Neoplasma Vol.60, No.5, p.553-561, 2013

The prognostic significance of myeloid antigen (MyAg) expression in acute lymphoblastic leukemias (ALL), especially in adult patients, is still controversial.

In the present report, frequency and clinical significance of MyAg (CD13 and/or CD33) in blast cells were assessed in 80 consecutive adult (≥18 years) patients with B-lineage acute lymphoblastic leukemia (B-ALL), representing 66.7% of 120 patients diagnosed as having ALL during the study period.

Immunophenotyping was used to classify leukemic cells as B or T lymphoblasts and to identify the aberrant expression of myeloid-associated antigens. MyAg expression was documented in 52.5% of the 80 B-ALL cases analyzed. CD13 was the most commonly antigen expressed (36.3%) followed by CD33 (28.8%).

No significant associations were found between the expression of MyAg and the presence of known adverse prognostic features (eg: age>30 years, male gender, high WBC count and Philadelphia positivity).

Also, we failed to observe any statistically significant difference between MyAg-positive and MyAg-negative patients in terms of achievement of complete remission and overall survival at 3 years. This study demonstrates that the presence of MyAg on lymphoblastic cells lacks prognostic value In Moroccan patients with adult B-ALL.