The effect of nasal Staphylococcus aureus colonization and antibiotic treatment on disease activity in ANCA-associated vasculitis: a retrospective cohort study in the Netherlands.

The aim of this study was to identify the role of nasal Staphylococcus aureus (S. aureus) colonization and the effect of systemic or local antibiotic treatment on disease activity in patients with antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis and ear nose and throat (ENT) involvement. Clinical, laboratory and histological data from all patients with ANCA-associated vasculitis and ENT involvement, who were diagnosed in two medical centres in The Netherlands between 1981 and 2020, were retrospectively collected. Nasal S. aureus colonization was defined as at least one positive nasal swab during follow-up. Data on systemic (cotrimoxazole and azithromycin) and local (mupirocin) antibiotic use were collected. Disease activity was divided into systemic and local disease activity. Univariate analyses and regression analyses (negative binomial Poisson and binary regression) were used. Two-hundred and thirteen patients were available for analysis. Median follow-up time was 8 (IQR 3-17) years. S. aureus colonization was tested in 100 (46.9%) cases of whom 44 patients (44%) tested positive. In these 100 patients, systemic and local disease activity at baseline and at last visit were comparable between patients with and without S. aureus colonization. Twenty-eight of the 44 S. aureus positive patients received antibiotics aimed at eradication of S. aureus. No statistically significant difference was found between the treated versus non-treated group with regard to systemic and local disease activity. Nasal S. aureus colonization does not influence systemic or local disease activity. Antibiotic treatment aimed at eradication did not modify disease activity.

Immunosuppressive Therapies in Ear, Nose, and Throat Involvement in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Results From a Multicenter Retrospective Cohort Study.

OBJECTIVE: The aim of this study was to evaluate the response of ear, nose, and throat (ENT) symptoms to different immunosuppressive therapies in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: In this cohort study, patients with AAV treated between January 2010 and April 2020 at 2 Dutch hospitals were included. Clinical, histological, and laboratory data were collected retrospectively. ENT involvement was defined as follows: (1) ≥ 1 ENT symptom according to the Birmingham Vasculitis Activity Score (version 3; BVAS3), and/or (2) presence of saddle nose deformity. Associations between therapy and ENT activity were assessed using logistic regression analysis. RESULTS: A total of 320 patients with AAV were included, of whom 209 (65.3%) had ENT involvement at some point throughout the disease course. In these 209 patients, median age at disease onset was 52.0 years (IQR 40.0-62.0) and 45.5% were male. Median BVAS3 was 12.0 (IQR 6.0-18.0) at diagnosis. Despite immunosuppressive therapy, 50% (n = 77) of the patients had ENT symptoms at relapse and 29.1% (n = 59) had ENT activity at their last visit. No statistically significant difference in ENT activity at last visit was observed between patients treated with oral or intravenous cyclophosphamide (CYC, n = 137) compared to rituximab (RTX, n = 55; adjusted odds ratio 0.59, 95% CI 0.33-1.06; P = 0.08). Lower age at disease onset and female sex were independently associated with ENT activity at last follow-up. CONCLUSION: In this cohort, CYC and RTX therapy had similar therapeutic effects on ENT symptoms in AAV. Persistent ENT activity is a common feature despite immunosuppressive therapy.