE, including the maintenance of remission.

Belimumab and Rituximab in Systemic Lupus Erythematosus: A Tale of Two B Cell-Targeting Agents

Given the centrality of B cells to systemic lupus erythematosus (SLE), it stands to reason that a candidate therapeutic agent that targets B cells could be efficacious. Both rituximab, a monoclonal antibody (mAb) that binds to CD20 on the surface of B cells, and belimumab, a mAb that binds and neutralizes the B cell survival factor BAFF, have been extensively studied for the treatment of SLE. Despite the greater ability of rituximab to deplete B cells than that of belimumab, randomized controlled trials of rituximab in SLE failed to reach their primary clinical endpoints, whereas the primary clinical endpoints were reached in four independent phase-III clinical trials of belimumab in SLE. Accordingly, belimumab has been approved for treatment of SLE, whereas use of rituximab in SLE remains off-label. Nevertheless, several case series of rituximab have pointed to some utility for rituximab in treating SLE. In this review, we provide a concise summary of the factors that led to belimumab's success in SLE as well an analysis of the elements that may have contributed to the lack of success seen in the rituximab randomized controlled trials in SLE.

Acquired Immunodeficiency from Maternal Chemotherapy and Severe Primary Pneumocystis Infection in an Infant

Pneumocystis jirovecii is recognized as an opportunistic pathogen in immunosuppressed patients. We report a case of severe Pneumocystis pneumonia (PCP) in an infant with acquired combined immunodeficiency secondary to maternal chemotherapy exposure during the second and third trimesters of pregnancy. The infant required cardiorespiratory support with veno-venous extracorporeal membrane oxygenation (VV-ECMO) for severe respiratory failure. This case highlights the potential for severe acquired immunodeficiency in this patient cohort and further postnatal surveillance is highly recommended.

An Update on Antibodies to Necleosome Components as Biomarkers of Sistemic Lupus Erythematosus and of Lupus Flares

Systemic lupus erythematosus (SLE) is an autoimmune disease with variable clinical expression. It is a potentially devastating condition affecting mostly women and leading to clinically unpredictable outcomes. Remission and flares may, in fact, alternate over time and a mild involvement limited to few articular sites may be followed by severe and widespread organ damage. SLE is the prototype of any autoimmune condition and has, for this reason, attracted the interest of basic immunologists. Therapies have evolved over time and clinical prognosis has, in parallel, been improved. What clinicians still lack is the possibility to use biomarkers of the disease as predictors of outcome and, in this area, several studies are trying to find solutions. Circulating autoantibodies are clearly a milestone of clinical research and the concrete possibility is to integrate, in the future, classical markers of activation (like C3) with target organ autoantibodies. Anti-dsDNA antibodies represent a basic point in any predictive attempt in SLE and should be considered the benchmark for any innovative proposal in the wide field of target organ pathologies related to SLE. DNA is part of the nucleosome that is the basic unit of chromatin. It consists of DNA wrapped around a histone octamer made of 2 copies each of Histone 2A, 2B, 3, and 4. The nucleosome has a plastic organization that varies over time and has the potential to stimulate the formation of antibodies directed to the whole structure (anti-nucleosome) or its parts (anti-dsDNA and anti-Histones). Here, we present an updated review of the literature on antibodies directed to the nucleosome and the nucleosome constituents, i.e., DNA and Histones. Wetriedto merge the data first published more than twenty years ago with more recent results to create a balanced bridge between old dogma and more recent research that could serve as a stimulus to reconsider mechanisms for SLE. The formation of large networks would provide the chance of studying large cohorts of patients and confirm what already presented in small sample size during the last years.

Assessment of Response to B-Cell Depletion Using Rituximab in Cutaneous Lupus Erythematosus

Importance

Cutaneous lupus erythematosus (CLE) can be severe and treatment resistant. B-cell depletion therapy (BCDT) with rituximab is well recognized in organ involvement in systemic lupus erythematosus (SLE), but its efficacy in cutaneous manifestations is less well established.

Objective

To evaluate the outcomes of BCDT in CLE and its clinical subtypes in the setting of associated SLE.

Design, Setting, and Participants

This single-center, retrospective, cohort study was performed at the adult tertiary referral Rheumatology Department of University College London Hospital, London, United Kingdom, from January 1, 2000, through March 31, 2016, with 12-month follow-up completed on March 31, 2017. Adult patients with carefully classified CLE and mucocutaneous British Isles Lupus Assessment Group (BILAG) grade A or B who were treated with rituximab BCDT were selected from a prospective database of 709 patients with SLE. Data were analyzed from April through December 2017.

