Rituximab versus azathioprine for maintenance of remission for patients with ANCA-associated vasculitis and relapsing disease: an international randomised controlled trial.

OBJECTIVE: Following induction of remission with rituximab in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) relapse rates are high, especially in patients with history of relapse. Relapses are associated with increased exposure to immunosuppressive medications, the accrual of damage and increased morbidity and mortality. The RITAZAREM trial compared the efficacy of repeat-dose rituximab to daily oral azathioprine for prevention of relapse in patients with relapsing AAV in whom remission was reinduced with rituximab. METHODS: RITAZAREM was an international randomised controlled, open-label, superiority trial that recruited 188 patients at the time of an AAV relapse from 29 centres in seven countries between April 2013 and November 2016. All patients received rituximab and glucocorticoids to reinduce remission. Patients achieving remission by 4 months were randomised to receive rituximab intravenously (1000 mg every 4 months, through month 20) (85 patients) or azathioprine (2 mg/kg/day, tapered after month 24) (85 patients) and followed for a minimum of 36 months. The primary outcome was time to disease relapse (either major or minor relapse). RESULTS: Rituximab was superior to azathioprine in preventing relapse: HR 0.41; 95% CI 0.27 to 0.61, p<0.001. 19/85 (22%) patients in the rituximab group and 31/85 (36%) in the azathioprine group experienced at least one serious adverse event during the treatment period. There were no differences in rates of hypogammaglobulinaemia or infection between groups. CONCLUSIONS: Following induction of remission with rituximab, fixed-interval, repeat-dose rituximab was superior to azathioprine for preventing disease relapse in patients with AAV with a prior history of relapse. TRIAL REGISTRATION NUMBER: NCT01697267; ClinicalTrials.gov identifier.

Humoral and cellular immunity in patients with rare autoimmune rheumatic diseases following SARS-CoV-2 vaccination.

OBJECTIVES: Coronavirus 2019 vaccine responses in rare autoimmune rheumatic diseases (RAIRDs) remain poorly understood; in particular there is little known about whether people develop effective T cell responses. We conducted an observational study to evaluate the short-term humoral and cell-mediated T cell response after the second severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in RAIRD patients compared with healthy controls (HCs). METHODS: Blood samples were collected after the second dose and anti-spike, anti-nucleocapsid antibody levels and SARS-CoV-2-specific T cell responses were measured and compared with those of HCs. Activation-induced marker and deep phenotyping assays were used to identify differences in T cells between high and no/low antibody groups, followed by multidimensional clustering. RESULTS: A total of 50 patients with RAIRDs were included (31 with AAV, 4 with other systemic vasculitis, 9 with SLE and 6 with myositis). The median anti-spike levels were significantly lower in RAIRD patients compared with HCs (P < 0.0001). Fifteen (33%) patients had undetectable levels and 26 (57%) had levels lower than the lowest HC. Rituximab in the last 12 months (P = 0.003) was associated with reduced immunogenicity compared with a longer pre-vaccination period. There was a significant difference in B cell percentages (P = 0.03) and spike-specific CD4+ T cells (P = 0.02) between no/low antibody vs high antibody groups. Patients in the no/low antibody group had a higher percentage of terminally differentiated (exhausted) T cells. CONCLUSIONS: Following two doses, most RAIRD patients have lower antibody levels than the lowest HC and lower anti-spike T cells. RAIRD patients with no/low antibodies have diminished numbers and poor quality of memory T cells that lack proliferative and functional capacities.

Antibody response to four doses of SARS-CoV-2 vaccine in rare autoimmune rheumatic diseases: an observational study.

