[Humoral immune response to HIV-2 in Mexico].
OBJECTIVE
To study the reactions of Mexican HIV-1 positive sera to HIV-2 antigens, and their relation to the mode of transmission and the clinical status of infected individuals.


METHODS
Six-hundred and fifty-four sera samples collected in Mexico were tested using HIV-2 immunoblot (IB) techniques; 492 samples were from HIV-1 positive cases and 162 from HIV-1 negative controls.


RESULTS
Seventy-nine percent (388/492) of the HIV-1 reactive sera showed reactivity with at least one HIV-2 protein: 71% (352/492) recognized the capsid protein p24, 24% (119/492) the transmembrane glycoprotein and 9% (44/492) the external glycoprotein of HIV-2. Considering the transmission mechanism, HIV-2 reactivity occurred in 81% (324/401) of the sexually infected patients, and only in 39% (16/41) of people infected through blood products. Ten highly reactive gp32 HIV-2 sera samples were titrated and results showed that reactivity with HIV-1 gp41 was always higher than that to HIV-2 gp32. HIV-1-HIV-2 dual infection was discarded by negative results with the commercial assay Liatek HIV 1+2.


CONCLUSIONS
We propose that the serological cross-reactivity found can be due to a possible initial introduction in Mexico of two different viral strains through the two main transmission routes and that the strains circulating in sexually infected individuals are more similar to the HIV-2 strains, at least with respect to their glycoproteins, than the HIV-1 strains predominant in other countries.
Valadez-González
N
N
Unidad de Investigación en Retrovirus Humanos, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México.
Soler-Claudín
C
C
D000163:Acquired Immunodeficiency Syndrome / Q000635:transmission; D003429:Cross Reactions; D005260:Female; D015483:HIV Antibodies / Q000032:analysis; D018023:HIV Seronegativity; D006679:HIV Seropositivity; D015497:HIV-1 / Q000276:immunology; D015498:HIV-2 / Q000276:immunology*; D006801:Humans; D008297:Male; D008800:Mexico; D065227:Transfusion Reaction
D015483:HIV Antibodies