Disparity in peripheral and renal B-cell depletion with rituximab in systemic lupus erythematosus: an opportunity for obinutuzumab?

Evolution and trajectory of B-cell targeted therapies in rheumatic diseases

Aberrant B-cell function, which could arise from various underlying causes, is central to the pathogenesis of diverse autoimmune rheumatic diseases. B cells remain the only cell type to be specifically therapeutically targeted through depletion and have the only therapy with a routinely available flow cytometric biomarker of treatment. Since first use and subsequent licensing for rheumatoid arthritis, rituximab has had a transformative impact on patients globally and across the rheumatic diseases. Further insights from B-cell-activating factor (BAFF) blockade with belimumab in systemic lupus erythematosus have followed. Examination of B-cell depletion, clinical outcomes, and re-emergent disease after treatment have deepened our understanding of the identity, detailed phenotype, biology, and kinetics of the B-cell subsets that are central to disease. This Review reflects on 20 years of clinical and translational insights drawn from B-cell targeted therapies for adult autoimmune rheumatic diseases, and highlights how these therapies have informed an exciting new era of future therapeutic developments.

CAR T cells in autoimmunity: game changer or stepping stone?

ABSTRACT

The advent of chimeric antigen receptor (CAR) T cells has revolutionized the treatment landscape for hematologic malignancies, and emerging evidence suggests their potential in autoimmune diseases (AIDs). This article evaluates the early successes and future implications of B-cell-targeting CAR T-cell therapy in AIDs. Initial applications, particularly in refractory systemic lupus erythematosus, have demonstrated significant and durable clinical remissions, with accompanying evaluation of the immune system suggesting a so-called "reset" of innate inflammation and adaptive autoimmunity. This has generated widespread interest in expanding this therapeutic approach. CAR T cells offer unique advantages over other treatment modalities, including very deep B-cell depletion and unique therapeutic activity within inflamed tissues and associated lymphoid structures. However, the field must address key concerns, including long-term toxicity, particularly the risk of secondary malignancies, and future accessibility given the higher prevalence of AIDs compared with malignancies. Technological advances in cell therapy, such as next-generation CAR T cells, allogeneic off-the-shelf products, and alternative cell types, such as regulatory CAR T cells, are being explored in AIDs to improve efficacy and safety. In addition, bispecific antibodies are emerging as potential alternatives or complements to CAR T cells, potentially offering comparable efficacy without the need for complex logistics, lymphodepletion, and the risk of insertional mutagenesis. As the field evolves, cellular therapists will play a critical role in the multidisciplinary teams managing these complex cases. The transformative potential of CAR T cells in AIDs is undeniable, but careful consideration of safety, efficacy, and implementation is essential as this novel therapeutic approach moves forward.

Rheumatoid arthritis unmasked: the power of B cell depletion therapy

Rheumatoid arthritis (RA) is an enduring autoimmune illness characterized by persistent inflammation and joint damage. Recent advancements in B cell depletion therapies (BCDTs) have provided new avenues for managing RA. This review article delves into the pathophysiology of RA, highlighting the pivotal role of B cells in disease progression. We explore the mechanisms underlying B cell depletion, focusing on monoclonal antibodies such as rituximab as well as innovative approaches like chimeric antigen receptor (CAR) T cell therapies. An in-depth analysis of clinical studies reveals the efficacy and limitations of these therapies, including success rates, side effects, and cost implications for patients. Despite promising outcomes, the incomplete depletion of B cells and associated risks underscore the need for further research. This review aims to provide a comprehensive understanding of BCDTs in RA, shed light on their potential and challenges, and guide future therapeutic strategies.

