We analyzed the expression of the MyAg CD13 and/or CD33 in a cohort of 377 adult patients with de novo ALL enrolled and treated in the GIMEMA ALL 0496 protocol.
Coexpression of myeloid antigens (CD13 and/or CD33) was observed in six of 16 common ALL patients as well as in the one child with early T-lineage ALL phenotype.
A newly established human leukemia cell line, OM9;22, is reported, with B-precursor immunophenotype (CD10+ CD19+ CD22+ HLA- DR+ C mu-) and CD13 antigen, originated from a 19-year-old female patient with Philadelphia (Ph) chromosome-positive acute lymphoblastic leukemia (ALL).
Thus, an identical clonality of monocytoid cells, temporally appearing after chemotherapies and leukemic lymphoblasts, was determined in this patient with CD13+ ALL.
Leukemic cells from 5 of these 6 cases (4 ANLL, and 1 ALL) coexpressed CD13, a myeloid-associated antigen, and CD2, a T-cell-associated antigen; blasts from the sixth case (ALL) coexpressed CD13 and CD19, a B-lineage-associated antigen.