Background: Adenosine deaminase (ADA) is an essential enzyme for the differentiation and proliferation of T lymphocytes and the monocyte-macrophage system. The basic immunitary response of brucellosis is cellular. To this end, ADA activity was evaluated in brucellosis.
Methods: Serum ADA activity was assessed by a colorimetric method in 67 patients with brucellosis, before therapy and at 1, 3 and 6 months of follow up.
Results: Serum ADA activity in brucellosis was higher than that in 52 healthy controls, both in those with the acute febrile noncomplicated form (48 patients) and in those with focal symptoms from one organ (19 patients) (p less than 0.0001 and p less than 0.001). There were no differences between both groups of brucellosis. There was a negative correlation between the duration of the disease and ADA activity. After therapy there was a rapid decrease of ADA values, more marked in patients with noncomplicated brucellosis. During the follow up, only one patient had a new increase in ADA activity, coincident with a clinical and bacteriological relapse, and previous to the increase of IgG anti-Brucella titers.
Conclusions: The results indicate that adenosine deaminase activity is increased during the active stage of brucellosis. It can be considered as a biochemical follow up marker of the disease and, probably, as a marker of relapses.