A Novel Targeted Screening Tool for Hypogammaglobulinemia: Measurement of Serum Immunoglobulin (IgG, IgM, IgA) Levels from Dried Blood Spots (Ig-DBS Assay). J Clin Immunol 2015 Aug;35(6):573-82
Date
08/16/2015Pubmed ID
26275445Pubmed Central ID
PMC4572045DOI
10.1007/s10875-015-0184-yScopus ID
2-s2.0-84942197873 (requires institutional sign-in at Scopus site) 11 CitationsAbstract
PURPOSE: To develop an assay to quantify serum immunoglobulin (IgG, IgM, IgA) levels using dried blood spots (DBS) obtained on collection cards to be used as a tool for targeted screening for hypogammaglobulinemia.
METHODS: DBS samples, along with simultaneous serum samples, were collected from 107 healthy individuals (11 months to 57 years of age). After eluting proteins from DBS, IgG, IgM, and IgA were quantified by an enzyme-linked immunosorbent assay (ELISA). The Ig-DBS assay was validated through calibration curve performance, intra- and inter-assay precision, accuracy, specificity, selectivity, and linearity. The ELISA measurements were compared with serum Ig levels obtained using a standard nephelometry assay on serum samples collected simultaneously with the DBS samples and the results of the two assays were correlated. The stability of IgG, IgM, and IgA in the DBS was tested at room temperature, 36° to 38 °C, 2 to 8 °C, and -25 to -40 °C, from 4 to 14 days.
RESULTS: The Ig-DBS assay demonstrated precision, accuracy, specificity, selectivity, and linearity. Using the identified correlation coefficients of 0.834 for IgG, 0.789 for IgM, and 0.918 for IgA, the standard nephelometry-based normal reference ranges for all 3 serum Ig isotypes could be used with the Ig-DBS assay in individuals ≥16 years of age. The DBS samples were stable for 14 days at room temperature in a closed polyethylene bag.
CONCLUSIONS: The Ig-DBS assay is both sensitive and accurate for quantification of serum immunoglobulins. Samples are sufficiently stable at ambient temperature to allow for convenient shipping and analysis at a centralized laboratory. This assay therefore presents a new option for screening patients ≥16 years of age for hypogammaglobulinemia in any setting.
Author List
Yel L, Rabbat CJ, Cunningham-Rundles C, Orange JS, Torgerson TR, Verbsky JW, Wang Y, Fu M, Robins TS, Edwards MS, Nymann-Andersen JAuthor
James Verbsky MD, PhD Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdolescentAdult
Agammaglobulinemia
Child
Child, Preschool
Dried Blood Spot Testing
Enzyme-Linked Immunosorbent Assay
Humans
Immunoglobulin A
Immunoglobulin G
Immunoglobulin M
Infant
Mass Screening
Middle Aged
Reproducibility of Results
Sensitivity and Specificity
Young Adult