Peripheral blood and bone marrow morphology, blood and bone marrow lym
phocyte subpopulation composition were studied in two children with cy
clic neutropenia, using flow cytofluorometry, monoclonal antibodies, c
olony-forming capacity of granulocytic macrophagal precursors in semi-
fluid agar. The studies were conducted in varying periods of the neutr
openic cycle. Differences were revealed in immunohematologic parameter
s and clinical course of neutropenia in the two patients. The analysis
of the literature data and the authors' own observations of the patie
nts with cyclic neutropenia permitted a suggestion on high heterogenei
ty of pathogenetic mechanisms of this disease.