Opportunities and limitations of B cell depletion approaches in SLE

B cell depletion with rituximab, a chimeric monoclonal antibody that selectively targets B cells by binding CD20, has been used off label in severe and resistant systemic lupus erythematosus (SLE) for over two decades. Several biological mechanisms limit the efficacy of rituximab, including immunological reactions towards the chimeric molecule, increased numbers of residual B cells, including plasmablasts and plasma cells, and a post-treatment surge in B cell-activating factor (BAFF) levels. Consequently, rituximab induces remission in only a proportion of patients, and safety issues limit its use. However, the use of rituximab has established the value of B cell depletion strategies in SLE and has guided the development of several improved B cell depletion therapies for SLE. These include enhanced monoclonal antibodies, modalities that redirect the specificity of patient T cells using chimeric antigen receptor T cells or bispecific T cell engagers, and combination treatment that simultaneously inhibits the BAFF pathway. In this Review, we consider evidence gathered from over two decades of using rituximab in SLE and examine how B cell depletion therapies could be further optimized to achieve immunological and clinical efficacy. In addition, we discuss the prospects of B cell depletion strategies for personalized treatment in SLE based on genetic research and studies in pre-symptomatic individuals.

[The combined regimen based on obinutuzumab plus glucocorticoid for 4 cases of relapsed iTTP]

Objective: To evaluate the efficacy and safety of obinutuzumab combined with glucocorticoid-based therapy in patients with relapsed immune thrombotic thrombocytopenic purpura (iTTP). Methods: This study analyzed the efficacy and adverse reactions of four patients with relapsed iTTP who were treated with a combination of obinutuzumab and glucocorticoids to assess the effectiveness and safety of the treatment. Results: All four patients had a history of multiple relapses and had previously undergone treatment with rituximab and bortezomib. Three patients exhibited additional autoantibodies. Following the combined therapy, all patients achieved clinical remission, with ADAMTS13 activity returning to normal levels and inhibitors testing negative. During a median follow-up period of 11 months (range: 3-17 months), all patients maintained sustained remission. No severe adverse events were reported during treatment or follow-up. Conclusion: The combination of obinutuzumab and glucocorticoid-based therapy is effective and safe for treating relapsed iTTP.

Innovations in Cutaneous Lupus

Cutaneous lupus erythematosus (CLE) is an autoimmune-mediated skin disease under the family of lupus erythematosus. Systemic immunosuppressants and topical treatments have been used to manage CLE; however, these treatments tend to be moderately efficacious and leave patients with unmet therapeutic needs. There is a need for medications that target pruritus, scarring, dyspigmentation, and other symptoms of chronic CLE that contribute to decreased quality of life. The introduction of new biologics and other systemic medications has expanded dermatologists' and rheumatologists' ability to manage CLE. This article discusses new pharmaceuticals and guidelines providing an updated overview of the clinical management of CLE.

Efficacy and safety of biologics, multitarget therapy, and standard therapy for lupus nephritis: a systematic review and network meta-analysis

OBJECTIVE

This study aimed to compare the efficacy and safety of biologics, multitarget therapy, and standard therapy for the induction of lupus nephritis.

METHODS

A systematic search of electronic databases (EMBASE, Web of Science, PubMed, Cochrane Library, and ClinicalTrials.gov) was conducted from inception to 30 August 2023. Our study included randomized controlled trials enrolling adult lupus nephritis patients treated with biologics or multitarget therapy, in comparison with standard therapy. The primary outcomes were the rates of complete renal remission (CRR) and serious adverse events (SAE). Stata 15.0 was used to conduct the network meta-analysis.

RESULTS

Ten randomized controlled trials with a total of 1989 patients met the inclusion criteria. The network meta-analysis indicated that compared with standard therapy, multitarget therapy, obinutuzumab, belimumab, and voclosporin therapy demonstrated superior efficacy in achieving complete renal remission. Among these options, multitarget therapy had the greatest effect (OR = 2.78, 95% CI = 1.81-4.26). Regarding safety, it was observed that there were no significant statistical differences among the various treatment options. Cluster analysis revealed that both obinutuzumab and belimumab exhibited good efficacy and safety.

CONCLUSIONS

belimumab and obinutuzumab stood out as promising treatments due to their good performance in terms of efficacy and safety. Multitarget therapy may be the most effective approach for treating lupus nephritis. However, since the study population consists exclusively of Asian patients, further research is needed to verify the efficacy of multitarget therapy in lupus nephritis patients of non-Asian descent.

