NONSPECIFIC INTERSTITIAL PNEUMONIA - INDIVIDUALIZATION OF A CLINICOPATHOLOGICAL ENTITY IN A SERIES OF 12 PATIENTS

Nonspecific interstitial pneumonia/fibrosis (NSIP) has recently been i ndividualized within the group of idiopathic interstitial pneumonias m ainly based on a pathologic pattern of temporally uniform lesions dist inct from usual, desquamative, and acute interstitial pneumonia. We st udied 12 consecutive patients with NSIP at lung biopsy done as a diagn ostic procedure for idiopathic interstitial lung disease. The patients were six males and six females, aged 52.5 +/- 11.8 yr. In 8 of 12 cas es the pathologic lesions consisted of both cellular interstitial infl ammation and fibrosis, whereas only cellular inflammation was present in three cases, and fibrosis in one. Dyspnea, cough, inspiratory crack les, and squeaks were the most common symptoms and signs. Six cases we re cryptogenic. An associated disorder or a presumed cause was present in the other six patients, including underlying connective tissue dis ease (n = 3), organic dust exposure (n = 2), and prior acute lung inju ry (n = 1). Lung function tests found a restrictive ventilatory defect (11/12), impairment of TLco (11/11), and hypoxemia at rest (7/12). Ch est X-ray showed infiltrative opacities in all cases. Computed tomogra phy of the chest in 11 cases mainly showed ground glass opacities (9/1 1), patchy areas of alveolar consolidation (6/11), and thickening of i nterlobular septas (5/11). All patients were treated with corticostero ids, and seven with immunosuppressive agents. All patients were alive at last follow-up, 50 +/- 40 mo after diagnosis. Ten patients (83%) we re clinically improved or stabilized. Thus, despite its heterogeneity, NSIP deserves to be individualized as an original clinicopathologic e ntity and should be clearly distinguished from usual interstitial pneu monia, especially because of a better prognosis.