Electron microscopical study on impaired phagocytic function of granulocytes in diabetics

Phagocytic ability of granulocytes obtained from 22 diabetic patients was studied by electron microscopy in order to explain their susceptibility to infection and was compared with that of granulocytes from 13 healthy controls. The main features of the procedure employed in this study were as follows; (1) morphologically quantitative assessment of phagocytosis, (2) no separate assay of engulfment and killing of bacteria, (3) granulocytes were mixed with 10 times their number of bacteria, (4) antibiotics were not used to kill extracellular bacteria, (5) use of a conic tube lined with collodion film for cell pellet formation, (6) each conic tube contained less than 1 X 10(6) granulocytes, (7) sections examined were the vertically cut surfaces of the thin buffy coat. Control subjects showed that most granulocytes did not contain intact intracellular bacteria. Assay of aliquots sampled after 30 minutes and 2 hours in controls showed no significant difference. However, in diabetics, eight cases showed similar results with controls and were thought to have normal function, and fourteen cases showed the increased number of granulocytes containing intact intracellular bacteria was much more marked in aliquots sampled after 2 hours and were considered as showing various degrees of impaired bactericidal ability.