Allelic HLA Matching and Pair Origin Are Favorable Prognostic Factors for Unrelated Hematopoietic Stem Cell Transplantation in Neoplastic Hematologic Diseases: An Italian Analysis by the Gruppo Italiano Trapianto di Cellule Staminali e Terapie Cellulari, Italian Bone Marrow Donor Registry, and Associazione Italiana di Immunogenetica e Biologia dei Trapianti.

HLA molecules are important for immunoreactivity in allogeneic hematopoietic stem cell transplantation (HSCT). The Gruppo Italiano Trapianto di Cellule Staminali e Terapie Cellulari, Italian Bone Marrow Donor Registry, and Associazione Italiana di Immunogenetica e Biologia dei Trapianti promoted a retrospective observational study to evaluate HLA matching and the impact of allelic HLA mismatching and non-HLA factors on unrelated Italian HSCT outcomes. From 2012 to 2015, 1788 patients were enrolled in the study. The average donor age was 29 years and the average recipient age was 49 years. As a conditioning regimen, 71% of the patients received myeloablative conditioning. For GVHD prophylaxis, 76% received either antithymocyte or anti-T lymphocyte globulin, cyclosporine A, and methotrexate. Peripheral blood was the stem cell source in 80%. The median duration of follow-up was 53 months. Regarding HLA matching, 50% of donor-recipient pairs were 10/10 matched, 38% had 1 mismatch, and 12% had 2 or more mismatches. A total of 302 pairs shared Italian origin. Four-year overall survival (OS), progression-free survival, GVHD-free relapse-free survival, and relapse rates were 49%, 40%, 22%, and 34%, respectively. The 4-year NRM was 27%, and the 100-day cumulative incidence of grade ≥II acute GVHD (aGVHD) was 26%. In multivariate analysis, 9/10 and ≤8/10 HLA allele-matched pairs were associated with worse OS (P = .04 and .007, respectively), NRM (P = .007 and P < .0001, respectively), and grade III-IV aGVHD (P = .0001 and .01, respectively). Moreover, the incidences of grade II-IV aGVHD (P = .001) and chronic GVHD (P = .002) were significantly lower in Italian pairs. In conclusion, 10/10 HLA matching is a favorable prognostic factor for unrelated HSCT outcome in the Italian population. Moreover, the presence of 2 HLA-mismatched loci was associated with a higher NRM (P < .0001) and grade II-IV aGVHD (P = .006) and a poorer OS (P = .001) compared with 1 HLA-mismatched locus in early or intermediate disease phases. Finally, we found that Italian donor and recipient origin is a favorable prognostic factor for GVHD occurrence.

Secondary oral cancer following hematopoietic cell transplantation.

The aim of this retrospective study was to determine the incidence and the clinical outcome of secondary oral cancer (SOC) and to assess potential risk factors in a large cohort of patients (n = 908), who received allogeneic hemopoietic cell transplantation (HCT) either for a malignant (n = 733) or nonmalignant hematologic disease (n = 175). The median follow-up of 438 transplant survivors was 17 years. Twelve patients developed SOC at a median of 13.5 years since HCT and at a median age of 47 years. The 35-year cumulative incidence function of SOC development was 3.47%. In univariate analysis, factors associated with increased incidence of SOC were reduced intensity conditioning and chronic graft-versus-host disease (cGvHD). On multivariate analysis, nonmalignant disease and duration of oral cGvHD ≥15 months were independent risk factors for SOC development. Nonmalignant disease recipients had 3.94× higher than expected rate of SOC (95% confidence interval, 1.50-10.39%, p = 0.0055). Recipients whose oral cGvHD persisted for more than ≥15 months had 58.6× higher than expected rate of SOC (95% confidence interval, 13.3-258.1%), p < 0.0001). This study demonstrates that oral cGvHD and a diagnosis of nonmalignant hematologic disease are strong risk factors in the SOC development.

NOTCH and Graft-Versus-Host Disease.

In allogeneic hematopoietic stem cell transplantation, which is the major curative therapy for hematological malignancies, T cells play a key role in the development of graft-versus-host disease (GvHD). NOTCH pathway is a conserved signal transduction system that regulates T cell development and differentiation. The present review analyses the role of the NOTCH signaling as a new regulator of acute GvHD. NOTCH signaling could also represent a new therapeutic target for GvHD.

