José L. Díez

Diagnosis of transfusion‐associated graft‐versus‐host disease by polymerase chain reaction in fludarabine‐treated B‐chronic lymphocytic leukaemia

Summary. Transfusion‐associated graft‐versus‐host disease (TA‐GVHD), has rarely been reported associated with B‐chronic lymphocytic leukaemia (B‐CLL). We report a patient diagnosed with B‐CLL, previously treated with fludarabine, who developed TA‐GVHD after being transfused during surgery for splenectomy. Diagnosis was confirmed by polymerase chain reaction (PCR) detection of donor DNA in the patient, by amplification of Y‐chromosome sequence and analysis of minisatellite polymorphisms. B‐CLL patients treated with fludarabine appear to be at risk for TA‐GVHD and should be regarded as candidates for transfusions with irradiated blood products. This case illustrates that PCR is a rapid technique for the early diagnosis of TA‐GVHD.

Favourable effect of the combination of acute and chronic graft-versus-host disease on the outcome of allogeneic peripheral blood stem cell transplantation for advanced haematological malignancies.

To assess the influence of graft‐versus‐host disease (GVHD) on the outcome of patients with advanced haematological malignancies (AHM) who received a primary, unmodified allogeneic peripheral blood progenitor cells transplant (allo‐PBT) from a human leucocyte antigen (HLA) identical sibling donor, we analysed 136 patients with myeloid neoplasms (n = 70) or lymphoproliferative disorders (n = 66), transplanted at 19 Spanish institutions. Median age was 35 years (range 1–61). The cumulative incidence of relapse for all patients was 34% (95% CI, 26–42%), 41% (95% CI, 33–49) for patients without GVHD and 14% (95% CI, 3–25) (P = 0·001) for patients with acute and chronic GVHD. After a median follow‐up of 11 months (range 2–49), 60 (44%) patients remained alive with an actuarial probability of overall survival and disease‐free survival (DFS) at 30 months of 31% (95% CI, 21–41%) and 28% (95% CI, 17–39%) respectively. In patients surviving > 100 d, the low incidence of relapse in those with acute and chronic GVHD led to a DFS of 57% (95% CI, 38–76%) compared with a DFS of 34% (95% CI, 17–51%) in the remaining patients (P = 0·03). Our results indicate a reduced incidence of relapse for patients with AHM receiving an unmodified allo‐PBT and developing acute and chronic GVHD, which results in an improved DFS.

PD-1 genotype of the donor is associated with acute graft-versus-host disease after HLA-identical sibling donor stem cell transplantation

Programmed death 1 (PD-1) activation triggers an immune checkpoint resulting in inhibition of T cells that leads to peripheral tolerance. Some PD-1 polymorphisms have been described and associated with the development of autoimmune diseases or cancer predisposition, but there are few data concerning the relevance of such polymorphisms on the clinical outcome after allogeneic hematopoietic stem cell transplant (alloHSCT). We analyzed the distribution of the SNPs PD-1.1G/A (rs36084323) and PD-1.3G/A (rs11568821) genotypes of the donor in a cohort of 1485 alloHSCT from HLA-identical sibling donors. We found an increased risk of grades II to IV graft-versus-host disease (GvHD) in patients receiving grafts from donors homozygous for the G allele at the rs36084323 SNP (P = 0.033; hazard ratio [HR] 2.2; 95% confidence interval [CI] 1.1 to 4.8) and also from donors homozygous for the A allele at the rs11568821 position (P < 0.001; HR 4.5, 95%CI 2.0 to 10.1). In contrast, the PD-1 genotype of the donor did not show association with overall survival or relapse incidence. These results suggest that the PD-1 genotype of the donor plays an important role for the development of acute GvHD after alloHSCT from HLA-identical sibling donors.

Donor CTLA-4 Genotype Modulates the Immune Response to Minor Histocompatibility Antigen Mismatches

Minor histocompatibility antigen (miHA) mismatches have been related to graft-versus-host disease (GVHD) after allogeneic stem cell transplantation, but this association remains controversial due to the lack of consistency in the results obtained by different groups. The CTLA-4 genotype of the donor has been reported to be relevant in the appearance of acute GVHD. We explored the effect of the donors CTLA-4 genotype in the incidence of acute GVHD associated with HA-1, HA-8, or H-Y miHA mismatches in a large cohort of 1295 patients receiving an allogeneic transplant from an HLA-identical sibling donor. The incidence of acute GVHD was higher if the donor and recipient were mismatched for HA-1, HA-8, or H-Y, but only when the donor had the CTLA-4 rs231775 AA genotype (hazard ratio [HR], 2.18; 95% confidence interval [CI], 1.27 to 3.75; P = .005; HR, 2.11, 95% CI, 1.06 to 4.18; P = .033; and HR, 1.50; 95% CI, 1.05 to 2.15; P = .025, respectively). In contrast, this increased risk of developing acute GVHD was not found when the donor presented the CTLA-4 rs231775 AG or GG genotypes. We conclude that the immune response to specific miHA mismatches is modulated by the CTLA-4 genotype of the donor.