Haploidentical hematopoietic transplantation from KIR ligand-mismatched donors with activating KIRs reduces nonrelapse mortality.

Because activating killer cell immunoglobulinlike receptors (KIRs) are heterogeneously expressed in the population, we investigated the role of donor activating KIRs in haploidentical hematopoietic transplants for acute leukemia. Transplants were grouped according to presence vs absence of KIR-ligand mismatches in the graft-vs-host direction (ie, of donor-vs-recipient natural killer [NK]-cell alloreactivity). In the absence of donor-vs-recipient NK-cell alloreactivity, donor activating KIRs had no effects on outcomes. In the 69 transplant pairs with donor-vs-recipient NK-cell alloreactivity, transplantation from donors with KIR2DS1 and/or KIR3DS1 was associated with reduced risk of nonrelapse mortality, largely infection related (KIR2DS1 present vs absent: hazard ratio [HR], 0.25; P = .01; KIR3DS1 present vs absent: HR, 0.18; P = .006), and better event-free survival (KIR2DS1 present vs absent: HR, 0.31; P = .011; KIR3DS1 present vs absent: HR, 0.30; P = .008). Transplantation from donors with KIR2DS1 and/or KIR3DS1 was also associated with a 50% reduction in infection rate (P = .003). In vitro analyses showed that KIR2DS1 binding to its HLA-C2 ligand upregulated inflammatory cytokine production by alloreactive NK cells in response to infectious challenges. Because ∼40% of donors able to exert donor-vs-recipient NK-cell alloreactivity carry KIR2DS1 and/or KIR3DS1, searching for them may become a feasible, additional criterion in donor selection.

HLA-haploidentical transplantation with regulatory and conventional T-cell adoptive immunotherapy prevents acute leukemia relapse.

Posttransplant relapse is still the major cause of treatment failure in high-risk acute leukemia. Attempts to manipulate alloreactive T cells to spare normal cells while killing leukemic cells have been unsuccessful. In HLA-haploidentical transplantation, we reported that donor-derived T regulatory cells (Tregs), coinfused with conventional T cells (Tcons), protected recipients against graft-versus-host disease (GVHD). The present phase 2 study investigated whether Treg-Tcon adoptive immunotherapy prevents posttransplant leukemia relapse. Forty-three adults with high-risk acute leukemia (acute myeloid leukemia 33; acute lymphoblastic leukemia 10) were conditioned with a total body irradiation-based regimen. Grafts included CD34(+) cells (mean 9.7 × 10(6)/kg), Tregs (mean 2.5 × 10(6)/kg), and Tcons (mean 1.1 × 10(6)/kg). No posttransplant immunosuppression was given. Ninety-five percent of patients achieved full-donor type engraftment and 15% developed ≥grade 2 acute GVHD. The probability of disease-free survival was 0.56 at a median follow-up of 46 months. The very low cumulative incidence of relapse (0.05) was significantly better than in historical controls. These results demonstrate the immunosuppressive potential of Tregs can be used to suppress GVHD without loss of the benefits of graft-versus-leukemia (GVL) activity. Humanized murine models provided insights into the mechanisms underlying separation of GVL from GVHD, suggesting the GVL effect is due to largely unopposed Tcon alloantigen recognition in bone marrow.

Haploidentical age-adapted myeloablative transplant and regulatory and effector T cells for acute myeloid leukemia.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the most effective treatment in eradicating high-risk acute myeloid leukemia (AML). Here, we present data from a novel HLA-haploidentical HSCT protocol that addressed the 2 remaining major unmet medical needs: leukemia relapse and chronic graft-versus-host disease (cGVHD). Fifty AML patients were enrolled in the study. The conditioning regimen included total body irradiation for patients up to age 50 years and total marrow/lymphoid irradiation for patients age 51 to 65 years. Irradiation was followed by thiotepa, fludarabine, and cyclophosphamide. Patients received an infusion of 2 × 106/kg donor regulatory T cells on day -4 followed by 1 × 106/kg donor conventional T cells on day -1 and a mean of 10.7 × 106 ± 3.4 × 106/kgpurified CD34+ hematopoietic progenitor cells on day 0. No pharmacological GVHD prophylaxis was administered posttransplantation. Patients achieved full donor-type engraftment. Fifteen patients developed grade ≥2 acute GVHD (aGVHD). Twelve of the 15 patients with aGVHD were alive and no longer receiving immunosuppressive therapy. Moderate/severe cGVHD occurred in only 1 patient. Nonrelapse mortality occurred in 10 patients. Only 2 patients relapsed. Consequently, at a median follow-up of 29 months, the probability of moderate/severe cGVHD/relapse-free survival was 75% (95% confidence interval, 71%-78%). A novel HLA-haploidentical HSCT strategy that combines an age-adapted myeloablative conditioning regimen with regulatory and conventional T-cell adoptive immunotherapy resulted in an unprecedented cGVHD/relapse-free survival rate in 50 AML patients with a median age of 53 years. This trial was registered with the Umbria Region Institutional Review Board Public Registry as identification code 02/14 and public registry #2384/14 and at www.clinicaltrials.gov as #NCT03977103.

