Transplantation from NK-alloreactive donors with B-haplotype telomeric KIR genes reduced infectious mortality and morbidity. (A) Cumulative incidence of infectious mortality in the 26 patients transplanted from NK-alloreactive donors with Tel-B/x genes and in the 43 patients transplanted from NK-alloreactive donors with Tel-A/A genes. Eighteen of 43 patients transplanted from donors with Tel-A/A genes died of infection (1 bacterial, 1 Toxoplasma gondii, 4 invasive fungal, 4 CMV, 2 human herpesvirus 6, 1 Epstein-Barr virus, 1 parainfluenza virus, 4 pneumonia and acute respiratory distress syndrome of unknown etiology). Only 2 of 26 patients transplanted from donors with Tel-B/x genes died of infection (1 CMV and 1 concomitant viral and fungal infection). (B) Data on infectious episodes were available for 63 of 69 patients transplanted from NK-alloreactive donors. Number of infectious episodes per month (mean ± standard deviation [SD]) in the first 6 months after transplant in patients transplanted from NK-alloreactive donors with Tel-A/A (open bar) and Tel-B/x genes (closed bar) are shown. Difference between the groups was tested by unpaired Student t test. (C) Ratios (mean with 95% CI) between the infection rates of patients transplanted from NK-alloreactive donors with Tel-B/x (diamonds) and infection rates of patients transplanted from NK-alloreactive donors Tel-A/A genes (dotted line) as evaluated monthly during the first 6 months after transplant.