[Expression of CD123 in lymphocytic leukemia and its significance for monitoring minimal residual diseases.].

ABSTRACT

OBJECTIVE: To investigate the expression of CD123 and its significance in lymphocytic leukemia. METHODS: CD123 expression in 139 lymphocytic leukemia patients and in lymphocytes from 10 normal bone marrows (BM) was analyzed by multi-parameter flow cytometry. Cytogenetic and minimal residual disease (MRD) analysis were performed in acute B-lymphocytic leukemia (B-ALL) patients. RESULTS: CD123 expression was absent in B lymphoid lineage stem-progenitor cells, mature B and T lymphocytes from 10 normal BM. Among 139 lymphocytic leukemia patients, CD123 was negative in 5 T-ALL and 23 B-CLL patients. However, among 111 B-ALL patients, CD123 was expressed in 106 (12 pro B-ALL, 57 common B-ALL and 37 Pre B-ALL) (95.49%) but not in 5 mature B-ALL patients. There was a positive correlation between CD123 and p-Akt expression, and CD123 expression was much higher in hyperdiploid than in non-hyperdiploid B-ALL patients. A statistically significant difference in relapse rate within 12 months (MRD positive group 63.04% vs MRD negative group 21.56%)and in disease free survival (DFS) time was found beween patients with MRD\[(36.06 +/- 2.62)%\] or not \[(48.23 +/- 1.82)%\] (P < 0.01). Moreover, stable CD123 expression could be observed in B-ALL patients in relapse. CONCLUSIONS: CD123 was predominantly expressed in B-ALL patients and remained in patients in relapsec, indicating that it may be an useful MRD marker in B-ALL patients.