Objective: To investigate the efficacy of glucocorticoid therapy in idiopathic nonspecific interstitial pneumonia (INSIP).
Methods: Twenty-nine cases of INSIP confirmed by clinical- radiological-pathological (CRP) diagnosis were collected and classified into 2 groups according to the degree of fibrosis: INSIP-1 (including 9 cases of cellular type) and INSIP-2 (20 cases of mixed and fibrotic type). Thirty cases of usual interstitial pneumonia (UIP) confirmed by CRP diagnosis served as the control. Clinical and pathological features, therapeutic effects of glucocorticoids and the follow-up results were retrospectively analyzed and the survival curves were evaluated by Kaplan-Meier method.
Results: The mean age at onset of INSIP-1 group [(48 ± 5) years] was significantly younger than INSIP-2 group [(52 ± 11) years] and the UIP group [(57 ± 14) years]. The course of disease in INSIP-1 group [(60 ± 28) months] was longer than that in INSIP-2 group [(48 ± 33) months] and that in the UIP group [(44 ± 23) months], but the differences were not statistically significant (F = 1.22, all P > 0.05). The efficacy rate of glucocorticoid treatment in INSIP-1 group (9/9) was higher than that in INSIP-2 group (11/20) and that in the UIP group (2/30), the differences being statistically significant (all P < 0.05). The follow-up period for INSIP-1 group [(56 ± 27) months] was significantly longer than for INSIP-2 group [(23 ± 18) months] and for the UIP group [(25 ± 17) months], and the rate of significant improvement (6/9) was higher than that of the INSIP-2 group (9/20) and the UIP group (0/30), the differences being statistically significant (F = 9.224, all P < 0.05). The mortality of INSIP-1 group (0/9) was lower than that in INSIP-2 group (4/20) and the UIP group (16/30), the difference being statistically significant (exact probability value 0.000 - 0.005, P < 0.05).
Conclusions: The degree of fibrosis of INSIP is closely correlated with the effect of glucocorticoid therapy and prognosis. The cellular type has a favorable reaction to glucocorticoid therapy and a better prognosis as compared to the fibrotic type.