Approaches to evaluation of fibrogenic pathways in surgical lung biopsy specimens

Idiopathic interstitial pneumonias (IIPs) are a heterogeneous group of pulmonary fibrotic disorders consisting of several clinicopathologic entities with differing histopathologic patterns, clinical course, response to therapy, and prognosis. It is now recognized that accurate diagnosis is required in IIP, particularly in distinguishing various clinicopathologic entities of this disease from usual interstitial pneumonia, the most common histological pattern in IIP. Although no longer considered the "gold standard" for diagnosis, surgical lung biopsies (SLBs) have provided clinicians and researchers with important clues as to the identity of soluble mediators that may account for the subtype differences in IIP. Given that the expression of chemokine ligands and chemokine receptors appear to be markedly altered during the development of pulmonary fibrosis in IIP , we have focused on the characterization of these mediators in IIP and non-IIP SLBs and in primary human fibroblast lines grown from these biopsies. Herein, we describe laboratory techniques routinely employed to detect these important profibrotic factors and their corresponding receptors in SLBs and in primary human fibroblast lines.