CHRONIC MYELOID-LEUKEMIA - CORRELATION BETWEEN PURINE METABOLISM ENZYME-ACTIVITIES AND MEMBRANE IMMUNOPHENOTYPE

Peripheral blood or bone marrow of 24 patients with chronic myeloid le ukemia (CML) were characterized for their surface membrane marker prof iles using flow cytometry and fluorescence microscopy. Purine metaboli sm enzyme activities were compared with membrane immunophenotype and c ytochemical stains. CML subtypes were correlated with the expression o f surface membrane antigens detected by the monoclonal antibodies. On the basis of immunophenotyping we found the following characteristic m arker profiles: In stable phase of CML (CML-SP) - CD15, CD11b, CDw65, CD13, in accelerated phase of CML (CML-AP) - CD15, CDw65, CD11b, CD13 and CD33, in myeloid blastic phase of CML (CML-BP-M) - CD13, CD33, HLA -DR, CD11b, CD15, CDw65, in myeloid and lymphoid (mixed) blastic phase of CML (CML-BP-M+L) - CD13, CD33, CD34, HLA-DR, CD11b, CD10 and in ch ronic myelomonocytic leukemia (CMML) - CD14, CDw65, CD11b, CD33 and HL A-DR. Analysis of purine metabolism enzyme activities showed that ther e was a correlation between the values of adenosine deaminase (ADA) an d purine nucleoside phosphorylase (PNP) and various types of CML. ADA levels in CML-SP, CML-AP and CMML were comparable with those in normal cells. In CML-BP-M, which represents proliferation of less mature mye loid cells (similar to less mature AML subtypes), ADA activity increas ed and PNP activity decreased. ADA activity was significantly differen t between control group and CML-BP-M (p < 0.01), between CML-SP and CM L-BP-M (p < 0.05). The values of PNP activity were the highest in stab le phase of CML (125 pkat.10(-6) cells) and the lowest (23 pkat.10(-6) cells) in CML-BP-M+L. PNP activity in the other groups corresponded t o control values. High ADA/PNP ratio was found in CML-BP-M and CML-BP- M+L (0.7 and 2.0, respectively) in comparison to CML-SP (0.2). It foll ows from our results that ADA/PNP ratio enables to discriminate betwee n stable and blast phases of CML (p < 0.01). The level of the cytochem ical enzymes (CHAE, MPO, SBB, ANAE and 5' NT) varied and reflected the degree of cell differentiation and maturation. CHAE and MPO were char acteristic enzymes for CML, ANBE for CMML and 5' NT for CML-BP-lymphoi d.