Francesca Re

Expression of CD86 in acute myelogenous leukemia is a marker of dendritic/monocytic lineage

OBJECTIVE The aim of this study was to determine whether expression of the CD86 costimulatory molecule in acute myeloid leukemia (AML) can identify blast cells committed to the monocytic/dendritic lineage. MATERIAL AND METHODS One hundred ten consecutive AML patients observed at diagnosis were studied by flow cytometry. In selected experiments, in vitro cultures with CD34(+)CD86(+) or CD34(-)CD86(+) blasts were performed in the presence of granulocyte-macrophage colony-stimulating actor (GM-CSF) with or without tumor necrosis factor-alpha (TNF-alpha) or GM-CSF + interleukin-4 (IL-4), respectively, to induce a dendritic differentiation, documented by morphologic and immunophenotypic assays. T-cell alloreactivity to CD86(+) AML cells and leukemic dendritic cells (AML-DC) was tested in mixed leukocyte cultures and anti-leukemic cytotoxic assays. RESULTS CD86 was expressed in 54% AML, whereas CD80 and CD1a were only occasionally positive. CD86(+) AML samples included M5 and M4, but also 47% M0-M1 FAB types, and were more frequently CD14(+) (p < 0.00001) and CD34(-) (p = 0.00005) than CD86(-)AML. Six different patterns of CD86(+) AML were identified, according to CD34 or CD14 total or partial coexpression. Four samples enriched in CD34(+)CD86(+) AML cells differentiated into AML-DC CD86(+), CD80(+), CD40(+), CD11c(+), HLA-DR(++), CD14(+/-) that also were CD1a(+) or CD83(+), after 6 days of in vitro culture with GM-CSF +/- TNF-alpha. CD34(-)CD86(+) AML cells differentiated into AML-DC after 3 to 5 days (n = 5 experiments), and trisomy 8 was found in two AML and AML-DC samples by fluorescence in situ hybridization analysis. Finally, AML-DC induced more potent allo-T-cell proliferation, cytokine release, and anti-leukemic cytotoxicity than CD86(+) blasts. CONCLUSIONS In AML, CD86 is a marker of monocytic/dendritic lineage. Because CD86(+) blasts may differentiate into DC rapidly, CD86(+)AML patients could be optimal candidates for immunotherapy studies, both in autologous and allogeneic settings.

Discrepancy between serological complete remission and concomitant new bone lytic lesions after infusion of escalating low doses of donor lymphocytes in multiple myeloma: a case report.

A graft-versus-myeloma effect has been previously induced by infusing high numbers of donor lymphocytes after allogeneic stem cell transplantation in relapsed/refractory multiple myeloma (MM) patients. A 43-year-old patient with MM refractory to standard chemotherapy and autologous transplantation received an allogeneic HLA-matched T cell-depleted marrow transplant from his sister after conditioning with single dose total-body irradiation, melphalan and cyclophosphamide. Twenty-four months after transplant neither a significant reduction of serum M protein nor evidence of acute or chronic graft-versus-host disease (GVHD) were observed. The patient was then treated with four escalating low doses of donor lymphocyte infusions (DLI) (0.1, 1.0, 5.0 and 5.0 × 106 CD3+ T cells/kg, respectively) over a 13 month period. Following the second infusion a mild liver acute GVHD and a partial, but transient, response occurred. After the last DLI the patient achieved a complete remission and developed extensive chronic GVHD. However, concomitant with the disappearance of clonal plasma cells from the marrow and of serum M protein, two new bone lytic lesions appeared requiring treatment with radiotherapy. In conclusion, escalating low doses of DLI may be effective in MM and may prevent severe acute but not chronic GVHD. However, the efficacy of DLI in extramedullary MM lesions is still unclear.

Human CD34+ blood cells induce T-cell unresponsiveness to specific alloantigens only under costimulatory blockade

OBJECTIVES The immunogenic role of human CD34(+) cells in allogeneic hematopoietic stem cell transplantation is controversial. In this study we tested the role of CD40 and CTLA4 ligands on CD34(+) cell costimulation of HLA-mismatched lymphocytes. MATERIALS AND METHODS An anti-CD40L monoclonal antibody (hu5C8) and/or CTLA4-Ig molecule were used in primary mixed lymphocyte culture (MLC) with irradiated CD34(+) blood cells and allogeneic responders. Then, secondary MLC, cytotoxic activity, and effector cytokine expression and production were measured. RESULTS Each reagent was able to reduce anti-CD34(+) cell alloreactivity, but only the combination of the anti-CD40L monoclonal antibody and CTLA4-Ig induced greater than 90% inhibition of T-cell response in primary MLC and prevented generation of cytotoxic T cells when priming with purified CD34(+) cells. Importantly, responder cells activated by allogeneic CD34(+) cells in the presence of anti-CD40L monoclonal antibody and CTLA4-Ig entered a state of antigen-specific unresponsiveness while responding to third party antigen, tetanus toxoid, or phytohemagglutinin, and showed suppression of interferon-gamma and increase of interleukin-10 expression and release. Interestingly, addition of interleukin-2 in secondary MLC did not reverse T-cell anergy. CONCLUSIONS The results demonstrate that human CD34(+) blood progenitors stimulate T-cell responses potently and can induce T-cell unresponsiveness only when both B7:CD28 and CD40:CD40L pathways are blocked, with an increase of interleukin-10-producing cells. Therefore, our data allow design of in vivo studies aimed at achieving T-cell tolerance across HLA barriers by using purified CD34(+) cells and costimulatory blockade.

