Sirolimus-based graft-versus-host disease prophylaxis promotes the in vivo expansion of regulatory T cells and permits peripheral blood stem cell transplantation from haploidentical donors.

Hematopoietic stem cell transplantation (HSCT) from human leukocyte antigen (HLA) haploidentical family donors is a promising therapeutic option for high-risk hematologic malignancies. Here we explored in 121 patients, mostly with advanced stage diseases, a sirolimus-based, calcineurin-inhibitor-free prophylaxis of graft-versus-host disease (GvHD) to allow the infusion of unmanipulated peripheral blood stem cell (PBSC) grafts from partially HLA-matched family donors (TrRaMM study, Eudract 2007-5477-54). Conditioning regimen was based on treosulfan and fludarabine, and GvHD prophylaxis on antithymocyte globulin Fresenius (ATG-F), rituximab and oral administration of sirolimus and mycophenolate. Neutrophil and platelet engraftment occurred in median at 17 and 19 days after HSCT, respectively, and full donor chimerism was documented in patients' bone marrow since the first post-transplant evaluation. T-cell immune reconstitution was rapid, and high frequencies of circulating functional T-regulatory cells (Treg) were documented during sirolimus prophylaxis. Incidence of acute GvHD grade II-IV was 35%, and occurrence and severity correlated negatively with Treg frequency. Chronic GvHD incidence was 47%. At 3 years after HSCT, transpant-related mortality was 31%, relapse incidence 48% and overall survival 25%. In conclusion, GvHD prophylaxis with sirolimus-mycophenolate-ATG-F-rituximab promotes a rapid immune reconstitution skewed toward Tregs, allowing the infusion of unmanipulated haploidentical PBSC grafts.

Bone marrow mammaglobin expression as a marker of graft-versus-tumor effect after reduced-intensity allografting for advanced breast cancer.

We assessed mammaglobin (MMG) gene expression in bone marrow (BM) aspirates from patients with advanced breast cancer who had received a reduced-intensity conditioning and stem cell allografting, in order to detect a graft-versus-tumor effect on micrometastatic disease. Nine patients received a reduced-intensity conditioning with fludarabine, cyclophosphamide, and thiotepa, followed by peripheral blood allografting from HLA-identical sibling donors. Nested RT-PCR analysis with sequence-specific primers for MMG was carried out on a monthly basis on BM samples. Three patients had MMG-positive BM, four patients had MMG-negative BM before allografting, and two were undetermined. In two patients, a clinical response after allografting (partial remission) occurred concurrently with the clearance of MMG expression, at a median of 6 months after allografting, following immune manipulation. In two patients, a prolonged stable disease and negative MMG expression occurred after day +360 from allografting. In two patients, progression of the disease was associated with MMG RT-PCR changing from negative to positive. In one case, a disease response occurring after donor lymphocyte infusion and grade II acute GVHD was heralded by negativization of MMG expression. Although preliminary, these data suggest that a graft-versus-breast cancer effect is detectable on micrometastatic BM disease.

Factors predicting response to splenectomy in adult patients with idiopathic thrombocytopenic purpura.

BACKGROUND AND OBJECTIVES: Splenectomy is the treatment of choice in the majority of patients affected by idiopathic thrombocytopenic purpura refractory to corticosteroid therapy, but it is not free from early and late complications. As the available literature does not seem to contain any precise indications concerning possible factors predicting the response to splenectomy, the aim of this retrospective study of 65 splenectomized patients was to attempt to identify potentially predictive clinical or laboratory parameters. DESIGN AND METHODS: For the purposes of statistical analysis, the patients were divided into two groups: the first included those with a complete (platelets > 100x10(9)/L) or partial response (platelets 50-100 x10(9)/L) to splenectomy; the second, the non-responders (platelets < 50x10(9)/L). The non-parametric tests were based on the Kruskal-Wallis method for independent samples, and the independent samples were compared using the Chi-square test according to Pearson. RESULTS: Univariate analysis did not reveal any significant correlation between successful splenectomy and age, sex, platelet count at diagnosis, anti-platelets antibody positivity, the site of platelet sequestration, the time between diagnosis and surgery, or the response to high intravenous immunoglobulin doses. However, the probability of success was greater in the patients with a complete or partial pre-operative response to steroid therapy (p<0.05). INTERPRETATION AND CONCLUSIONS: The factor most frequently associated with the success of splenectomy is the site of autologous platelet sequestration. Our study did not identify any clinical or laboratory parameter clearly predictive of post-splenectomy cure other than a transient response to steroid treatment. This finding needs further confirmation in larger patient populations.