Correlation of viral load and CD8 T-lymphocytes with development of neurological manifestations in vertically HIV-1-infected infants. A prospective longitudinal study

To assess the predictive power of immunological and virological markers for the development of neurological syndromes, 39 HIV-1-infected infants with a mean age of 4.05+/-0.5 months and without neurological manifestations at enrolment were studied. They had neither been previously treated with antir etroviral therapy, nor had their mothers been given such treatment during p regnancy. They were routinely assessed for signs of neurological impairment during follow-up (19.54+/-3.37 months). Cox regression analysis was used t o evaluate the risk of appearance of neurological signs, associated to vira l load and T-lymphocyte subsets. A HR>1 for viral load, and <1 for CD8+, bu t not for CD4+ T-lymphocyte percentage, was observed, indicating that highe r viral load and lower CD8+ T-lymphocytes percentages are risk factors for developing neurological signs. By applying the Kaplan-Meier method we found that infants with viral load >5 log(10) copies/ ml or <20% CD8+ T lymphocy te had higher relative risk for developing neurological impairment than tho se with these two parameters below or above these values, respectively. Fin ally, CD8+ T lymphocyte had a stronger prognostic value to predict neurolog ical manifestations than viral load. Our data strongly suggest that in the early postnatal period viral load and CD8+ percentages are useful markers i n predicting neurological impairment. To our knowledge, this is the first t ime that CD8+ T-lymphocyte levels are related to development of neurologica l disorders in AIDS.