The effects of drugs that cause neutropenia upon colony formation by bone marrow cells in semi-solid agar

Quinine-induced agranulocytosis: toxic effect of quinine bisulphate on bone marrow cultures in vitro

In a case of quinine-induced agranulocytosis marrow culture studies confirmed the inhibitory effect on the patient's cells of equivalent therapeutic plasma concentrations of quinine. Similar concentrations had no effect on normal marrow cells. Quinidine, the stereoisomer of quinine, had no effect on either cells from the patient or normal cells. The results encourage the use of in-vitro bone marrow cultures for identifying drugs responsible for agranulocytosis.

Depression of bone marrow colony formation in gold-induced neutropenia

Bone marrow culture in semi-solid agar was used to assess the proliferative activity and the response to sodium aurothiomalate of the myeloid precursor cells from patients during and after recovery from neutropenia associated with the use of this drug. Colony formation was reduced during the neutropenia and returned to normal after recovery. The rheumatoid process itself did not impair colony formation even in patients with Felty's syndrome. Sodium aurothiomalate inhibited colony formation by normal marrow in a dose-dependent manner. Bone marrow colonies from patients who had recovered from neutropenia induced by sodium aurothiomalate were not abnormally sensitive to the inhibitory effect of the drug in vitro. The metabolism of gold is probably altered in a small proportion of patients, which causes high local concentrations within the bone marrow leading directly to marrow depression.