Objective: To analyse the expression of myeloid markers and CD34 antigen on lymphoblasts in adult ALL and its relationship with prognosis.
Method: Immunophenotypes were examined using indirect immunofluorescence method in 102 de novo ALL.
Results: The incidence of myeloid antigen expression in adult ALL was 21.6% and the commonest one was CD33 (15.7%). There was a higher incidence of myeloid antigens expression in ALL-L2 than in ALL-L1 (25.6% vs 5.3%, P = 0.05). CD34 was expressed in lymphoblasts from 30 of 56 patients (53.6%). Incidence of CD34 expression in B-ALL was higher than that in T-ALL (61.7% vs 11.1%, P < 0.01). No relationship between CD34, myeloid antigens and cell maturity was found within B-ALL. There was no relation between expression of myeloid antigens and CD34. The CR rate in My(+)-ALL was lower than that in My(-)-ALL (52.6% vs 80.0%, P < 0.025), and was no relation with CD34 expression. In addition, Ph chromosome and/or bcr/abl fusion gene was positive in 35.9% of the patients, and CR rate of Ph positive patients was higher than that in Ph negative patients.
Conclusion: Expression of myeloid antigens was related to FAB subtype and cell maturity in adult ALL. There was no relationship between myeloid antigen expression and CR rate. A higher incidence of CD34 expression was found in Pro-B-ALL than in common-ALL and Pre-B-ALL. Expression of CD34 had no relation with CR rate.