[Clinical significance of cationic proteins of leukocyte lysosomes: cationic leukocyte antigen (CLA) as a marker of blast crisis in chronic myelocytic leukaemia (author's transl)].

Cationic leukocyte antigen (CLA) was estimated in urine of acute and chronic leukaemics using quantitative immuno-precipitation techniques. The studies demonstrated that CLA is a marker of the (myelo-) blast crisis in patients with chronic myelocytic leukaemia (CML). By these studies the value of the determination of CLA for the differential diagnosis of acute myeloblastic leukaemia versus initial (myelo-) blast crisis in CML and the lymphatic leukaemias, respectively, was evident. The terminal blastic transformation in CML was indicated early by an elevation of the urinary CLA-level. The blast-crisis was accompanied by a heavy CLA-uria. The results are documented by demonstration of special studies of characteristic cases and discussed in the light of recent results of immunological and cytochemical findings on the nature of blast crisis in CML.