Main Outcomes and Measures

Clinical response was examined at 6 and 12 months after treatment for CLE and its subtypes acute CLE (ACLE), subacute CLE (SCLE), chronic CLE (CCLE), and nonspecific LE (NSLE). A complete response was defined as achieving BILAG grade D; partial response, BILAG grade C; stable disease, no change; and disease flare, change from BILAG grade C or D to grade A or B.

Results

A total of 50 patients with SLE were eligible for inclusion; mean (SD) age at diagnosis was 26.9 (12.1) years, and 49 (98%) were women. Twenty-one patients had ACLE; 6, SCLE; 10, CCLE; and 11, NSLE (including 2 with concurrent ACLE and CCLE). Overall, at 6 months, 38 patients (76%) improved their mucocutaneous BILAG grade A or B status, including 20 (40%) with a complete response. At 12 months, 28 of 46 patients (61%) maintained this response, including 24 (52%) with a complete response. Two of 6 patients (33%) with SCLE showed a complete response at 6 and 12 months. Five of 12 patients (42%) with CCLE showed a complete response at 6 months, and 5 of 11 (45%), at 12 months. Fifteen patients (30%) required further rituximab therapy within 12 months for cutaneous involvement.

Conclusions and Relevance

B-cell depletion therapy using rituximab appears effective in patients with SLE and severe active CLE; however, outcomes are variable in those with SCLE and CCLE subtypes.

Unmet Needs in the Pathogenesis and Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease with a prevalence of approximately 1 in 1000. Over the last 30 years, advances in treatment such as use of corticosteroids and immunosuppressants have improved life expectancy and quality of life for patients with lupus and the key unmet needs have therefore changed. With the reduced mortality from disease activity, development of cardiovascular disease (CVD) has become an increasingly important cause of death in patients with SLE. The increased CVD risk in these patients is partly, but not fully explained by standard risk factors, and abnormalities in the immune response to lipids may play a role. Invariant natural killer T cells, which are triggered specifically by lipid antigens, may protect against progression of subclinical atherosclerosis. However, currently our recommendation is that clinicians should focus on optimal management of standard CVD risk factors such as smoking, blood pressure and lipid levels. Fatigue is one of the most common and most limiting symptoms suffered by patients with SLE. The cause of fatigue is multifactorial and disease activity does not explain this symptom. Consequently, therapies directed towards reducing inflammation and disease activity do not reliably reduce fatigue and new approaches are needed. Currently, we recommend asking about sleep pattern, optimising pain relief and excluding other causes of fatigue such as anaemia and metabolic disturbances. For the subgroup of patients whose disease activity is not fully controlled by standard treatment regimes, a range of different biologic agents have been proposed and subjected to clinical trials. Many of these trials have given disappointing results, though belimumab, which targets B lymphocytes, did meet its primary endpoint. New biologics targeting B cells, T cells or cytokines (especially interferon) are still going through trials raising the hope that novel therapies for patients with refractory SLE may be available soon.

Rituximab treatment for chronic steroid-dependent Henoch-Schonlein purpura: 8 cases and a review of the literature

BACKGROUND

Henoch-Schonlein purpura (HSP) is a small vessel vasculitis that is characterized by non-thrombocytopenic purpura, abdominal pain, arthritis, and glomerulonephritis. Typically, HSP is self-limited requiring only supportive care, but more severe cases may require corticosteroid (CS) treatment. Rarely, a subset of these patients has persistent rash, arthritis, abdominal involvement, or renal disease despite treatment with CS, or has disease recurrence on CS tapering. Refractory HSP has been effectively treated with a variety of CS sparing therapies. For life-threatening refractory HSP, the B cell depleting agent, rituximab (RTX), has been reported as beneficial for children with substantial renal or central nervous system involvement. However, RTX use for children with less severe HSP, but chronic CS dependent disease refractory to CS sparing immunomodulatory agents, has been less well explored. Herein, we describe 8 children treated with RTX for chronic refractory HSP and report a reduction in recurrent hospitalizations and eventual CS discontinuation.

METHODS

This is a retrospective analysis of eight children who were treated with RTX for chronic CS dependent HSP during the years 2006-2014 at a single institution. A chart review of the electronic medical record was performed to determine the presenting symptoms, the type and duration of treatment received, and the number of hospitalizations prior to and after RTX. The number of hospitalizations and oral corticosteroid burden were analyzed using the Wilcoxon signed rank test.

