CTLA-4 +49A>G polymorphism of recipients of HLA-matched sibling allogeneic stem cell transplantation is associated with survival and relapse incidence.

Conflicting observations have been reported about the role of CTLA-4 gene polymorphisms in the clinical outcome of allogeneic hematopoietic stem cell transplantation (HSCT). We have investigated three polymorphisms of the CTLA-4 gene (-318C>T, +49A>G, CT60G>A) in 133 donor/recipient pairs who underwent HLA-matched sibling donor HSCT for hematological malignancies. We found no association of the clinical outcome of the HSCT with either recipient or donor -318C>T and CT60G>A polymorphisms. At variance, we found a significant association of donor +49A>G G/G genotype with longer overall survival (OS; log-rank test, P = 0.04), and the number of +49A>G G-alleles in the recipient with longer OS (P = 0.027), longer disease-free survival (P = 0.036) and reduced relapse rate (P = 0.042). However, only recipient +49A>G polymorphism was retained as independent prognostic factor in a multivariate analysis, suggesting that the expression of CTLA-4 on the cells of recipient may be relevant for the clinical outcome of HSCT.

Clonal granulocytes in polycythaemia vera and essential thrombocythaemia have shortened telomeres.

Summary The purpose of this study was to evaluate telomere length in peripheral blood granulocytes and mononuclear cells collected from 22 women with polycythaemia vera (PV) and essential thrombocythaemia (ET). PV and ET are chronic myeloproliferative diseases whose heterogeneity of stem cell origin and clonal development has been established through analysis of X-chromosome inactivation patterns. The results from clonality assay and determination of telomere length show that only clonal granulocytes have shortened telomeres.

High telomerase activity in granulocytes from clonal polycythemia vera and essential thrombocythemia.

Essential thrombocythemia (ET) and polycythemia vera (PV) are chronic myeloproliferative disorders that share the involvement of a multipotent progenitor cell and dominance of the transformed clone over normal hematopoiesis. On the other hand, the heterogeneity of these diseases with respect to clonal development from a common progenitor has been well established. To identify useful prognostic indicators, we analyzed telomerase activity (TA), a known marker of neoplastic proliferation, in granulocytes (PMNs) and mononuclear cells (MNCs) from 22 female patients with ET and PV. Clonality status was determined by investigation of X chromosome inactivation patterns (XCIPs). We found a statistically significant positive correlation between high TA and monoclonal pattern of XCIP. Therefore, our data suggest that the use of multiple tumor markers may contribute to a better understanding of the deregulated physiology of these disorders and provide useful prognostic factors.

Expression of CD10 by B-chronic lymphocytic leukemia cells undergoing apoptosis in vivo and in vitro.

BACKGROUND AND OBJECTIVES: B-cell chronic lymphocytic leukemia (B-CLL) is an accumulating disease of slowly proliferating cells. CD10 is not normally expressed on the surface of B-CLL cells. The aim of this study was to ascertain whether B-CLL cells, induced into apoptosis, expressed surface CD10, since a correlation between apoptosis and CD10 expression has been demonstrated. DESIGN AND METHODS: Peripheral blood cells from 31 untreated B-CLL patients were induced into apoptosis by etoposide, fludarabine or Ga(mu)-Ab treatment and tested for CD10 expression by flow cytometry. Normal CD5+ B cells were also induced into apoptosis and tested for CD10 expression. RESULTS: CD10 positive cells were absent in B-CLL cell suspensions, but were detected following in vitro culture, and their appearance paralleled that of apoptotic cells. Treatment with etoposide, fludarabine or Ga(mu)-Ab enhanced both apoptosis and CD10 expression. Inhibition of apoptosis by VAD-fmk or Ga(delta)-Ab prevented CD10 expression. Cell separation tests following induction of apoptosis demonstrated that CD10+ cells were apoptotic. CD10+ cells were observed in the peripheral blood of two patients within a few hours following fludarabine infusion. In another patient, who failed to respond, no CD10+ cells were seen. Expression of CD10 was observed also in normal CD5+ B cells when these were induced into apoptosis. INTERPRETATION AND CONCLUSIONS: This study demonstrates that B-CLL cells, as well as normal CD5+ B cells, become CD10+ following apoptosis induction in vitro. Some of the data obtained also suggest a use for CD10 to monitor apoptosis of B-CLL in a clinical setting.

Influenza vaccine in chronic lymphoproliferative disorders and multiple myeloma.

OBJECTIVE: Vaccination against influenza in patients with chronic lymphoproliferative disorders (CLPD) and multiple myeloma (MM) is still a matter of clinical uncertainty. The aim of this study was to determine the safety, immunogenicity and clinical response to a commercially available vaccine against influenza in a group of such patients. METHODS: Thirty-four patients with CLPD and MM and 34 immunologically normal subjects were vaccinated with the same vaccine against influenza. Patients were observed during the epidemic season from October 1999 to April 2000, and monitored for side-effects of the vaccine, seroprotection and seroconversion after vaccination. The prevaccination level of immunoglobulins was also determined. Occurrence of influenza episodes was demonstrated with the positive isolation of a viral strain from a pharyngeal swab. RESULTS: No patient had untoward reactions to the vaccine used. Seroconversion and seroprotection were up to the standard established by the European Agency for the Evaluation of Medicinal Products. Only one patient developed influenza during follow-up. CONCLUSIONS: Influenza vaccine is effective and well tolerated in patients with CLPD and MM. No contraindications exist for its use, and it should become a routine practice, in order to prevent serious complications during the influenza epidemic season.

Exposure of erythrocytes to methylene blue shows the active role of catalase in removing hydrogen peroxide.

Methylene blue (MB) is a powerful reducing agent that is widely used in clinical practice as well as for metabolic studies of the erythrocyte. We have investigated the role of catalase as a specific enzyme for the removal of hydrogen peroxide by measuring the in vitro effects of MB on human red cells. In the presence of MB, catalase underwent inactivation even with the co-existence of active generation of NADPH, leaving the glutathione concentration unaffected. The data obtained in the present investigation show, using a different tool (MB), that catalase is the active enzyme in H2O2 detoxification and that its integrity is largely dependent on an adequate generation of NADPH.