Alkaline phosphatase band-10 fraction as a possible surrogate marker for human immunodeficiency virus type 1 infection in children.

We report the utility of a possible lymphocyte fraction of alkaline phosphatase (ALP band-10) activity in serum to predict human immunodeficiency virus type 1 (HIV-1) infection in children born to HIV-1-seropositive mothers. The presence of ALP band 10 in serum consistently correlated with HIV-1 infection status as judged by positive HIV-1 culture, two consecutive HIV-1 p24 antigen results greater than 30 pg/mL in serum, and the subsequent confirmation of seroconversion to HIV-1 antibody after clearance of maternal IgG anti-HIV-1 antibody ascertained between 15 to 24 months post partum. Infection with HIV-1 was correctly identified in 31 samples from 18 patients ranging in age between 0.1 to 10 years; the absence of similar infection was noted in 14 samples from nine patients who served as controls and whose serum samples did not exhibit ALP band-10 activity. This ability of serum ALP band-10 activity to predict HIV-1 infection status in children as young as 2 months may be useful as a surrogate marker for early identification of HIV-1 infection in infants born to HIV-1-seropositive women long before the clearance of maternal anti-HIV-1 antibodies can be ascertained.