Cutting-edge approaches to B-cell depletion in autoimmune diseases

B-cell depletion therapy (BCDT) has been employed to treat autoimmune disease for ~20 years. Immunoglobulin G1 (IgG1) monoclonal antibodies targeting CD20 and utilizing effector function (eg, antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, antibody-dependent cellular phagocytosis) to eliminate B cells have historically been the predominant therapeutic approaches. More recently, diverse BCDT approaches targeting a variety of B-cell surface antigens have been developed for use in hematologic malignancies, including effector-function-enhanced monoclonal antibodies, chimeric antigen receptor T-cell (CAR-T) treatment, and bispecific T-cell engagers (TCEs). The latter category of antibodies employs CD3 engagement to augment the killing of target cells. Given the improvement in B-cell depletion observed with CAR-T and TCEs compared with conventional monospecific antibodies for treatment of hematologic malignancies and the recent case reports demonstrating therapeutic benefit of CAR-T in autoimmune disease, there is potential for these mechanisms to be effective for B-cell-mediated autoimmune disease. In this review, we discuss the various BCDTs that are being developed in autoimmune diseases, describing the molecule designs, depletion mechanisms, and potential advantages and disadvantages of each approach as they pertain to safety, efficacy, and patient experience. Additionally, recent advances and strategies with TCEs are presented to help broaden understanding of the potential for bispecific antibodies to safely and effectively engage T cells for deep B-cell depletion in autoimmune diseases.

Sustained depression of B cell counts in lupus nephritis after treatment with rituximab and/or belimumab is associated with fewer disease flares

OBJECTIVE

To study the risk of lupus nephritis flare (LNF) or severe lupus flare (SLF) as a function of B cell count kinetics in lupus nephritis (LN) patients after they achieve at least a partial renal response (PRR) with induction treatment that includes rituximab (RTX) and/or belimumab (BLM).

METHODS

We performed a retrospective analysis of a cohort of 19 patients with severe LN that received a B cell agent (BCA), RTX and/or BLM, as part of an initial treatment regimen for an LN flare and had subsequent CD19+ B cell measurements in peripheral blood. We then characterized the follow-up periods, after B cell depressions occurred and PRR were achieved, by the corresponding trajectories of B cell counts (BCC). Time periods with sustained low BCC were type 1 (T1) episodes, while those with repletion of BCC>100 cells/μL were called type 2 (T2) episodes. Time periods with rapid BCC repletion, defined as >50 cells/μL in ≤6 months, were called T2b episodes. Corresponding C3, C4, and anti-dsDNA levels were recorded for each episode. The time from PRR until an event, either a LNF or SLF, or to censoring, either at the end of the study period or the end of available patient follow-up, was assessed for each episode type. Kaplan-Meier survival analysis was used to compare time to flare between T1 and T2 episodes.

RESULTS

There were 26 episodes of B cell depression. Seventeen (65%) were T1 and 9 (35%) were T2. Compared to T1 episodes, T2 episodes were 9.0 times more likely to result in flare over the follow-up period (hazard ratio (HR) = 9.0, 95% CI for HR = 2.2-36.7); this risk was even larger for T2b vs T1 episodes. Median BCC was 14 cells/μL in T1 and 160 cells/μL in T2 episodes. Both C3 and C4 levels significantly increased over the duration of the episode in T1 episodes only.

CONCLUSION

Sustained low BCC was associated with prolonged serologic and clinical response, whereas repletion, and particularly rapid repletion, of B cells after treatment with BCA was associated with subsequent disease flare.

Disrupting B and T-cell collaboration in autoimmune disease: T-cell engagers versus CAR T-cell therapy?

