The aim of this study was to determine the efficacy of early tocilizumab treatment for hospitalized patients with COVID-19 disease. Open-label randomized phase II clinical trial investigating ...tocilizumab in patients with proven COVID-19 admitted to the general ward and in need of supplemental oxygen. The primary endpoint of the study was 30-day mortality with a prespecified 2-sided significance level of alpha = 0.10. A post-hoc analysis was performed for a combined endpoint of mechanical ventilation or death at 30 days. Secondary objectives included comparing the duration of hospital stay, ICU admittance and duration of ICU stay and the duration of mechanical ventilation. A total of 354 patients (67% men; median age 66 years) were enrolled of whom 88% received dexamethasone. Thirty-day mortality was 19% (95% CI 14%-26%) in the standard arm versus 12% (95% CI: 8%-18%) in the tocilizumab arm, hazard ratio (HR) = 0.62 (90% CI 0.39-0.98; p = 0.086). 17% of patients were admitted to the ICU in each arm (p = 0.89). The median stay in the ICU was 14 days (IQR 9-28) in the standard arm versus 9 days (IQR 5-14) in the tocilizumab arm (p = 0.014). Mechanical ventilation or death at thirty days was 31% (95% CI 24%-38%) in the standard arm versus 21% (95% CI 16%-28%) in the tocilizumab arm, HR = 0.65 (95% CI 0.42-0.98; p = 0.042). This randomized phase II study supports efficacy for tocilizumab when given early in the disease course in hospitalized patients who need oxygen support, especially when concomitantly treated with dexamethasone.
The formation of neutrophil extracellular traps induced by antineutrophil cytoplasmic autoantibodies has been implicated in the pathogenesis of antineutrophil cytoplasmic autoantibody–associated ...vasculitis. Kraaij et al. now provide evidence that excessive neutrophil extracellular trap formation in vitro induced by sera from patients with antineutrophil cytoplasmic autoantibody–associated vasculitis is associated with active disease but is not dependent on the presence of antineutrophil cytoplasmic autoantibodies.
Granulomatosis with polyangiitis (GPA) is an autoimmune disease affecting mainly small blood vessels. B-cells are important in the GPA pathogenesis as precursors of autoantibody-producing cells but ...likely also contribute (auto)antibody-independently. This has been underlined by the effectiveness of B-cell-depletion (with Rituximab) in inducing and maintaining disease remission. Mycophenolate-mofetil (MMF) and azathioprine (AZA) are immunosuppressive therapies frequently used in GPA-patients. Interestingly, MMF-treated GPA-patients are more prone to relapses than AZA-treated patients, while little is known about the influence of these drugs on B-cells. We investigated whether MMF or AZA treatment (or their active compounds) alters the circulating B-cell subset distribution and has differential effects on in vitro B-cell proliferation and cytokine production in GPA-patients that might underlie the different relapse rate. Circulating B-cell subset frequencies were determined in samples from AZA-treated (n = 13), MMF-treated (n = 12), untreated GPA-patients (n = 19) and matched HCs (n = 41). To determine the ex vivo effects of the active compounds of MMF and AZA, MPA and 6-MP respectively, on B-cell proliferation and cytokine production, PBMCs of untreated GPA-patients (n = 29) and matched HCs (n = 30) were cultured for 3-days in the presence of CpG-oligodeoxynucleotides (CpG) with MPA or 6-MP. After restimulation (with phorbol myristate acetate, calcium-ionophore), cytokine-positive B-cell frequencies were measured. Finally, to assess the effect of MMF or AZA treatment on in vitro B-cell proliferation and cytokine production, PBMCs of MMF-treated (n = 18), and AZA-treated patients (n = 28) and HCs (n = 41) were cultured with CpG. The memory B-cell frequency was increased in AZA- compared to MMF-treated patients, while no other subset was different. The active compounds of MMF and AZA showed in vitro that MPA decreased B-cell proliferation in GPA-patients and HCs. B-cell proliferation in MMF- and AZA-treated patients was not different. Finally, the IL-6.sup.+ B-cell frequency was decreased by MPA compared to 6-MP. No differences in IL-10.sup.+, IL-6.sup.+ or TNFalpha.sup.+ B-cell proportions or proliferation were found in MMF- and AZA-treated patients. Our results indicate that MMF could be superior to AZA in inhibiting B-cell cytokine production in GPA-patients. Future studies should assess the effects of these immunosuppressive drugs on other immune cells to elucidate mechanisms underlying the potential differences in relapse rates.
