Neutrophil‐specific granule deficiency

Abstract

A blood film showed neutrophils with reduced granulation and incomplete nuclear segmentation with some bilobed forms, such that they could be difficult to differentiate from monocytes (top). His mother and sister have identical cytological features. Manual neutrophil and monocyte counts were normal and examination of the automated analyser forward/side scatter plot (Sysmex XE-2100) showed many of the neutrophils to have much reduced side scatter such that they were superimposed on the monocyte zone (centre patient left, control right, neutrophils red, monocytes blue, lymphocytes green). A diagnosis of neutrophil-specific granule deficiency (NSGD), previously known as lactoferrin deficiency, was made. Low numbers of neutrophil type 1 and type 2 granules were demonstrated by electron microscopy (bottom left, control right) with resultant reduced myeloperoxidase and lactoferrin. Neutrophil membrane expression of CD15, CD16 and CD66 was reduced. NSGD is a rare inherited defect with only a few families reported. A CEBPE mutation is sometimes identified. The neutrophils show impaired chemotaxis, phagocytosis and bactericidal activity resulting in recurrent pyogenic infections from infancy.