Eosinophil colonies in agar

Abstract

Using the agar culture system and human placental conditioned medium as a stimulus, we have examined some in vitro characteristics of eosinophil colony forming cells. Eosinophil colonies are compact and first appear after 10 d of culture. They continue to proliferate while other colony types are dying and at the end of a 3 wk culture period they are the predominant colony type. The number of eosinophil colonies are linear in relation to the number of cells cultured and are dependent on CSF for in vitro proliferation. In bone marrow cultures from 30 patients with non-haemopoietic disease, the frequency of eosinophil colonies was 15% (range 3-40%). Eosinophil progenitor levels were elevated in some cultures from 10 patients with Hodgkin’s disease (mean 25% and 3-67%) and 6 patients with chronic myeloid leukaemia 41% range 9-60%. In acute myeloid leukaemia there was no eosinophil colony formation although clusters were observed. In 3 cases of chronic myeloid leukaemia, eosinophil colonies were karyotyped and found to be Philadelphia chromosome positive. Using the agar culture system and human placental conditioned medium as a stimulus, we have examined some in vitro characteristics of eosinophil colony forming cells. Eosinophil colonies are compact and first appear after 10 d of culture. They continue to proliferate while other colony types are dying and at the end of a 3 wk culture period they are the predominant colony type. The number of eosinophil colonies are linear in relation to the number of cells cultured and are dependent on CSF for in vitro proliferation. In bone marrow cultures from 30 patients with non-haemopoietic disease, the frequency of eosinophil colonies was 15% (range 3-40%). Eosinophil progenitor levels were elevated in some cultures from 10 patients with Hodgkin’s disease (mean 25% and 3-67%) and 6 patients with chronic myeloid leukaemia 41% range 9-60%. In acute myeloid leukaemia there was no eosinophil colony formation although clusters were observed. In 3 cases of chronic myeloid leukaemia, eosinophil colonies were karyotyped and found to be Philadelphia chromosome positive.