The Association of KIR2DS4 and Its Variant KIR1D with CMV Infection after HLA-Matched Sibling Hematopoietic Stem Cell Transplantation

Objective To expolore the association of KIR2DS4 and its variant KIR1D with cytomegalovirus(CMV) infection after HLA-matched sibling hematopoietic stem cell transplantation.

Methods Polymerase chain reaction with sequence-specific primers (PCR-SSP) method was used to genotype KIR genes in 267 donor-recipient pairs from Oct 2005 to Apr 2014. Posttransplant monitoring for CMV infection was performed by immune histochemically assays .165 donor-recipient pairs who belong to KIR gene haplotype AA were analyzed for the presence of KIR2DS4 and its variant KIR1D and then further subdivided into the following groups: 2DS4-/1D+ (homozygous for the deletion variant KIR1D), 2DS4+/1D+ (heterozygous), 2DS4+/1D- (two intact KIR2DS4 alleles). Furthermore, we investigated the influence of the KIR2DS4 variants on CMV infection of 165 patients receiving Sibling related HLA matched transplantation.

Results There were no significant differences in frequency of KIR2DS4 or KIR1D between donors and recipients in the haplotype AA group. The ratio of 2DS4+ and KIR1D in haplotype AA group was 2:1.There was no difference on neutrophil engraftment and platelet recovery among the three groups after hematopoietic stem cell transplantation. The CMV infection rate was significantly higher in 2DS4+/1D- group compared with 2DS4+/1D+ group (44.0% vs 19.0%，P=0.002)．In 2DS4-/1D+ group ，the CMV infection rate was higer than that in 2DS4+KIR1D+ group (50.0% vs 19%，P=0.028). However，there was no difference in CMV infection rate between 2DS4+/1D-group and 2DS4-/1D+ group.

Conclusion KIR2DS4 and its variant KIR1D are associated with CMV infection after HLA-matched sibling hematopoietic stem cell transplantation