Background/Purpose
Staphylococcus aureus (SA) nasal carriage has been reported to be more frequent and associated with persistent ANCA-positivity and relapse in patients with granulomatosis with polyangiitis (GPA). Antibiotics, including cotrimoxazole (CTX), usually active against SA, have been shown to prevent relapses in some GPA patients. Nasal carriage of SA and its small colony variants (SCV; intracellular SA with altered virulence phenotypes involved in chronic recurrent infection models) is unknown, respectively, during other ANCA-associated vasculitides (AAV), and those AAV and GPA.
Methods
All consecutive patients (09/2012–05/2013) with GPA, eosinophilic granulomatosis with polyangiitis (EGPA) or microscopic polyangiitis (MPA), followed at the French National Vasculitis Referral Center, and hospitalized patients, without vasculitis or specific risk factors for SA carriage (controls), were enrolled. All had bilateral anterior nasal swab cultures and SA-carriage frequencies were determined for each group. The French National Reference Center for Staphylococci identified the strains. Associations between SA nasal carriage and clinical manifestations, Birmingham Vasculitis Score (BVAS)-assessed disease activity, ANCA or C-reactive protein (CRP) level, and CTX impact on SA nasal carriage and BVAS were analyzed.
Results
A total of 119 AAV (GPA, n=80; EGPA, n=28; MPA, n=11) patients and 28 controls were enrolled. SA nasal carriage among the 3 AAV groups did not differ: 24 (30%) GPA, 8 (28.6%) EGPA and 3 (27.3%) MPA (P=0.971). Controls had non-significantly less frequent SA carriage (13.8%; P=0.39). SA-SCV phenotypes were identified in samples from 5/24 (20.8%) GPA, 1/8 (12.5%) EGPA and 2/3 (66.7%) MPA patients. SA nasal carriage was not significantly associated with number of prior relapse (P=0.866), BVAS (P=0.724), ANCA-positivity (P=0.657) or CRP level (P=0.340) for AAV, or GPA prior relapses (P=0.971) or BVAS (P=0.485). However, CTX use (usually as prophylaxis) was associated with a lower BVAS (P=0.029) and tended to be associated with a lower SA nasal carriage rate [9/43 (20.9%) patients on CTX vs 25/71 (35.2%) not on CTX; P=0.09].
Conclusion Based on our results, SA nasal carriage did not differ among the AAV considered but seemed more frequent than in controls. Notably, CTX use, but not SA carriage, was associated with a lower BVAS and might reflect its intrinsic antiinflammatory rather than antimicrobial activity. Further bacterial analyses are needed to determine SA-strain susceptibility to CTX and identify known epidemic SA clones among those isolated from AAV carriers.
Disclosure:
B. K. Tan,
None;
Y. Crabol,
None;
J. Tasse,
None;
F. Laurent,
None;
X. Puechal,
None;
C. Vinter,
None;
L. Guillevin,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/staphylococcus-aureus-nasal-carriage-and-relapses-bvas-anca-positivity-and-cotrimoxazole-use-in-anca-associated-vasculitis/