Objective: Antibody responses to coronavirus disease 2019 (COVID-19) vaccines are reduced among immunocompromised patients but are not well quantified among people with rare disease. We conducted an observational study to evaluate the antibody responses to the booster SARS-CoV-2 vaccine in people with rare autoimmune rheumatic diseases (RAIRD). Methods: Blood samples were collected after second, before third, after third and after fourth vaccine doses. Anti-spike and anti-nucleocapsid antibody levels were measured using an in-house ELISA. Logistic regression models were built to determine the predictors for non-response. Results were compared with age- and sex-matched healthy controls. Results: Forty-three people with RAIRD were included, with a median age of 56 years. Anti-spike seropositivity increased from 42.9% after second dose to 51.2% after third dose and 65.6% after fourth dose. Median anti-spike antibody levels increased from 33.6 (interquartile range 7.8-724.5) binding antibody units after second dose to 239.4 (interquartile range 35.8-1051.1) binding antibody units after the booster dose (third dose, or fourth dose if eligible). Of the participants who had sufficient antibody levels post-second dose, 22.2% had insufficient levels after the booster, and 34.9% of participants had lower antibodies after the booster than the lowest healthy control had after the second dose. Rituximab in the 6 months prior to booster (P = 0.02) and non-White ethnicity (P = 0.04) were associated with non-response. There was a dose-response relationship between the timing of rituximab and generation of sufficient antibodies (P = 0.03). Conclusion: Although the booster dose increased anti-spike IgG and seropositivity rates, some people with RAIRD, particularly those on rituximab, had insufficient antibody levels despite three or four doses.

Complement receptor CD46 co-stimulates optimal human CD8+ T cell effector function via fatty acid metabolism.

The induction of human CD4+ Th1 cells requires autocrine stimulation of the complement receptor CD46 in direct crosstalk with a CD4+ T cell-intrinsic NLRP3 inflammasome. However, it is unclear whether human cytotoxic CD8+ T cell (CTL) responses also rely on an intrinsic complement-inflammasome axis. Here we show, using CTLs from patients with CD46 deficiency or with constitutively-active NLRP3, that CD46 delivers co-stimulatory signals for optimal CTL activity by augmenting nutrient-influx and fatty acid synthesis. Surprisingly, although CTLs express NLRP3, a canonical NLRP3 inflammasome is not required for normal human CTL activity, as CTLs from patients with hyperactive NLRP3 activity function normally. These findings establish autocrine complement and CD46 activity as integral components of normal human CTL biology, and, since CD46 is only present in humans, emphasize the divergent roles of innate immune sensors between mice and men.

Long-term outcomes of daily oral vs. pulsed intravenous cyclophosphamide in a non-trial setting in ANCA-associated vasculitis.

We aimed to compare risk of death, relapse, neutropenia and infection requiring hospital admission between unselected ANCA-associated vasculitis (AAV) patients according to whether cyclophosphamide induction was by daily oral (PO) or pulse intravenous (IV) route. We identified all newly diagnosed AAV patients treated with PO or IV cyclophosphamide between March 2007 and June 2013. We used Cox and logistic regression models to compare mortality, relapse and adverse events and adjusted these for age, renal function and other significant confounders. Fifty-seven patients received PO and 57 received IV cyclophosphamide. One-year survival was 86.0% in PO and 98.2% in IV patients; all-time adjusted hazard ratio (HR) for PO compared to that of IV cyclophosphamide was 1.8 (95% CI 0.3-10.6, P = 0.54). One-year relapse-free survival was 80.7% in PO compared to 87.3% in IV patients, all-time adjusted HR 3.8 (0.2-846, P = 0.37). During the first 12 months, neutropenia of ≤ 0.5 × 109/L occurred in 9 (16%) PO and 0 (0%) IV cyclophosphamide patients (P = 0.003). The number of patients admitted with one or more infections was 16 (28%) in the PO group and 9 (16%) in the IV group, adjusted OR 2.2 (0.6-8.6, P = 0.23). We observed an increased risk of neutropenia, a trend towards increased risk of death and an admission with infection with PO cyclophosphamide. This adds certainty to previous studies, indicating that PO administration induces greater marrow toxicity. Infection-related admissions within 12 months of starting cyclophosphamide were higher than those in clinical trials, possibly reflecting the unselected nature of this cohort.

