A highly sensitive immunoassay for interleukin-6 in dried blood spots

Authors

  • Elizabeth M. Miller,

    1. Department of Anthropology, Northwestern University, Evanston, Illinois 60208
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  • Thomas W. Mcdade

    Corresponding author
    1. Department of Anthropology, Northwestern University, Evanston, Illinois 60208
    2. Cells to Society (C2S): The Center on Social Disparities and Health, Institute for Policy Research, Northwestern University, Evanston, Illinois 60208
    • Department of Anthropology, 1810 Hinman Ave., Evanston, IL 60208
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Abstract

Objective:

Interleukin-6 (IL-6) is a pro-inflammatory cytokine that is associated with the production of C-reactive protein, the acute phase response, and chronic low-grade inflammation. In this report, we describe and validate a highly sensitive enzyme-linked immunosorbent assay (ELISA) for quantifying IL-6 at low concentrations in samples of capillary whole blood collected from a simple finger stick and dried on filter paper (dried blood spots, DBS).

Methods:

A commercially available ELISA for IL-6 was modified to develop a protocol for the quantification of IL-6 in DBS samples. Procedures for sample elution and incubation were optimized for precision, reliability, accuracy, and lower limit of detection using small volumes of DBS. A set of 46 matched serum/DBS samples were used to evaluate agreement between serum and DBS results.

Results:

The protocol demonstrated acceptable levels of precision, reliability, accuracy, and agreement with serum-based results. The lower limit of detection was sufficiently low to measure levels of IL-6 associated with both chronic, low-grade inflammation, and acute increases in inflammatory activity.

Conclusions:

This protocol adds to the growing panel of analytes validated for quantification in DBS samples and should facilitate future research on the causes and consequences of inflammation in diverse non-clinical settings. Am. J. Hum. Biol., 2012. © 2012 Wiley Periodicals, Inc.

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