Prophylaxis Against Respiratory Infection Tested Among Patients with AAV

Analysis of data from the Rituximab versus Cyclophosphamide for ANCA-Associated Vasculitis (RAVE) trial concluded that patients with antineutrophil cytoplasm antibody-associated vasculitis (AAV) were less likely to develop severe infections when treated prophylactically with trimethoprim-sulfamethoxazole (TMP/SMX), no matter which treatment for AAV they received.

The authors of the study noted, “Severe infections contribute to morbidity and mortality in antineutrophil cytoplasm antibody-associated vasculitis (AAV). This study aimed to identify risk factors associated with severe infections” among the trial participants, who received either rituximab (RTX) or cyclophosphamide (CYC), followed by azathioprine (AZA).

Among 197 patients whose data were analyzed, 18 of 22 (82%) severe infections occurred within 6 months of entering the trial; 15 of the 22 severe infections (68%) were respiratory.  

“At baseline, lower absolute numbers of CD19+ cells were observed in patients with severe infections either receiving RTX or CYC/AZA at baseline, while CD5+B and CD3+T cells did not differ between groups,” the authors reported. “In Cox-regression analysis, higher baseline serum immunoglobulin M levels were associated with the risk of severe infections, whereby a higher baseline total CD19+B cell number and prophylaxis against Pneumocystis jirovecii with trimethoprim-sulfamethoxazole (TMP/SMX) with decreased risk of severe infections. Use of TMP/SMX was associated with lower risk of severe infections in both groups, receiving either RTX or CYC/AZA.”

The investigators concluded, “The use of low-dose TMP/SMX is associated with reduced risk of severe infections in patients with AAV treated with either RTX or CYC/AZA. Reduced B cell subpopulations at start of treatment might be a useful correlate of reduced immunocompetence.”

—Rebecca Mashaw

Reference:

Odler B, Riedl R, Gauckler P, et al. Risk factors for serious infections in ANCA-associated vasculitis. Ann Rheum Dis. 2023;82(5):681-687. doi: 10.1136/ard-2022-223401.