A Study of Immune Mechanisms in the Mouth in Relation to Oral Disease

McKean, Frances Jane (1973) A Study of Immune Mechanisms in the Mouth in Relation to Oral Disease. PhD thesis, University of Glasgow.

Abstract

The evidence to date, from clinical, epidemiological and laboratory investigations, underlines the causal role of bacterial plaque in two of the most prevalent oral diseases i. e. periodontal disease and dental caries. The possibility of controlling plaque formation or of inhibiting its harmful effects on the teeth and gingivae by the production of salivary and/or tissue antibodies was investigated. Saliva is a more difficult and variable substance with which to work than serum, and although extensive research has been carried out on the nature of the salivary immune system, with especial reference to Secretory IgA, gingival fluid and gingival tissue immune reactions, there seems to be little correlation of the methodology, the results and their interpretation. A number of related problems in connection with saliva and gingivae and the possible roles of their components in relation to oral disease were investigated in both humans and small laboratory animals. Little data exists on the increase in salivary immunoglobulin levels following the concentration of saliva by volume reduction. Lyophilisation, ultrafiltration and polyacrylamide gel were compared as to their efficiency in concentrating stimulated, mixed, human saliva, the total protein and individual immunoglobulins being determined and compared. Reliability and feasability of method were evaluated using solutions of human gamma globulin and chymotrypsinogen. It was found that neither total protein nor individual immunoglobulin concentration increased linearly with reduction in volume, therefore volume reduction alone cannot be taken as a reliable indication of concentration of immunoglobulins or total protein in saliva. Although Secretory IgA is known to differ from serum IgA in that it contains a secretory piece, it has always been assumed that salivary albumin is identical to plasma albumin. The results reported in this thesis suggest the contrary. Immunoelectrophoresis has confirmed the presence of an albumin-like component in mixed saliva. However, although a precipitin arc occurs in the albumin region of mixed saliva against rabbit anti-mixed saliva serum, the arc shows a reaction of non-identity with the plasma albumin anti-plasma albumin arc; this arc is still present after adsorption of mixed saliva with anti-human plasma albumin. Thus it appears that the mixed saliva:anti-mixed saliva arc in the albumin region does not result from plasma-like albumin. Double-diffusion results in a reaction of identity between salivary and plasma albumins, suggesting antigenic similarities between them; this does not exclude the possibility of a secretory piece. Furthermore, after intravenous injection of human plasma albumin into rabbits, the human albumin appearing in the saliva seems to be a single entity. These results suggest the existence of both a serum-type and salivary-type albumin in saliva, with at least one identical antigenic component, the concentration of the serum---type, being related to the degree of periodontal disease and therefore tissue destruction. A comparison of salivary and serum IgA levels of patients presenting with different periodontal diseases, with a clinically healthy control group, closely matched for age, sex, medical histories and caries rates was made. Little regard has been taken of the amount of caries or systemic disease in previous similar studies, with subsequent difficulty in relating the results purely to the type of periodontal disease under investigation ( and vice-versa). Classification by longevity of the inf laminatory lesions resulted in more significant differences between the male salivas and the controls, than the females. On sub-division, trends to definite differences between health and specific diseases appeared. Significant differences in salivary values were recorded in the acute grouping with Acute Ulcerative Gingivitis, Herpes plus Acute Ulcerative Gingivitis, Aphthous Ulceration (in agreement with LEHNER, 1969,b) and acute Herpes plus chronic Gingivitis; serum levels differed in 'convalescent' groups of Acute Ulcerative Gingivitis, chronic Gingivitis and Rheumatoid patients. All values were calculated on the basis of the World Health Organization standards to enable correlation with any future results reported from other laboratories. The study discusses the value of immunoglobulin measurements and emphasises the need for maximum control and correlation of all variables apart from the disease under study to obtain fully meaningful results. Implantation of cariogenic bacteria in the mouths of rabbits fed a cariogenic diet resulted not in caries, but in gingivitis with a marked inflammatory cell infiltration. No salivary antibody was detected to these organisms (which adhered to the oral tissues) not normally present in the rabbit mouth. These results were compared to those of humans, by estimating if salivary antibodies were present in control and diseased mouths to an organism implicated in the pathogenesis of periodontal disease; the control group have a higher level than the latter. The role of salivary antibodies compared to tissue immune mechanisms is discussed in relation to these results.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Immunology, Dentistry, Pathology
• Date of Award: 1973
• Depositing User: Enlighten Team
• Unique ID: glathesis:1973-78640
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:07
• Last Modified: 30 Jan 2020 15:07
• URI: https://theses.gla.ac.uk/id/eprint/78640