Association of ICAM-1 K469E polymorphism with dengue infection in North Indian population.

Dengue infection is caused by flavivirus is one of the leading cause of mortality. There are certain factors which play role in the transformation of a mild form of the disease (DF) into a severe form (DHF) but the most important ones are: viral strain virulence, host genetics, and host immune status. In severe dengue infection, plasma leakage occurs due to vascular endothelial cell activation through expression of adhesion molecule like intercellular cell adhesion molecule-1 (ICAM-1). A total of 100 dengue patients (DF; n = 53 and DHF/DSS; n = 47) and 200 healthy controls were included in the study. ICAM-1 K469E genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP). Expression of ICAM-1 mRNA was done by Real time reverse transcription- PCR (rRT-PCR). Patients with homozygous genotype (EE) have 3.22 fold risk (P = 0.008) of developing severe form of disease (DHF/DSS) as compared to other genotypes. Patients with DHF/DSS exhibit higher expression of ICAM-1 mRNA as compared to dengue fever and controls (P = 0.001 and < 0.001). Patients (DHF/DSS) with homozygous (EE) genotype exhibit higher expression of ICAM-1 mRNA when compared with wild type (KK) genotype (P = 0.005). This study suggests a possible association between the ICAM-1 polymorphism and the disease severity.