Ikaros expression is associated with an increased risk of chronic graft-versus-host disease.

Immune reconstitution after hematopoietic stem cell transplantation (HSCT) is a complex and extremely variable process. The Ikaros transcription factor plays an important role in hematopoiesis in several cell lines, especially in the lymphoid lineage. We hypothesized that Ikaros might influence immune reconstitution, and consequently, the risk of opportunistic infections, relapse, and graft versus host disease (GVHD). Samples were collected from the graft and from the peripheral blood (PB) of the recipients 3 weeks after neutrophil recovery. Real-time polymerase chain reaction (RT-PCR) was performed to analyze the absolute and relative Ikaros expression. Patients were divided into two groups, according to Ikaros expression in the graft and in the recipients' PB based on the ROC curves for moderate/severe cGVHD. A cutoff of 1.48 was used for Ikaros expression in the graft, and a cutoff of 0.79 was used for Ikaros expression in the recipients' PB. Sixty-six patients were included in this study. Median age of patients was 52 years (range 16-80 years), 55% of them were male, and 58% of them had acute leukemia. Median follow-up period was 18 months (range 10-43 months). There was no association between Ikaros expression and the risk of acute GVHD, relapse, or mortality. However, a significant association was observed with the risk of chronic GVHD. Higher Ikaros expression in the graft was associated with a significantly higher cumulative incidence (CI) of moderate/severe chronic GVHD according to the National Institute of Health (NIH) classification at two years (54% vs. 15% for patients with lower expression, P = 0.03). A higher Ikaros expression in the recipients' PB 3 weeks after engraftment was also associated with a significantly higher risk of moderate/severe chronic GVHD (65% vs. 11%, respectively, P = 0.005). In conclusion, Ikaros expression in the graft and in the recipients' PB after transplantation was associated with a higher risk of moderate/severe chronic GVHD. Ikaros expression should be evaluated in larger prospective trials as a potential biomarker for chronic GVHD.

Impact of rabbit ATG-containing myeloablative conditioning regimens on the outcome of patients undergoing unrelated single-unit cord blood transplantation for hematological malignancies.

This study aimed to assess the impact of antithymocyte globulin (ATG) on patient outcome in a retrospective series of 91 patients (median age: 12 years) who underwent unrelated single-unit cord blood transplantation (allo-CBT) following a myeloablative conditioning regimen. Cord blood units were HLA-matched (6/6, n=18; 21%), one-Ag mismatched (n=30, 35%) or two-Ag mismatched (n=38; 44%). In this series, the OS, nonrelapse mortality (NRM) and cumulative incidence of relapse were 47±6%, 23±4% and 48±5%, respectively. Among 46 patients who received ATG as part of the conditioning regimen, the incidence of acute and chronic GVHD was lower than that in the group of 45 patients who did not receive ATG (20% vs 43%; P=0.03). However, multivariate statistical analysis revealed that the ATG use was associated with decreased OS and EFS rates and a high incidence of NRM (hazard ratio (HR)=1.99, 95% confidence interval (CI): 1.11-3.59, P=0.02), (HR=1.83, 95% CI: 1.08-3.10, P=0.02) and (HR=2.54, 95% CI: 1.03-6.26, P=0.04), respectively. Therefore, our results do not support the use of ATG as part of a myeloablative-conditioning regimen before single-unit allo-CBT in younger patients with hematological malignancies.

Risk factors for outcomes after unrelated cord blood transplantation for adults with acute lymphoblastic leukemia: a report on behalf of Eurocord and the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation.

We performed a retrospective analysis on 421 adult patients who underwent unrelated cord blood transplantation (UCBT) for ALL. Median age was 32 years; 46% were in first CR (CR1), 32% in CR2 and 22% had advanced disease. Double UCBT was performed in 173 patients (41%). Myeloablative conditioning (MAC) was given to 314 patients (75%). Cumulative incidence (CI) of 60-day neutrophil recovery was 78%. CI of acute and chronic GVHD was 33 and 26%, respectively. Non-relapse mortality (NRM) at 2 years was 42%. Age⩾35 years (P<0.0001), advanced disease at UCBT (P<0.0001) and use of MAC (P<0.0001) were associated with increased NRM. Relapse incidence (RI) at 2 years was 28%; use of reduced intensity conditioning (RIC) (P=0.0002) was associated with increased RI. Two-year leukemia-free survival (LFS) was 39% for patients in CR1, 31% for CR2 and 8% for advanced disease. In multivariate analysis, factors associated with decreased LFS rate were: age ⩾35 years (P=0.034), use of MAC (P=0.032) and advanced disease (P<0.0001). These results show that UCBT is a valuable option to treat high-risk adult ALL when in remission. Strategies to decrease toxicity and relapse are needed to improve final outcomes.