Adenosine deaminase activity and its isoenzyme pattern in women with recurrent spontaneous abortions

Normal pregnancy is characterized by suppressed cell-mediated immunity. Adenosine deaminase (ADA) is a purine metabolic enzyme enriched in trophoblast cells of the placenta. It is an early marker of trophoblast cell differentiation. Also, the activation of ADA gene expression in the placenta is crucial and essential for proper fetal development. The activity of ADA shows changes in diseases characterized by the alteration of cell-mediated immunity. The purpose of this study was to assess the possible role of the alteration of cell-mediated immunity in women with recurrent spontaneous abortions (RSA) as a cause of changes in tADA activity, and also to evaluate the extent of the contribution of ADA1 and ADA2 to changes of tADA activity in serum and peripheral blood lymphocytes (PBLs). We measured in serum and in PBLs activities of tADA, ADA1 and ADA2 of 25 married women with RSA (group A) and of 28 healthy non-pregnant women (group B). According to our results in women with RSA, mean serum tADA, ADA1 and ADA2 activities were significantly higher than those of non-pregnant women (p < 0.001, p < 0.05 and p < 0.05 respectively). In women with RSA, mean PBLs tADA, ADA1 and ADA2 activities were significantly higher than those of non-pregnant women (p < 0.001, p < 0.05 and p < 0.05 respectively). The findings of this study show a marked increase of serum and PBLs ADA activities, which is derived from an increase of ADA2 and ADA1 activity in women with RSA. These changes reflect cell-mediated immunological changes.