Clinical And Prognostic Significance Of CD56Antigen Expression In Patients With Acute Monocytic Leukemia

Background and ObjectiveAcute myeloid leukemia(AML), belongs to one kind of maliganances in the high degree of heterogeneity, usually differ in morphology, immunophenotyping and cytogenetics. Further understanding of these characteristics would help clinicians better judge the prognostis and search for better treatment for patients. There are many reports about correlations between the immunophenotyping and clinic outcomes and prognosis of patients in AML, such as the expression of some antigen markers:TdT, CD7, CD9, CD11b, CD13, CD14, CD33, CD34, and CD56, more resently. CD56antigen, a200-220Kda cell surface glycoprotein belongs to the immunoglobulin supergene family and has been identified as an isoform of the neural cell adhesion molecule(NCAM). This antigen mediated cell to cell interactions.Moreover, some data suggeseted that CD56antigen expression is frequently associated with acute monocytic leukemia(AML-M5), and had significant effect on the achievement of CR and survival. To investigate the relevance of clinical features, immunophenetyping, CR, remission time, prognosis with CD56expression in patients with acute monocytic leukemia(AML-M5), we studied76de novo AML-M5 patients in our hospital, from June2007to June2012.MethodAnalyzed the data of76de novo AML-M5patients from our hospital, divided them into two groups that CD56+(21patients of76) and CD56—(55patients), and compared the clinical features, CR rate, relapse rate, the duration of CR, and the prognostic between the two groups.ResultCD56+antigen was recorded in21patients(27.6%), the median patient age was51.5years, with a range16-70. Of the21CD56+patients, high WBC count rate was taken by57.1%(12/21), compared to15%(8/55) with CD56—. More patients of CD56+group had extramedullary disease (62%v33%, p=0.021, respectively). All cases were immunophenotypically highly expression of CD13, CD33, CD64, CDllb, cMPO, CD38, only the expression frequency of CD11b was positively related with CD56(r=0.574, P＜0.001). CD56positivity had no significant influence on CR rate (P＞0.05), but it had an effect on relapse rate(P=0.042), the mean duration of CR was5.5months(95%CI,3.1-8.6, P=0.002), and median overall survival was10.1months(95%CI,2.3-16.3, P=0.001).Conclusion(1) CD56+group was more clined to have high WBC counts and extramedullary disease, and had a significant influence on short duration of CR, high relapse rate, poor overall survival and prognosis.(2) The expression of CDllb was positively related with CD56.