Impact of KIR B/X Genotype and Missing KIR Ligands in HLA-Matched Unrelated Donor HSCT

To study the prognostic impact of missing ligands for inhibitory killer immunoglobulin-like receptor(KIR) and donor KIR B/X genotype in HLA-matched hematopoietic stem cell transplantation(HSCT) using unrelated donor.

HLA genotype of 51 patients (ALL 22 cases,AML 13 cases,CML 14 cases,MDS 1 case and HAL 1 case) and their matched unrelated donors was determined by polymerase chain reaction sequence oligonucleotide probes(PCR- SSOP) and sequence specific primers (PCR-SSP).The KIR genotype was determined by PCR-SSP.

Patients were divided into two groups. Group A consisted of 16 patients with donor KIR B/X genotype and missing HLA class I ligands for donor inhibitory KIR, and group B consisted of 35 patients without KIR B/X or missing KIR ligands.The 3-year overall survival(OS) rate for group A was 93.8%, and the OS rate for group B was 61.7% (P=0.058).The 3-year continuous complete remission(CCR) rate for the two groups was 83.3% and 57.2%,respectively(P=0.098).There was no significant difference in neutrophil and platelet recovery,≥ III° acute GVHD(6.3% vs 20.0%,P>0.05) and extensive chronic GVHD (25.0% vs 17.1%,P>0.05) between the two groups.

In HLA-matched unrelated donor HSCT,donor KIR B/X genotype and missing KIR ligands may be associated with decreased severely acute GVHD,improved CCR and OS.

No relevant conflicts of interest to declare.