B and T cells collaborate to drive autoimmune disease (AID). Historically, B- and T-cell (B-T cell) co-interaction was targeted through different pathways such as alemtuzumab, abatacept, and dapirolizumab with variable impact on B-cell depletion (BCD), whereas the majority of patients with AID including rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, and organ transplantation benefit from targeted BCD with anti-CD20 monoclonal antibodies such as rituximab, ocrelizumab, or ofatumumab. Refractory AID is a significant problem for patients with incomplete BCD with a greater frequency of IgD-CD27+ switched memory B cells, CD19+CD20- B cells, and plasma cells that are not directly targeted by anti-CD20 antibodies, whereas most lymphoid tissue plasma cells express CD19. Furthermore, B-T-cell collaboration is predominant in lymphoid tissues and at sites of inflammation such as the joint and kidney, where BCD may be inefficient, due to limited access to key effector cells. In the treatment of cancer, chimeric antigen receptor (CAR) T-cell therapy and T-cell engagers (TCE) that recruit T cells to induce B-cell cytotoxicity have delivered promising results for anti-CD19 CAR T-cell therapies, the CD19 TCE blinatumomab and CD20 TCE such as mosunetuzumab, glofitamab, or epcoritamab. Limited evidence suggests that anti-CD19 CAR T-cell therapy may be effective in managing refractory AID whereas we await evaluation of TCE for use in non-oncological indications. Therefore, here, we discuss the potential mechanistic advantages of novel therapies that rely on T cells as effector cells to disrupt B-T-cell collaboration toward overcoming rituximab-resistant AID.

Management of Cardiovascular Complications in Antiphospholipid Syndrome: A Narrative Review with a Focus on Older Adults

Antiphospholipid syndrome (APS), also known as Hughes syndrome, is an acquired autoimmune and procoagulant condition that predisposes individuals to recurrent thrombotic events and obstetric complications. Central is the role of three types of antiphospholipid antibodies that target phospholipid-binding proteins: lupus anticoagulant (LAC), anti-β2-glycoprotein I (β2-GPI-Ab), and anti-cardiolipin (aCL). Together with clinical data, these antibodies are the diagnostic standard. However, the diagnosis of APS in older adults may be challenging and, in the diagnostic workup of thromboembolic complications, it is an underestimated etiology. The therapeutic management of APS requires distinguishing two groups with differential risks of thromboembolic complications. The standard therapy is based on low-dose aspirin in the low-risk group and vitamin K antagonists in the high-risk group. The value of direct oral anticoagulants is currently controversial. The potential role of monoclonal antibodies is investigated. For example, rituximab is currently recommended in catastrophic antiphospholipid antibody syndrome. Research is ongoing on other monoclonal antibodies, such as daratumumab and obinutuzumab. This narrative review illustrates the pathophysiological mechanisms of APS, with a particular emphasis on cardiovascular complications and their impact in older adults. This article also highlights advancements in the diagnosis, risk stratification, and management of APS.

Proteinase 3-specific antineutrophil cytoplasmic antibody-associated vasculitis

Proteinase 3 (PR3)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is one of two major ANCA-associated vasculitis variants and is pathogenically linked to granulomatosis with polyangiitis (GPA). GPA is characterised by necrotising granulomatous inflammation that preferentially affects the respiratory tract. The small vessel vasculitis features of GPA are shared with microscopic polyangiitis. Necrotising granulomatous inflammation of GPA can lead to PR3-ANCA and small vessel vasculitis via activation of neutrophils and monocytes. B cells are central to the pathogenesis of PR3-ANCA-associated vasculitis. They are targeted successfully by remission induction and maintenance therapy with rituximab. Relapses of PR3-ANCA-associated vasculitis and toxicities associated with current standard therapy contribute substantially to remaining mortality and damage-associated morbidity. More effective and less toxic treatments are sought to address this unmet need. Advances with cellular and novel antigen-specific immunotherapies hold promise for application in autoimmune disease, including PR3-ANCA-associated vasculitis. This Series paper describes the inter-related histopathological and clinical features, pathophysiology, as well as current and future targeted treatments for PR3-ANCA-associated vasculitis.

Novel and potential future therapeutic options in systemic autoimmune diseases

Autoimmune inflammation is caused by the loss of tolerance to specific self-antigens and can result in organ-specific or systemic disorders. Systemic autoimmune diseases affect a significant portion of the population with an increasing rate of incidence, which means that is essential to have effective therapies to control these chronic disorders. Unfortunately, several patients with systemic autoimmune diseases do not respond at all or just partially respond to available conventional synthetic disease-modifying antirheumatic drugs and targeted therapies. However, during the past few years, some new medications have been approved and can be used in real-life clinical settings. Meanwhile, several new candidates appeared and can offer promising novel treatment options in the future. Here, we summarize the newly available medications and the most encouraging drug candidates in the treatment of systemic lupus erythematosus, rheumatoid arthritis, Sjögren's disease, systemic sclerosis, systemic vasculitis, and autoimmune myositis.

