ANCA detection with solid phase chemiluminescence assay: diagnostic and severity association in vasculitis.

ANCA-associated vasculitis (AAV) comprises a group of necrotizing vasculitis that mainly affects small- and medium-sized vessels. Serum anti-neutrophil cytoplasmic antibodies (ANCA), mainly anti-myeloperoxidase (anti-MPO) and anti-proteinase 3 (anti-PR3), levels may correlate to severity, prognosis, and recurrence of the disease. A retrospective analysis of 101 patients with MPO-positive and 54 PR3-positive vasculitis was performed, using laboratory established cut-off value, measured by chemiluminescence. Furthermore, data of renal disease and pulmonary involvement were collected at vasculitis diagnosis, as well as the progress, requiring dialysis, transplant, or mortality. For anti-MPO antibodies with a diagnosis of vasculitis (n = 77), an area under the curve (AUC) was calculated (AUC = 0.8084), and a cut-off point of 41.5 IU/ml was determined. There were significant differences in anti-MPO levels between patients with renal or pulmonary dysfunction (n = 65) versus those without them (n = 36) (p = 0.0003), and a cut-off threshold of 60 IU/ml was established. For anti-PR3 antibodies with a diagnosis of vasculitis (n = 44), an area under the curve (AUC) was calculated (AUC = 0.7318), and a cut-off point of 20.5 IU/ml was determined. Significant differences in anti-PR3 levels were observed between those patients with renal or pulmonary dysfunction (n = 30) and those without them (n = 24) (p = 0.0048), and a cut-off threshold of 41.5 IU/ml was established. No significant differences between those patients who had a worse disease progression and those who did not were found for anti-MPO and anti-PR3. Anti-MPO and anti-PR3 levels at the moment of vasculitis diagnosis are related with disease severity but not with disease outcome or vasculitis recurrence.

Intravenous immunoglobulin therapy in antineutrophil cytoplasmic antibody-associated vasculitis.

INTRODUCTION: Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) includes three heterogeneous and difficult to treat clinical entities. Intravenous immunoglobulins (IVIG) may constitute a good therapeutic option, although data hitherto are scarce. The aim of this study was to assess the effectiveness and safety of IVIG in AAV in a real-world setting. METHODS: Single center observational study of patients with AAV with at least one cycle of IVIG since January of 2000 to December of 2020. AAV diagnosis was based on a compatible clinical presentation and positive ANCA serology and/or compatible histology. Disease activity was assessed by the Birmingham Vasculitis Activity Score (BVAS). The effectiveness was evaluated by clinical and laboratory parameters (CRP, ESR) and its glucocorticoid-sparing effect. These variables were measured at one, six, twelve and twenty-four months of IVIG treatment. The doses of IVIG were 2g/kg in the following cycles of administration: 1 g/kg/day in 2 days (n=12); 0.5 g/kg/day in 4 days (n=11); 0.4 g/kg/day in 5 days (n=5). The clinical improvement was classified according to BVAS categories in remission, partial response and no response. RESULTS: Twenty-eight patients (15 granulomatosis-polyangiitis, 10 microscopic polyangiitis and 3 eosinophilic granulomatosis with polyangiitis) were included. Reasons for using IVIG were relapse/refractory disease (n=25), active or suspected infection (n=3), and both (n=5). We observed a rapid and maintained BVAS score improvement, increasing from 34.6% at 1 month to 56.5% at 2 years of follow-up (p=0.12), and a reduction of glucocorticoids dose. Therapy was well tolerated and adverse events mild and scarce. CONCLUSION: IVIG represents an effective and relative safe therapeutic alternative in relapsing/refractory AAV or in presence of a concomitant active infection.

Coronavirus disease 2019 in patients with rheumatic immune-mediated diseases in a single University Hospital, matched case-control study and literature review.

Background: COVID-19 may present different degrees of severity. Viral infections in patients with rheumatic inflammatory diseases (R-IMID) trend to present more severe disease. However, data comparing the severity of the disease between R-IMID and the general population are scarce. Objectives: To compare predisposing factors, clinical, serological features, and severity of COVID-19 infection in patients with and without R-IMID. Methods: Case-control study in a single University Hospital. We included all consecutive patients with a diagnosis of an R-IMID and COVID-19 infection up to March 31st, 2021. This cohort was compared to patients without R-IMID and not receiving immunosuppressive therapy, matched for sex and age (±5 years). Confirmed infection was defined if a patient had a positive nasopharyngeal swab for SARS-CoV-2. Severity was divided into mild, moderate, severe and critical according to the United States National Institute of Health (NIH) guidelines. Results: We included 274 R-IMID patients (185 women/89 men), mean age 59.1 ± 18 years. More frequent R-IMID were: Rheumatoid arthritis (28.8%), Psoriatic Arthritis (20.1%), axial Spondyloarthritis (12.4%), Polymyalgia Rheumatica (8%) and Systemic Lupus Erythematosus (8%). Hypertension and dyslipidemia were more frequent in patients with R-IMID. Although most of the cases were mild, critical cases and deaths were more frequent in R-IMID. When adjusted by comorbidities, no statistical differences were observed. Conclusion: R-IMID have a very similar clinical presentation when compared to the general population. There is a trend to an increased severity of the disease in patients with R-IMID.