A Novel Immunological Assay for Hepcidin Quantification in Human Serum

Contains fulltext : 81054.pdf (publisher's version ) (Open Access)BACKGROUND: Hepcidin is a 25-aminoacid cysteine-rich iron regulating peptide. Increased hepcidin concentrations lead to iron sequestration in macrophages, contributing to the pathogenesis of anaemia of chronic disease whereas decreased hepcidin is observed in iron deficiency and primary iron overload diseases such as hereditary hemochromatosis. Hepcidin quantification in human blood or urine may provide further insights for the pathogenesis of disorders of iron homeostasis and might prove a valuable tool for clinicians for the differential diagnosis of anaemia. This study describes a specific and non-operator demanding immunoassay for hepcidin quantification in human sera. METHODS AND FINDINGS: An ELISA assay was developed for measuring hepcidin serum concentration using a recombinant hepcidin25-His peptide and a polyclonal antibody against this peptide, which was able to identify native hepcidin. The ELISA assay had a detection range of 10-1500 microg/L and a detection limit of 5.4 microg/L. The intra- and interassay coefficients of variance ranged from 8-15% and 5-16%, respectively. Mean linearity and recovery were 101% and 107%, respectively. Mean hepcidin levels were significantly lower in 7 patients with juvenile hemochromatosis (12.8 microg/L) and 10 patients with iron deficiency anemia (15.7 microg/L) and higher in 7 patients with Hodgkin lymphoma (116.7 microg/L) compared to 32 age-matched healthy controls (42.7 microg/L). CONCLUSIONS: We describe a new simple ELISA assay for measuring hepcidin in human serum with sufficient accuracy and reproducibility

Selective sigma-2 ligands preferentially bind to pancreatic adenocarcinomas: applications in diagnostic imaging and therapy

<p>Abstract</p> <p>Background</p> <p>Resistance to modern adjuvant treatment is in part due to the failure of programmed cell death. Therefore the molecules that execute the apoptotic program are potential targets for the development of anti-cancer therapeutics. The sigma-2 receptor has been found to be over-expressed in some types of malignant tumors, and, recently, small molecule ligands to the sigma-2 receptor were found to induce cancer cell apoptosis.</p> <p>Results</p> <p>The sigma-2 receptor was expressed at high levels in both human and murine pancreas cancer cell lines, with minimal or limited expression in normal tissues, including: brain, kidney, liver, lung, pancreas and spleen. Micro-PET imaging was used to demonstrate that the sigma-2 receptor was preferentially expressed in tumor as opposed to normal tissues in pancreas tumor allograft-bearing mice. Two structurally distinct sigma-2 receptor ligands, SV119 and WC26, were found to induce apoptosis to mice and human pancreatic cancer cells <it>in vitro </it>and <it>in vivo</it>. Sigma-2 receptor ligands induced apoptosis in a dose dependent fashion in all pancreatic cell lines tested. At the highest dose tested (10 μM), all sigma-2 receptor ligands induced 10–20% apoptosis in all pancreatic cancer cell lines tested (p < 0.05). In pancreas tumor allograft-bearing mice, a single bolus dose of WC26 caused approximately 50% apoptosis in the tumor compared to no appreciable apoptosis in tumor-bearing, vehicle-injected control animals (p < 0.0001). WC26 significantly slowed tumor growth after a 5 day treatment compared to vehicle-injected control animals (p < 0.0001) and blood chemistry panels suggested that there is minimal peripheral toxicity.</p> <p>Conclusion</p> <p>We demonstrate a novel therapeutic strategy that induces a significant increase in pancreas cancer cell death. This strategy highlights a new potential target for the treatment of pancreas cancer, which has little in the way of effective treatments.</p

Human Peripheral Blood Mononuclear Cells Exhibit Heterogeneous CD52 Expression Levels and Show Differential Sensitivity to Alemtuzumab Mediated Cytolysis

Alemtuzumab is a monoclonal antibody that targets cell surface CD52 and is effective in depleting lymphocytes by cytolytic effects in vivo. Although the cytolytic effects of alemtuzumab are dependent on the density of CD52 antigen on cells, there is scant information regarding the expression levels of CD52 on different cell types. In this study, CD52 expression was assessed on phenotypically distinct subsets of lymphoid and myeloid cells in peripheral blood mononuclear cells (PBMCs) from normal donors. Results demonstrate that subsets of PBMCs express differing levels of CD52. Quantitative analysis showed that memory B cells and myeloid dendritic cells (mDCs) display the highest number while natural killer (NK) cells, plasmacytoid dendritic cells (pDCs) and basophils have the lowest number of CD52 molecules per cell amongst lymphoid and myeloid cell populations respectively. Results of complement dependent cytolysis (CDC) studies indicated that alemtuzumab mediated profound cytolytic effects on B and T cells with minimal effect on NK cells, basophils and pDCs, correlating with the density of CD52 on these cells. Interestingly, despite high CD52 levels, mDCs and monocytes were less susceptible to alemtuzumab-mediated CDC indicating that antigen density alone does not define susceptibility. Additional studies indicated that higher expression levels of complement inhibitory proteins (CIPs) on these cells partially contributes to their resistance to alemtuzumab mediated CDC. These results indicate that alemtuzumab is most effective in depleting cells of the adaptive immune system while leaving innate immune cells relatively intact

