Outcomes of patients with myeloid malignancies treated with allogeneic hematopoietic stem cell transplantation from matched unrelated donors compared with one human leukocyte antigen mismatched related donors using HLA typing at 10 loci.

Most candidates for hematopoietic stem cell transplantation (HSCT) lack a human leukocyte antigen (HLA)-identical sibling donor. Some patients may have a related donor with whom they are mismatched at 1 antigen/allele. It is not known whether such a match is preferable to a matched unrelated donor (MUD). We evaluated the outcomes (survival, relapse, nonrelapse mortality [NRM]) of all 28 patients with a single HLA antigen/allele mismatch identified through high-resolution HLA typing at HLA-A, -B, -C, -DRB1, and -DQB1, and all 318 patients with myeloid malignancies who received transplants from a 10/10 MUD treated during the same period of time at a single institution. Overall, outcomes for patients treated from a 1-antigen/allele mismatch related donor were significantly worse than from a MUD, primarily because of increased NRM. Overall survival (OS) rates at 3 years for 1-antigen/allele mismatched related donor and MUD transplant recipients were 19% and 45% (P = .007), and NRM rates were 40% and 26% (P = .05), respectively. Patients with class I mismatches appeared to have poorer OS than did patients with class II mismatches. A higher incidence of graft rejection was identified in the mismatched related donor group (P = .02). These results indicate that transplant outcomes are better with a MUD than with a 1 antigen/allele-mismatched related donor.

Donor-recipient mismatches in MHC class I chain-related gene A in unrelated donor transplantation lead to increased incidence of acute graft-versus-host disease.

The polymorphic products of major histocompatibility complex class I-related chain A (MICA) genes are important in solid organ transplantation rejection. MICA expression is limited to gut epithelium and may play a role in triggering acute graft-versus-host disease (aGVHD). A total of 236 recipients of unrelated donor transplantation were studied. Donor-recipient human leukocyte antigen (HLA) match was 10/10 human leukocyte antigen (HLA-A, -B, -C, -DRB1, -DQB1) in 73% and MICA mismatch in 8.4%. Because of physical vicinity of the loci, MICA mismatch was significantly associated with mismatch at HLA-B and HLA-C. A higher rate of grade II-IV aGVHD was seen in MICA-mismatched patients (80% vs 40%, P = .003) irrespective of degree of HLA matching (HLA 10/10 match: 75% vs 39%, P = .02) and HLA any mismatch (83% vs 46%, P = .003). The rate of grade II-IV gastrointestinal aGVHD was also higher in MICA-mismatched patients (35% vs 17%, P = .05). We conclude that MICA may represent novel a transplantation antigen recognized by human allogeneic T cells. This study was registered at ClinicalTrials.gov (Identifier NCT00506922).

Resolved hepatitis B virus infection is not associated with worse outcome after allogeneic hematopoietic stem cell transplantation.

Serologic evidence of resolved hepatitis B virus (HBV) infection has been associated with reactivation of hepatitis after allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the true impact of this finding is unknown. We conducted a retrospective matched-control analysis of the outcomes of 76 patients with positive HBV core antibody (HBcAb) and negative HBV surface antigen (HBsAg) at the time of allo-HSCT for hematologic or solid malignancies. Control patients (matched controls), with negative serology for HBV and other viral hepatitides, were matched by age, diagnosis, disease risk, intensity of conditioning regimen, and donor type. In addition, the HBcAb-positive patients and all seronegative patients (all controls, n = 1858) undergoing transplantation during the same period were compared to adjust for other confounding effects. Patient characteristics and baseline hepatic function studies were similar in the HBcAb-positive and matched control groups. The cumulative incidence of hepatitis B reactivation (defined as the emergence of HBsAg in serum) was 11.6% at 3 years. There were no significant differences in overall survival, relapse, nonrelapse mortality, and incidence of acute graft-versus-host disease between the HBcAb-positive and control groups. Our data suggest that seropositivity for HBcAb and seronegativity for HBsAg at the time of transplantation does not seem to adversely affect outcome after allo-HSCT.

