[Use of thymus hormone in the demonstration of acute T-null cell lymphocytic leukemia].

The Authors studied the effect of the human serum thymic factor on the peripheral-blood leukocytes from ALL patients, by testing the frequency of the E+cells by means of the e rosette assay before and after cell incubation with the above mentioned factor. In 3 out of 24 patients tested, the thymic factor incubation of peripheral-blood mononuclears increased the number of E+cells. The shift from R to E+cells caused by the human serum thymic factor occurred among null cells (E-, SM-Ig-). The possible value of the test in investigating whether a T0 leukemia might really exists is pointed out, as well as its prospective importance in monitoring the variations of the immature T cell counts in relationship to the patient's treatment and his disease course.