Can we routinely measure patient involvement in treatment decision-making in chronic kidney care? A service evaluation in 27 renal units in the UK.

BACKGROUND: Shared decision making is considered an important aspect of chronic disease management. We explored the feasibility of routinely measuring kidney patients' involvement in making decisions about renal replacement therapy (RRT) in National Health Service settings. METHODS: We disseminated a 17-item paper questionnaire on involvement in decision-making among adult patients with established kidney failure who made a decision about RRT in the previous 90 days (Phase 1) and patients who had been receiving RRT for 90-180 days (Phase 2). Recruitment rates were calculated as the ratio between the number of included and expected eligible patients (I : E ratio). We assessed our sample's representativeness by comparing demographics between participants and incident patients in the UK Renal Registry. RESULTS: Three hundred and five (Phase 1) and 187 (Phase 2) patients were included. For Phase 1, the I : E ratio was 0.44 (range, 0.08-2.80) compared with 0.27 (range, 0.04-1.05) in Phase 2. Study participants were more likely to be white compared with incident RRT patients (88 versus 77%; P < 0.0001). We found no difference in age, gender or social deprivation. In Phases 1 and 2, the majority reported a collaborative decision-making style (73 and 69%), and had no decisional conflict (85 and 76%); the median score for shared decision-making experience was 12.5 (Phase 1) and 10 (Phase 2) out of 20. CONCLUSION: Our study shows the importance of assessing the feasibility of data collection in a chronic disease context prior to implementation in routine practice. Routine measurement of patient involvement in established kidney disease treatment decisions is feasible, but there are challenges in selecting the measure needed to capture experience of involvement, reducing variation in response rate by service and identifying when to capture experience in a service managing people's chronic disease over time.

CD8 T cells induce T-bet-dependent migration toward CXCR3 ligands by differentiated B cells produced during responses to alum-protein vaccines.

Antibody-forming cells (AFCs) expressing the chemokine receptor CXCR3 are recruited to sites of inflammation where they help clear pathogens but may participate in autoimmune diseases. Here we identify a mechanism that induces CXCR3 expression by AFC and germinal center (GC) B cells. This happens when CD8 T cells are recruited into CD4 T cell-dependent B-cell responses. Ovalbumin-specific CD4 T cells (OTII) were transferred alone or with ovalbumin-specific CD8 T cells (OTI) and the response to subcutaneous alum-precipitated ovalbumin was followed in the draining lymph nodes. OTII cells alone induce T helper 2-associated class switching to IgG1, but few AFC or GC B cells express CXCR3. By contrast, OTI-derived IFN-γ induces most responding GC B cells and AFCs to express high levels of CXCR3, and diverse switching to IgG2a, IgG2b, with some IgG1. Up-regulation of CXCR3 by GC B cells and AFCs and their migration toward its ligand CXCL10 are shown to depend on B cells' intrinsic T-bet, a transcription factor downstream of the IFN-γR signaling. This model clarifies how precursors of long-lived AFCs and memory B cells acquire CXCR3 that causes their migration to inflammatory foci.

Measurement of antibodies to pneumococcal, meningococcal and haemophilus polysaccharides, and tetanus and diphtheria toxoids using a 19-plexed assay.

