Impact of Missing KIR Ligands in HLA-Matched Unrelated Donor HSCT.

To analyze the prognostic impact of missing ligands for inhibitory killer-immunoglobulin receptor(KIR) 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 cases and HAL 1 cases) 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 those with(n=37) and those without(n=14) missing 1 or more HLA class I ligands for donor inhibitory KIR. The period of platelet reconstruction was shorter in patients [ 13 d(10d∼27d)] with missing KIR ligands than those[14d(12d∼21d)] without missing KIR ligands(P=0.046). There was no significant difference in neutrophil recovery, ≥II° acute GVHD(13.5% vs 35.7%, P>0.05) and extensive chronic GVHD (16.2% vs 28.6%, P>0.05) between the two groups. The 3-year continuous complete remission(CCR) rate for patients with and without missing KIR ligands was 73.6% and 37.4%, respectively(P=0.183). The 3-year overall survival(OS) rate for the two groups was 77.5% and 52.4%, respectively(P=0.533).

In HLA-matched unrelated donor HSCT, missing KIR ligands may be associated with enhanced engraftment, decreased severe GVHD, improved CCR and OS.

No relevant conflicts of interest to declare.