Natural killer cells in patients with polycythemia vera.

Natural killer cells (NK) are pivotal cells of innate immunity. They are potent antileukemic cytotoxic effectors. A defect in their cytotoxicity has been described in some hematopoietic malignancies such as acute myeloid leukemia, multiple myeloma and myelodysplastic syndromes.

Distribution of lymphocyte subpopulations in patients with polycythemia vera.

Polycythemia vera (PV) is a disease with slow development. Nonetheless, the immune response is unable to eliminate the uncontrolled proliferating hematopoietic cells, leading to treatment of patient by phlebotomy and/or cytotoxic drugs. In addition, a higher incidence of cancers is observed in PV patients, independently of treatment.

Effects of 5-azacytidine on natural killer cell activating receptor expression in patients with refractory anemia with excess of blasts.

Epigenetic drugs modify DNA methylation and are used in refractory anemia with excess of blasts (RAEB). These drugs may reactivate anti-oncogene expression and restore a normal phenotype instead of inducing antitumor toxicity, although they also have immunosuppressive effects on T-lymphocytes [1] In RAEB and acute myeloid leukemia, a defect in natural killer (NK) cell cytotoxicity has been shown, which relies on abnormal expression of activating receptors. Previous study has shown that 5-azacytidine impaired mRNA synthesis and induced apoptosis in NK cells [2].

Characterization of the novel Sezary lymphoma cell line BKP1.

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of lymphomas primarily involving the skin. The most common types are mycosis fungoides (MF) and Sezary Syndrome (SS). We report a novel long-term fast-growing SS line termed BKP1 that was characterized by flow cytometry (FC), conventional and molecular cytogenetic [FISH/multi-FISH together with array comparative genomic hybridization (aCGH)].

Expression of activating receptors on natural killer cells from AIDS-related lymphoma patients.

Background: Abnormal NK phenotype and cytotoxic functions have been described in acute myeloid leukemia, chronic lymphocytic leukemia, myeloma and myelodysplastic syndromes. Defective NK cytotoxicity is due to decreased expression of the Natural Cytotoxicity Receptors (NCRs), 2B4/CD244/p38, or NKG2D. This prompted us to test the expression of these molecules on circulating NK cells from patients with AIDS-related lymphomas (RL) in comparison with HIV + patients without lymphoma, healthy subjects and HIV-negative patients with lymphoma.

Differential expression of natural killer cell activating receptors in blood versus bone marrow in patients with monoclonal gammopathy.

In monoclonal gammopathies (MG) and multiple myeloma (MM), normal natural cytotoxicity receptors (NCR) expression (NCR1/NKp46, NCR2/NKp44, NCR3/NKp30) is observed in natural killer (NK) cells. Nonetheless, except in plasma cell leukemia, few tumor plasmocytes are present in PB, while NK studies have been performed on peripheral blood (PB). For this reason we focused our attention on NK from bone marrow (BM).

Hematological malignancies escape from NK cell innate immune surveillance: mechanisms and therapeutic implications.

Hematological malignancies treatment improved over the last years resulting in increased achievement of complete or partial remission, but unfortunately high relapse rates are still observed. Therefore, sustainment of long-term remission is crucial. Immune system has a key role in tumor surveillance.

Expression of natural killer cell activating receptors in patients with chronic lymphocytic leukaemia.

Recent advances in chronic lymphocytic leukaemia (CLL) treatment, more particularly through upfront use of anti-CD20 monoclonal antibodies, have prolonged patient progression-free survival. Nonetheless, apart from allogeneic stem cell transplantation, no curative treatment is available. One possible explanation for the lack of cure in CLL could be a defective immune anti-tumour response.

Peripheral T-cell lymphoma gene expression profiling and potential therapeutic exploitations.

Peripheral T-cell lymphomas constitute a heterogeneous group with regard to diagnosis, treatment and prognosis. Efforts have been made to combine novel techniques with cytology and immunochemistry in order to more precisely define these entities. Molecular profiling has contributed to novel insights in the biology of T-cell lymphoma.