Low-dose trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis is associated with a lower risk for severe infections in patients with antineutrophil cytoplasm antibodies (ANCA)-associated vasculitis receiving rituximab or cyclophosphamide followed by azathioprine, according to a recent study.
Balazs Odler, MD, PhD, of the University of Cambridge in the UK and the Medical University of Graz in Austria, and colleagues analyzed data from 197 patients in the RAVE (Rituximab versus Cyclophosphamide for ANCA-Associated Vasculitis) clinical trial. Of 22 severe infections that developed during the trial, 18 (82%) occurred within 6 months of study entry and 15 (68%) were respiratory tract infections, the investigators reported in the Annals of the Rheumatic Diseases. A higher CD19+ B cell number at study entry and TMP-SMX prophylaxis against Pneumocystis jirovecii pneumonia (PJP) were associated with a reduced risk for severe infections. TMP/SMX prophylaxis was significantly associated with a nearly 77% lower risk for severe infections compared with no TMP/SMX prophylaxis.
Dr Odler and colleagues concluded that their study demonstrates that use of TMP/SMX prophylaxis against PJP “is significantly associated with reduced risk of severe infections in patients with [ANCA-associated vasculitis], independent of the choice of therapy used to induce remission. These data further suggest that certain B cell subpopulations may serve as a useful tool to determine general immunocompetence of [ANCA-associated vasculitis] patients, and to identify individuals at higher risk of infectious complications.”
Odler B, Riedl R, Gauckler P, et al. Risk factors for serious infections in ANCA-associated vasculitis. Ann Rheum Dis. Published online January 26, 2023. doi:10.1136/ard-2022-223401