Population Pharmacodynamic Modelling of the CD19+ Suppression Effects of Rituximab in Paediatric Patients with Neurological and Autoimmune Diseases

BACKGROUND

Limited pharmacotherapy and the failure of conventional treatments in complex pathologies in children lead to increased off-label use of rituximab. We aimed to characterize the time course of CD19+ B lymphocytes (CD19+) under treatment with intravenous rituximab in children with neurologic and autoimmune diseases and to evaluate the impact of covariates (i.e., demographics, diagnosis and substitution between innovator and biosimilar product) on rituximab pharmacodynamics and disease activity.

METHODS

Pre- and post-drug infusion CD19+ in peripheral blood were prospectively registered. A population pharmacodynamic model describing the time course of CD19+ was developed with NONMEM v7.4. Simulations of three different rituximab regimens were performed to assess the impact on CD19+. Logistic regression analysis was performed to identify predictors of clinical response recorded through disease activity scores.

RESULTS

281 measurements of CD19+ lymphocyte counts obtained from 63 children with neurologic (n = 36) and autoimmune (n = 27) diseases were available. The time course of CD19+ was described with a turn-over model in which the balance between synthesis and degradation rates is disrupted by rituximab, increasing the latter process. The model predicts half-lives (percent coefficient of variation, CV(%)) of rituximab and CD19+ of 11.6 days (17%) and 173.3 days (22%), respectively. No statistically significant effect was found between any of the studied covariates and model parameters (p > 0.05). Simulations of different regimens showed no clinically significant differences in terms of CD19+ repopulation times. A trend towards a lack of clinical response was observed in patients with lower CD19+ repopulation times and higher areas under the CD19+ versus time curve.

CONCLUSIONS

Rituximab pharmacodynamics was described in a real-world setting in children suffering from autoimmune and neurologic diseases. Diagnosis, substitution between innovator rituximab and its biosimilars or type of regimen did not affect rituximab-induced depletion of CD19+ nor the clinical response in this cohort of patients. According to this study, rituximab frequency and dosage may be chosen based on clinical convenience or safety reasons without affecting CD19+ repopulation times. Further studies in larger populations are required to confirm these results.

Infection Risk, Mortality, and Hypogammaglobulinemia Prevalence and Associated Factors in Adults Treated with Rituximab: A Tertiary Care Center Experience

BACKGROUND

Rituximab is a human monoclonal antibody directed against the B-cell transmembrane protein CD20. Although well-tolerated, given its mechanism of action, rituximab can induce a state of severe immunosuppression, increasing the risk of opportunistic and fulminant infection and mortality.

AIM

To evaluate the risk of infection, mortality, and hypogammaglobulinemia and their associated factors among rituximab receivers.

METHOD

This was a single-center retrospective cohort study of adults treated with rituximab for various indications. Hypogammaglobulinemia was defined by a cut-off value below the normal limit (an IgG level of <7.51 g/L, an IgM level of <0.46 g/L, and/or an IgA level of <0.82 g/L). Patients who met the definition of hypogammaglobinemia solely based on IgA were excluded. Severe infection was defined as any infection that required intensive care unit admission.

RESULTS

A total of 137 adults with a mean age of 47.69 ± 18.86 years and an average BMI of 28.57 ± 6.55 kg/m2 were included. Hematological malignancies and connective tissue diseases were the most common primary diagnoses for which rituximab was used. More than half of the patients received the 375 mg/m2 dose. Rituximab's mean cumulative dose was 3216 ± 2282 mg, and the overall mortality rate was 22.6%. Hypogammaglobulinemia was diagnosed in 43.8% of the patients, and it was significantly more prevalent among males and the 375 mg/m2 and 500 mg doses. Hematological malignancy was the only predictor for infection. Patients with blood type AB or B, hematological malignancies, and corticosteroids had a significantly higher mortality rate. Receiving the 1000 mg dose and having a low CD19 were associated with a significantly lower risk of infection and mortality, respectively.