Treg-protected donor lymphocyte infusions: a new tool to address the graft-versus-leukemia effect in the absence of graft-versus-host disease in patients relapsed after HSCT.

In high-risk acute leukemia patients undergoing haploidentical hematopoietic stem cell transplantation (HSCT), adoptive immunotherapy with T regulatory cells (Tregs) and T conventional cells (Tcons) prevented acute and chronic graft-versus-host disease (GvHD), favored post-transplant immunological reconstitution and was associated with a powerful graft-versus-leukemia (GvL) effect. With a particularly innovative approach, we developed a treatment with a Treg-protected donor lymphocyte infusion (DLI) for patients with early relapse after HSCT and we report here the results obtained in the first patient with APL (M3v) relapsed after a second matched allogeneic HSCT (15% blasts and 75% of donor cells in bone marrow). The patient received a first infusion of 2.5 × 106/kg Tregs derived from matched donor followed 7 days later by 5 × 106/kg Tcons. GvL effect was strongly evident as the percentage of leukemic cells decreased to 5%. A second infusion of Tregs (2.5 × 106/kg) and Tcons (2 × 106/kg) was performed. No GvHD was observed. Disease evaluation showed the absence of blastic cells at flow-cytometry, a normal caryotype and full donor chimerism. We also observed NOTCH1 down-regulation in peripheral blood. This new immunotherapy approach showed that Treg-protected DLI is effective in preventing GvHD and is associated with a strong GvL effect.

Haploidentical, unmanipulated, G-CSF-primed bone marrow transplantation for patients with high-risk hematologic malignancies.

UNLABELLED: Eighty patients with high-risk hematologic malignancies underwent unmanipulated, G-CSF­primed BM transplantation from an haploidentical family donor. Patients were transplanted in first or second complete remission (CR, standard-risk: n =45) or in > second CR or active disease (high-risk: n =35). The same regimen for GVHD prophylaxis was used in all cases. The cumulative incidence (CI) of neutrophil engraftment was 93% 0.1%. The 100-day CIs for II-IV and III-IV grade of acute GVHD were 24% 0.2% and 5% 0.6%, respectively. The 2-year CI of extensive chronic GVHD was 6% 0.1%. The 1-year CI of treatment-related mortality was 36% 0.3%. After a median follow-up of 18 months, 36 of 80 (45%) patients are alive in CR. The 3-year probability of overall and disease-free survival for standard-risk and high-risk patients was 54% 8% and 33% 9% and 44% 8% and 30% 9%, respectively. In multivariate analysis, disease-free survival was significantly better for patients who had standard-risk disease and received transplantations after 2007. We conclude that unmanipulated, G-CSF­primed BM transplantation from haploidentical family donor provides very encouraging results in terms of engraftment rate, incidence of GVHD and survival and represents a feasible, valid alternative for patients with high-risk malignant hematologic diseases, lacking an HLA identical sibling and in need to be urgently transplanted. KEY POINTS: Haploidentical, unmanipulated, G-CSF-primed bone marrow transplantation. Haploidentical hematopoietic stem cell transplantation for hematologic malignancies.

Long-term results of survival in patients with thalassemia major treated with bone marrow transplantation.

Allogeneic bone marrow transplantation (BMT) is the only available curative approach for thalassemia major, although long-term morbidity and mortality are not established. The aim of this study was to assess the long-term clinical and hematological results in children and adults with thalassemia major treated with BMT. We analyzed the outcome of 115 patients (median age 9 years, range 11 months to 28 years) with thalassemia major undergoing BMT from a related donor between 1983 and 2006. All patients received the same protocol, consisting of busulfan and cyclophoshamide as conditioning therapy and cyclosporin (CSA) alone or CSA and methotrexate for graft-versus-host disease (GvHD) prophylaxis. The cumulative probability of graft rejection was 6.7%. The transplant-related mortality at 1 year was 8.7%. The 20-year Kaplan-Meier estimate of overall survival and disease-free survival was 89.2% and 85.7%, respectively. Ninety-nine patients out of 103 survivors were in excellent clinical and hematological conditions at last visit following a median follow-up of 15 years (range, 1-24 years) with the exception of two patients who had invalidating chronic GvHD. This study conducted with a large cohort of patients and covering a long period of observation time, showed BMT to be curative for the majority of patients with thalassemia major. The impact of long-term transplant-related sequelae was very limited.