Hemorrhagic cystitis after allogeneic hematopoietic stem cell transplants is the complex result of BK virus infection, preparative regimen intensity and donor type.

BACKGROUND: Hemorrhagic cystitis is a common cause of morbidity after allogeneic stem cell transplantation, frequently associated with BK virus infection. We hypothesized that patients with positive BK viruria before unrelated or mismatched related donor allogeneic hematopoietic stem cell transplantation have a higher incidence of hemorrhagic cystitis. DESIGN AND METHODS: To test this hypothesis, we prospectively studied 209 patients (median age 49 years, range 19-71) with hematologic malignancies who received bone marrow (n=78), peripheral blood (n=108) or umbilical cord blood (n=23) allogeneic hematopoietic stem cell transplantation after myeloablative (n=110) or reduced intensity conditioning (n=99). Donors were unrelated (n=201) or haploidentical related (n=8). RESULTS: Twenty-five patients developed hemorrhagic cystitis. Pre-transplant BK viruria detected by quantitative PCR was positive in 96 patients. The one-year cumulative incidence of hemorrhagic cystitis was 16% in the PCR-positive group versus 9% in the PCR-negative group (P=0.1). The use of umbilical cord blood or a haploidentical donor was the only significant predictor of the incidence of hemorrhagic cystitis on univariate analysis. There was also a trend for a higher incidence after myeloablative conditioning. Multivariate analysis showed that patients who had a positive PCR pre-transplant and received haploidentical or cord blood grafts with myeloablative conditioning had a significantly higher risk of developing hemorrhagic cystitis (58%) than all other recipients (7%, P<0.001). CONCLUSIONS: Hemorrhagic cystitis is the result of a complex interaction of donor type, preparative regimen intensity, and BK viruria.

Impact of hepatitis C virus seropositivity on survival after allogeneic hematopoietic stem cell transplantation for hematologic malignancies.

BACKGROUND: Because hepatitis C virus infection causes hepatic and immunological dysfunction, we hypothesized that seropositivity for this virus could be associated with increased non-relapse mortality after allogeneic hematopoietic stem cell transplantation. DESIGN AND METHODS: We performed a case-control study of the outcomes of patients who were hepatitis C virus seropositive at the time of allogeneic hematopoietic stem cell transplantation (N=31). Patients positive for hepatitis C virus were considered candidates for stem cell transplantation only if they had no significant evidence of hepatic dysfunction. Matched controls (N=31) were seronegative for viral hepatitides and were paired according to age, diagnosis, disease stage, conditioning regimen and donor type. We also compared the hepatitis C virus seropositive patients to all seronegative patients (all controls, N=1800) transplanted during the same period, to adjust for other confounding effects. RESULTS: The median age of the seropositive patients was 49 (range 26-72); 15 had acute myeloid leukemia/myelodysplastic syndrome, 6 had chronic myeloid leukemia/myeloproliferative disease, 6 non-Hodgkin's lymphoma, 2 myeloma, 1 acute lymphocytic leukemia and 1 Hodgkin's lymphoma; 61% had poor risk disease; 68% had related donors; 68% received reduced intensity conditioning; 7 patients had mildly abnormal alanine transaminase levels (all less than three times the upper limit of normal) and 1 patient had minimally elevated bilirubin. These characteristics were similar to those of the matched control group. Median overall survival was 3, 18 and 20 months, and 1-year survival was 29%, 56% and 56%, in the hepatitis C virus, matched and all controls groups, respectively (hazard ratio for death 3.1, 95% confidence interval 1.9-5.6, p<0.001 in multivariate analysis). Non-relapse mortality at 1 year was 43%, 24% and 23%, respectively (hazard ratio 3.3, 95% confidence interval 1.8-7.1, p<0.01). Disease progression and graft-versus-host disease rates were comparable. CONCLUSIONS: Hepatitis C virus seropositivity is a significant risk factor for non-relapse mortality after allogeneic hematopoietic stem cell transplantation even in patients with normal or minimally abnormal liver function tests.