Highly specific V3 peptide enzyme immunoassay for serotyping HIV-1 specimens from Thailand.
OBJECTIVE
To develop and evaluate a simple V3 peptide-based enzyme immunoassay (EIA) for large-scale serotyping of HIV-1 specimens from Thailand.


METHODS
Serologic reactivities with synthetic peptides derived from the V3 loop of gp120 were used for typing HIV-1 specimens.


METHODS
Synthetic peptides PND-A and PND-B, derived from the consensus amino-acid sequences of the V3 loop of gp120 from two major genomic variants of HIV-1 in Thailand (A and B), were evaluated in an EIA on 61 Thai HIV-1 sera for which genotypes had been determined by polymerase chain reaction. The peptide EIA was then applied to sera from 188 HIV-1-infected patients, selected in non-random, convenience samples of known risk groups from four geographic regions of Thailand.


RESULTS
The sensitivities and specificities of PND-A and PND-B were 86% (30 out of 35) and 96% (25 out of 26) and 92% (24 out of 26) and 94% (33 out of 35), respectively, with 100% predictive values of a monoreactive positive test for both peptides. The assay classified 101 specimens as serotype A, 39 as serotype B, eight as serotype AB (dually reactive), and 40 as untypable (non-reactive). Excluding dual reactors and non-reactors, 92% (77 out of 84) of specimens from patients probably infected by sexual contact were serotype A; conversely, 76% (28 out of 37) of injecting drug users were serotype B.


CONCLUSIONS
The serologic results corroborated previous findings, in a smaller subset of samples, of an apparent segregation of viral subtypes by mode of transmission, suggesting two separate HIV-1 epidemics in Thailand. This peptide EIA could be a valuable epidemiologic tool in determining the dynamics of the rapid spread of HIV-1 in Thailand.
Pau
C P
CP
Division of HIV/AIDS, Centers for Disease Control, Atlanta, Georgia 30333.
Lee-Thomas
S
S
Auwanit
W
W
George
J R
JR
Ou
C Y
CY
Parekh
B S
BS
Granade
T C
TC
Holloman
D L
DL
Phillips
S
S
Schochetman
G
G
D015897:Comorbidity; D004196:Disease Outbreaks; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000032:analysis*; D015658:HIV Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D015528:HIV Seroprevalence; D015497:HIV-1 / Q000145:classification* / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D010446:Peptide Fragments / Q000032:analysis* / Q000138:chemical synthesis / Q000276:immunology; D016133:Polymerase Chain Reaction; D012703:Serotyping; D011477:Sex Work; D015819:Substance Abuse, Intravenous / Q000453:epidemiology; D013785:Thailand / Q000453:epidemiology
D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments