High leukocytes

Key words: Infections, Leukocytosis, Primary immunodeficiency, Leukocyte adhesion deficiency

Leukocytosis is a common finding in children evaluation. In order to highlight the underlying cause, it is necessary to investigate which leukocyte subset is involved. Usually, leukocytosis is observed in children with infectious diseases. However, high white blood cell counts can be due to other causes including leukaemia. Leukocytosis can be also a manifestation of a primary immunodeficiency suck as leukocyte adhesion deficiency. So a flow cytometry should be performed to measure integrins’ expression on the cells. Genetic analysis confirms clinical and laboratory diagnosis.