Prognostic significance of adenosine deaminase determinations in subjects with the lymphoadenopathy syndrome

The association between human immunodeficiency virus type I (HIV-I) infection and high levels of erythrocyte adenosine deaminase (ADA) has been suggested by Cowan et al [1986]. We have analyzed the specific activities of the same enzyme during different stages of acquired immunodeficiency syndrome (AIDS), including asymptomatic subjects at high risk and patients with lymphoadenopathy syndrome (LAS), AIDS-related complex (ARC), full-blown AIDS, and AIDS encephalopathy (AIDS enc). The ADA activities were significantly higher (P less than .05) in asymptomatic HIV-I serum-positive individuals (13.1 U +/- 1.1) and in different groups of patients (LAS = 23.6 U +/- 10.2; ARC = 23.7 +/- 4.1) than those found in controls (9.5 U +/- 1.8) and in HIV-I serum-negative subjects (10.4 +/- 1.5). In patients with AIDS the mean ADA activity was of 32.3 U +/- 7.1, whereas in two cases with AIDS enc it was of 10 U. A tendency to increase in median ADA values with the progression of the disease was observed. In LAS patients the ADA values presented two distinct subsets falling below and above the cut-off line of 15 U/10(9) erythrocytes, respectively. A specific correlation to drug addition and its duration was observed: LAS subjects who discontinued drug abuse (median addiction time: 3 years) presented ADA values (median = 13 U) that are lower than for addicts (median = 27.2 U; median addiction time = 7 years) and are close to those observed for asymptomatic HIV-I serum-positive group. Evidence was also obtained for a progressive increase of ADA values of LAS patients with disappearance of the product of gag gene. These results suggest that LAS subjects with elevated ADA activities present a longer history of HIV-I infection and a higher probability of developing AIDS.