[Evaluation of serum adenosine deaminase as a prognostic marker in the treatment of human immunodeficiency virus infection with zidovudine].

BACKGROUND

Adenosine deaminase (ADA) is a key enzyme in cellular immunity. It catalyses the reaction 2'deoxyadenosine to 2'deoxiinosine, a critical step in the production of essential metabolites for the synthesis of nucleic acids. Its main physiological activity occurs in T cells of lymphoid tissue. The advanced HIV infection is characterized by a severe and progressive cellular immunity compromise. Partial positive results have been obtained with Zidovudine (AZT), a drug which Serum adenosine deaminase has been proposed as a useful marker for the assessment of the therapy response in these patients.

METHODS

Serum ADA activity was determined in patients infected with HIV in stage II, before and after four months of therapy with AZT, regarding variations in its activity with improvements in biological parameters--CD4 and CD8 lymphocytes.

RESULTS

Patients infected with HIV showed a significant increase in ADA activity compared with patients in the control group: 21.6 +/- 5.4 vs. 10.4 +/- 2.3 U/l (p < 0.001). Therapy with AZT decreased ADA activity: 21.6 +/- 5.4 vs. 15.2 +/- 4.3 U/l (p < 0.001) and correlated with an increase in CD4 counts: 187 +/- 105 vs. 353 +/- 145/mm3 (p < 0.001) and in CD4/CD8 ratio: 0.188 +/- 0.10 vs. 0.382 +/- 0.18 (p < 0.001).

CONCLUSIONS

The detection of a decrease in ADA correlates significantly with a favourable outcome in immunological parameters in individuals infected with HIV in stage II of disease treated with AZT.