Prevention of infections in patients with antineutrophil cytoplasm antibody-associated vasculitis: potential role of hydroxychloroquine

In a recent observational study, Kronbichler et al recorded 95 severe/life-threatening infections in 49 of 192 patients (25.5%) with associated vasculitides (AAV) within approximately 2 years following rituximab initiation.1 Respiratory tract infections were the most common infectious complications. In patients with a positive culture, opportunistic pathogens were frequently seen, though Pneumocystis jirovecii was identified in only one case. Trimethoprim/sulfamethoxazole prophylaxis was administered in 73 of 192 patients (38.0%) and resulted in an impressive reduction in the risk of severe infectious complications by 70%. Approximately half of patients were treated with 480 mg or 960 mg on alternate days. The optimum prophylactic dose of trimethoprim/sulfamethoxazole in patients with non-HIV remains unknown. The current recommendations for the management of AAV encourage prophylaxis against P. jirovecii infection with trimethoprim/sulfamethoxazole 960 mg on alternate days or 480 mg daily in all patients being treated with cyclophosphamide, where not contraindicated.2 There is some evidence suggesting that a lower dose of trimethoprim/sulfamethoxazole may be equally effective and more safe than 480 mg daily. In a randomised controlled …