Nonspecific interstitial pneumonia/fibrosis: clinical manifestations, histologic and radiologic features

Customarily used classification of IPF did not satisfy a sizable group of patients with IPF that in the past had been lumped with UIP and now currently has begun to be recognized as nonspecific interstitial pneumonia/fibrosis (NIP). There are few reports about the clinical features of NIP.

The pathologic slides of 66 patients having open lung biopsy (OLB) for the differential diagnosis of interstitial lung diseases (ILD) from 1984 to 1995 were reviewed. Seven cases were confirmed as NIP. The clinical record, pulmonary function tests (PFT), chest PA and HRCT were reviewed and analysed retrospectively.

Six patients with NIP were female. The median age was 56 years. Mean duration of symptoms was 4 months. Five patients had systemic flu-like symptoms, the most common respiratory symptom was gradual dyspnea. Two patients revealed a mild degree of anemia. Four cases had leukocytois of more than 10,000/mm3. ESR and CRP O.K. elevated in all measured cases. Anti-nuclear antibody (ANA) was positive in three of six patients and ds-DNA antibody was positive in one of six patients. Restrictive pattern of PFT was predominant. Diffusion capacity of carbon monoxide (DLCO) decreased markedly. In bronchoalveolar lavage (BAL), total cell counts elevated about three times of normal value. On differential counts of BAL cells, lymphocytes, neutrophils and eosinophils were higher than those of normal controls. The prominent finding of chest radiology was bilaterally patchy opacifications in parenchyme of lower lung zones. On HRCT, bilaterally patchy areas of ground-glass attenuation and/or areas of alveolar consolidation were commonly shown. The number of pathologic type was one case of group I, four cases of group II and two cases of group III. The average period from diagnosis to the last follow-up was 24.8 months. Five patients were clinically recovered to the previously well-being state.

Patients with NIP had different clinical features from UIP, AIP and DIP. They also had characteristic findings of radiology and their prognosis seems to be better than UIP.