T-lymphocyte colonies in normal blood, bone marrow and lymphoproliferative disorders.

The formation of T-lymphocyte colonies was studied in normal individuals and in different lymphoproliferative disorders, using the double layer technique of Lowenberg & de Zeeuw (1977). All normal peripheral blood and bone marrow samples formed colonies: range 102-270 (mean 177) and 55-245 (mean 138) per 1 X 10(5) cells, respectively. Bone marrows from acute leukaemias in complete remission showed normal or increased colony formation. The T cell nature of the colonies was shown by rosette formation with sheep and human red blood cells (RBC). Most lymphoproliferative disorders of T and B cell either failed to grow colonies or showed reduced colony numbers. This was of particular interest in the chronic T cell disorders in which a high proportion of T cells was plated. This technique may help in the further characterization of leukaemic cell populations and may also provide clues on the distribution of particular subsets of T-lymphocytes in peripheral blood and bone marrow.