Comparison of Western blot (immunoblot) based on recombinant-derived p41 with conventional tests for serodiagnosis of human immunodeficiency virus infections.
To evaluate the performance of a serological test for human immunodeficiency virus type 1 (HIV-1) infections based on the use of a recombinant envelope gene-derived protein as the antigen, we caused expression of a 1.4-kilobase fragment of HIV.DNA that codes for the complete gp41 transmembrane protein in an Escherichia coli expression vector and used Western blots (WB; immunoblots) prepared with recombinant material (pEX-41) to detect antibodies to HIV-1. This test detected all 339 sera which were positive by a combination of conventional serodiagnostic assays and produced no false-positive results with 311 negative samples. Also no false-positive results were obtained with 20 sera from systemic lupus erythematosus patients which had high titers of cross-reactive autoantibodies. In six cases, the pEX-41 WB proved to be more sensitive than individual assays applied on their own, and in five cases it was even more sensitive than a combination of conventional assays. We tested 221 sera in both our pEX-41 WB and a commercially available recombinant enzyme immunoassay (EIA [Abbott]). The results were identical in 188 cases. A total of 27 sera containing antibodies to gp41 as demonstrated in the pEX-41 WB, as well as the Abbott recombinant EIA, had no antibodies to the recombinant core antigen as measured in the Abbott EIA. However, 25 of these sera did stain the 24-kilodalton band on a WB with purified virus. Six sera that were positive in all of the conventional confirmatory assays and reacted strongly with the pEX-41 WB did not recognize the surface antigen used in the Abbott recombinant EIA. We conclude that the use of WB prepared with recombinant-derived p41 offers a very sensitive and specific method to detect antibodies to HIV.
Hofbauer
J M
JM
Institut für Hygiene, Universität Innsbruck, Austria.
Schulz
T F
TF
Hengster
P
P
Larcher
C
C
Zangerle
R
R
Kofler
H
H
Fritsch
P
P
Wachter
H
H
Dierich
M P
MP
D000163:Acquired Immunodeficiency Syndrome / Q000175:diagnosis*; D000914:Antibodies, Viral / Q000032:analysis*; D001323:Autoantibodies / Q000276:immunology; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005455:Fluorescent Antibody Technique; D006678:HIV / Q000276:immunology*; D015483:HIV Antibodies; D015700:HIV Envelope Protein gp41; D006801:Humans; D007118:Immunoassay; D007124:Immunoenzyme Techniques; D011934:Reagent Strips; D011994:Recombinant Proteins / Q000276:immunology; D012191:Retroviridae Proteins / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology*
D000914:Antibodies, Viral; D001323:Autoantibodies; D015483:HIV Antibodies; D015700:HIV Envelope Protein gp41; D011934:Reagent Strips; D011994:Recombinant Proteins; D012191:Retroviridae Proteins; D014759:Viral Envelope Proteins