Salivary defense factors and oral health in patients with common variable immunodeficiency

Salivary Alterations of Myeloperoxidase in Patients with Systemic Diseases: A Systematic Review

Salivary myeloperoxidase (MPO) is a key mediator of the oral immune system, acting as an enzyme that utilises H2O2 to generate molecules with high bactericidal activity. While MPO determination in plasma is quite common, the use of saliva is still rare. Our systematic review was designed to answer the question "Are salivary levels of myeloperoxidase altered in patients with systemic diseases?". Following the inclusion and exclusion criteria, we included twenty-six studies. Altered MPO levels in saliva were most commonly found in patients with cardiovascular and gastrointestinal diseases. Most studies concerned unstimulated whole saliva, and only a few of them stimulated, mainly by chewing paraffin. Enzyme-linked immunosorbent assay (ELISA) was the most common method for determination of MPO concentrations in saliva. Increased salivary MPO levels were more often observed for inflammatory diseases, except patients with inflammatory bowel diseases who were eligible for biologic therapy. In conclusion, MPO could be altered in the saliva of patients with systematic diseases, especially cardiovascular or gastrointestinal diseases. However, further investigations are recommended to validate these outcomes.

Salivary Immunoglobulins in Individuals with Common Variable Immunodeficiency

Oral manifestations of common variable immunodeficiency (CVID) are rare, have rarely been studied and have given controversial results. There are few data about IgA, IgG, and IgM antibody salivary levels in the literature, and there are few papers about the clinical impact of antibody deficiencies and CVID on the oral health of such patients. The aim of this study was to measure serum and salivary IgA, IgG, and IgM levels in CVID participants and controls, and to associate immunoglobulin levels with caries and periodontal disease. This was a case-control study involving 51 CVID individuals and 50 healthy controls. All participants underwent examination for dental caries and periodontal disease. Blood and whole saliva samples were collected on the same day of the oral examination. Serum IgA, IgM, and IgG levels were measured by turbidimetry and salivary IgA, IgM, and IgG titers were assessed by enzyme-linked immunosorbent assay. Incidences of caries and gingivitis were significantly higher in the CVID group than in the control group (p<0.05). Salivary and blood IgA and IgM titers were significantly reduced in the CVID group, but there was no association of salivary immunoglobulin levels with periodontal disease or with caries incidence (p>0.05 for both). Although CVID was associated with increased susceptibility to caries and gingivitis, it was not associated with low salivary levels of IgA and IgM.

Clinical trials of yeast-derived β-(1,3) glucan in children: effects on innate immunity

BACKGROUND

The role of glucan in the stimulation of immune reactions is well established. In our report, we focused on the effects of orally administered glucan on nonspecific immunity of children with chronic respiratory problems.

MATERIALS AND METHODS

We measured the levels of albumin, lysozyme. C-reactive protein (CRP) and calprotectin in the saliva of 60 children ages 8-12 years and evaluated the effects of 30-day treatment with 100 mg/d oral dose of glucan.

RESULTS

We found a significant increase in the production of lysozyme, CRP and calprotectin in glucan-treated children.

CONCLUSIONS

Short-term oral application of natural immunomodulator β-glucan significantly stimulated mucosal immunity of children with chronic respiratory problems.

Placebo-driven clinical trials of yeast-derived β-(1-3) glucan in children with chronic respiratory problems

BACKGROUND

The role of glucan in stimulation of immune reactions has been studied for several decades. In this report we focused on the effects of orally administered glucan in children with chronic respiratory problems.

MATERIALS AND METHODS

We measured the levels of albumin, lysozyme and CRP in saliva of 40 children aged 8-12 years and evaluate the effects of 100 mg/d oral dose of glucan.

RESULTS

We found a significant increase in production of changes in production of lysozyme and CRP in glucan-treated children. In addition, a strong improvement in general conditions was found.

CONCLUSIONS

Short-term oral application of natural immunomodulator β-glucan stimulated mucosal immunity of children with chronic respiratory problems.

Oral manifestations in patients with hypogammaglobulinemia

OBJECTIVE

The overall objective of this study was to assess the oral manifestations and their association with immunologic status and health history, of individuals with hypogammaglobulinemia.

STUDY DESIGN

A case-controlled study of 100 subjects with hypogammaglobulinemia and 93 control individuals was performed. All participants were examined for dental caries, periodontal disease, mucosal lesions/infections, and general oral health problems. Decayed, missing, filled teeth and community periodontal index were recorded. Complete blood count, serum immunoglobulins, and lymphocyte immunophenotyping were measured on the same day of the oral health assessment.

RESULTS

Individuals with hypogammaglobulinemia showed higher prevalence of enamel hypoplasia and complaints of dry mouth, and lower prevalence of dental caries and periodontal disease.

CONCLUSIONS

The systemic conditions associated with hypogammaglobulinemia were not associated with enhanced susceptibility to caries, gingivitis, or periodontitis; however, individuals with hypogammaglobulinemia were more likely to report more episodes of recurrent aphthous ulcers compared with control individuals.

Origin, structure, and biological activities of peroxidases in human saliva

Human whole saliva contains two peroxidases, salivary peroxidase (hSPO) and myeloperoxidase (hMPO), which are part of the innate host defence in oral cavity. Both hSPO as well as human milk lactoperoxidase (hLPO) are coded by the same gene, but to what extent the different producing glands, salivary and mammary glands, affect the final conformation of the enzymes is not known. In human saliva the major function of hSPO and hMPO is to catalyze the oxidation of thiocyanate (SCN(-)) in the presence of hydrogen peroxide (H(2)O(2)) resulting in end products of wide antimicrobial potential. In addition cytotoxic H(2)O(2) is degraded. Similar peroxidation reactions inactivate some mutagenic and carcinogenic compounds, which suggests another protective mechanism of peroxidases in human saliva. Although being target of an active antimicrobial research, the structure-function relationships of hSPO are poorly known. However, recently published method for recombinant hSPO production offers new tools for those investigations.

