MMP-9 1562C>T Gene Polymorphism and Efficacy of Glucocorticoid Therapy in Idiopathic Pulmonary Fibrosis Patients.

OBJECTIVE: To investigate the relationship between matrix metalloproteinase 9 (MMP-9) gene polymorphism and the efficacy of glucocorticoid therapy in idiopathic pulmonary fibrosis (IPF) patients.

METHODS: We conducted a case-control study. Between January 2013 and September 2014, 115 patients at the Nine Department of Respiratory Medicine, Nanjing Chest Hospital, diagnosed with IPF were enrolled to be the IPF group and 100 healthy subjects were enrolled to be the control group. Prednisone was used to treat IPF patients. Polymerase chain reaction-restriction fragment length polymorphism was used to identify MMP-9 1562C> T polymorphism. The Sandwich enzyme-linked immunosorbent assay was used to measure the serum level of MMP-9 and tissue inhibitor of metalloproteinases 1 (TIMP-1) in the IPF patients before and after the glucocorticoid treatment.

RESULTS: The frequencies of the TT genotype and the T allele of MMP-9 1562C> T gene were found significantly higher in the IPF group compared with the control group (both p < 0.05). Serum levels of MMP-9 and TIMP-1 in IPF patients in each of the three genotype groups before glucocorticoid treatment were significantly higher than those in the control group (all p < 0.05). After the glucocorticoid treatment, MMP-9 and TIMP-1 levels decreased significantly compared with the levels before the glucocorticoid treatment in the IPF patients in each genotype group (all p < 0.05), but were still higher than those in the control group (all p < 0.05). The proportion of "remarkable effect" in the IPF patients of the CC genotype group was significantly higher than that in the other two genotype groups, while the rate of adverse reactions of the CC group was significantly lower than the other two groups (all p < 0.05).

CONCLUSION: MMP-9 gene 1562C> T polymorphism may affect the efficacy of the glucocorticoid therapy for IPF and may be a predictor of IPF treatment outcome.