Reversible IgA deficiency after severe Gram-negative bacteria infection in a patient with systemic sclerosis

A 43-year-old woman with systemic sclerosis (SSc) developed IgA deficiency (IgAD) after cholecystitis. The severe decrease of IgA (<10 mg/dl) partially recovered after 5 years. She had repeated episodes of infection during IgAD. Anti-IgA antibody was not detected. Flow cytometric analysis showed that peripheral CD19+IgA+ and CD38+IgA+ cells were normally present. Although the mechanism of secondary IgAD is still vague, its association with autoimmune diseases including SSc and also with bacterial infection is discussed.