[Eosinophilic leukemia with cyclic eosinophilic leukocytosis].

A 36-year-old male was admitted to the Ehime University Hospital with anemia, eosinophilia and hepatosplenomegaly. Peripheral blood examination demonstrated severe anemia (Hb 7.1g/dl), thrombocytopenia (Plt 6.8 x 10(4)/microliters) and increase of peripheral leukocyte counts (53,000/microliters) with 32.0% of eosinophils which had lobulated nuclei, abnormal distribution of eosinophilic granules and a few vacuoles. The level of serum IgE was low (< 5IU/ml), while that of serum vitamin B12 was elevated. A diagnosis of eosinophilic leukemia was made. He was noted to have spontaneous fluctuations in his eosinophil and total leukocyte counts. To analyze the mechanism of cyclic eosinophilic leukocytosis, we examined eosinophil colony stimulating activity of the serum and plasma of the patient. These examination showed that eosinophil colony-stimulating activity was not found in his serum and plasma, and cyclic eosinophilic leukocytosis was due to the hemopoietic stem cell disorder.

EoL-1, a human eosinophilic cell line.

EoL-1 cells, a recently established human eosinophilic leukemia cell line, have cytological features of myeloblasts under normal culture conditions, and differentiate not only phenotypically but also functionally into eosinophils by a number of stimuli. EoL-1 cells are particularly useful for analyzing leukemic cell differentiation and the properties of malignant eosinophils. EoL-1 cells are also a useful in vitro model for studying human eosinophil functions and their regulation.

Granulocytic differentiation of the human myelomonocytic leukaemia cell line ME-1 in serum-free culture.

We have recently established ME-1, a human myelomonocytic leukaemia cell line derived from acute myelomonocytic leukaemia with eosinophilia (M4E0). When ME-1 cells were cultured in serum-free medium, they stopped proliferating and began to differentiate morphologically, functionally and phenotypically to mature granulocyte-like cells. The protein kinase inhibitor, 1-(5-isoquinolinyl-sulphonyl)-2-methylpiperazine (H-7) enhanced this differentiation dose-dependently. Upon addition of fetal calf serum (FCS) to the serum-free medium, the differentiation of ME-1 cells into granulocyte-like cells was inhibited and they resumed cell growth. We have recently reported that the differentiation of ME-1 cells into macrophage-like cells induced by IL-3 and GM-CSF involved the activation of protein kinase C. The present results indicate that ME-1 is a bipotential cell line that can differentiate into granulocyte-like cells or macrophage-like cells, and that protein kinase C is closely related to each form of differentiation.

[A case of eosinophilic leukemia]. / Przypadek bialaczki kwasochlonnej.

The clinical course and diagnostic difficulties in a case of eosinophilic leukaemia are described. For a long time period the case showed clinical manifestations of a hypereosinophilia syndrome. Shortly before death clinical signs of leukaemia developed, and the diagnosis was confirmed on autopsy.