Mixed T cell CHIMERISM in bone marrow at day+30 after allogeneic stem cell transplantation: Correlation with acute GVHD grades III-IV and no impact on relapse and overall survival.

OBJECTIVES: Early chimerism analysis is important to assess engraftment in allogeneic hematopoietic stem cell transplantations. METHODS: We retrospectively investigated the impact of T-cell chimerism at day 30 in bone marrow on acute graft-versus-host disease (aGVHD), relapse, and overall survival in 142 adult allo-transplanted patients. RESULTS: The majority of patients (89%) received myeloablative conditioning and 90% have undergone T-cell replete donor graft. At day 30, 103 patients showed T-complete chimerism with prevalence in haploidentical transplants, whereas 39 cases had CD3+ mixed chimerism, including 30 patients transplanted with HLA identical donors, and 21 with T-cell donors<90%. T-cell chimerism at day 30 was weakly inversely related to aGVHD grades II-IV (p = .078) with no cases of grades III-IV aGVHD in patients with CD3+ <95%. Mixed T-cell chimerism did not impact on relapse (p = .448) and five of the seven patients who relapsed had T-cell chimerism ≤90%. Older age and active disease at transplant had a statistically significant negative effect on overall survival (p = .01 and p = .0001, respectively), whereas mixed CD3+ chimerism did not. CONCLUSIONS: T lymphocyte chimerism analysis at day +30 in bone marrow could identify allo-transplanted patients at major risk of aGVHD grades III-IV (CD3+ donors >95%) mainly post-myeloablative conditioning regimen.

Impact of the preparation method of red cell concentrates on transfusion indices in thalassemia patients: A randomized crossover clinical trial.

BACKGROUND: The average hemoglobin content of red cell concentrates (RCC) varies depending on the method of preparation. Surprisingly less data are available concerning the clinical impact of those differences. STUDY DESIGN AND METHODS: The effects of two types of RCC (RCC-A, RCC-B) on transfusion regime were compared in a non-blinded, prospective, randomized, two-period, and crossover clinical trial. RCC-A was obtained by whole blood leukoreduction and subsequent plasma removal, RCC-B removing plasma and buffy coat first, followed by leukoreduction. Eligible patients were adult, with transfusion-dependent thalassemia (TDT). RESULTS: RCC-A contained 63.9 (60.3-67.8) grams of hemoglobin per unit (median with 1st and 3rd quartile), RCC-B 54.5 (51.0-58.2) g/unit. Fifty-one patients completed the study. With RCC-B, the average pre-transfusion hemoglobin concentration was 9.3 ± 0.5 g/dl (mean ± SD), the average transfusion interval 14.2 (13.7-16.3) days, the number of RCC units transfused per year 39.3 (35.4-47.3), and the transfusion power index (a composite index) 258 ± 49. With RCC-A, the average pre-transfusion hemoglobin concentration was 9.6 ± 0.5 g/dl (+2.7%, effect size 0.792), the average transfusion interval 14.8 (14.0-18.5) days (+4.1%, effect size 0.800), the number of RCC units transfused per year 34.8 (32.1-42.5) (-11.4%, effect size -1.609), and the transfusion power index 272 ± 61 (+14.1%, effect size 0.997). All differences were statistically highly significant (p < .00001). The frequency of transfusion reactions was 0.59% with RCC-A and 0.56% with RCC-B (p = 1.000). CONCLUSION: To reduce the number of RCC units consumed per year and the number of transfusion episodes, TDT patients should receive RCC with the highest average hemoglobin content.