Morphology of azurophil lysosomes in polymorphonuclear leukocytes from humans with rapidly progressive periodontitis

Previous investigations have shown that subjects with rapidly progressive periodontitis (RPP), an early-onset aggressive form of periodontitis, have polymorphonuclear leukocytes (PMNs) with increased intracellular levels of beta-glucuronidase, a characteristic enzyme of azurophil lysosomes. The current study attempted to account for that increase. Ten healthy controls and 10 otherwise healthy subjects with RPP participated. PMNs from peripheral blood were separated, fixed and reacted for peroxidase to identify azurophil lysosomes. Using transmission electron microscopy, 20 PMNs per subject were photographed at 10,000x. Photographs were subsequently digitized and analyzed by computer. RPP PMNs had a higher percentage of the area of the cell profile occupied by azurophil lysosomes compared to control subjects' PMNs. The RPP subjects also had greater absolute numbers of azurophil lysosomes per cell. Lysosome shape was assessed visually. There were no differences between RPP and control groups for lysosome shape, with the majority of lysosomes in each group exhibiting a round or oval shape. RPP lysosomes did exhibit a significantly greater mean size.