Diagnosis and analysis of the clinical course of T-phenotype acute lymphoblastic leukemia.

We refer to the diagnostic possibilities in T-phenotype acute lymphoblastic leukemia. Immunophenotyping based on the proof of T-differentiation antigens by means of specific monoclonal antibodies and assessment of the E receptor, as well as examination of enzymatic activities of adenosine deaminase and purinenucleoside phosphorylase, were performed. Thirty patients with acute lymphoblastic leukemia of T-phenotype were examined. The monoclonal antibodies used demonstrated a heterogeneity in this type of leukemia reflecting the stage of thymocyte differentiation. The cells of some patients with T-phenotype acute lymphoblastic leukemia expressed simultaneously the common acute lymphoblastic leukemia antigen and Ia molecules. Examination of enzyme activities demonstrated a characteristic pattern with a significantly increased adenosine deaminase activity and simultaneously decreased purinenucleoside phosphorylase activity in T-phenotype acute lymphoblastic leukemia. The unfavorable course of disease in patients with T-phenotype acute lymphoblastic leukemia was demonstrated analyzing a group of 50 children with acute lymphoblastic leukemia. By means of statistical methods the cumulative rate of children surviving with acute lymphoblastic leukemia of common and T-phenotypes have been expressed. The results showed the need for a more effective treatment aimed at the T-phenotype of acute lymphoblastic leukemia.