Subclinical alveolitis in immunologic systemic disorders.

Subclinical alveolitis is a frequent finding in immunologic systemic disorders. However the significance of subclinical alveolar inflammation does not seem to be univocal and varies according to the disease. The fact that pulmonary involvement is rare during the course of extrathoracic granulomatosis like Crohn's disease or primary cirrhosis and that subclinical alveolitis is frequent suggests that alveolar inflammation may be the expression in the lung of a systemic immune disorder. In contrast subclinical alveolitis in collagen-vascular diseases, particularly progressive systemic sclerosis, is frequently associated with abnormalities of lung parenchyma as assessed by CT scan supporting the hypothesis that subclinical alveolitis is associated with development of ILD. Close follow-up of these patients is needed to better determine whether subclinical alveolitis precedes ILD and whether early detection of subclinical alveolitis in immunologic systemic disorders may identify those patients that are at risk for the development of ILD in the future.