Objective: To determine the characteristics of immunophenotype in T-lineage acute lymphoblastic leukemia (T-ALL). Methods: Case series analysis. Using flourescent monoclonal antibodies and analysing results on FACS Canto II system with Diva software to perform immunophenotyping on the specimens of bone marrow aspirate or peripheral blood samples from T-ALL patients. Results: In 49 T-ALL cases, there are 35 bone marrow samples and 14 peripheral blood samples. The median age is 12
the male and female ratio is 2.5:1. The blasts with T-ALL patients express CD45 variable, SSC Jow, FSC variable
cyCD3 positive in 100 percent cases but smCD3 absent in 50 percent. The blast markers (such as CD34, TdT, CD1a, HLH.DR) appear unfrequently, in some cases blast marker did not appear. More than 80 percent cases espress commonly CD7+, CD2+ and CD5+. The immunophenotype CD4+, CD8+ commonly was seen in 72 percent cases, the next was CD4+, CD8+ (14 percent), and CD4+CD8-(14 percent). The other lineage antigens, such as CD33, CD13, and CD56 were seen. Conclusion: Immunophenotypes commonly found in T-ALL were CD3-, cyCD3+
CD2, CD5, and CD7 were strongly positive in frequently
CD4, and CD8 were mostly negative
the blast marker appear distinctly
different lineage antigens were positive sometimes.