Coexisting systemic lupus erythematosus and sickle cell disease: a diagnostic and therapeutic challenge.

Systemic lupus erythematosus (SLE) and sickle cell disease (SCD) are relatively common disorders with comparable prevalence among blacks. The coexistence of these 2 conditions in the same individual appears to be rare. We report 4 cases of coexisting SLE and SCD. These patients displayed a broad spectrum of musculoskeletal, central nervous system, and renal complications that may be associated with either SCD or SLE. Because of a substantial overlap between the clinical manifestations of these 2 disorders, the diagnosis of SLE in patients with SCD may be difficult to establish and is often delayed. Up to 23% of patients with SCD may have antinuclear antibodies. All patients in this series had antecedent SCD but new important complications from SLE.