Objective: The aim of this study is to investigate the effect of myeloid marker positivity on prognosis and its relationship with classical prognostic factors in acute lymphoblastic leukemia (ALL).

Methods: Cases who were newly diagnosed with ALL, followed up in our hospital were included. CD13, CD14 and CD33 were used as myeloid markers by immunophenotyping with flow cytometry in the bone marrow samples. Any parameter higher than 20% was accepted as positive.Modified BFM-2000 protocol was used in treatment and ALL-BFM-95 residual protocols were used in relapses. Risk groups were determined according to the Trall-BFM-2000 protocol. Clinical, laboratory and demographic characteristics of participants such as age, gender, leukocyte count at the time of diagnosis, were all recorded. Patients were divided into three groups according to myeloid markers; those with negative myeloid markers (Group-I), positive one of the myeloid markers (Group-II), those with multiple positive myeloid markers (Group-III). For overall survival, death only was accepted, relapse or death were taken as failure for event free survival (EFS).

Results: A total of 96 ALL cases were included. 44 of the patients were male and 52 were female. Their ages were between 10-204 months and median value was 4.5 years. Nine patients were T-ALL (9.4%), one had biphenotype ALL (1%), and 86 had B precursor cell ALL (89.6%). Group-I had 47 patients. One or more myeloid markers were found to be positive in 49 patients (51.1%). While 42 of them consisted group-II, group-III had 7 patients. The EFS distribution for all patients was between 43,16-52 months, with a median of 45.58 months. There was no difference between the groups in terms of EFS (p 0.871).

Conclusion: This study revealed that myeloid markers had no effect on prognosis. When compared with parameters with prognostic significance, no difference was found except between FAB morphology and myeloid markers. Therefore, studies involving more patients are needed to obtain more precise information on the subject.

Keywords: Acute lymphoblastic leukemia, myeloid marker, child