AEGiS-14IAC: Evaluation of the sensitivity an specificity of IgA immunoblot assay and PCR for diagnosing perinatal HIV infection in children younger than 24 months born to seropositive women.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Evaluation of the sensitivity an specificity of IgA immunoblot assay and PCR for diagnosing perinatal HIV infection in children younger than 24 months born to seropositive women.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. B10219)

Basualdo MC, Moran K, Alcantara P, Puentes E, Soler C
UNAM, Mexico D.F., Mexico

OBJECTIVE:-To evaluate sensitivity and specificity of IgA immunoblot assay and PCR in order to use as confident and efficiently auxiliary diagnosis of HIV perinatal infection using as reference viral isolation. Samples:90 infected an 153 non-infected children less than 24 months born form HIV infected women were analyzed.

METHODS: HIV-1 was isolated by co-cultures, evaluating HIV p24 antigen presence in culture supernatant. IIIb/LAV nitrocellulose strips were prepared and run with a 1:10 plasma dilution. 1:500 conjugated anti IgA-HRP-buffer was used. A sample was considered positive if at least one of the following viral proteins was detected:gp160, gp120,gp41,p55/51 or p24. Well known SK431/SK462 primers were used to amplify a gag region. Statistical analysis of results was performed with SPSS 10.0.

RESULTS: Overall IgA Immunoblot gave a sensitivity of 82.2%(72%-89%) and an specificity of 96.1%(91%-98%) with Kappa of 0.801. Considering that an IgA response in children younger than 3 months is rare values were calculated excluding children under 3 months,obtaining a sensitivity of 89.2%(79.3%-94.9%) and specificity of 97.1% (91.2%-99.9%) with Kappa of 0.872. Meanwhile, PCR presented an overall sensitivity of 98.3% (89.5%-99.9%) and specificity of 100% (92.1%-100%) with Kappa of 0.988. If both assays were run, the sensitivity increases to 100% with an specificity of 96%.

CONCLUSIONS: Our results indicate that a very high sensitivity and specificity is reached when using together PCR and IgA immunoblot for perinatal diagnosis of HIV-1, eliminating the need for viral isolation which is very expensive, technically demanding and with a longer time needed to reach a diagnosis.

Keywords: AEGIS, HIV Infections, HIV-1, Evaluation Studies, Sensitivity and Specificity, HIV Seropositivity, Immunoblotting, Polymerase Chain Reaction, HIV Core Protein p24, AIDS Serodiagnosis, Greece, Child, Human, Female, Diagnosis, immunology

020707
B10219