Idiopathic pulmonary hemosiderosis and related syndromes

Abstract

Idiopathic pulmonary hemosiderosis (IPH) is a distinct clinical and pathologic entity. Four of every five patients are children, the rest are young adults. The incidence is sporadic, and IPH shows no predilection for either sex or for a particular season or geographic area. No hereditary tendency has been apparent. The clinical course and all abnormal laboratory test results observed can be explained by repeated episodes of multifocal hemorrhages originating from the alveolar capillaries. We suggest that IPH is primarily an abnormality of pulmonary alveolar epithelial growth and function resulting directly in alveolar capillary bleedings. Bleeding may be protracted and not clinically apparent, except for gradual development of iron deficiency anemia, dyspnea, weight loss and pulmonary hemosiderosis with fibrosis. Secondary pulmonary hypertension is a rare and late complication. The hemorrhages do not appear to be precipitated by an exogenous or endogenous factor, nor can hemodynamic alterations or autoimmune mechanisms be implicated as the primary event. Short-term corticosteroid therapy may be beneficial during acute bleeding episodes. The prognosis is unpredictable for any one patient, but prolonged survival is not rare and may become more frequent by skillful symptomatic management of bleeding episodes, once the diagnosis is established. The early stages of “Goodpasture's syndrome,” when alveolar hemorrhages precede a fulminant glomerulonephritis, are difficult to differentiate from IPH clinically. This condition, however, mainly affects young male adults, and the renal disease is rapidly fatal. Frequently, inflammation of the alveolar wall and fibrin deposition in the alveolar lumens are present. In one patient with “Goodpasture's syndrome” a lesion of the alveolar capillary basement membrane occurred that resembled the glomerular alterations in membranous glomerulonephritis.