Abstract Risk factors for acute GVHD (AGVHD), overall survival, and transplant-related mortality were evaluated in adults receiving allogeneic hematopoietic cell transplants (1999-2005) from HLA-identical sibling donors (SDs; n = 3191) or unrelated donors (URDs; n = 2370) and reported to the Center for International Blood and Marrow Transplant Research, Minneapolis, MN. To understand the impact of transplant regimen on AGVHD risk, 6 treatment categories were evaluated: (1) myeloablative conditioning (MA) with total body irradiation (TBI) + PBSCs, (2) MA + TBI + BM, (3) MA + nonTBI + PBSCs, (4) MA + nonTBI + BM, (5) reduced intensity conditioning (RIC) + PBSCs, and (6) RIC + BM. The cumulative incidences of grades B-D AGVHD were 39% (95% confidence interval [CI], 37%-41%) in the SD cohort and 59% (95% CI, 57%-61%) in the URD cohort. Patients receiving SD transplants with MA + nonTBI + BM and RIC + PBSCs had significantly lower risks of grades B-D AGVHD than patients in other treatment categories. Those receiving URD transplants with MA + TBI + BM, MA + nonTBI + BM, RIC + BM, or RIC + PBSCs had lower risks of grades B-D AGVHD than those in other treatment categories. The 5-year probabilities of survival were 46% (95% CI, 44%-49%) with SD transplants and 33% (95% CI, 31%-35%) with URD transplants. Conditioning intensity, TBI and graft source have a combined effect on risk of AGVHD that must be considered in deciding on a treatment strategy for individual patients.
The graft-versus-leukemia effect using matched unrelated donors is not superior to HLA-identical siblings for hematopoietic stem cell transplantation
AbstractDo some patients benefit from an unrelated donor (URD) transplant because of a stronger graft-versus-leukemia (GVL) effect? We analyzed 4099 patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML) undergoing a myeloablative allogeneic hematopoietic cell transplantation (HCT) from an URD (8/8 human leukocyte antigen [HLA]–matched, n = 941) or HLA-identical sibling donor (n = 3158) between 1995 and 2004 reported to the CIBMTR. In the Cox regression model, acute and chronic GVHD were added as time-dependent variables. In multivariate analysis, URD transplant recipients had a higher risk for transplantation-related mortality (TRM; relative risk [RR], 2.76; P < .001) and relapse (RR, 1.50; P < .002) in patients with AML, but not ALL or CML. Chronic GVHD was associated with a lower relapse risk in all diagnoses. Leukemia-free survival (LFS) was decreased in patients with AML without acute GVHD receiving a URD transplant (RR, 2.02; P < .001) but was comparable to those receiving HLA-identical sibling transplants in patients with ALL and CML. In patients without GVHD, multivariate analysis showed similar risk of relapse but decreased LFS for URD transplants for all 3 diagnoses. In conclusion, risk of relapse was the same (ALL, CML) or worse (AML) in URD transplant recipients compared with HLA-identical sibling transplant recipients, suggesting a similar GVL effect.
Risk Factors for Acute Graft-Versus-Host Disease After Human Leukocyte Antigen–Identical Sibling Transplants for Adults With Leukemia
Purpose Acute graft-versus-host disease (GVHD) causes substantial morbidity and mortality after human leukocyte antigen (HLA)-identical sibling transplants. No large registry studies of acute GVHD risk factors have been reported in two decades. Risk factors may have changed in this interval as transplant-related techniques have evolved. Patients and Methods Acute GVHD risk factors were analyzed in 1,960 adults after HLA-identical sibling myeloablative transplant for acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), or chronic myeloid leukemia (CML) reported by 226 centers worldwide to the Center for International Blood and Marrow Transplant Research from 1995 to 2002. Outcome was measured as time from transplant to onset of grade 2 to 4 acute GVHD, with death without acute GVHD as a competing risk. Results Cumulative incidence of grade 2 to 4 acute GVHD was 35% (95% CI, 33% to 37%). In multivariable analyses, factors significantly associated with grade 2 to 4 acute GVHD were cyclophosphamide + total-body irradiation versus busulfan + cyclophosphamide (relative risk [RR] = 1.4; P < .0001), blood cell versus bone marrow grafts in patients age 18 to 39 years (RR = 1.43; P = .0023), recipient age 40 and older versus age 18 to 39 years receiving bone marrow grafts (RR = 1.44; P = .0005), CML versus AML/ALL (RR = 1.35; P = .0003), white/Black versus Asian/Hispanic race (RR = 1.54; P = .0003), Karnofsky performance score less than 90 versus 90 to 100 (RR = 1.27; P = .014), and recipient/donor cytomegalovirus-seronegative versus either positive (RR = 1.20; P = .04). Stratification by disease showed the same significant predictors of grade 2 to 4 acute GVHD for CML; however, KPS and cytomegalovirus serostatus were not significant predictors for AML/ALL. Conclusion This analysis confirmed several previously reported risk factors for grade 2 to 4 acute GVHD. However, several new factors were identified whereas others are no longer significant. These new data may facilitate individualized risk estimates and raise several interesting biologic questions.