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Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers

Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers Najib Aziz 1 , Parunag Nishanian 1 , Ronald Mitsuyasu 2 , Roger Detels 3 , and John L. Fahey 1 , 2 , * CIRID at University of California, Los Angeles, Department of Microbiology and Immunology, 1 Department of Medicine, the Jonsson Comprehensive Cancer Center, and the UCLA AIDS Institute, UCLA School of Medicine, 2 and Department of Epidemiology, UCLA School of Public Health, 3 Los Angeles, California 90095 ABSTRACT Cytokines and soluble immune activation markers that reflect cytokine activities in vivo are increasingly being measured in plasma, serum, and other body fluids. They provide useful diagnostic and prognostic information as well as insight into disease pathogenesis. Assays of neopterin, β2-microglobulin, soluble interleukin-2 receptor, and soluble tumor necrosis factor receptor type II as well as of the cytokines tumor necrosis factor alpha and gamma interferon (IFN-γ) were evaluated by using serum and plasma samples of human immunodeficiency virus (HIV)-positive and HIV-negative subjects. Many factors were found to influence the outcomes of these assays. Substantial differences in apparent levels of analytes were frequently found when enzyme-linked immunosorbent assay (ELISA) kits from different manufacturers were used. In some cases, differences were found in the standards provided by separate manufacturers. Furthermore, the analytic results from different lots of ELISA kits supplied by single manufacturers differed by as much as 50%. The need for uniformity in the standards for quantitative assays was clearly illustrated. International reference standards are available for cytokines but not for soluble cytokine receptors or soluble activation markers. Marker levels in serum or in plasma were similar except those for IFN-γ. Most of the analytes were stable under several storage conditions. Thus, batch testing of frozen stored samples is feasible. The findings indicate that for longitudinal studies, the levels of cytokines and immune activation markers in plasma or serum should be measured by using preverified reagents from one manufacturer. The quality of laboratory performance can have an impact on clinical relevance. Proficiency testing and external quality assurance programs can help to develop the needed consensus. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Clinical and Vaccine Immunology American Society For Microbiology

Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers

Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers

Clinical and Vaccine Immunology , Volume 6 (1): 89 – Jan 1, 1999

Abstract

Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers Najib Aziz 1 , Parunag Nishanian 1 , Ronald Mitsuyasu 2 , Roger Detels 3 , and John L. Fahey 1 , 2 , * CIRID at University of California, Los Angeles, Department of Microbiology and Immunology, 1 Department of Medicine, the Jonsson Comprehensive Cancer Center, and the UCLA AIDS Institute, UCLA School of Medicine, 2 and Department of Epidemiology, UCLA School of Public Health, 3 Los Angeles, California 90095 ABSTRACT Cytokines and soluble immune activation markers that reflect cytokine activities in vivo are increasingly being measured in plasma, serum, and other body fluids. They provide useful diagnostic and prognostic information as well as insight into disease pathogenesis. Assays of neopterin, β2-microglobulin, soluble interleukin-2 receptor, and soluble tumor necrosis factor receptor type II as well as of the cytokines tumor necrosis factor alpha and gamma interferon (IFN-γ) were evaluated by using serum and plasma samples of human immunodeficiency virus (HIV)-positive and HIV-negative subjects. Many factors were found to influence the outcomes of these assays. Substantial differences in apparent levels of analytes were frequently found when enzyme-linked immunosorbent assay (ELISA) kits from different manufacturers were used. In some cases, differences were found in the standards provided by separate manufacturers. Furthermore, the analytic results from different lots of ELISA kits supplied by single manufacturers differed by as much as 50%. The need for uniformity in the standards for quantitative assays was clearly illustrated. International reference standards are available for cytokines but not for soluble cytokine receptors or soluble activation markers. Marker levels in serum or in plasma were similar except those for IFN-γ. Most of the analytes were stable under several storage conditions. Thus, batch testing of frozen stored samples is feasible. The findings indicate that for longitudinal studies, the levels of cytokines and immune activation markers in plasma or serum should be measured by using preverified reagents from one manufacturer. The quality of laboratory performance can have an impact on clinical relevance. Proficiency testing and external quality assurance programs can help to develop the needed consensus.

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Publisher
American Society For Microbiology
Copyright
Copyright © 1999 by the American society for Microbiology.
ISSN
1556-6811
eISSN
1556-679X
Publisher site
See Article on Publisher Site

Abstract

Variables That Affect Assays for Plasma Cytokines and Soluble Activation Markers Najib Aziz 1 , Parunag Nishanian 1 , Ronald Mitsuyasu 2 , Roger Detels 3 , and John L. Fahey 1 , 2 , * CIRID at University of California, Los Angeles, Department of Microbiology and Immunology, 1 Department of Medicine, the Jonsson Comprehensive Cancer Center, and the UCLA AIDS Institute, UCLA School of Medicine, 2 and Department of Epidemiology, UCLA School of Public Health, 3 Los Angeles, California 90095 ABSTRACT Cytokines and soluble immune activation markers that reflect cytokine activities in vivo are increasingly being measured in plasma, serum, and other body fluids. They provide useful diagnostic and prognostic information as well as insight into disease pathogenesis. Assays of neopterin, β2-microglobulin, soluble interleukin-2 receptor, and soluble tumor necrosis factor receptor type II as well as of the cytokines tumor necrosis factor alpha and gamma interferon (IFN-γ) were evaluated by using serum and plasma samples of human immunodeficiency virus (HIV)-positive and HIV-negative subjects. Many factors were found to influence the outcomes of these assays. Substantial differences in apparent levels of analytes were frequently found when enzyme-linked immunosorbent assay (ELISA) kits from different manufacturers were used. In some cases, differences were found in the standards provided by separate manufacturers. Furthermore, the analytic results from different lots of ELISA kits supplied by single manufacturers differed by as much as 50%. The need for uniformity in the standards for quantitative assays was clearly illustrated. International reference standards are available for cytokines but not for soluble cytokine receptors or soluble activation markers. Marker levels in serum or in plasma were similar except those for IFN-γ. Most of the analytes were stable under several storage conditions. Thus, batch testing of frozen stored samples is feasible. The findings indicate that for longitudinal studies, the levels of cytokines and immune activation markers in plasma or serum should be measured by using preverified reagents from one manufacturer. The quality of laboratory performance can have an impact on clinical relevance. Proficiency testing and external quality assurance programs can help to develop the needed consensus.

Journal

Clinical and Vaccine ImmunologyAmerican Society For Microbiology

Published: Jan 1, 1999

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