Association Between Single Nucleotide Polymorphisms and Viral Load in Congenital Cytomegalovirus Infection

BACKGROUND: There are limited data on factors that determine viral load (VL) in congenital cytomegalovirus (cCMV) infection. Single nucleotide polymorphisms (SNPs) might influence individual host response to infection. This study aimed to investigate the association between SNPs in genes encoding cytokines or cytokine receptors and VL in newborns with cCMV. MATERIAL AND METHODS: Eight polymorphisms (IL1B rs16944, IL12B rs3212227, IL28B rs12979860, CCL2 rs1024611, DC-SIGN rs735240, TLR2 rs5743708, TLR4 rs4986791 and TLR9 rs352140) were analyzed in study population of 233 newborns, including 92 cCMV-infected newborns (73 symptomatic and 19 asymptomatic) by TaqMan SNP Predesigned Genotyping Assays. The association analysis was performed using SNPStats software and STATISTICA10. RESULTS: The association between IL12B polymorphism and viruria was observed (p = 0.029). In multiple comparison tests, heterozygous T/G genotype of IL12B was associated with higher viruria than T/T genotype (p = 0.041) in cCMV-infected newborns. In allele analysis, T allele of IL12B was associated with higher viremia (p = 0.037) in symptomatic newborns. We observed higher VL in symptomatic newborns in comparison to asymptomatic (median viremia: 1.7 × 10(4) copies/mL vs. 2.0 × 10(3) copies/mL (p = 0.002), median viruria: 1.0 × 10(7) copies/mL versus 6.9 × 10(5) copies/mL (p = 0.001), respectively). CONCLUSIONS: IL12B rs3212227 was associated with VL in cCMV. Symptomatic newborns had significantly higher viremia and viruria. The role of SNPs in pathogenesis of cCMV warrants further investigations.