Nocardiosis in systemic lupus erythematosus patients treated with rituximab: Report of two cases and systematic review of literature.

This article focuses on the occurrence of nocardiosis, an opportunistic infection caused by Nocardia bacteria, in patients with systemic lupus erythematosus (SLE) treated with rituximab, a B-cell depleting immunosuppressant. It presents two clinical cases of SLE patients who developed disseminated Nocardia farcinica infections following treatment with rituximab and other immunosuppressants, alongside a systematic review identifying only one additional similar case in the literature. The findings suggest that immune dysfunction involving T lymphocytes—due to SLE itself, rituximab, and concomitant immunosuppressive therapies—predisposes these patients to nocardiosis, which requires high clinical suspicion and prolonged microbiological testing for diagnosis. Treatment considerations include the use of beta-lactams and quinolones as alternatives to trimethoprim/sulfamethoxazole and linezolid, which may exacerbate hematological toxicity, and amikacin, which can worsen lupus nephritis. The article highlights the need for larger studies to better guide diagnosis and management of nocardiosis in this patient population.