Staphylococcus aureus and Wegener's granulomatosis

Wegener's granulomatosis (WG) is a form of systemic vasculitis. It is characterized by granulomatous inflammation in the upper and lower airways, vasculitis and necrotizing glomerulonephritis, and is strongly associated with antineutrophil cytoplasmic antibodies against proteinase 3. Since the etiology of the disease is not clear, treatment, consisting of corticosteroids and immunosuppressives, is nonspecific and associated with severe side effects. Pinpointing the trigger(s) of the disease would highly improve treatment. Clinical evidence shows that an infectious agent, the bacterium Staphylococcus aureus, is a risk factor for disease relapse, suggesting its involvement in the pathogenesis of WG. Here we review both clinical and experimental data that either indicate or support a role for S. aureus in WG

Evaluation of antibodies against human HSP60 in patients with MPO-ANCA associated glomerulonephritis: a cohort study

BACKGROUND: Human Heat Shock Protein 60 (hHSP60) has been implicated in autoimmunity through molecular mimicry, based on the high degree of homology with HSP65 of micro-organisms leading to autoimmune recognition of the human protein. Additionally, sequence homology between hHSP60 and myeloperoxidase (MPO) has been described. MPO is a major autoantigen in vasculitis associated with antineutrophil cytoplasmic antibodies (ANCA). We hypothesized that infections may trigger the ANCA response against MPO through hHSP60. METHODS: In 86 consecutive patients with ANCA-associated vasculitis (AAV), anti-hHSP60 and anti-mycobacterial HSP65 were measured by ELISA. Patients were compared with 69 healthy controls (HC). Continuous data between groups were compared using Wilcoxon signed rank test and Kruskal-Wallis test with Dunn's post-test when appropriate. Correlations between data were derived using Spearman correlation. Odds ratios and 95% confidence intervals were obtained using Fisher's exact test. RESULTS: At diagnosis, median anti-mHSP65 level was higher in AAV (median [range]: 42.5 [0–500]), and subsequently in MPO-ANCA (44 [7–500]), compared to HC (22 [0–430]). Anti-hHSP60 levels in AAV were not higher compared to HC (18 [0–319] and 18.5 [0–98], respectively). However, in MPO-ANCA anti-hHSP60 levels were increased (32.5 [0–319]) compared to PR3-ANCA (13 [0–79]) and HC. We could not detect cross-reactivity between hHSP60 and MPO-ANCA. There was a correlation between anti-mHSP65 and anti-hHSP60 levels (r = 0.32, P = 0.003) but not between anti-hHSP60 and MPO-ANCA (r = -0.064, P = 0.69). CONCLUSION: Antibodies against mHSP65 are higher in AAV compared to HC, and anti-hHSP60 antibodies are higher in patients with MPO-ANCA than in patients with PR3-ANCA and HC. Although this finding may be indicative for cross-reactivity between MPO-ANCA and hHSP60, additional assays did not support this hypothesis

T cells in ANCA-associated vasculitis: what can we learn from lesional versus circulating T cells?

Anti-neutrophil cytoplasmic antibody (ANCA) - associated vasculitis (AAV) is a life-threatening autoimmune disease characterized by an antibody-mediated glomerulonephritis and necrotizing vasculitis. Apart from antibodies, T cells are also involved in disease pathogenesis. This review stresses the hallmarks of T cell-mediated pathology in AAV and highlights the characteristics of lesional and circulating T cells in the immune response in AAV. Circulating effector T-cell populations are expanded and are in a persistent state of activation. Circulating regulatory T-cell subsets are less well characterized but seem to be impaired in function. Lesional effector T cells are present in granulomas, vasculitic lesions, and nephritis. Lesional T cells usually show pro-inflammatory properties and promote granuloma formation. Apart from T cells, dendritic cells are abundantly present at the sites of inflammation and locally orchestrate the immune response. Targeting the above-mentioned T cell-mediated disease mechanisms will potentially provide powerful therapeutic tools for AAV

Randomised controlled trial of prolonged treatment in the remission phase of ANCA-associated vasculitis.

