Impacts of Matrix Metalloproteinase-9 Promoter Genotypes on Asthma Risk

Background/Aim: The overexpression of matrix metalloproteinase-9 (MMP9) has been observed in asthmatic patients, yet the role of MMP9 genotype in determining asthma susceptibility remains unresolved. This study aimed to elucidate the contribution of MMP9 promoter rs3918242 genotype to asthma risk in Taiwan. Materials and Methods: A cohort comprising 453 non-asthmatic healthy controls and 198 asthmatic cases was assembled, and the MMP9 rs3918242 genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism methodology. Results: Our findings indicated that people carrying the variant CT or TT genotype of MMP9 rs3918242 did not demonstrate an elevated risk of asthma compared to wild-type CC carriers (odds ratio=1.28 and 1.72, 95% confidence interval=0.87-1.87 and 0.72-4.13; p=0.2417 and 0.3201, respectively). Furthermore, individuals carrying the T allele at MMP9 rs3918242 did not exhibit a higher risk of asthma than those carrying the C allele (odds ratio=1.31, 95% confidence interval=0.96-1.79, p=0.0869). Interestingly, a positive association was observed between MMP9 rs3918242 CT or TT genotypes and the severity of asthma symptoms among asthmatic patients (p=0.0035). Conclusion: Although the T allele at MMP9 rs3918242 was not associated with asthma risk, it may serve as a predictor for asthma symptom severity. These findings warrant validation in larger and more diverse populations to further elucidate the significance of MMP9 in asthma etiology.