Clinical evaluation of idiopathic interstitial pneumonia and interstitial pneumonia associated with collagen vascular disease using logistic regression analysis.

OBJECTIVE: To clarify the differences in the clinical features between idiopathic interstitial pneumonia (IIP) and interstitial pneumonia associated with collagen vascular diseases (CVD-IP).

METHODS: Symptoms, radiographic findings, pulmonary function, blood chemistry data including autoantibody, and bronchoalveolar lavage fluid (BALF) findings were compared using multiple logistic regression analysis.

PATIENTS: The subjects were 44 patients clinically diagnosed with IIP and 33 patients with CVD-IP.

RESULTS: The clinical features related to IIP were as follows: male sex, advanced age, past history of hypertension, presence of cough, exertional dyspnea, digital clubbing, an increased level of gamma-globulin, decreased lung volume on chest X-ray, and typical type according to the criteria for IIP on chest X-ray. Increased levels of rheumatoid factor and total cell number in BALF were related to CVD-IP.

CONCLUSION: These findings are considered to be useful to differentiate IIP and CVD-IP.