Relationships between genetic polymorphisms of triggering receptor expressed on myeloid cells-1 and septic shock in a Chinese Han population

BACKGROUND: Triggering receptor expressed on myeloid cells-1 (TREM-1) is a cell surface receptor expressed on neutrophils and monocytes. TREM-1 acts to amplify inflammation and serves as a critical mediator of inflammatory response in the context of sepsis. To date, the predisposition of TREM-1 gene polymorphisms to septic shock has not been reported. This study was designed to investigate whether TREM-1 genomic variations are associated with the development of septic shock. METHODS: We genotyped two TREM-1 single nucleotide polymorphisms (SNPs, rs2234237 and rs2234246) and evaluated the relationships between these SNPs and septic shock on susceptibility and prognosis. RESULTS: TREM-1 rs2234246 A allele in the promoter region was significantly associated with the susceptibility of septic shock in recessive model (AA, OR=3.10, 95%CI 1.15 to 8.32, P=0.02), and in codominant model (AG, OR=0.72, 95%CI 0.43-1.19, P=0.02; AA, OR=2.71, 95%CI 1.00-7.42; P=0.03). However, in three inherited models (dominant model, recessive model, and codominant model), none of the assayed loci was significantly associated with the prognosis of septic shock. The non-survivor group demonstrated higher plasma IL-6 levels (99.7±34.7 pg/mL vs. 61.2±26.5 pg/mL, P<0.01) than the survivor group. Plasma concentrations of IL-6 among the three genotypes of rs2234246 were AA 99.4±48.9 pg/mL, AG 85.4±43 pg/mL, and GG 65.3±30.7 pg/mL (P<0.01). The plasma concentrations of IL-6 in patients with AA genotypes were significantly higher than those in patients with GG genotypes (P<0.01). CONCLUSION: TREM-1 genetic polymorphisms rs2234246 may be significantly correlated only with susceptibility to septic shock in the Chinese Han population.