A. Mangano et al., RELIABILITY OF LABORATORY MARKERS OF HIV-1 INFECTION IN ARGENTINEAN INFANTS AT RISK OF PERINATAL INFECTION, AIDS patient care and STDs, 12(9), 1998, pp. 691-696
Early and accurate diagnosis of HIV-1 infection in infants born to HIV
-1-seropositive mothers is of great importance. Polymerase chain react
ion (PCR), HIV culture, and p24 antigen detection assays were evaluate
d for their ability to detect the presence of HIV in 195 infants at ri
sk of perinatal infection. Using the Centers for Disease Control and P
revention guidelines for assessing HIV infection status in children yo
unger than 18 months, 70 infants (36%) were diagnosed as HIV-1 infecte
d and 125 (64%) lacked virologic and clinical evidence of infection. P
CR and HIV culture were the most sensitive laboratory markers, detecti
ng 100% and 98% of positive samples, respectively, regardless of age a
t testing. HIV-1 p24 antigen assay was detected in 26 of 38 positive s
amples but not in negative samples. PCR was performed with three diffe
rent sets of primers (SK38/SK39-SK19-gag, SK68/SK69-SK70-env, and SK15
0/SK431-SK102-gag). The sensitivity/specificity of the individual assa
ys were for SK19, 96.1%/94.25%; SK70, 89.6%/100%; and SK102, 100%/100%
. A sample was considered HIV-1 positive when two positive PCR results
were obtained with two different pairs of primers, and negative if th
e sample was negative when three sets of primers were used. False-posi
tive results were occasionally obtained with probe SK19 in six serorev
erter infants before serologic status was known. This suggested that t
he infection was caused by nonreplicative strains or were false-positi
ve results probably by nonspecific amplification due to cross-reaction
with other microorganisms; contamination was discarded because there
was no specific amplification with the other two primers. All the HIV-
1-infected infants were correctly identified with PCR; all except one
could be identified with coculture and only 68.4% were confirmed with
p24 antigen assay. No seroreverter infant was misdiagnosed using the c
riteria selected.