Molecular and functional bases of self-antigen recognition in long-term persistent melanocyte-specific CD8+ T cells in one vitiligo patient.

Vitiligo patients possess high frequencies of circulating CD8+ T lymphocytes specific for the melanocyte differentiation antigen Melan-A/MART-1. These self-specific T cells exhibit intact functional properties and their T cell receptors are selected for a narrow range of high affinities of antigen recognition, suggesting their important role in the pathogenesis of vitiligo. In order to understand the molecular base for this unexpected, optimal T cell receptor recognition of a self-antigen, a tetramer-guided ex vivo analysis of the T cell receptor repertoire specific for the Melan-A antigen in a patient affected by vitiligo is reported. All T cell receptors sequenced corresponded to different clonotypes, excluding extensive clonal expansions and revealing a large repertoire of circulating Melan-A-specific T lymphocytes. A certain degree of T cell receptor structural conservation was noticed, however, as a single AV segment contributed to the alpha chain rearrangement in 100% of clones and a conserved amino acid sequence was found in the beta chain complementarity determining region 3 of various high affinity cells. We suggest that the conserved alpha chain confers self-antigen recognition, necessary for intrathymic selection and peripheral homeostasis, to many synonymous T cell receptors, whereas the beta chain fine tunes the T cell receptor affinity of the specific cells. In addition, we demonstrate that many high avidity T cell clones from this patient were capable of specifically lysing normal, HLA-matched melanocytes. These autoreactive clones persisted for more than 3 y in the patient's peripheral blood. These data, together with the skin-homing potential of the clones, directly point to the in vivo pathogenic role of melanocyte-specific cytotoxic T lymphocytes in vitiligo.

Evaluation of infectious complications and immune recovery following high-dose chemotherapy (HDC) and autologous peripheral blood progenitor cell transplantation (PBPC-T) in 148 breast cancer patients.

BACKGROUND AND OBJECTIVES: High-dose chemotherapy (HDC) with autologous PBPC-T has been reported to be effective in hematological and in selected solid malignancies. In this setting, infectious complications represent a relevant cause of morbidity. PATIENTS AND METHODS: To ascertain the incidence, types and factors influencing the development of early and late infections, we retrospectively analyzed 148 consecutive breast cancer (BC) patients receiving HDC and PBPC-T, both for primary high-risk BC (pBC) and metastatic disease (mBC). RESULTS: Early infection strongly associated with the occurrence of grade 4 mucositis (p < 0.001), was documented in 28 patients (19%). Late re-activation of varicella zoster virus (VZV) occurred in 14 patients (9%); an inverse correlation between the VZV re-activation and the total amount of T-cells transferred with the graft was observed. Evaluation of immune reconstitution, carried out in 10 out of 148 patients, showed a long-lasting CD+ T-cells depression (> 2 year), mainly involving the naive CD4+ T-cell subset. Conversely, the analysis of the frequency of proliferating T-lymphocyte precursors, specific for antigens expressed by 3 different widespread pathogens, demonstrated that, notwithstanding the delayed recovery of CD4+ cells, many T-lymphocyte functions were within normal range 1 year after PBPC-T. CONCLUSION: Altogether these results show that severe mucositis is associated with early bacterial infections and the infusion of large numbers of T-cells plays a role in controlling late VZV reactivation.

Retrorectal tumours: a case report.

The authors describe a case of retrorectal tumour in a 48-year-old female. Retrorectal tumours are rare, and their diagnosis is notoriously difficult and late. In this case the first-step diagnosis was made on the basis of clinical findings and radiological investigations such as abdominal ultrasonography. The second step included pelvic CT scans and MR imaging which yielded more precise anatomical details and information for the best surgical approach. We opted for a posterior approach with complete, easy removal of the tumour mass which, after pathological examination, turned out to be an epidermoid cyst. The postoperative course was uneventful and, one year after operation, the patient complains only of mild, irregular perineal pain with completely negative radiological investigations (US and CT scan).

Allogeneic blood stem cell transplantation after a reduced-intensity, preparative regimen: a pilot study in patients with refractory malignancies.

