Quantitative and qualitative deficiency of T-lymphocyte colony formation in T-cell lymphoma-leukaemia

T-lymphocyte colony formation in a patient with T-cell lymphoma-leukaemia was found to be defective in three ways. Colony numbers in patient cultures were reduced below those of 20 normal donors. Colony size in patient cultures was uniformly small. Colony formation by patient cells was inhibited in co-cultures of patient and normal cells. These observations indicate that the leukaemic T cells in this rare entity have a defective T-cell function.