RESULTS

Prior to receiving RTX, seven patients had at least one hospitalization for HSP (median 1.5, range 0-3). Following RTX, only two patients were hospitalized, each a single time for recurrent abdominal pain. The median oral CS burden was 0.345 mg/kg/day before RTX and 0 mg/kg/day at 6 months (p = 0.078), 1 year (p = 0.0625), and 2 years (p = 0.03) following RTX infusion. Seven out of eight children met remission criteria, defined as no active rash, arthritis, nephritis (hematuria and proteinuria), or gastrointestinal distress following RTX. No serious adverse events were noted.

CONCLUSION

Overall, RTX effectively reduced the number of hospital admissions and oral CS burden. RTX also helped most all children achieve clinical remission. RTX appears to be an effective and safe alternative for chronic CS dependent and immunomodulatory refractory childhood HSP.

The long and the short of it: insights into the cellular source of autoantibodies as revealed by B cell depletion therapy

High titers of pathogenic autoantibodies are a hallmark of many autoimmune diseases. However, much remains unknown about the self-reactive plasma cells that are key mediators of disease. We propose a model in which the varying efficacy of precursor B cell depletion for the treatment of humoral autoimmunity can be explained by differences in the relative contributions of pathogenic antibodies by short-lived versus long-lived plasma cells. Beyond therapeutic considerations, this model suggests that we can infer the cellular source of disease-associated autoantibodies by the durability of serum titers following B cell depletion. Data from clinical trials and animal models across different autoimmune diseases may provide useful insights into the lifespan, lifestyle and fate of autoreactive plasma cells.

Short-term efficacy and safety of rituximab therapy in refractory systemic lupus erythematosus: results from the British Isles Lupus Assessment Group Biologics Register

Objectives

To describe the baseline characteristics of SLE patients requiring biologic therapy in the UK and to explore short term efficacy and infection rates associated with rituximab (RTX) use.

Methods

Patients commencing biologic therapy for refractory SLE and who consented to join BILAG-BR were analysed. Baseline characteristics, disease activity (BILAG 2004/SLEDAI-2K) and rates of infection over follow-up were analysed. Response was defined as loss of all A and B BILAG scores to ⩽ 1 B score with no new A/B scores in other organ systems at 6 months.

Results

Two hundred and seventy SLE patients commenced biologic therapy from September 2010 to September 2015, most commonly RTX (n = 261). Two hundred and fifty (93%) patients were taking glucocorticoids at baseline at a median [interquartile range (IQR)] oral dose of 10 mg (5–20 mg) daily. Response rates at 6 months were available for 68% of patients. The median (IQR) BILAG score was 15 (10–23) at baseline and 3 (2–12) at 6 months (P < 0.0001). The median (IQR) SLEDAI-2K reduced from 8 (5–12) to 4 (0–7) (P < 0.001). Response was achieved in 49% of patients. There was also a reduction in glucocorticoid use to a median (IQR) dose of 7.5 mg (5–12 mg) at 6 months (P < 0.001). Serious infections occurred in 26 (10%) patients, being more frequent in the first 3 months post-RTX therapy. A higher proportion of early infections were non-respiratory (odds ratio = 1.98, 95% CI: 0.99, 3.9; P = 0.049).

Conclusion

RTX is safe and is associated with improvement in disease activity in refractory SLE patients with concomitant reductions in glucocorticoid use. Early vigilance for infection post-infusion is important to further improve treatment risks and benefits.

Targeting B Cells and Plasma Cells in Autoimmune Diseases

Success with B cell depletion using rituximab has proven the concept that B lineage cells represent a valid target for the treatment of autoimmune diseases, and has promoted the development of other B cell targeting agents. Present data confirm that B cell depletion is beneficial in various autoimmune disorders and also show that it can worsen the disease course in some patients. These findings suggest that B lineage cells not only produce pathogenic autoantibodies, but also significantly contribute to the regulation of inflammation. In this review, we will discuss the multiple pro- and anti-inflammatory roles of B lineage cells play in autoimmune diseases, in the context of recent findings using B lineage targeting therapies.