Erythropoiesis-stimulating agents in oncology: a study-level meta-analysis of survival and other safety outcomes

BACKGROUND: Cancer patients often develop the potentially debilitating condition of anaemia. Numerous controlled studies indicate that erythropoiesis-stimulating agents (ESAs) can raise haemoglobin levels and reduce transfusion requirements in anaemic cancer patients receiving chemotherapy. To evaluate recent safety concerns regarding ESAs, we carried out a meta-analysis of controlled ESA oncology trials to examine whether ESA use affects survival, disease progression and risk of venous-thromboembolic events

Neutrophil 5-nucleotidase reaction in chronic myelogenous leukemia, myelofibrosis with myeloid metaplasia, and polycythemia vera

A readable and reproducible 5-nucleotidase (5N) cytochemical reaction was developed for blood smear preparation, after modification of the technique of Wachstein and Meisel [37]. The reaction was applied to normal polymorphonuclear neutrophils (NPN) and to neutrophils from patients with chronic myelogenous leukemia (CML), myelofibrosis with myeloid metaplasia (MMM), and polycythemia vera (PV). The following observations were made: (a) 5N was present in NPN, with a mean score of 83.2+/-15.7. (b) In patients with MMM and PV an increased 5N score was observed (mean score 111+/-63.8 and 178.3+/-83.3, respectively). (c) In CML the mean score was 4.9+/-2.2. (c) A statistical comparison of neutrophil 5-nucleotidase (N5N) between CML and MMM and PV patients demonstrated a highly significant difference (p&lt;0.0001). In the present study, we showed that the N5N activity parallels that of NAP in chronic myeloproliferative disorders such as CML, MMM, and PV. It appears that, apart from the already known activity of NAP in myeloproliferative disorders, other enzymes (e.g., N5N) can present a similar behavior with increased or decreased activity

INTERFERON-ALFA-2B THERAPY IN UNTREATED EARLY STAGE, B-CHRONIC LYMPHOCYTIC-LEUKEMIA PATIENTS - ONE-YEAR FOLLOW-UP

Recent reports have shown that interferon alpha is effective in B-chronic lymphocytic leukaemia (B-CLL). In a previous study from our unit we obtained a 50% response rate with interferon alfa-2b in B-CLL in early stages. Subsequently, we performed the present study randomizing 34 Binet stage AI, B-CLL patients who were not previously treated (eight controls and 2 6 who were to receive interferon alfa-2b (IFN-alpha-2b) (Intron-A) according to a randomized schedule as follows: 1.5 MU/d in eight patients, 1.5 MU three times a week in 10 patients and 3.0 MU three times a week in eight patients). At 3 months complete response (CR) was obtained in one, partial haematologic response (PHR) in nine and minor haematologic response (MHR) in seven patients with an overall response rate 17/26 or 65%. No bone marrow changes regarding the pattern or degree of infiltration was noticed in any of the responding patients except for the complete responder. Treatment was continued in 15 patients (reduced to two-thirds of the initial dose in the PHR and to one third of the initial dose in the MHR) while in 11 patients it was discontinued because of no response, negative response or toxicity. At 6 months sustained response was observed in 10 patients, while in the remaining five an increase of blood lymphocytes was seen at numbers similar or higher to those noted prior to interferon alfa-2b therapy. Two of the 10 patients in whom blood lymphocytes were still reduced to less than 50% of the pretreatment values, developed gradual lymph node enlargement and therapy had to be discontinued. During the following 6 months the interferon alfa-2b dose was further reduced in all remaining responders to 1.5 MU once or twice a week and their counts remained at the same level as at 6 months of therapy. At 12 months, 18 of our patients were still in stage A while seven had progressed (five to stage B and two to stage C). The overall response after 12 months of therapy was sustained in 8/17 responders. We conclude from our study that interferon alfa-2b is effective in untreated B-CLL patients in early stages and therefore should be investigated in combination with conventional chemotherapy. Clinical trials utilizing interferon alfa-2b and chlorambucil in combination in untreated B-CLL patients are currently in progress in our unit