The online version of this article has a Supplementary Appendix. BackgroundThere is evidence suggesting that sirolimus, in combination with tacrolimus, is active in the prevention of graft-versus-host disease. Sirolimus-based immune suppression may suppress alloreactive T cells, while sparing the survival and function of regulatory T cells. Design and MethodsWe conducted a randomized trial to compare the impact of sirolimus/tacrolimus against that of methotrexate/tacrolimus on the prevention of graft-versus-host disease and regulatory T-cell reconstitution. ResultsSeventy-four patients were randomized 1:1 to sirolimus/tacrolimus or methotrexate/ tacrolimus, stratified for type of donor (sibling or unrelated) and the patients' age. The rate of grade II-IV acute graft-versus-host disease at 100 days was 43% (95% CI: 27-59%) in the sirolimus/tacrolimus group and 89% (95% CI: 72-96%) in the methotrexate/tacrolimus group (P<0.001). The rate of moderate/severe chronic graft-versus-host disease was 24% (95% CI: 7-47%) in the sirolimus/tacrolimus group and 64% (95% CI: 41-79%) in the methotrexate/tacrolimus group (P=0.008). Overall survival and patient-reported quality of life did not differ between the two groups. On days 30 and 90 post-transplant, sirolimus-treated patients had a significantly greater proportion of regulatory T cells among the CD4 + cells in the peripheral blood, and isolated regulatory T cells were functional. ConclusionsThese data demonstrate that sirolimus/tacrolimus prevents grade II-IV acute graft-versus-host disease and moderate-severe chronic graft-versus-host disease more effectively than does methotrexate/tacrolimus, and supports regulatory T-cell reconstitution following allogeneic hematopoietic cell transplantation. ABSTRACT© F e r r a t a S t o r t i F o u n d a t i o n

Relapse remains a leading cause for treatment failure after hematopoietic cell transplantation (HCT) in patients with intermediate-or high-risk myelodysplastic syndrome (MDS). To discern the impact of 5-azacitine treatment pretransplant on the risk for relapse after HCT, we analyzed the post transplant outcomes of all 54 consecutive patients with MDS or chronic myelomonocytic leukemia who received HCT from HLA-compatible donors according to pretransplant 5-azacitidine exposure. Thirty patients received a median of four (1-7) cycles of 5-azacitidine, and 24 patients did not receive 5-azacitidine before HCT. The 1-year estimates of overall survival, relapse-free survival and cumulative incidence of relapse were 47, 41 and 20%, for 5-azacitidine patients and 60, 51 and 32%, respectively, for non-5-azacytidine patients. These observations suggest that outcomes are similar in both groups with a trend toward decreased early relapse in patients receiving 5-azacitidine. 5-Azacitidine may be of value in stabilizing the disease, thereby allowing time for patients to reach transplant and does not appear to affect transplant outcomes.

Tacrolimus (Tac) plus methotrexate (MTX) is a standard regimen for graft-versus-host disease (GVHD) prophylaxis. Mycophenolate mofetil (MMF) is sometimes used instead of MTX to minimize toxicity, despite the lack of controlled studies demonstrating efficacy. We conducted a single-center, randomized phase II trial comparing Tac + MMF to Tac + MTX. Intent-to-treat analyses included 42 patients randomized to Tac + MMF and 47 to Tac + MTX. Patient characteristics were not different between the study arms. Patients in the Tac + MMF arm were less likely to experience severe mucositis, require narcotic analgesia and parenteral nutrition, and had earlier hospital discharge. The Tac + MMF arm had the same time to neutrophil recovery, but earlier platelet recovery. The cumulative incidence of grade II-IV acute GVHD (aGVHD) at 100 days was similar (P = .8), but grade III-IV aGVHD was higher in the Tac + MMF arm (19% versus 4%; P = .03); this was predominantly seen in unrelated donor transplants (26% versus 4%; P = .04), and less in related donor transplants (11% versus 4%; P = n.s.). Moderate or severe chronic GVHD was similar (P = .71). There were no significant differences between the arms in relapse, nonrelapse mortality, or overall and relapse-free survivals. MMF was associated with less early toxicity than MTX but was not as effective in preventing severe aGVHD, especially in unrelated donor transplants.

Acute graft-versus-host disease (GVHD) is diagnosed by clinical and histologic criteria that are often nonspecific and typically apparent only after the disease is well established. Because GvHD is mediated by donor T cells and other immune effector cells, we sought to determine whether changes within a wide array of peripheral blood lymphocyte populations could predict the development of GvHD. Peripheral blood samples from 31 patients undergoing allogeneic blood and marrow transplant were analyzed for the proportion of 121 different subpopulations defined by 4-color combinations of lymphocyte phenotypic and activation markers at progressive time points posttransplant. Samples were processed using a newly developed high content flow cytometry technique and subjected to a spline- and functional linear discriminant analysis (FLDA)-based temporal analysis technique. This strategy identified a consistent posttransplant increase in the proportion and extent of fluctuation of CD3+CD4+CD8beta+ cells in patients who developed GVHD compared to those that did not. Although larger prospective clinical studies will be necessary to validate these results, this study demonstrates that high-content flow cytometry coupled with temporal analysis is a powerful approach for developing new diagnostic tools, and may be useful for developing a sensitive and specific predictive test for GVHD.