Different immune reconstitution in multiple myeloma, chronic myeloid leukemia and acute myeloid leukemia patients after allogeneic transplantation of peripheral blood stem cells

In this study we compared the lymphocyte reconstitution in 13 multiple myeloma (MM), nine acute myeloid leukemia (AML) and 10 chronic myeloid leukemia (CML) patients after allogeneic G-CSF-mobilized PBSC transplantation from HLA-identical siblings. Conditioning regimens included standard total body irradiation + cyclophosphamide (CY), or busulphan + CY, whereas VP-16 was added in patients with advanced disease. Overall comparable numbers of mononuclear cells, CD34+ cells and CD3+ T cells were infused in each group. A significantly higher CD3+ T cell number was observed in MM and AML than in CML patients 1 month after transplant. However, MM patients showed a faster and better recovery of CD4+ T cells than both AML and CML patients at 3 months (P = 0.01 and P = 0.01, respectively) and 12 months (P = 0.01 vs AML, while P = NS vs cml) after transplant, and had a cd4:cd8 ratio >1 with a median CD4+ t cell value >400/μl 1 year after transplant. development of acute graft-versus-host disease (gvhd) did not affect cd4:cd8 ratios but patients who experienced acute gvhd >grade I had lower CD4+ and CD8+ t cell numbers at all time points. however, after excluding patients with gvhd >grade I, MM patients still showed a significantly higher CD4+ T cell value than patients with myeloproliferative diseases 1 year after transplant. These findings suggest that although allogeneic PBSC transplantation induces rapid immune reconstitution, different kinetics may occur among patients with hematological malignancies. In particular, the rapid reconstitution of CD4+ T cells in MM patients may contribute to the low transplant-related mortality achieved in this disease. Bone Marrow Transplantation (2000) 26, 1325–1331.

Use of 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography in patients with Hodgkin lymphoma in daily practice: a population-based study from Northern Italy.

We conducted a population-based study to assess how positron emission tomography (PET) is currently used in patients with Hodgkin lymphoma (HL). Four cancer registries from northern Italy were used to identify patients with HL diagnosed from 2006 to 2008. Computed tomography (CT) and PET scans were collected before treatment start (B), at the end (F), and during treatment (I). One hundred and thirty-six patients were identified as the study population. B-PET, I-PET, and F-PET were performed in 82%, 65%, and 85% of patients, respectively. Overall, I-PET was coded as positive in 16% of cases. F-PET was positive in 13% of cases. The I-PET result was a prognostic factor for failure-free survival (FFS) (hazard ratio [HR] 5.33); the F-PET result was the only prognostic factor for overall survival (OS) (HR 14.2). This population-based study confirms the prognostic role of I-PET for FFS also in daily practice; the results of F-PET can be used to predict OS.

Efficacy of bendamustine and rituximab as first salvage treatment in chronic lymphocytic leukemia and indirect comparison with ibrutinib: a GIMEMA, ERIC and UK CLL FORUM study

We performed an observational study on the efficacy of ben-damustine and rituximab (BR) as first salvage regimen in chronic lymphocytic leukemia (CLL). In an intention-to-treat analysis including 237 patients, the median progression-free survival (PFS) was 25 months. The presence of del(17p), unmutated IGHV and advanced stage were associated with a shorter PFS at multivariate analysis. The median time-to-next treatment was 31.3 months. Front-line treatment with a chemoimmunotherapy regimen was the only predictive factor for a shorter time to next treatment at multivariate analysis. The median overall survival (OS) was 74.5 months. Advanced disease stage (i.e. Rai stage III-IV or Binet stage C) and resistant disease were the only parameters significantly associated with a shorter OS. Grade 3-5 infections were recorded in 6.3% of patients. A matched-adjusted indirect comparison with ibrutinib given second-line within Named Patient Programs in the United Kingdom and in Italy was carried out with OS as objective end point. When restricting the analysis to patients with intact 17p who had received chemoimmunotherapy in first line, there was no difference in OS between patients treated with ibrutinib (63% alive at 36 months) and patients treated with BR (74.4% alive at 36 months). BR is an efficacious first salvage regimen in CLL in a real-life population, including the elderly and unfit patients. BR and ibrutinib may be equally effective in terms of OS when used as first salvage treatment in patients without 17p deletion.