Cloning and characterization of bone marrow cells from patients with acutelymphoid leukemia (ALL) in agar cultures

Acute lymphoid leukemias (ALL) represent malignant clonal expansions of lym phoid hemopoietic cells arrested at different stages of B- or T-cell matura tion. We studied surface marker profiles and cloning capability of bone mar row (BM) cells from 22 adult ALL-patients at diagnosis (n = 15) or relapse (n = 7) in agar cultures under different culture conditions in order to dev elop a screening system for the classification of ALL and the detection of residual leukemia. Immunophenotyping of those 22 BM-samples enabled a classification in B- or T-linear ALL. Colony growth of BM-cells could be obtained in four out of 20 cases of ALL at diagnosis and in one case at relapse. Different stimulatin g factors and their combinations (GM-CSF; IL-1; IL-2; IL-3; IL-4; IL-6; pla centa conditioned media (PCM); Phytohemagglutinin (PHA, 40%) and lipopolisa ccaride (LPS, 1.25%) - containing conditioned media ('B-ly'); IL-1+IL-3; IL -1+IL-4; IL-1+IL-6; IL-1+B-ly) did not show an overall significant differen ce in stimulating ALL-clones. Immunological phenotyping of ALL-clones in th ese 5 cases could prove the lymphoid leukemic character of the clones obtai ned. Conclusions: Our data show that colony growth of ALL-BM-cells is difficult. Nevertheless, in cases where colony growth could be obtained those clones showed the original surface marker profile of the leukemic cells proving th e specificity of our colony assay.