Investigation of IL-18 gene polymorphisms in chronic otitis media: a case-control study

INTRODUCTION: Chronic otitis media (COM) is associated with impairments in language development and communication, poor quality of life, and severe complications. It includes chronic inflammation and immunologic mechanisms. IL-18 also is involved in chronic inflammation and inflammatory conditions. This study aims to examine the association of IL-18 gene -137 G/C and -607 C/A polymorphisms with COM.
METHODS: The study included 195 COM patients and 185 healthy individuals. DNA isolation was performed according to the Poncz method and polymorphisms were identified by polymerase chain reaction (PCR). The COM group was divided into two groups according to presence/absence of cholesteatoma.
RESULTS: Genotype frequencies for IL-18 -137 G/C polymorphism were 42.56% GG, 45.13% GC, and 12.31% CC in the COM group, and 42.70%, 43.78%, and 13.52% in the control group (p=0.88, p=0.73). For IL-18 -607 C/A, frequencies were 41.54% CC, 37.44% CA, and 21.02% AA in COM, compared to 41.62%, 32.97%, and 25.41% in controls (p=0.58, p=0.48). No significant differences were found, but -137 CC and -607 AA genotypes were associated with reduced COM risk.
DISCUSSION AND CONCLUSION: Although no statistically significant association was found, -137 CC and -607 AA genotypes may have a protective role in COM. These findings highlight the potential role of genetic factors in COM pathogenesis, contributing to future diagnostic and therapeutic strategies.