Systemic lupus erythematosus complicating autoimmune pulmonary alveolar proteinosis that was worsened by immunosuppressive therapy.

A 26-year-old Japanese woman developed autoimmune pulmonary alveolar proteinosis (PAP) during glucocorticoid therapy for systemic lupus erythematosus (SLE). Intensive immunosuppressive therapy worsened the PAP. De-escalation of immunosuppressive therapy improved the PAP. Autoimmune PAP is rarely associated with systemic autoimmune diseases, and the present case is the first case of autoimmune PAP associated with SLE. Moreover, the present case suggests that immunosuppressive therapy should be avoided or used carefully for the treatment of patients with anti-GM-CSF antibody, such as those with autoimmune PAP.