[The usefulness of different markers in the diagnosis of advanced HIV infection].

Background: The aim of this study was to evaluate the usefulness of different markers to diagnose advanced infection by the human immunodeficiency virus (HIV) (AIDS or CD4 lymphocyte < 0.2 x 10(9)/L), establish the degree of correlation and define markers of advanced infection in primary health care.

Methods: Clinical, hematological, biochemical, cellular, serological and immunological variables were analyzed in 146 patients diagnosed for the first time with HIV infection. The patients were classified into three stages: A (II, III, CDC-1987), B (IV-A, IV-C2) and C or advanced (IV-C1, IV-D). The following data were compared: the results in the three stages, the degree of correlation, the specificity and sensitivity to the diagnosis of AIDS. Two multiple logistic regression models were established: the first for all the variables and the second for only those available in primary health care.

Results: All the markers except the triglycerides, IgG, IgM, and beta 2-microglobulin presented significant differences in the stages (p < 0.05). With the exception of the CD3+, CD4+ and CD8+ lymphocytes (r > or = 0.6 or -0.6) the remaining variables were independent. The decrease in CD4+ and the increase in neopterin were very sensitive markers (> 95%) but only hyperamylasemia demonstrated a specificity greater than 95% for the diagnosis of advanced infection. Oropharyngeal candidiasis (OR = 4.80) and the CD4+ lymphocyte (OR = 0.99) had the greatest weight in the first model. In the second model the most significant markers were weight loss (OR = 4.41), a decrease in lymphocytes (OR = 7.65) and an increase in IgA (OR = 5.82) with p < 0.01 and a predictive value of 85.16%.

Conclusions: The presence of weight loss, lymphocyte count < 1 x 10(9)/L and an increase in IgA may be used in primary health care to diagnose advanced infection by the human immunodeficiency virus. Asymptomatic hyperamylasemia with no apparent cause suggests advanced infection.