The measurement of antibody responses to vaccination is useful in the assessment of immune status in suspected immune deficiency. Previous reliance on enzyme-linked immunoabsorbent assays (ELISA) has been cumbersome, time-consuming and expensive. The availability of flow cytometry systems has led to the development of multiplexed assays enabling simultaneous measurement of antibodies to several antigens. We optimized a flow cytometric bead-based assay to measure IgG and IgM concentrations in serum to 19 antigens contained in groups of bacterial subunit vaccines: pneumococcal vaccines, meningococcal vaccines, Haemophilus influenzae b (Hib), and tetanus and diphtheria toxoid vaccines. 89-SF was employed as the standard serum. The assay was used to determine specific antibody levels in serum from 193 healthy adult donors. IgG and pneumococcal IgM antibody concentrations were measurable across 3 log10 ranges encompassing the threshold protective IgG antibody levels for each antigen. There was little interference between antibody measurements by the 19-plexed assay compared with monoplexed assays, and a lack of cross-reactive IgG antibody, but evidence for cross-reacting IgM antibody for 3/19 pneumococcal antigens. 90th centile values for 15/19 IgG concentrations and 12/12 IgM concentrations of the 193 adult sera were within these ranges and percentages of sera containing protective IgG antibody levels varied from 4% to 95% depending on antigen. This multiplexed assay can simultaneously measure antibody levels to 19 bacterial vaccine antigens. It is suitable for use in standard clinical practice to assess the in vivo immune response to test vaccinations and measure absolute antibody levels to these antigens.

A multicenter survey of rituximab therapy for refractory antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVE: B cell depletion with rituximab has allowed remissions in relapsing or refractory antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis in small studies. The aim of this study was to determine the efficacy and safety of rituximab for ANCA-associated vasculitis in a larger multicenter cohort. This permitted comparison of rituximab dosing regimens, the value of continuing immunosuppression, and investigation of ANCA and B cell levels as re-treatment biomarkers. METHODS: Retrospective, standardized data collection from 65 sequential patients receiving rituximab for refractory ANCA-associated vasculitis at 4 centers in the UK was used. RESULTS: All patients achieved B cell depletion. Complete remission occurred in 49 of the 65 patients (75%), partial remission in 15 (23%), and no response in 1 (2%). The prednisolone dosage was reduced from 12.5 mg/day (median) to 9.0 mg/day at 6 months (P = 0.0006). Immunosuppressive therapy was withdrawn in 37 of 60 patients (62%). Twenty-eight of 49 patients who achieved full remission (57%) experienced relapse (median 11.5 months). B cell return preceded relapse in 14 of 27 patients (52%). Although ANCA levels fell after rituximab therapy, relapse was not associated with ANCA positivity or a rise in ANCA levels. Neither the initial rituximab regimen (4 infusions of 375 mg/m(2) each given 1 week apart or 2 infusions of 1 gm each given 2 weeks apart) nor withdrawal of immunosuppressive therapy (37 of 60 patients [62%]) influenced the timing of relapse. Thirty-eight patients received >or=2 courses of rituximab, and complete remission was induced or maintained in 32 of them (84%). IgM levels fell, although IgG levels remained stable. Forty-six serious adverse events occurred, including 2 episodes of late-onset neutropenia, which were attributed to rituximab. CONCLUSION: Rituximab was effective remission induction therapy for refractory ANCA-associated vasculitis in this study. There was no difference in efficacy between the 2 main treatment regimens. Continuing immunosuppression did not reduce relapses. Relapses occurred, but re-treatment was effective and safe. There was no clear influence of rituximab on the frequency of serious adverse events. ANCA and B cell levels lacked sufficient sensitivity to guide the timing of re-treatment.

Relapsed Wegener's granulomatosis after rituximab therapy--B cells are present in new pathological lesions despite persistent 'depletion' of peripheral blood.

Wegener's granulomatosis (WG) is a chronic, relapsing, systemic autoimmune disease. Rituximab, a monoclonal antibody against human CD20, has shown promise as a novel treatment for WG. The monitoring of therapeutic B-cell 'depletion' by peripheral blood flow cytometry has been proposed to help monitor rituximab therapy. We report the case of a patient with known WG and granulomatous disease, successfully treated with rituximab, who relapsed whilst peripheral blood monitoring apparently indicated persistent B-cell depletion. Further investigations demonstrated CD20(+) B cells in tissue at sites of active disease. The implications for disease pathogenesis and clinical monitoring of disease are discussed.

Social support is positively associated with the immunoglobulin M response to vaccination with pneumococcal polysaccharides.

