Detection of antibodies to human immunodeficiency virus type 1 in oral fluids: a large-scale evaluation of immunoassay performance

Abstract

Paired serum and oral-fluid (OF) specimens (n = 4,448) were collected from blood donors and patients attending local sexually transmitted disease clinics in Trinidad and Tobago and the Bahamas and were tested for the presence of human immunodeficiency virus type 1 (HIV-1) antibodies. Sera were tested by Abbott AB HIV-1/HIV-2 (rDNA) enzyme immunoassay (EIA), and positive specimens were confirmed by Cambridge HIV-1 and HIV-2 Western blotting (WB). OF specimens were collected with the OraSure collection device and were tested by Murex GACELISA and by two EIAs from Organon Teknika (the Oral Fluid Vironostika HIV-1 Microelisa System [OTC-L] and the Vironostika HIV-1 Microelisa System [OTC-M]). EIA-reactive OF specimens were confirmed by miniaturized WB (OFWB). GACELISA detected all 474 HIV-1 seropositive specimens (sensitivity, 100%). OTC-L detected 470 positive specimens (sensitivity, 99.2%), while OTC-M detected 468 positive specimens (sensitivity, 98.8%). Specificities ranged from 99.2 to 100% for the three assays. Concordance of OFWB with serum WB was 99.4%, and banding patterns determined by the two methods were similar. The immunoglobulin G (IgG) concentration of OF specimens ranged from 0.21 to 100 microg/ml, with a mean of 17.1 microg/ml. Significant differences in OF IgG concentrations were observed between HIV antibody-positive and HIV antibody-negative persons (31.94 versus 15.28 microg/ml, respectively [P < 0.0001]). These data further confirm the suitability of OF specimens for detection of HIV-1 antibodies. Currently available HIV-1 antibody assays provide sensitivities and specificities with OF specimens comparable to those achieved with serum specimens.

PIP: The use of oral fluid (OF) as a specimen for detecting antibodies to infectious agents has become increasingly popular since the approach was first described in the 1980s. OF is a mixture of saliva, mucosal and bacterial products, and gingival crevicular fluid. 4448 paired serum and OF specimens collected from 4448 blood donors and patients attending 3 sexually transmitted disease clinics in Trinidad and Tobago and the Bahamas were tested for the presence of HIV-1 antibodies. The sera were tested by Abbott AB HIV-1/HIV-2 (rDNA) enzyme immunoassay (EIA), and positive specimens were confirmed by Cambridge HIV-1 and HIV-2 Western blotting (WB). OF specimens were collected using the OraSure collection device and were tested by Murex GACELISA and 2 EIAs from Organon Teknika (OTC-L and OTC-M). EIA-reactive OF specimens were confirmed by miniaturized WB (OFWB). GACELISA detected all 474 HIV-1 seropositive specimens, OTC-L detected 470 positive specimens, and OTC-M detected 468 positive specimens. Specificities were 99.2-100% for the three assays. There was a 99.4% concordance of OFWB with serum WB, and banding patterns determined by the two methods were similar. The immunoglobulin G (IgG) concentration of OF specimens was 0.21-100 mcg/ml, with a mean of 17.1 mcg/ml. Significant differences in OF IgG concentrations were observed between HIV antibody-positive and HIV antibody-negative persons. These data support the suitability of OF specimens for detecting HIV-1 antibodies. Currently available HIV-1 antibody assays provide sensitivities and specificities with OF specimens comparable to those achieved with serum specimens.

FIG. 1

Correlation of S/CO ratios for OF specimens tested by GACELISA (A), OTC-M (B), and OTC-L (C) with S/CO ratios for specimens tested by serum EIA (Abbott). Data include all specimens initially HIV antibody reactive by any of the OF or serum EIAs and 250 HIV antibody-negative specimens.