Morphologic, Cytogenetic and Immunophenotypic Characteristics of CD56 expression in Acute Leukemia / 대한진단검사의학회지

ABSTRACT

BACKGROUND: CD56 is generally considered to be a natural killer (NK) cell marker, but it is also found in various tissues including acute leukemia. Recently, some reports have showed that positive CD56staining by blast cells is associated with an unfavorable outcome in AML with either t(8;21) or t(15;17)and in some ALL. This study investigated the characteristics of morphology, immunophenotype and cytogenetics and correlated the expression of CD56 of blast cells in 262 acute leukemia patients. METHODS: We analyzed 153 AML and 109 ALL, who underwent flow cytometry for CD56 at diagnosis at Chonnam National University Hospital between January 1999 and May 2003, for morphology, immunophenotype, and cytogenetics, retrospectively. RESULTS: The CD56 antigen was positive in 47 out of 163 AML cases (28.8%) and in 4 out of 109 ALL cases (3.7%). There were no statistically significant differences in the hematological parameters between the CD56+ and CD56- groups in ALL. However, the CD56 expression in AML was significantly high (81.8%) in AML-M2 with t(8;21) and low (5%) in AML-M3 with t(15;17) and was associatedwith the frequent expression of CD34 and HLA-DR. CONCLUSIONS: In conclusion, the CD56 expression in AML is associated with specific translocation, FAB subtype, some antigens CD34 and HLA-DR, and is significantly higher than in ALL.