BACKGROUND: The immune-mediated graft-versus-tumor (GVT) effect plays a therapeutic role in the treatment of patients with hematologic malignancies who undergo allogeneic hematopoietic stem cell transplantation (HSCT). More recently, it was reported that a GVT effect also occurred in patients who underwent transplantation for metastatic renal carcinoma. The authors carried out a pilot trial of allogeneic transplantation after a reduced-intensity, preparative regimen in patients with refractory malignancies, including solid tumors. The objectives of the current study were to evaluate the feasibility of this approach in terms of toxicity and engraftment and to document evidence of GVT effects. METHODS: Seventeen patients with Stage IV malignancies (7 patients with renal cell carcinoma, 3 patients with sarcoma, 2 patients with breast carcinoma, 2 patients with Hodgkin disease, 1 patient with ovarian carcinoma, 1 patient with melanoma, and 1 patient with both melanoma and renal cell carcinoma) that were not amenable to further conventional treatment were enrolled. The median patient age was 43 years (range, 10-60 years). The Eastern Cooperative Oncology Group performance status (PS) was 0-1 in 11 patients and 2-3 in 6 patients. Preparative treatment consisted of reduced-intensity chemotherapy with fludarabine (30 mg/m(2) per day for 4 consecutive days) and cyclophosphamide (30 mg/Kg per day for 2 consecutive days) prior to allogeneic HSCT from a human leukocyte antigen-identical sibling. The median number of CD34+ cells infused was 6.06 x 10(6)/kg (range, 1.5-14.0 x 10(6)/kg). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin-A and short-term methotrexate. RESULTS: Patients who had a PS of 2-3 prior to undergoing HSCT experienced Grade 4 hematologic toxicities and Grade > or = 3 organ toxicities and died of either treatment-related complications or disease progression within 100 days from transplantation. By contrast, 10 of 11 patients who had a PS of 0-1 prior to undergoing HSCT experienced only short-lasting, Grade < or = 3 neutropenia and thrombocytopenia and no organ toxicity; 1 of 10 patients died of graft failure on Day +29 after undergoing HSCT. By Day +90, 100% donor chimerism was documented in all patients with a past history of heavy chemotherapy, whereas mixed donor chimerism was observed in the 4 patients with a past history of only 1 line of chemotherapy and/or immunotherapy prior to entering the HSCT program. Grade 2-3 acute GVHD occurred in 5 patients. Among patients with a follow-up > 100 days, 2 complete responses and 3 transitory partial responses were recorded. CONCLUSIONS: With this conditioning regimen, full donor chimerism was achieved rapidly only in patients who had received previous intensive chemotherapy. In a proportion of patients with refractory malignancies, allogeneic transplantation resulted in tumor regression. This novel therapeutic strategy may provide little benefit in patients with poor PS and rapidly progressing disease.

Dendritic cells are functionally defective in multiple myeloma: the role of interleukin-6.

We studied concentration, phenotype, and function of peripheral blood (PB) dendritic cells (DCs) from patients with multiple myeloma (MM). The absolute number of circulating precursors of myeloid and plasmacytoid DCs was significantly lower in MM patients than in healthy subjects. After maturation, PBDCs from MM patients showed significantly lower expression of HLA-DR, CD40, and CD80 antigens and impaired induction of allogeneic T-cell proliferation compared with controls. Remarkably, they were not capable of presenting the patient-specific tumor idiotype to autologous T cells. Conversely, DCs generated in vitro from CD14(+) monocytes from the same patients, and PBDCs freshly isolated from healthy donors efficiently stimulated allogeneic and autologous T cells. To clarify the mechanism of PBDC deficiency in MM, we investigated the effects of the main plasma cell growth factor, interleukin-6 (IL-6), on the development of DCs from CD34(+) cells. IL-6 inhibited the colony growth of CD34(+) DC progenitors and switched the commitment of CD34(+) cells from DCs to CD14(+) CD1a(-) CD86(-)CD80(-) CD40(+/-)HLA-DR +/- monocytic cells exerting potent phagocytic activity but no antigen-presentation capacity. This effect was reversed by anti-IL-6 antibodies. Growing CD34(+) cells in the presence of autologous serum (without IL-6) also suppressed the development of functional DCs. This study demonstrates that PBDCs from MM patients are functionally defective, partially because of IL-6-mediated inhibition of development. This brings into question the advisability of using PBDCs as antigen carriers for immunotherapy trials in MM. The results also suggest a novel mechanism whereby myeloma cells escape immune recognition.