Antibody avidity measurement and immune complex dissociation for serological diagnosis of vertically acquired HIV-1 infection.
Differences in avidity between HIV-1 antibodies transmitted passively and antibodies synthesized by children born to HIV-1-positive mothers can be measured using a commercially available competitive enzyme immunoassay kit. The avidity determination method is based on the competition between an anti-HIV-1-peroxidase-labeled antibody at a stable and known concentration and the anti-HIV-1 antibodies (IgA, IgG, IgM) present in the child's serum at various and increasing dilutions. The shift in the competition/dilution curves between serum samples taken at the third and the sixth month of the child's life showed either the loss or the synthesis of anti-HIV-1 antibodies. The antibody avidity determination combined with a test detecting free or complexed p24 antigen is a workable and inexpensive serological method for the follow-up of children born to seropositive mothers. Combining these two complementary methods, HIV-1 infection has been established at 6 months of age in 13 of 13 infants, and positive results were confirmed by coculture and by PCR. An HIV-1 infection was excluded at 6 months of age in 17 of 17 infants, results otherwise confirmed by virological and clinical follow-up. These new and convenient approaches to the diagnosis of vertically acquired HIV-1 could be used worldwide, including in developing countries.
Simon
F
F
Laboratoire de Virologie, Hôpital Bichat-Cl. Bernard, Paris, France.
Rahimy
C
C
Krivine
A
A
Levine
M
M
Pepin
J M
JM
Lapierre
D
D
Denamur
E
E
Vernoux
L
L
De Crepy
A
A
Blot
P
P
D015492:AIDS Serodiagnosis / Q000379:methods; D000704:Analysis of Variance; D000915:Antibody Affinity; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001667:Binding, Competitive; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015483:HIV Antibodies / Q000096:biosynthesis / Q000097:blood / Q000276:immunology*; D016655:HIV Core Protein p24 / Q000097:blood / Q000276:immunology; D015658:HIV Infections / Q000175:diagnosis* / Q000276:immunology / Q000635:transmission; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007124:Immunoenzyme Techniques; D007223:Infant; D007231:Infant, Newborn; D016133:Polymerase Chain Reaction; D011247:Pregnancy
D000936:Antigen-Antibody Complex; D015483:HIV Antibodies; D016655:HIV Core Protein p24