Allelic, Genotypic, and Haplotypic Analysis of Cytokine IL17A, IL17F, and Toll-like Receptor TLR4 Gene Polymorphisms in Metabolic-Dysfunction-Associated Steatotic Liver Disease: Insights from an Exploratory Study.

(1) Background: Interleukin 17 (IL17) and toll-like receptor 4 (TLR4) elevate the risk of metabolic and liver diseases. (2) Methods: This study's objective was to explore the association of IL17 and TLR4 gene polymorphisms with MASLD susceptibility and test their effect on serum IL17 and TLR4 levels. A total of 43 patients with MASLD (MASH/MAFL) and 38 healthy individuals were genotyped for IL17F-, IL17A-, TLR4-, and TLR4- polymorphisms using PCR-RFLP. ELISA methods determined IL17F, IL17A, and TLR4 serum levels. (3) Conclusions: Patients carrying the variant genotypes () of IL17- (OR = 5.25), () of (OR = 10.57), () of TLR4- (OR = 3.52), or () of TLR4- (OR = 9.87) had significantly increased odds of MASH. Genotype () of IL17- was significantly associated with the odds of MAFL ( = 0.0166). Allele of the polymorphism was significantly related to increased odds of MAFL (OR = 4.13, = 0.0133). In contrast, allele of IL17- (OR = 5.41, = 0.008), allele of TLR4- (OR = 3.19, = 0.046), and allele of TLR4- (OR = 6.94, = 0.008) polymorphisms were significantly related to an increased risk of MASH. Allele of IL17A-, allele of TLR4-, and allele of TLR4- gene polymorphisms were significantly associated with the increased odds of MASLD. In patients with MASLD, we found significant influence from the IL17A- gene polymorphism on IL17F levels ( = 0.0343).