Prognostic Significance of CD7 Expression in Acute Myeloid Leukemia.

Abstract

Background: Expression of the T-cell lymphoid marker CD7 in acute myeloid leukemia (AML) is considered a poor prognostic factor. In 88% of AML cases, aberrant expression of phenotypic markers has been reported. Objectives: To determine the frequency of aberrantly expressed CD7 in adult patients with AML and its effect on their response to induction therapy in AML subtypes. Patients and Methods: This cross-sectional study included 50 adult patients diagnosed with de novo AML at Baghdad Teaching Hospital, Medical City Complex, from January to December 2019.  Based on the French-American-British (FAB) criteria, the patients were divided into two groups: monocytic and non-monocytic. Flow cytometry was used to demonstrate CD7 expression in blasts in whole blood or bone marrow aspirate samples. Response to induction therapy was determined after 4–5 weeks. The chi-square test was used to explore associations between discrete variables. Results: CD7 was expressed in 36% of AML patients, and 88.9% of these patients had incomplete remission. Thirty patients (60%) had non-monocytic AML subtypes, and 20 patients (40%) had M4 or M5 subtypes. A significant positive association between CD7 expression and poor response to remission induction was found. There was no statistically significant difference between CD7 expression and either monocytic or non-monocytic AML subtypes. Only 20 patients (40%) achieved complete remission (CR) after induction therapy. The other 30 patients (60%) had incomplete remission (IR). Conclusions: CD7 is expressed in a substantial portion of AML patients. High levels of this lymphoid marker correlate with incomplete remission following induction therapy, which portending poor prognosis.