CONCLUSIONS

Hypogammaglobulinemia was diagnosed in 43.8% of the patients, and it was significantly more common among males and the 375 mg/m2 and 500 mg doses. Hematological malignancies were significantly associated with higher infection and mortality rates, while corticosteroids were significantly associated with a higher mortality. Since the culprit of mortality was infection, these findings highlight the critical need for more frequent immunological monitoring during rituximab treatment period to mitigate the burden of infection and identify candidates for immunoglobulin replacement.

B cells and antibodies in refractory immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired bleeding disorder mediated by pathogenic autoantibodies secreted by plasma cells (PCs) in many patients. In refractory ITP patients, the persistence of splenic and bone marrow autoreactive long-lived PCs (LLPCs) may explain primary failure of rituximab and splenectomy respectively. The reactivation of autoreactive memory B cells generating new autoreactive PCs contributes to relapses after initial response to rituximab. Emerging strategies targeting B cells and PCs aim to prevent the settlement of splenic LLPCs with the combination of anti-BAFF and rituximab, to deplete autoreactive PCs with anti-CD38 antibodies, and to induce deeper B-cell depletion in tissues with novel anti-CD20 monoclonal antibodies and anti-CD19 therapies. Alternative strategies, focused on controlling autoantibody mediated effects, have also been developed, including SYK and BTK inhibitors, complement inhibitors, FcRn blockers and inhibitors of platelet desialylation.

An update on the biologics for the treatment of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombosis and pregnancy morbidity with the persistent presence of antiphospholipid antibodies (aPLs). Although anticoagulation is the primary treatment for APS, it fails in approximately 20-30% of obstetric APS cases and more than 30% of thrombotic APS cases. Therefore, there is a need for new, targeted treatments beyond anticoagulants. Biologics, such as rituximab and eculizumab, have been recommended for refractory catastrophic APS. This review focuses on the recent advancements in the pathogenesis of APS and explores the potential of targeted treatments, including eculizumab, rituximab, belimumab, daratumumab, obinutuzumab, and anti-TNF-α antibodies, for APS management.

Combination strategies for lupus nephritis: facts and controversies

INTRODUCTION

There is an unmet need to improve the efficacy of therapeutic regimens in lupus nephritis (LN). Cocktail immunosuppressive therapy for the synergistic effect of individual drugs may enhance efficacy and enable dosage reduction. However, the potential increase in the risk of serious and opportunistic infections is a concern. Moreover, the timing of combination therapy, adoption of a step-up or step-down approach, and the choice of drugs is still controversial, partly related to the cost-effectiveness issue.

AREAS COVERED

Evidence of a combination of conventional, newer immunosuppressive, and biologic/targeted agents in LN.

EXPERT OPINION

Early combination of conventional regimens with anti-B cell activation factor (anti-BAFF) or calcineurin inhibitors (CNIs) enhances the therapeutic effect without increasing serious adverse events in LN. However, combining anti-CD20 and anti-BAFF biologics appears to be less promising from the results of clinical trials. Initial combination strategy may be more cost-effective for patients at risk of treatment failure and renal function deterioration. With the availability of more options, the treat-to-target approach in LN is increasingly feasible and further studies are needed to compare the step-up and step-down approaches in the treatment of LN.

Treatment of membranous nephropathy: Perspectives on current and future therapies

