Differential T_H1/T_H2 chemokine expression in interstitial pneumonia

Background: T-helper (Th)-2 background in the lungs may favor the development of pulmonary fibrosis. We hypothesized that usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP), major pathologic patterns of chronic interstitial pneumonia, would have different expression profiles of T_H1 and T_H2 chemokines. Methods: Total RNA was isolated from lung tissues obtained by surgical biopsy (18 cases of UIP and 29 cases of NSIP). The expression of ligands for CXCR3 [T_H1 cells chemoattractant: monokine induced by interferon (IFN)-γ (MIG), IFN-γ-inducible protein of 10 kD, and IFN-inducible T cell α chemoattractant] and ligands for CCR4 [T_H2 cells chemoattractant: thymus- and activation-regulated chemokine and macrophage-derived chemokine (MDC)] were analyzed by real-time reverse transcriptase polymerase chain reaction. Results: MIG and IFNγ-inducible protein of 10 kD expression were significantly higher in NSIP compared with UIP. MDC expression was increased in UIP compared with NSIP, although the difference was not significant. MIG/MDC is significantly elevated in NSIP but not UIP. Interestingly, MIG/MDC was significantly higher in NSIP group 3 (NSIP with extensive fibrosis) compared with UIP. Conclusions: These results may indicate that these 2 diseases have a different pathophysiology. MIG/MDC may be a useful marker to distinguish these 2 diseases.