Clinical predictors of a diagnosis of idiopathic pulmonary fibrosis.

RATIONALE

Idiopathic pulmonary fibrosis (IPF) and other idiopathic interstitial pneumonias (IIPs) have similar clinical and radiographic features, but their histopathology, response to therapy, and natural history differ. A surgical lung biopsy is often required to distinguish between these entities.

OBJECTIVES

We sought to determine if clinical variables could predict a histopathologic diagnosis of IPF in patients without honeycomb change on high-resolution computed tomography (HRCT).

METHODS

Data from 97 patients with biopsy-proven IPF and 38 patients with other IIPs were examined. Logistic regression models were built to identify the clinical variables that predict histopathologic diagnosis of IPF.

MEASUREMENTS AND MAIN RESULTS

Increasing age and average total HRCT interstitial score on HRCT scan of the chest may predict a biopsy confirmation of IPF. Sex, pulmonary function, presence of desaturation, or distance walked during a 6-minute walk test did not help discriminate pulmonary fibrosis from other IIPs.

CONCLUSIONS

Clinical data may be used to predict a diagnosis of IPF over other IIPs. Validation of these data with a prospective study is needed.