Influence of Prednisone and Cytostatics on Human Blood B‐, T‐ and O‐Lymphocytes in Diseases

B-, T- and O-lymphocytes detected as EAC-, E- and non-rosette forming lymphocytes were investigated in venous blood in 49 patients with connective tissue diseases, psoriasis and chronic lymphogenous leukaemia (CLL) during treatment with either prednisone alone, prednisone and cytostatic agents or cytostatic agents alone. Prednisone alone did not change the B-, T- and O-lymphocyte counts. Cytostatics alone or in combination with prednisone reduced the B- and T-lymphocyte counts concomitant with a significant increase in the O-lymphocyte count. The findings could be explained by assuming that cytostatics disturb the immunological functions of the lymphocytes and finally deprive the cells of their B- and T-markers. The optimal immunosuppressive treatment with cytostatic agents may be associated with a certain reduction of B- and T-lymphocytes which may be used as a guideline for dosage.