Use of DPB1 T-cell epitope algorithm among italian transplant centers: A survey on behalf of Associazione Italiana di Immunogenetica e Biologia dei Trapianti.

The HLA-DPB1 locus has been demonstrated to have a significant role on patients' outcome after allogeneic HSCT, and the so-called T-cell epitope (TCE) algorithm has been incorporated in international guidelines for the selection of unrelated donors. The purpose of the present study is to measure, through a national survey conducted on behalf of the Associazione Italiana di Immunogenetica e Biologia dei Trapianti (AIBT), the extent of awareness and use of HLA-DPB1 TCE-based algorithms during the donor search. 89% of the HLA laboratories answered to a short questionnaire and the results showed a progressive increase of the laboratories typing DPB1 in patients and their potential donors during the search (from 44% to 79% during the 2010-2019 period) as well as the application of a TCE-based algorithm for the donor choice whenever possible (from 24% to 65% during the same period). The DP-permissiveness status is detailed in the official HLA typing report by 12%, 32% and 50% of laboratories in 2010, 2015 and 2019, respectively. The present data indicate an encouraging raise in the awareness of the HLA-DPB1 role in unrelated donor selection; noteworthy, mentioning the TCE-based permissiveness status in the HLA typing report of each potential unrelated donor represents a notable mean to raise awareness among transplant physicians and to support them in their task of choosing the best donor. Nonetheless, despite the compelling evidence of the predictive ability of TCE-based algorithms, further efforts are still needed to extend its application to all transplant centers in Italy.

Biological markers and DNA flow cytometric analysis in radically resected patients with non-small cell lung cancer. A study of the Perugia Multidisciplinary Team for Thoracic Tumors.

AIMS AND BACKGROUND: The aim of this study was to evaluate the relationship between a panel of biological markers (p53, Bcl-2, HER-2, Ki67, DNA ploidy and S-phase fraction) and clinical-pathological parameters and its impact on outcome in non-small cell lung cancer (NSCLC). METHODS AND STUDY DESIGN: Tumor tissue specimens obtained after surgical resection were collected from consecutive patients with NSCLC. We used an immunocytochemical technique for p53, Bcl-2, HER-2 and Ki67 analysis in fine-needle aspirates obtained from surgical samples that were also evaluated by flow cytometric DNA analysis using a FACScan flow cytometer. RESULTS: From April 2000 to December 2005, 136 patients with radically resected NSCLC were recruited. Median age was 66 years (range, 31-84 years), male/female ratio 117/19, ECOG performance status 0/1 127/4, stage I/II/III 76/25/35, squamous/adenocarcinoma/large-cell/mixed histology 62/49/17/8, smokers yes/no 121/11. Positivity of p53, Bcl-2, HER-2 and Ki67 was detected in 51.4%, 27.9%, 25.0% and 55.8% of the samples, respectively; 82.9% of the cases revealed aneuploid DNA histograms and 56.7% presented an S-phase fraction of more than 12%. Statistically significant associations between high Ki67 and poorly differentiated tumors (P = 0.016) and a smoking history (P = 0.053); p53 positivity and high Ki67 (P = 0.002); HER-2 positivity and adenocarcinoma subtype (P = 0.015) and presence of lymph node involvement (P = 0.006); and Bcl-2 positivity and squamous cell carcinoma subtype (P = 0.058) were observed. At univariate analysis, high Ki67 proved to be the only marker associated with disease-free survival (P = 0.047). After adjusting for stage, none of the examined immunocytochemical markers emerged as an independent factor for disease-free and overall survival; only pathological stage was identified as an independent prognostic factor for disease-free survival (P = 0.0001) and overall survival (P = 0.0001). In the group of 76 patients classified as TNM stage I, high Ki67 was the only marker associated with recurrence of disease (P = 0.05). CONCLUSIONS: Our data do not support a relevant prognostic role of immunocytochemical markers in NSCLC, even if the Ki67 index might have particular relevance to identify patients with more aggressive tumors who are at high risk for disease relapse.