OBJECTIVES: A prospective randomised trial to compare two different durations of maintenance immunosuppressive therapy for the prevention of relapse in anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). METHODS: Patients with AAV were recruited 18-24 months after diagnosis if they were in stable remission after cyclophosphamide/prednisolone-based induction followed by azathioprine/prednisolone maintenance therapy. They were randomised (1:1) to receive continued azathioprine/prednisolone to 48 months from diagnosis (continuation group) or to withdraw azathioprine/prednisolone by 24 months (withdrawal group). The primary endpoint was the relapse risk, from randomisation to 48 months from diagnosis. RESULTS: One hundred and seventeen patients were randomised and 110 remained to the trial end. At entry, median serum creatinine was 116 μmol/L (range 58-372), 53% were ANCA positive. The percentage of patients presenting with relapse was higher in the withdrawal than in the continuation treatment group (63% vs 22%, p<0.0001, OR 5.96, 95% CI 2.58 to 13.77). ANCA positivity at randomisation was associated with relapse risk (51% vs 29%, p=0.017, OR 2.57, 95% CI 1.16 to 5.68). Renal function, ANCA specificity, vasculitis type and age were not predictive of relapse. Severe adverse events were more frequent in the continuation than withdrawal groups (nine vs three events), but the continuation group had better renal outcome (0 vs 4 cases of end-stage renal disease), with no difference in patient survival. CONCLUSIONS: Prolonged remission maintenance therapy with azathioprine/prednisolone, beyond 24 months after diagnosis reduces relapse risk out to 48 months and improves renal survival in AAV. TRIAL REGISTRATION NUMBER: ISRCTN13739474

Understanding COVID-19 vaccine hesitancy in vasculitis patients

ObjectiveTo identify the factors that impact COVID-19 vaccine decision-making in vaccine-hesitant vasculitis patients, and compare their perceptions with other rheumatology patients, given existence of data suggesting rheumatology patients may have disease-specific factors that influence their COVID-19 vaccine decision-making.MethodsThis cross-sectional study surveyed adult rheumatology patients from the Kaye Edmonton Clinic Rheumatology Clinic, in Canada, between June and August 2021, using an anonymous online questionnaire. Survey responses were analyzed for statistical differences using chi-square analysis.ResultsThe COVID-19 Vaccine Perceptions Survey had a response rate of 70.9%. Of the total 231 respondents, 103 patients were diagnosed with vasculitis. At the time of the survey, 10.6% of vasculitis patients refused to receive a COVID-19 vaccine compared to 6.3% for other rheumatology patients. Compared to other rheumatology patients, vaccine-hesitant vasculitis patients were significantly more concerned about almost every aspect of available COVID-19 vaccines [e.g., safety (p &lt; 0.001), components (p &lt; 0.001)], and feared that they could contract SARS-CoV-2 from a vaccine (p &lt; 0.001). These vaccine-hesitant patients were also significantly less pleased with the government's pandemic response, less confident in healthcare team-provided information (p &lt; 0.001), and more likely to report that healthcare providers had no role in their COVID-19 vaccine decision-making (p &lt; 0.001).ConclusionVaccine-hesitant vasculitis patients may have multiple considerations influencing COVID-19 vaccine hesitancy, including vaccine and disease-specific concerns, along with unfavorable perceptions of the healthcare system (government and healthcare providers). Healthcare providers can address some of these concerns by initiating patient-centered discussions around immunizations to help support educated decision-making

Metabolomic and immune alterations in long COVID patients with chronic fatigue syndrome

IntroductionA group of SARS-CoV-2 infected individuals present lingering symptoms, defined as long COVID (LC), that may last months or years post the onset of acute disease. A portion of LC patients have symptoms similar to myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), which results in a substantial reduction in their quality of life. A better understanding of the pathophysiology of LC, in particular, ME/CFS is urgently needed.MethodsWe identified and studied metabolites and soluble biomarkers in plasma from LC individuals mainly exhibiting ME/CFS compared to age-sex-matched recovered individuals (R) without LC, acute COVID-19 patients (A), and to SARS-CoV-2 unexposed healthy individuals (HC).ResultsThrough these analyses, we identified alterations in several metabolomic pathways in LC vs other groups. Plasma metabolomics analysis showed that LC differed from the R and HC groups. Of note, the R group also exhibited a different metabolomic profile than HC. Moreover, we observed a significant elevation in the plasma pro-inflammatory biomarkers (e.g. IL-1α, IL-6, TNF-α, Flt-1, and sCD14) but the reduction in ATP in LC patients. Our results demonstrate that LC patients exhibit persistent metabolomic abnormalities 12 months after the acute COVID-19 disease. Of note, such metabolomic alterations can be observed in the R group 12 months after the acute disease. Hence, the metabolomic recovery period for infected individuals with SARS-CoV-2 might be long-lasting. In particular, we found a significant reduction in sarcosine and serine concentrations in LC patients, which was inversely correlated with depression, anxiety, and cognitive dysfunction scores.ConclusionOur study findings provide a comprehensive metabolomic knowledge base and other soluble biomarkers for a better understanding of the pathophysiology of LC and suggests sarcosine and serine supplementations might have potential therapeutic implications in LC patients. Finally, our study reveals that LC disproportionally affects females more than males, as evidenced by nearly 70% of our LC patients being female