Primary membranous nephropathy remains one of the most frequent causes of nephrotic syndrome in adults. It is an autoimmune disorder in which auto-antibodies target antigens at the podocytes cell membrane-basement membrane interface. Our understanding of membranous nephropathy has expanded dramatically as of late. After the initial discovery of the phospholipase A2 receptor auto-antibody in 2009, eight more antigens have been discovered. These discoveries have led to refinement in our understanding of the pathogenesis, diagnosis, and natural history of primary membranous nephropathy. Now, many experts advocate for redefining primary membranous nephropathy based on antigen, potentially shedding the primary and secondary nomenclature. Recently, therapies for primary membranous have also expanded. Immunosuppressive therapies like cyclophosphamide and rituximab, which primarily target B-cells, remain the cornerstone of therapy. However, there is still significant room for improvement, as many as 30-40% do not respond to this therapy according to recent trials. Additionally, drugs targeting complement, and other novel therapies are also under investigation. In this review we will discuss the available therapies for primary membranous nephropathy in light of recent clinic trials like GEMRITUX, MENTOR, RI-CYCLO, and STARMEN, as well as management strategies. While the last 10 years have seen a boom in our mechanistic understanding of this ever-diversifying disease, we are likely to see a similar boom in the therapeutic options in the years to come.

Duration biased distribution of clinical and immunological phenotypes in active SLE

Introduction

This study is aimed to map the clinical and immunological features of active lupus patients with different disease duration.

Methods

For clinical phenotype analysis, we enriched eligible medical records with active SLE (SLEDAI-2k≥8) from the Renji Lupus registry, a single-center database of hospitalized SLE patients with standard care, which covered national-wide patients. Patients with repeated hospitalization records in this enrichment were analyzed longitudinally as validation for the cross-sectional study above.

Results

We enriched a total of 1313 eligible records on active SLE (SLEDAI-2k≥8) for cross-sectional analysis. Stratified into four groups by a 5-year interval of disease duration, these active SLE patients showed a significantly shifting clinical phenotype along with the duration (ascending nephritis, pulmonary hypertension and descending fever, cutaneous symptoms, arthritis, and neuropsychiatric manifestations), especially in stratifications with disease onset age ≤ 45 years old. A longitudinal analysis of 55 patients with repeated hospitalizations for active lupus showed a similar trend. In the cross-sectional study of 222 records with full information on serology and lymphocyte subsets, peripheral B cell proportion, anti-dsDNA antibody, and serum IgG/IgM negatively correlated with duration, while CD8+ T cell proportion was positively correlated (P values, 0.029-4.8×10^-17), which were supported by the sensitivity analysis in patient subgroups according to disease onset age and recent treatment. Multivariate linear regression identified duration as the only significant associator with both B cell and CD8+ T cell proportion (P values, 8.9×10^-8 and 7.6×10^-5, respectively). These duration biased immune phenotypes were highly consistent with the longitudinal observation in 14 patients with repeated hospitalizations.

Conclusions

Both clinical and immunological features of active SLE are significantly duration biased distributed, which merits further investigations in the evolution of SLE pathogenesis.

Rituximab Therapy for Adults with Nephrotic Syndromes: Standard Schedules or B Cell-Targeted Therapy?

Rituximab is a chimeric anti-CD20 monoclonal antibody. It acts mainly through complement-dependent cytotoxicity on B cells expressing the CD20 marker. In this review, we analyse the efficacy and possible pitfalls of rituximab to treat nephrotic syndromes by taking into account pharmacological considerations and CD19 marker testing utility. Despite the fact that the drug has been in use for years, efficacy and treatment schedules in adults with nephrotic syndrome are still a matter of debate. Clinical trials have proven the efficacy and safety of rituximab in idiopathic membranous nephropathy. Data from observational studies also showed the efficacy of rituximab in minimal change disease and focal segmental glomerulosclerosis. Rituximab use is now widely recommended by new Kidney Disease Improved Outcome (KDIGO) guidelines in membranous nephropathy and in frequent-relapsing, steroid-dependent minimal change disease or focal segmental glomerulosclerosis. However, rituximab response has a large interindividual variability. One reason could be that rituximab is lost in the urine at a higher extent in patients with nonselective nephrotic proteinuria, exposing patients to different rituximab plasma levels. Moreover, the association between CD19+ levels and clinical response or relapses is not always present, making the use of this marker in clinical practice complex. High resolution flow cytometry has increased the capability of detecting residual CD19+ B cells. Moreover, it can identify specific B-cell subsets (including IgG-switched memory B cells), which can repopulate at different rates. Its wider use could become a useful tool for better understanding reasons of rituximab failure or avoiding unnecessary retreatments.