Plasma adenosine deaminase sub(2) is a marker for human immunodeficiency virus-1 seroconversion

Plasma adenosine deaminase sub(2) (ADA sub(2)) has recently been proposed to be a marker for human immunodeficiency virus-1 (HIV) infection. We measured ADA sub(2) levels in plasma from two groups of white homosexual males at 6-month intervals for a total of 2.5 years. One group consisted of 6 subjects who seroconverted for HIV, and the other consisted of 8 HIV seropositive patients who progressed from asymptomatic (CDC Groups II/III) to symptomatic (CDC Group IV) disease. Seroconversion was associated with a significant increase in plasma ADA sub(2) which persisted throughout follow-up of 1.5 years. However, disease progression in HIV seropositive patients was not associated with any significant change in plasma ADA sub(2). In conclusion, ADA sub(2) may represent a unique marker for HIV seroconversion which does not change with later progression to symptomatic disease.