Objective
Several lines of evidence indicate that B cells may be involved in the immunopathology of giant cell arteritis (GCA) and polymyalgia rheumatica (PMR). This study was undertaken to examine ...the distribution of defined B cell subsets, including effector B (Beff) cells and regulatory B (Breg) cells, in patients with GCA and patients with PMR before and after corticosteroid treatment.
Methods
Circulating B cells were analyzed in 34 newly diagnosed, untreated patients with GCA or PMR, and in 44 followup samples from patients with GCA or PMR who received corticosteroids for 2 weeks or 3 months. For comparison, 40 age‐matched healthy controls and 11 rheumatoid arthritis (RA) patients were included. Serum BAFF levels were determined, and temporal arteries were studied by immunohistochemistry.
Results
Patients newly diagnosed as having GCA or PMR, but not patients with RA, had decreased numbers of circulating B cells compared to healthy controls. B cell numbers recovered rapidly in treated patients with GCA and PMR in remission. This recovery was not achieved by compensatory hyperproliferation or enhanced bone marrow production. B cell numbers inversely correlated with erythrocyte sedimentation rates, C‐reactive protein levels, and serum BAFF levels. Tumor necrosis factor α–positive Beff cells, but not interleukin‐10 (IL‐10)–positive Breg cells, were decreased in patients newly diagnosed as having GCA or PMR. Following treatment, circulating numbers of Beff cells normalized. The returning Beff cells demonstrated an enhanced capacity to produce IL‐6. Few B cells were found in temporal artery biopsy specimens from GCA patients.
Conclusion
We show for the first time that the distribution of B cells is highly disturbed in GCA and PMR and that B cells likely contribute to the enhanced IL‐6 response in both diseases.
Introduction
Immunoglobulin G (IgG) contains a conserved N-glycan in the fragment crystallizable (Fc), modulating its structure and effector functions. In anti-neutrophil cytoplasmic antibody ...(ANCA)-associated vasculitis (AAV) alterations of IgG Fc-glycosylation have been observed to correlate with the disease course. Here, we examined longitudinal changes in N
-
linked Fc glycans of IgG in an AAV patient cohort and their relationship with disease flares.
Methods
Using liquid chromatography coupled with mass spectrometry, we analysed IgG Fc-glycosylation in 410 longitudinal samples from 96 individuals with AAV.
Results
Analysis of the cross-sectional differences as well as longitudinal changes demonstrated that IgGs of relapsing PR3-ANCA patients have higher ΔFc-bisection at diagnosis (
P =
0.004) and exhibit a decrease in Fc-sialylation prior to the relapse (
P =
0.0004), discriminating them from non-relapsing patients. Most importantly, PR3-ANCA patients who experienced an ANCA rise and relapsed shortly thereafter, exhibit lower IgG Fc-fucosylation levels compared to non-relapsing patients already 9 months before relapse (
P =
0.02).
Discussion
Our data indicate that IgG Fc-bisection correlates with long-term treatment outcome, while lower IgG Fc-fucosylation and sialylation associate with impending relapse. Overall, our study replicated the previously published reduction in total IgG Fc-sialylation at the time of relapse, but showed additionally that its onset precedes relapse. Furthermore, our findings on IgG fucosylation and bisection are entirely new. All these IgG Fc-glycosylation features may have the potential to predict a relapse either independently or in combination with known risk factors, such as a rise in ANCA titre.
