Cellular immune functions after heart operations

Eight patients were observed by mitogen stimulation and E-rosetting after heart operations with and without cardiopulmonary bypass. The first sample of blood was taken before surgery, the second on the afternoon of the same day and for a week daily examinations were carried out. A depression of mitogen-stimulated lymphocyte transformation was observed, parallel with a simultaneous T cell depression and a general decrease in the total WBC count. The lowest values were found during the first three days after both open and closed heart operations. After open heart surgery it took a longer time until the values had returned to normal. In two other cases the lymphocytes were examined for suppressor activity. The suppressive effect exerted on the response to mitogenic and allogeneic stimulation was not uniform. Suppressor activity was more affected by surgery than the helper effect in these two cases.