Ultrastructure of the specific granules of human neutrophil granulocytes. Studies in fatal granulomatous disease and toxic granulation.

Electron microscopic studies of circulating neutrophil granulocytes of a boy suffering from Fatal Granulomatous Disease (FGD) showed two abnormal kinds of cytoplasmic granules, both larger than normal granules. One was characterized by a homogeneous matrix of very low electron density, the other contained one or more crystalloid inclusions of larger size than found in normal neutrophils. In neutrophil granulocytes from adults with long-standing bacterial infection, by light microscopy showing toxic granulation, the granules displayed the same ultrastructural abnormalities as in FGD. It is concluded that the ultrastructure of the granules of neutrophils in FGD reflects non-specific toxic granulation. The functional defect of the granules in FGD has no known morphological counterpart.