Table 1

Clinical data and transplantation outcomes in HLA haplotype-mismatched transplants with and without KIR ligand incompatibility in the GVH direction. KIR ligand incompatibility in the GVH direction was defined as absence in recipients of donor class I allele group(s) recognized by KIRs (9–11). Such groups are HLA-C alleles with Asn77-Lys80, Cw2, 4, 5, 6, and related alleles; HLA-C alleles with Ser77-Asn80, Cw1, 3, 7, 8, and related alleles; HLA-Bw4 alleles; and HLA-A3/A11. Twenty-six pairs (11 in ALL and 15 in AML) were mismatched for HLA-C groups, 8 (3 in ALL, and 5 in AML) were mismatched for HLA-Bw4 group; the HLA-A3/A11 mismatch was never found alone but only in conjunction with HLA-C group mismatches (2 pairs).

KIR ligand incompatibility in GVH direction Number of transplants No 58 Yes 34
Donors displaying antirecipient NK clones1/5834/34*
Transplantation outcomes
Acute GVHD, ≥ grade II13.7%0%*
Probability of relapse at 5 years
ALL 90%85%
AML 75% 0%**
  • P ≤ 0.01;

  • ** P < 0.0008 (22).