[A non-invasive equation in diagnosis of idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia].Zhonghua Nei Ke Za Zhi. 2010 May; 49(5):376-9.ZN
Idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP) are the two largest subsets of idiopathic interstitial pneumonia (IIP). They have a sharply differences in therapy and survival, however, the identification of them is difficult. In general, NSIP has a much better responsiveness to therapy and good survival. On the other hand, in IPF, was demonstrated to be associated with poorer survival and responsiveness to therapy. To diagnosis of IPF and NSIP need histopathologic classification which however, requires surgical lung biopsy. Therefore, we try to set up an equation using those data from non-invasive methods to identify IPF and NSIP.
A retrospective review of 32 patients with IPF (n = 14) and NSIP (n = 18) was carried out. General clinical data, pulmonary function, chest radiographic, and bronchoalveolar lavage fluid were recorded. The statistical methods of logistic regression and multiple linear regression are used to establish the equation. The method of curve fitting is used to find the critical value of the equation to the differential diagnosis between the IPF and NSIP.
(1) Compare to NSIP, patients of IPF are older, more males than females, having a bigger proportion of smokers. (2) Compared with NSIP patients, IPF patients have higher CT score of "grid shadow", "cellular shadow" and lower CT score of "ground-glass shadow". (3) Bronchoalveolar lavage (BAL) lymphocytosis was more frequently observed in NSIP than IPF. (4) We get an equation: y = 0.9 + 0.123 x 1 - 0.045 x 2 + 0.009 x 3 + 0.033 x 4 and it can improve the differential diagnosis between the IPF and NSIP in this group of patients.
Clinical, high resolution computerized tomography and BAL are useful non-invasive tools in diagnosis IPF and NSIP. The equation:y = 0.9 + 0.123 x 1 - 0.045 x 2 + 0.009 x 3 + 0.033 x 4 can help us to distinguish the IPF and NSIP.