Cytokinetic studies in children with untreated acute lymphocytic leukaemia (ALL): relationship to "T" cell markers.

"The labelling index (LI), mitotic index (MI) of marrow lymphoblasts and the percent of peripheral blood lymphocytes and lymphoblasts that form rosettes with sheep red cells at 4 degrees C ("T4"), were measured at presentation in 33 children with ALL. There was a significant correlation between LI and MI, but no significant correlations between them and the total white cell count at diagnosis or the "T4" percent. Three patients had greater than 55% "T4" rosettes and showed increased LI and MI, and 2 have relapsed; 12 had less than 20% "T4" rosettes, showed an increased LI (LI greater than 8% in 8 of 12) but not MI, and 5 have relapsed; 18 had 20--55% "T4" rosettes and generally had the lowest LI (LI less than 8% in 11 of 18), and only 3 have relapsed. Our findings suggest that patients with high and low percentage of "T4" rosettes in the peripheral blood have an increased fraction of leukaemic cells in DNA synthesis and have a diminished chance of prolonged remission.