Evidence shows that psychosocial factors are associated with immunoglobulin G response to medical vaccinations. As yet, there are no reports of whether the earlier immunoglobulin M response is similarly susceptible. This study examined the association between psychological stress, social support and the immunoglobulin M response to vaccination with pneumococcal capsular polysaccharides. Stressful life events in the previous year and customary social support were measured by standard questionnaires at baseline in 74 healthy students (41 females). The response to five common pneumococcal serotypes was assessed at baseline and 5 days following vaccination. Social support, particularly tangible social support, was positively associated with the antibody response to two of five serotypes, after controlling for baseline titre. These associations survived adjustment for demographics and health behaviours. There was no association between life events stress and immunoglobulin M response. It appears that psychosocial factors affect both the immunoglobulin M and immunoglobulin G responses to vaccination.

Levels of autoantibodies, unlike antibodies to all extrinsic antigen groups, fall following B cell depletion with Rituximab.

Many autoantibodies have variable-region sequences indicating their production in an affinity-matured antibody response involving germinal centers (GC). Plasma cells from GC can be long-lived, do not express CD20 and thus should not be depleted by a therapeutic monoclonal Ab against human CD20 - Rituximab. Nevertheless, autoantibody titers often fall following Rituximab treatment. To test if this reflects exclusive production by short-lived plasma cells in extrafollicular Ab responses, we monitored, after Rituximab treatment, levels of natural Ab and Ab against extrinsic antigens that do not induce productive GC. Eleven patients with active vasculitis and anti-proteinase-3 (PR3) Ab were assessed before and during 5 months after Rituximab therapy. Blood B cells were undetectable within 2 wk, and all patients achieved clinical remission. Levels of natural Ab - isohemagglutinins and anti-phosphorylcholine Ab - and Ab levels against thymus-independent and thymus-dependent extrinsic antigens were little affected. By contrast, 5 months after Rituximab, IgG autoantibody against PR3 had fallen to a median of 22% of pretreatment values. While the kinetics of this fall do not suggest an intrinsically short lifespan of autoantibody-producing cells, the data are consistent with Rituximab causing loss of sites within inflammatory tissues that selectively sustain autoantibody-producing cells.

Psychosocial factors are associated with the antibody response to both thymus-dependent and thymus-independent vaccines.

The present study examined the association between psychological stress, social support and antibody response to both thymus-dependent and thymus-independent vaccinations. Stressful life events in the previous year and customary social support were measured by standard questionnaires at baseline in 75 (41 females) healthy students. Antibody status was assessed at baseline, 4 and 18 weeks following vaccination with formaldehyde inactivated hepatitis A virus and pneumococcal polysaccharides, which induce thymus-dependent and -independent antibody responses respectively. Controlling for baseline antibody status, life event stress was negatively associated with antibody response to the hepatitis A vaccine at the 18-week follow-up; participants reporting a greater number of stressful life events had a poorer antibody response. There was no relationship between psychological stress and antibody response to pneumococcal vaccination. Social support was not associated with the antibody response to hepatitis A vaccination. However, there was a significant association between support and the antibody response to the thymus-independent pneumococcal vaccine at 4-week follow-up; participants with larger social networks mounted a better response. These relationships could not be accounted for by age and sex, or by variations in health behaviours. Psychosocial factors would appear to influence the response to both thymus-dependent and thymus-independent vaccines, but not in the same manner.

Pathogenic mechanisms of anti-neutrophil cytoplasm antibody-associated vasculitis.

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides are rare autoimmune diseases that can often be life threatening. They particularly affect the kidneys and lungs but can also affect many other organs. Various hypotheses have been proposed to explain the loss of tolerance against ANCA antigens (present in granules of neutrophils and monocytes); however, clear mechanisms remain elusive. Clinical observation, in vitro studies and newly developed animal models implicate ANCAs in disease pathogenesis and relevant mechanisms are now being characterized. Abnormalities in patient's T-cell populations exist and the increasingly recognized role of B cells in ANCA-associated vasculitis is also discussed.