La/SSB chimeric autoantibody receptor modified NK92MI cells for targeted therapy of autoimmune disease

It has been long sought to specifically eliminate B-cell clones that generate autoreactive antibodies, while sparing the immune system when combating autoimmune disease. Although it was impossible to achieve this goal before, newly developed techniques have made it feasible today. Autoantibodies against La/SSB were involved in several autoimmune diseases. Here, we aimed to introduce La/SSB epitope-based chimeric autoantibody receptors (CAAR) into NK92MI cells enabled it to destroy the corresponding La/SSB-specific B cell receptor (BCR) -bearing lymphoma cells (LaA-BCR-Romas, LaA-BCR-Maver-1, and LaA-BCR-Jurkat cells). Such cell lines could eliminate a part of the B-cells in the blood of patients positive for anti-La/SSB antibodies. The CAAR we used in this study was constructed by fusing fragments from the nucleus protein, La/SSB, with the TCR signaling molecules, CD28, CD137, and CD3ζ. Thus, this method could specifically destroy the La/SSB autoreactive B-cell clones. Our results might provide a new strategy to combat antibody-mediated autoimmune diseases.

Efficacy and safety of anti-CD20 antibody rituximab for patients with refractory systemic lupus erythematosus

Objective

We examined the efficacy and safety of rituximab in patients with refractory systemic lupus erythematosus (SLE).

Methods

The study enrolled 63 SLE patients who were treated with rituximab between 2002 and 2015. The participants underwent a battery of tests before treatment and at one year. Treatment ranged from two to four times at 500 or 1000 mg.

Results

Baseline characteristics were males:females = 6:57, age 33.9 years, and disease duration 87.2 months. The primary endpoint: The rate of major clinical response (MCR) was 60% while the partial clinical response (PCR) was 25%. Thirty of 36 (83%) patients with lupus nephritis (WHO II: 2, III: 5, IV: 22, V: 4, IV+V: 2, not assessed: 1) and 22 of 24 patients (92%) with neuropsychiatric SLE, who could be followed at one year, showed changes from BILAG A or B score to C or D score at one year. Multivariate analysis identified high anti-dsDNA antibody and shorter disease duration as significant determinants of MCR at one year. Repeat examination was conducted at five years. Primary failure was recorded in 8.8% and secondary failure in 32.4% (time to relapse: 24.4 months). Rituximab was well tolerated although 65 adverse events, mostly infections, were recorded within one year.

Conclusion

Rituximab is potentially efficacious for the treatment of patients with refractory SLE.

Juvenile-onset systemic lupus erythematosus (jSLE) - Pathophysiological concepts and treatment options

The systemic autoimmune/inflammatory condition systemic lupus erythematosus (SLE) manifests before the age of 16 years in 10-20% of all cases. Clinical courses are more severe, and organ complications are more common in patients with juvenile SLE. Varying gender distribution in different age groups and increasing severity with younger age and the presence of monogenic disease in early childhood indicate distinct differences in the pathophysiology of juvenile versus adult-onset SLE. Regardless of these differences, classification criteria and treatment options are identical. In this article, we discuss age-specific pathomechanisms of juvenile-onset SLE, which are currently available and as future treatment options, and propose reclassification of different forms of SLE along the inflammatory spectrum from autoinflammation to autoimmunity.

Outcomes of rituximab therapy in refractory lupus: A meta-analysis

OBJECTIVE

Conventional treatment of systemic lupus erythematosus (SLE) and lupus nephritis (LN) is associated with damage accrual, hence increased morbidity rate. Off-label use of rituximab (RTX) has shown significant promise in this patient group; however, data are still controversial. We aimed to analyze the outcomes of RTX therapy in refractory lupus using a meta-analysis approach.

METHODS

Electronic search of the medical literature was conducted using a combination of relevant keywords to retrieve studies on the safety and efficacy of RTX in SLE and LN patients. Results were screened against our inclusion and exclusion criteria and two reviewers independently extracted the data for analysis. Comprehensive meta-analysis software was used to pool the data from individual studies and provide summary effect estimates.

RESULTS

Thirty-one studies that enrolled 1112 patients were finally eligible for the meta-analysis. The overall global, complete, and partial response rates to RTX therapy were 72%, 46%, and 32%, respectively. RTX significantly decreased Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and British Isles Lupus Activity Group (BILAG) scores (p<0.001). Prednisone dose was significantly reduced after RTX treatment in both SLE and LN groups (p<0.001), and proteinuria was lowered in SLE (p<0.001) than in LN patients (p=0.07). Infection and infusion-related reactions were the most common side effects.

CONCLUSION

RTX therapy in refractory SLE and LN patients proved clinical efficacy and favorable safety outcomes. Larger well-designed randomized clinical trials are warranted.

