Pulmonary hemorrhage in lupus erythematosus without evidence of an immunologic cause

Intra-alveolar hemorrhage is a known complication of lupus erythematosus (LE), but its cause is controversial. Some authors have shown immune complexes (ICs) deposited at various sites in the alveolar septae and postulated that these deposits result in pulmonary hemorrhage (PH). A patient with LE and PH had no detectable IC deposits at a time when IC disease was present in the kidney and vasculitis was active in the skin. Reviewing the literature, we show that IC deposits in the lung are nonspecific and are not correlated with PH. We propose that classification schemes that differentiate between IC-mediated PH and idiopathic PH are arbitrary, and that patients thought to have idiopathic PH should be followed up prospectively to monitor the development of possible immunologic disease.