Reproducibility in quality control of protein (Western) immunoblot assay for antibodies to human immunodeficiency virus.
The protein (Western) immunoblot assay (IB) for antibodies to human immunodeficiency virus, like other laboratory procedures, sometimes gives variable results. In the Transfusion Safety Study, indistinguishable aliquots of four quality control (QC) samples have been routinely submitted for IB with each group of patient specimens. A false negative IB result was obtained for 1.7% of 179 assays of two known positive (QC) standards and a false positive result for 2.0% of 101 assays of two known negative (QC) standards. In addition, a test panel of 24 samples was sent on a single occasion to three widely used laboratories. A false positive result was reported by one laboratory and a false negative by a second. Although generally reliable, IB results may occasionally be in error. There is much more technical variability in the relative frequencies of antigen-antibody bands than has been recognized. These interlaboratory and intralaboratory comparisons show quality control checks are essential for all laboratories, and more than one specimen should be tested if its applicability to a specific patient is questionable. Specific bands are sufficiently inconstant for the same specimen to make appearance or disappearance on successive specimens prognostically unreliable.
Edwards
V M
VM
Department of Medicine, University of Southern California, Los Angeles 90032.
Mosley
J W
JW
D015153:Blotting, Western; D006678:HIV / Q000032:analysis*; D006801:Humans; D011786:Quality Control; D015203:Reproducibility of Results