Alopecia Areata After Belimumab Use in a Patient With Systemic Lupus Erythematosus: A Paradoxical Case of Autoimmunity

This case report describes a 31-year-old woman with systemic lupus erythematosus (SLE) who developed alopecia areata (AA) approximately 1 year after starting treatment with belimumab, an anti-BLYS monoclonal antibody. Despite initial clinical and laboratory improvements in SLE symptoms, the patient experienced severe hair loss, which regressed after discontinuing belimumab. The report suggests that belimumab may interfere with the immune privilege of hair follicles and affect cytokine balance, potentially leading to autoreactivity of CD8+ T lymphocytes. This paradoxical autoimmune response highlights the need for further studies and similar case reports to understand the relationship between belimumab and AA.