PROGNOSTIC SIGNIFICANCE OF CD56 EXPRESSION IN ACUTE LEUKEMIAS

Abstract

<p><strong>Background.</strong> CD56 expression was extensively investigated in cases of acute leukemia. Many studies associated it with short overall survival, unfavorable outcome, lower rates or short complete remission, however the results remain controversial.<br /><strong>Objectives.</strong> The aim of this study was to investigate the frequency and prognostic relevance of CD56 expression in patients with acute leukemia and to compare its value with other standard prognostic factors, such as age, gender, leukocytosis, morphologic subtypes, extramedullary invasion, cytogenetic abnormalities and performance status.<br /><strong>Methods.</strong> Forty cases of acute leukemia treated at Ain Shmas University hospitals were investigated. They were classified by the French-American-British group (FAB) criteria, flow cytometry, and cytogenetics data. They included twenty cases of acute myeloid leukemia (AML) and twenty cases of acute lymphoblastic leukemia (ALL).<br /><strong>Results.</strong> CD56 positive expression was detected in nine cases of AML (45 %), and only in two patients with ALL (10 %). The highest incidence of CD56 positivity was in FAB subtypes M1 (35 %) and M2 (35 %).Association studies between CD56 expression and other prognostic factors in AML cases showed no significant association with age, gender, clinical presentation, hematological data or cytogenetic risk groups. Incidence of relapse was higher in AML patients expressing CD56 than those who did not (66.7 % vs 10 %, P=0.01). Higher death rates were encountered in AML cases with CD56 expression than those without (55.6 % vs 10 %, P=0.032).<br /><strong>Conclusions.</strong> CD56 antigenic expression in AML cases represents an adverse prognostic factor. It should be regularly investigated in cases of AML for better prognostic stratification and assessment.</p><p><br /><strong>KEY WORDS:</strong> CD56; leukemia, myeloid; prognosis</p>