The significance of electron microscopic examination of gingiva in cases of Hunter syndrome and hereditary gingival fibromatosis.
BACKGROUND
Electron microscopy has been for decades a basic morphological method still used in diagnostic protocols of some pathological conditions affecting the ultrastructure of cells and extracellular matrix. The aim of this study was an ultrastructural description of gingiva of patients with Hunter syndrome and hereditary gingival fibromatosis.


METHODS
Gingival biopsies were obtained during surgical periodontal treatment from a 9-year-old boy with Hunter disease (with enzyme replacement therapy with recombinant human idursulphase) and a 15-year-old girl with hereditary gingival fibromatosis. Gingival samples obtained from the upper anterior region were processed and examined with transmission electron microscope.


RESULTS
In the case of Hunter syndrome due to the genetic lack of one lysosomal enzyme, an intercellular accumulation of glycosaminoglycans occurs. Within the gingiva of a patient with Hunter syndrome we observed membrane-bound storage vesicles in the cytoplasm of fibroblasts, endothelial cells of capillaries, surface epithelial cells, mast cells, and macrophages. Despite a long-term enzyme replacement therapy which improves clinical manifestations of Hunter syndrome, on the cellular level we still found marked accumulations of glycosaminoglycans in the cytoplasm of different cells as well as in the extracellular matrix. Hereditary gingival fibromatosis is a benign, slowly progressive and non-inflammatory gingival enlargement with a predominance of randomly oriented collagen fibrils in the gingival lamina propria. Some of these fibrils exhibited loops. Another unusual ultrastructural finding is the presence of empty perinuclear space in the cytoplasm of epithelial cells. The origin and significance of these non-membrane bound spaces are unknown.


CONCLUSIONS
In both genetically determined diseases, the electron microscopic examination may be useful, and physicians get relevant information about the progress of illness.
Department of Dentistry, Faculty of Medicine, Slovak Medical University, Bratislava, Slovakia.
Michal
M
Straka
Institute of Medical Biology, Genetics and Clinical Genetics, Faculty of Medicine, Comenius University in Bratislava, Slovakia.
Lubos
L
Danisovic
First Department of Paediatrics, Faculty of Medicine, Comenius University and Children´s Faculty Hospital, Bratislava, Slovakia.
Vladimir
V
Bzduch
Institute of Histology and Embryology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
Stefan
S
Polak
Institute of Histology and Embryology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
Ivan
I
Varga
D000293:Adolescent; D002648:Child; D004847:Epithelial Cells / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000648:ultrastructure; D005260:Female; D005351:Fibromatosis, Gingival / Q000473:pathology*; D005881:Gingiva / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D016532:Mucopolysaccharidosis II / Q000473:pathology*