소아 급성 백혈병에서 비전형적 면역표현형 발현 양상

Abstract

Background: As immunophenotyping became broadly practiced, more and more cases of unusual antigen(Ag) expression are being reported. Although there are reports on mixed lineage leukemia, studies on leukemia with ectopic Ag expression in chldhood are rare. This study was performed In order to find the correlation of unusual Ag expression with the clinical characterizations and the prognostic values. Methods: 153 newly diagnosed acute leukemia patients were studied. 10 patients with mixed lineage leukemia were excluded and the remaining 143 patients were studied on their clinical characterizations and prognostic value. Results: Myeloid cell antigen positive acute lymphoblastic leukemia(My+ ALL) comprised 5 out of 114 ALL cases (4.4% ), while lymphoid cell antigen positive acute nonlymphoblastic leukemia(Ly+ ANLL) comprised 8 out of 29 ANLL cases (27.6% ). The mean age for each group were 8.5 and 9.5 years, respectively. There was no sexual predominance. Clinical manifestation showed no statistically meaningful differences in each group. Cases showing unusual immunophenotypes, the predominant FAB classification were L2 and M4. Among the My+ALL patients, 4 cases were CD13+ and 1 case was CD33+. Among the Ly+ ANLL patients, 3 cases were CD2+, 2 cases were CD19+, and CD7+, CD10+, SIg+ accounted for 1 case each. The complete remission was induced in all cases of My+ ALL, but 1 case who expressed CDl3 relapsed at bone marrow during the maintenance treatment. Among 5 treated Ly+ ANLL patients, 2 patients achieved the complete remission and other 3 patients were died during the course of remission induction. Conclusion: In childhood acute leukemia, incidence of My+ ALL was 4.4%, Ly+ ANLL was 27.6%. There were no differences in the clinical features. The disease free survival rate in cases showing unusual Ag expression was lower than without unusual Ag expression. Although this report alone would not be sufficient to set a guide line as to the prognosis of he acute leukemia with unusual antigen expression in childhood, it could be assessed that therapeutic consideration and further long term follow up would be needed in cases showing the above mentioned subclasses.