Current perspective on rituximab in rheumatic diseases

The steadily increasing knowledge regarding pathogenetic mechanisms in autoimmune rheumatic diseases has paved the way to different therapeutic approaches. In particular, the market entry of biologics has dramatically modified the natural history of rheumatic chronic inflammatory diseases with a meaningful impact on patients’ quality of life. Among the wide spectrum of available biological treatments, rituximab (RTX), first used in the treatment of non-Hodgkin’s lymphoma, was later approved for rheumatoid arthritis and anti-neutrophil cytoplasmic antibodies-associated vasculitis. Nowadays, in rheumatology, RTX is also used with off-label indications in patients with systemic sclerosis, Sjögren’s syndrome and systemic lupus erythematosus. RTX is a monoclonal antibody directed to CD20 molecules expressed on the surfaces of pre-B and mature B lymphocytes. It acts by causing apoptosis of these cells with antibody- and complement-dependent cytotoxicity. As inflammatory responses to cell-associated immune complexes are key elements in the pathogenesis of several autoimmune rheumatic diseases, such an approach might be effective in these patients. In fact, RTX, by promoting the rapid and long-term depletion of circulating and lymphoid tissue-associated B cells, leads to a lower recruitment of these effector cells at sites of immune complex deposition, thus reducing inflammation and tissue damage. RTX is of the most interest to rheumatologists as it represents an important additional therapeutic approach. Thus, the advent in clinical practice of approved RTX biosimilars, such as CT-P10, may be of help in improving treatment access as well as in reducing costs.

HM71224, a selective Bruton's tyrosine kinase inhibitor, attenuates the development of murine lupus

Background

Systemic lupus erythematosus (SLE) is associated with B cell hyperactivity, and lupus nephritis (LN), in particular, is promoted by the production of autoantibodies and immune complex deposition. Bruton’s tyrosine kinase (BTK) plays critical roles in B cell receptor-related and Fc receptor-related signaling. We aimed to investigate the impact of therapeutic intervention with HM71224 (LY3337641), a selective BTK inhibitor, on the development of murine SLE-like disease features.

Methods

We examined the therapeutic effects of HM71224 on SLE-like disease features in MRL/lpr and NZB/W F1 mice. The disease-related skin lesion was macroscopically observed in MRL/lpr mice, and the impact on splenomegaly and lymphadenopathy was determined by the weight of the spleen and cervical lymph node. The renal function was evaluated by measuring blood urea nitrogen, serum creatinine, and urine protein, and the renal damage was assessed by histopathological grading. Survival rate was observed during the administration period. The impact of B cell inhibition was investigated in splenocytes from both mice using flow cytometry. Autoantibody was measured in serum by ELISA.

Results

HM71224 effectively suppressed splenic B220⁺GL7⁺, B220⁺CD138⁺, and B220⁺CD69⁺ B cell counts, and anti-dsDNA IgG and reduced splenomegaly and lymph node enlargement. The compound also prevented skin lesions caused by lupus development, ameliorated renal inflammation and damage with increased blood urea nitrogen and creatinine, and decreased proteinuria. Furthermore, HM71224 also decreased mortality from lupus development in both mouse models.

Conclusion

Our results indicate that inhibition of BTK by HM71224 effectively reduced B cell hyperactivity and significantly attenuated the development of SLE and LN in rodent SLE models.

Treatment of lupus nephritis: current paradigms and emerging strategies

PURPOSE OF REVIEW

Lupus nephritis is the most common organ-threatening manifestation of lupus and continues to result in end-stage renal disease. This review describes the contemporary treatment of lupus nephritis as well as emerging therapeutic strategies.

RECENT FINDINGS

Lupus nephritis management consists of an initial (induction) phase and a maintenance (extended) phase in which steroids are used in combination with another immunosuppressive medication. Current treatments are incompletely effective and associated with substantial toxicity. Despite disappointing results of several recent trials, novel therapies targeting diverse immunologic pathways are being actively studied in lupus nephritis. Two promising strategies include the use of B-cell depletion therapy and multitarget therapy with calcineurin inhibitors. In parallel with the conduct of these trials, there are ongoing efforts to improve trial design. Two recent studies of outcome measures reported that a level of proteinuria of less than 0.7-0.8 g at 12 months is most predictive of good long-term renal outcome, and that the inclusion of urine red blood cells worsens the predictive value of proteinuria alone.

SUMMARY

Improved understanding of lupus nephritis pathogenesis, development of novel therapies, and optimization of clinical trial design are leading the path forward for successful drug development in lupus nephritis. The ultimate goal of these efforts is to treat our patients in a more strategic, personalized manner that improves long-term outcomes.

