Vaccine Weekly

Studies from University of Texas yield new data on Chagas disease

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"We identified 121 subjects who were seropositive for T. cruzi-specific antibodies, a finding indicative of an 8.5% seroprevalence in the rural population from Chiapas. Seropositive and seronegative subjects were examined for plasma levels of biomarkers of inflammation, i.e., myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), and xanthine oxidase (XOD), as well as for oxidative (advanced oxidation protein products [AOPPs]) and nitrosative (3-nitrotyrosine [3NT]) biomarkers. The seropositive subjects exhibited a significant increase in MPO activity and protein level, the indicator of neutrophil activation. Subsequently, a corresponding increase in AOPP contents, formed by MPO-dependent hypochlorous acid and chloramine formation, was noted in seropositive subjects. The plasma level of 3NT was significantly increased in seropositive subjects, yet we observed no change in XOD activity (O2(center dot-) source) and nitrate/nitrite contents (denotes iNOS activation and (NO)-N-center dot production), which implied that direct peroxynitrite formation does not contribute to increased nitrosative damage in chagasic subjects. Instead, a positive correlation between increased MPO activity and protein 3NT formation was observed, which suggested to us that MPO-dependent formation of nitrylchloride that occurs in the presence of physiological (NO)-N-center dot and O-2(center dot-) concentrations contributes to protein nitration. Overall, our data demonstrate that T. cruzi-induced neutrophil activation is pathological and contributes to MPO-mediated collateral protein oxidative and nitrosative damage in human patients with Chagas' disease," wrote M. Dhiman and colleagues, University of Texas.

The researchers concluded: "Therapies capable of suppressing MPO activity may be useful in controlling the inflammation and oxidative/ nitrosative pathology in chagasic cardiomyopathy.."

Dhiman and colleagues published their study in Clinical and Vaccine Immunology (Increased Myeloperoxidase Activity and Protein Nitration Are Indicators of Inflammation in Patients with Chagas' Disease. Clinical and Vaccine Immunology, 2009;16(5):660-666).

Additional information can be obtained by contacting N.J. Garg, University of Texas Med Branch, Dept. of Microbiology & Immunology, 3-142C Med Research Bldg, 301 University Blvd., Galveston, TX 77555, USA.

The publisher of the journal Clinical and Vaccine Immunology can be contacted at: American Society Microbiology, 1752 N St. NW, Washington, DC 20036-2904, USA.

Keywords: United States, Galveston, Biotechnology, Chagas Disease, Chromatography, Cytometry, Drugs, Enzyme Research, Enzymes, Enzymology, Immunization, Immunology, Inflammation, Myeloperoxidase, Nitric Oxide, Oxidase, Pharmaceuticals, Proteins, Proteomics, Synthase, Therapy, Treatment, Vaccines, Xanthine Oxidase, University of Texas.

This article was prepared by Vaccine Weekly editors from staff and other reports. Copyright 2009, Vaccine Weekly via NewsRx.com.