Adenosine deaminase activity in human cord blood lymphocyte subpopulations

Abstract The immunocompetence of cord blood lymphocytes has been extensively studied. From this viewpoint we have studied adenosine deaminase (ADA) activity in these lymphocytes. We found that their enzymatic activity was higher than that in peripheral lymphocytes from healthy adult donors and that it was also higher in E-rosette-forming cells and in EAC-rosette-forming cells than in the same cells from adults. The enzymatic activity was found to be higher in Erosette-forming cells, but EAC-rosette-forming cells too showed a high activity. We can suppose that lymphocytic immaturity, active DNA synthesis, and/or functional suppressor activity could be involved in causing increased ADA activity.