Bronchiolitis obliterans and IgA nephropathy. A new cause of pulmonary-renal syndrome.

IgA nephropathy is a common form of glomerulonephritis, classically manifested by asymptomatic hematuria. Although the exact pathophysiologic mechanism is still unknown, renal damage has been related to mesangial deposition of IgA-containing immune complexes. In recent years, some lung diseases have been associated with IgA nephropathy, including pulmonary hemorrhage and sarcoidosis. We report a patient with idiopathic bronchiolitis obliterans who developed a rapidly progressive glomerulonephritis due to IgA deposits. Extensive deposits of IgA were also found in the lungs, thus suggesting a pathogenetic role for IgA in tissue injury at both organ levels. To our knowledge this association has not been previously described in the literature.