Profile of killer cell immunoglobulin-like receptor and its human leucocyte antigen ligands in dengue-infected patients from Western India.

Killer cell immunoglobulin-like receptors (KIRs) regulate the activation of natural killer cells (NKs). Qualitative and quantitative differences in the type and the number of KIRs expressed on NK cells affect its activation which would influence the outcome of the disease. In this study, 114 hospitalized cases of dengue [82 dengue fever (DF) and 32 dengue haemorrhagic fever (DHF) cases] and 104 healthy controls (HC) without no known history of hospitalization for dengue-like illness were investigated for their KIR gene profile to find out the association of KIR genes with dengue disease severity. KIR gene profile was investigated using duplex sequence-specific priming polymerase chain reaction-based typing system. The results revealed a higher frequency of KIR3DL1 gene [P = 0.0225; odds ratio (OR) 4.1 95% confidence interval (CI) 1.1-14.8] and lower frequency of KIR3DS1/3DS1 genotype [P = 0.0225; OR 0.24 95% CI (0.068-0.88)] in DF cases compared to HC. Immunoglobulin-like receptor gene frequencies were not different between DHF and DF or HC. The results suggest that KIR3DL1/KIR3DS1 locus might be associated with the risk of developing DF.