The introduction of immunosuppressive therapy for ANCA-associated vasculitis (AAV) has greatly improved outcomes, though patients now accumulate damage from vasculitis activity and adverse effects of ...treatment. Prediction of treatment outcomes using gene variants might help reduce this damage by allowing for personalized treatment. Several studies have studied genetic polymorphisms in relation to treatment outcomes of AAV. This review gives an overview of these studies, discussing both gene polymorphisms associated with inflammatory pathways (potentially influencing disease outcomes such as activity, severity, and relapse risk) and pharmacogenetics (potentially influencing drug metabolism and/or drug response). Subsequently, potential benefits of testing genetic variants for AAV and the steps needed for its implementation in clinical practice are discussed. The conclusion of this review is that measurement of most polymorphisms is currently not indicated in clinical practice.
Azathioprine is a widely used immunosuppressive drug. Genetic polymorphisms and activity of the enzyme thiopurine methyltransferase (TPMT) have been associated with azathioprine efficacy and toxicity ...in several populations. We investigated whether these associations also exist for ANCA associated vasculitis (AAV) patients, who receive azathioprine maintenance therapy after remission induction with cyclophosphamide.
207 AAV patients treated with cyclophosphamide induction and azathioprine maintenance therapy were included and followed for 60 months. TPMT genotype and tertiles of TPMT activity were compared to relapse free survival and occurrence of adverse events, particularly leukopenia. Multivariable regression was performed to account for confounders.
In univariable analysis, relapse free survival was not significantly associated with TPMT genotype (P = 0.41) or TPMT activity (P = 0.07), although it tended to be longer in lower tertiles of TPMT activity. There was no significant association of TPMT genotype and activity with occurrence of any adverse event. In multiple regression, leukocyte counts at the end of cyclophosphamide induction were related to risk of leukopenia during azathioprine therapy P<0.001; OR 0.54 (95% CI 0.43-0.68) and risk of relapse during follow-up P = 0.001; HR 1.17 (95% CI 1.07-1.29) irrespective of TMPT genotype or activity.
TPMT genotype and activity were not independent predictors of relapse, and could not predict leukopenia or other adverse effects from azathioprine. Leukocyte counts after cyclophosphamide induction were related to both outcomes, implying a greater influence of cyclophosphamide response compared to azathioprine and TPMT in AAV patients.
Human CD4
FoxP3
T-cells are heterogeneous in function and include not only suppressive cells (Tregs), but also effector cells that transiently express FoxP3 upon activation. Previous studies in ...Granulomatosis with Polyangiitis (GPA-)patients have demonstrated an increase in FoxP3
T-cells with impaired suppressive capacity and an increase in Th17 cells. We hypothesized that the increase in FoxP3
T-cells results from an increase in non-suppressive effector-like cells. The frequency of circulating CD4
FoxP3
T-cell subsets were determined by flow cytometry in 46 GPA-patients in remission and 22 matched healthy controls (HCs). Expression levels of FoxP3 and CD45RO were used to distinguish between CD45RO
FoxP3
resting Tregs (rTreg), CD45RO
FoxP3
activated Tregs (aTreg) and CD45RO
FoxP3
proinflammatory non-suppressive T-cells (nonTreg). Intracellular expression of IFNγ, IL-17, and IL-21 was compared within these subsets. We found a significant increase in the frequency of nonTreg cells in GPA-patients as compared with HCs. Importantly, within the nonTreg subset, antineutrophil cytoplasmic autoantibody (ANCA-)positive patients demonstrated a significantly higher percentage of IL-17+ and IL-21+ cells when compared with ANCA-negative patients and HCs. Moreover, expanded nonTregs from ANCA-positive patients induced excessive proliferation of responder cells in vitro and exhibited higher IL-21 production. Production of IL-17 and IL-21 in non-suppressive FoxP3
T-cells may point toward a pathogenic role in ANCA formation.
Autoreactive B cells are key drivers of pathogenic processes in autoimmune diseases by the production of autoantibodies, secretion of cytokines, and presentation of autoantigens to T cells. However, ...the mechanisms that underlie the development of autoreactive B cells are not well understood. Here, we review recent studies leveraging novel techniques to identify and characterize (auto)antigen-specific B cells. The insights gained from such studies pertaining to the mechanisms involved in the escape of tolerance checkpoints and the activation of autoreactive B cells are discussed. In addition, we briefly highlight potential therapeutic strategies to target and eliminate autoreactive B cells in autoimmune diseases.
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