OBJECTIVETo find out the distributed characteristics of KIR2DL1 alleles frequencies and the recognition HLA-C ligand in the Chinese Han population.

METHODSThe 111 patients and 116 donors from CMDP were performed the KIR2DL1 high-resolution typing and KIR genotyping using sequence-based testing (SBT) and PCR-SSP methods.

RESULTSA total of 224 individuals with KIR2DL1 locus was predominantly observed and accounted for 98.68% (224/227). There were 3 different KIR2DL1 alleles, including KIR2DL1*00302, *00201 and *00401 alleles polymorphism. The most common phenotype observed were KIR2DL1*00302 (84.82%, 380/448), KIR2DL1*00201 (12.05%, 54/448) and KIR2DL1*00401(3.13%,14/448), present at allele genotype frequencies of 61.04%,6.22% and 1.58% respectively. The allele homozygotic types of KIR2DL1*00302 and KIR2DL1*00302 were the most frequent in 6 KIR2DL1 allele by high resolution typing. The allele heterozygous types of KIR2DL1*00302 and KIR2DL1*00401 presented statistically different in haplotypes A/A and B/x (P=0.001), and KIR2DL1*00401 lacked of all A/A haplotype. The KIR2DL1*00302 and KIR2DL1*00201 allele had significant positive associations between different KIR pairs of KIR2DS1, KIR2DL3, KIR2DS4 and KIR3DL1/S1 using linkage disequilibrium analysis (P<0.01), respectively. In the receptor-ligand of KIR/HLA model after allo-HSCT, KIR2DL1*00302 alleles correlated with their HLA-C2 group ligands. KIR2DL1*00302 and HLA-C*06:02 was the most common combination ligand model, but KIR2DL1*00302 and HLA-C*01:02 was the most frequent mismatch ligand model with the development of NK cell-induced alloreactivity, meanwhile there was statistically significant difference of frequency distribution (P<0.05).

CONCLUSIONThe KIR2DL1*00302 was the most frequent allele in Chinese Han population. The KIR2DL1 high resolution typing would be beneficial for predicting donor NK cells all activity after hematopoietic stem cell transplantation and selecting suitable donors.