Detection of anti-HIV IgA in tears of children born to seropositive mothers is highly specific

Human immunodeficiency virus antibody testing by enzyme-linked fluorescent and western blot assays using serum, gingival-crevicular transudate, and urine samples

The aim of the present study was to evaluate the possible utilization of saliva and urine as alternative samples to serum for the diagnosis of human immunodeficiency virus (HIV) infection. A total of 302 individuals participated in the study: 187 HIV-infected individuals (106 had Centers for Disease Control and Prevention [CDC] stage II infection, 19 had CDC stage III infection, and 62 had CDC stage IV infection) and 115 noninfected persons (46 of the noninfected persons were blood donors and 69 belonged to a group at high risk of HIV infection). Paired saliva and urine samples were taken from each of the participants in the study. The presence of HIV-specific antibodies was detected by an enzyme-linked fluorescent assay (ELFA), and the result was confirmed by Western blot analysis (WB). The ELFA with saliva gave maximum sensitivity and specificity values, while ELFA had lower sensitivity (95.2%) and specificity (97. 4%) values for detection of HIV antibody in urine samples. WB with all saliva samples fulfilled the World Health Organization criterion for positivity, while only 96.8% of the urine samples were confirmed to be positive by WB. Among the four reactivity patterns found by WB of these alternative samples, the most frequent included bands against three groups of HIV structural proteins (was ENV, POL, and GAG). The reactivity bands most frequently observed were those for the proteins gp160 and gp120. The least common reactivity band was the band for protein p17. The detection of HIV antibodies in saliva samples by means of ELFA with the possibility of later confirmation by WB makes saliva an alternative to serum for possible use in the diagnosis of infection. In contrast, HIV antibody detection in urine samples by the same methodology (ELFA) could be taken into consideration for use in epidemiological studies.

Vertical transmission

Since AIDS was first described in children, much has been learnt about the epidemiology, clinical presentations and natural history of perinatally acquired HIV disease. As yet, several questions remain unanswered about the pathogenesis of vertical transmission, the relative risk associated with each mode of transmission, the rate of transmission from mother to child, and the factors that might contribute to the efficiency of transmission. Data presented thus far suggest that intrauterine exposure poses the greatest risk, but more recent reports have reopened speculation that infection could occur at or around the time of delivery. The prospects for intervention, to stop transmission from mother to child, rest on the ability to identify HIV-infected women; the knowledge of how and when the virus infects the fetus; and how to identify, as early as possible, those truly infected infants. Resources should therefore be set aside for routine screening for HIV in antenatal women. There is also a need to quantify the contribution made by intrauterine versus intrapartum events. Lastly, promising new techniques designed to detect neonatal HIV infection must be properly evaluated against standard methods, and correlated with clinical outcome. Only then can the efficacy of antiretroviral therapy be tried, to prevent vertical transmission.