[Classification of acute leukemias according to the first latin-american consensus conference for the immunophenotyping of leukemias].Rev Invest Clin. 2000 Sep-Oct; 52(5):524-8.RI
To evaluate the recommendations of the First Latinamerican Consensus Conference for the Immunophenotyping of Acute Leukemia in untreated patients with de novo disease immunologically classified employing flow cytometry and an extended panel of monoclonal antibodies.
MATERIAL AND METHODS
In that conference it was recommended the use of the following antibodies: cytoplasmic CD79a (cCD79a) and CD19 to define B-progenitor acute lymphoblastic leukemia (B-ALL); cCD3 and CD7 for T-cell ALL (T-ALL), and CD13, CD33 and myeloperoxidase (cMPO) for acute myeloblastic leukemia (AML). We analyzed the expression of these cellular antigens in 91 non-consecutive patients classified with the extended panel as: B-ALL 28 cases; T-ALL 7; B-T-ALL 2; AML 47; and mixed-lineage acute leukemia 7 cases.
All 28 B-ALL cases were positive with each of the two recommended antibodies cCD79a and CD19, whereas in 24 AML cases (the expression of cCD79a was not assayed in 23 cases) and in 7 T-ALL patients both antigens were absent. cCD3 and CD7 antigens were identified in 71% and 100% of T-ALL, respectively. CD7 antigen was not detected in any of the 28 patients with B-ALL but it was expressed in 6 of 47 AML cases, while none of 75 B-ALL and AML cases were positive to cCD3. Forty nine percent of AML were positive for the three recommended markers: cMPO, CD13 and CD33, and 51% of AML cases reacted with one or two of these three monoclonal antibodies. Six out of 28 cases of B-ALL had aberrant expression of myeloid antigen (CD33 in 3 cases and CD13 in 3 cases).
There was no difference in the definition of AL lineage between employing the extended antibody panel and that recommended by the Latinamerican consensus.