Improving B-cell depletion in systemic lupus erythematosus and rheumatoid arthritis

INTRODUCTION

Rituximab-based B-cell depletion (BCD) therapy is effective in refractory rheumatoid arthritis (RA) and although used to treat patients with refractory systemic lupus erythematosus (SLE) in routine clinical practice, rituximab failed to meet the primary endpoints in two large randomised controlled trials (RCTs) of non-renal (EXPLORER) and renal (LUNAR) SLE. Areas covered: We review how BCD could be improved to achieve better clinical responses in RA and SLE. Insights into the variability in clinical response to BCD in RA and SLE may help develop new therapeutic strategies. To this end, a literature search was performed using the following terms: rheumatoid arthritis, systemic erythematosus lupus, rituximab and B-cell depletion. Expert commentary: Poor trial design may have, at least partly, contributed to the apparent lack of response to BCD in the two RCTs of patients with SLE. Enhanced B-cell depletion and/or sequential therapy with belimumab may improve clinical response at least in some patients with SLE.

Rethinking biologics in lupus nephritis

Lupus nephritis (LN) is a chronic and devastating complication of systemic lupus erythematosus. Despite advances in our understanding of LN and the availability of effective therapies, LN remains a difficult clinical problem, and progression to end stage renal disease remains a significant challenge. Though the advent of biologics has revolutionized the treatment of many rheumatological conditions, and several clinical trials of biologics have been conducted in LN, the promise of biologics remains unfulfilled. The experience gained from these initial clinical trials can help tailor approaches in future clinical trials, and the lessons learned can be applied to find a cure for this condition.

B-cell subsets, signaling and their roles in secretion of autoantibodies

B cells play a pivotal role in the pathogenesis of autoimmune diseases. In patients with systemic lupus erythematosus (SLE), the percentages of plasmablasts and IgD−CD27− double-negative memory B cells in peripheral blood are significantly increased, while IgD+CD27+ IgM memory B cells are significantly decreased compared to healthy donors. The phenotypic change is significantly associated with disease activity and concentration of autoantibodies. Treatment of B-cell depletion using rituximab results in the reconstitution of peripheral B cells in SLE patients with subsequent improvement in disease activity. Numerous studies have described abnormalities in B-cell receptor (BCR)-mediated signaling in B cells of SLE patients. Since differences in BCR signaling are considered to dictate the survival or death of naïve and memory B cells, aberrant BCR signal can lead to abnormality of B-cell subsets in SLE patients. Although Syk and Btk function as key molecules in BCR signaling, their pathological role in SLE remains unclear. We found that Syk and Btk do not only transduce activation signal through BCR, but also mediate crosstalk between BCR and Toll-like receptor (TLR) as well as BCR and JAK-STAT pathways in human B cells in vitro. In addition, pronounced Syk and Btk phosphorylation was observed in B cells of patients with active SLE compared to those of healthy individuals. The results suggest the involvement of Syk and Btk activation in abnormalities of BCR-mediated signaling and B-cell phenotypes during the pathological process of SLE and that Syk, Btk and JAK are potential therapeutic targets in SLE.

Success and failure of biological treatment in systemic lupus erythematosus: A critical analysis

Patients affected with systemic lupus erythematosus (SLE) still display increased mortality and decreased quality of life in respect to general population. The major determinant of poor long term prognosis is organ damage, which is predictive of more damage and death. Damage is in turn triggered by uncontrolled disease activity and especially by the long-standing corticosteroid use which often accompanies SLE patients over their disease course, owing both to the need of reaching disease remission and to the habit of keeping patients on a small steroid dose for an indefinite period of time. Hence, the need for new drugs and therapeutic strategies aiming at minimizing damage accrual through a better control of disease activity and a steroid-sparing potential is paramount. So far, however, the therapeutic strategy in SLE requires a multitarget approach which is not devoid of widespread immunesuppression. In fact, several studies have been carried out in recent years targeting both the adaptive and the innate immune system, the majority of which did not achieve their primary endpoint, being often divergent from successful clinical experience and thereby committing physician to off-label use of targeted therapies in face of refractory SLE manifestations. The study designs and the chosen endpoints were often blamed for inadequacy, being at least in part responsible for study failures. In this review, we go over major clinical trials conducted in SLE by analyzing any critical aspects related to study design, predefined endpoints and biological activity of novel compounds that may have hampered study outcome, despite the great effort of providing less toxic drugs within a targeted, pathogenic-based approach.