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Comparison of False‐Positive Reactions in Direct‐Binding Anti‐HIV ELISA Using Cell Lysate or Recombinant Antigens
Author(s) -
Craske J.,
Turner A.,
Abbott R.,
Collier M.,
Gunson H.H.,
Lee D.,
Martlew V.,
Howell P.,
Love E.
Publication year - 1990
Publication title -
vox sanguinis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.68
H-Index - 83
eISSN - 1423-0410
pISSN - 0042-9007
DOI - 10.1111/j.1423-0410.1990.tb00851.x
Subject(s) - antigen , western blot , recombinant dna , immunoassay , human immunodeficiency virus (hiv) , antibody , medicine , immunology , lysis , virology , biology , biochemistry , gene
. In a 2‐year study of false‐positive anti‐HIV‐1 tests in blood donors at Manchester and Lancaster Blood Banks, the reactions associated with a HIV‐infected cell lysate antigen were compared with those using recombinant‐antigen‐based tests. In year 1 (cell lysate test) at Manchester BTS 0.21% of 119,178 donations were repeatedly reactive, compared with 0.53% of 119,004 donations in year 2 (recombinant antigen). Reactive sera were tested at Manchester PHL by three different immunoassays. Referred specimens were classified as anti‐HIV positive (95–100% reactive in all the assays), equivocal or negative (negative results in all three immunoassays). Two donors were confirmed to be anti‐HIV positive over the 2‐year period. Most sera were negative by confirmatory immunoassays in years 1 and 2. In year 1, a study of 60 referred sera with sex‐ and age‐matched controls showed high correlation between a reactive anti‐HIV‐1 screening test and indeterminate anti‐HIV‐1 patterns on Western blot showing reactions with HIV gag‐coded proteins. In year 2, less than 10% of referred sera were reactive by Western blot, and there was no correlation between a reactive screening anti‐HIV test, the strength of signal in the test or a reactive Western blot. Follow‐up showed that donors whose sera were reactive in years 1 and 2 by the anti‐HIV‐1 screening test formed almost two different populations. Four donors with equivocal anti‐HIV‐1 confirmatory tests had anti‐HIV ‘envelope’ reactions. The follow‐up of donors with equivocal confirmatory immunoassays on Western blot failed to show an increase in the strength of immunoassay reaction or Western blot reaction, with the possible exception of 1 donor with an anti‐HIV‐p24 reaction by Western blot. Most confirmatory testing can be done using immunoassays. The significance of the Western blot reactions needs further investigation.