Salivary lysozyme levels in patients with primary immunodeficiencies

BACKGROUND

Lysozyme is a muramidase that acts on the peptideoglycan wall of Gram positive bacteria, causing cell death. It plays part in innate immunity and is present in blood, external fluid, as well in lysossomal granules of the phagocytes. Primary Immunodeficiencies are a diverse group of illnesses that, as a result of abnormalities of the immune system, increase susceptibility to infection. Among the examples of impaired natural immunity are defects in phagocytes and in the complement system. Innate immunity could be important in protecting mucosas against infections in patients with different forms of primary immunodeficiencies. The aim of this study was to investigate lysozyme concentrations in saliva from patients with primary immunodeficiencies.

METHODS

Lysozyme levels in saliva samples from 34 patients with primary immunodeficiency (30 children and adolescents between the age of 3-13 years and 4 adults between the age of 20-33) and 60 age-matched healthy controls (49 children and adolescents between the ages of 3-15 and 11 adults between the ages of 22-42) were determined by the lysoplate method.

RESULTS

There was no statistically significant difference between the lysozyme concentrations in the saliva of the immunodeficient subjects and those of the healthy controls.

CONCLUSION

The results in the present work clearly show that salivary lysozyme levels in primary immunodeficient patients are equivalent to those found in healthy controls, suggesting that this enzyme still represents a remaining (but not a compensatory mechanism), contributing to the protection of there patients against infections.

Neuroendocrine regulation of salivary IgA synthesis and secretion: implications for oral health

Secretory immunoglobulin A (S-IgA) represents the main adaptive immune mechanism in the oral cavity. The regulation of secretion and synthesis of S-IgA is not only dependent on prior antigenic stimulation, but is also under strong neuroendocrine control. Thus, alterations in neuroendocrine functioning (such as induced by stress, exercise, pregnancy, menstrual cycle, and pharmacological interventions) may affect salivary IgA levels. This review deals with the neuroendocrine regulation of synthesis and secretion of salivary IgA and its potential role in the maintenance of oral health.

Clinical applications of antimicrobial host proteins lactoperoxidase, lysozyme and lactoferrin in xerostomia: efficacy and safety

Innate human salivary defence proteins, lysozyme, lactoferrin and peroxidase, are known to exert a wide antimicrobial activity against a number of bacterial, viral and fungal pathogens in vitro. Therefore, these proteins, alone or in combinations, have been incorporated as preservatives in foods and pharmaceuticals as well as in oral health care products to restore salivas' own antimicrobial capacity in patients with dry mouth. These antimicrobials used in oral health care products, such as dentifrices, mouth-rinses, moisturizing gels and chewing gums, have been purified from bovine colostrum. In this review I critically evaluate the clinical efficacy and safety of this kind of preventive approach against various oral diseases and symptoms.

Antifungal effects of lysozyme and lactoferrin against genetically similar, sequential Candida albicans isolates from a human immunodeficiency virus-infected southern Chinese cohort

A variety of innate defense factors in saliva such as lysozyme and lactoferrin contribute to mucosal protection and modulate Candida populations in the oral cavity. It is also known that in human immunodeficiency virus (HIV)-infected individuals significant variations in the concentrations of lysozyme and lactoferrin in saliva occur during disease progression. Therefore, the aim of this study was to determine the in vitro susceptibility to human lactoferrin and hen egg white lysozyme of genotypically similar oral Candida albicans isolates obtained from six HIV-infected ethnic Chinese during sequential visits over a 12-month period. The similarity of the genotypes (50 in total) was evaluated using a randomly amplified polymorphic DNA assay. A blastospore viability assay was performed to evaluate the sensitivity of the organisms to lysozyme and lactoferrin. Exposure to physiological concentrations of either lysozyme (30 microg/ml) or lactoferrin (20 microg/ml) caused a rapid loss of viability among all isolates to a varying extent. None of the sequential C. albicans isolates demonstrated significant differences in sensitivity to either protein from one visit to the next; similar results were noted when the different genotypes from the same individual were compared. On Spearman correlation analysis of two genotypes that were sequentially isolated from a single patient, a significant negative correlation between lysozyme (r = -0.88; P < 0.02) (but not lactoferrin) resistance and the duration of HIV disease was seen. These results imply that a minority of C. albicans isolates that persist intraorally in individuals with HIV disease develop progressive resistance to innate salivary antifungal defenses such as lysozyme, possibly as an adaptive response. However, the vast majority of the Candida isolates appear to succumb to these nonspecific host immune mediators abundantly present in the oral environment.

Changes in whole saliva in patients with coeliac disease

Many systemic diseases impair salivary flow rate and composition and therefore incite oral pathological processes. This study analyses the composition of whole saliva in patients with diagnosed coeliac disease (CD) and in healthy controls, and monitors possible changes in saliva composition after a short oral gluten challenge. Paraffin-stimulated whole saliva was collected from 128 CD patients and 55 healthy controls. In a separate study, paraffin-stimulated whole saliva samples were collected from 33 CD patients and 10 controls both before and 24 h after an oral mucosal and submucosal gluten challenge. No difference in saliva flow rate was observed, but total protein (P</=0.001), albumin (P</=0.001), IgA (P</=0.01) and IgG (P</=0.001) concentrations, as well as salivary peroxidase (P</=0.001) and myeloperoxidase (P</=0.001) activities, were significantly higher in CD patients than in healthy controls. The relative amounts of secreted proteins (mg/mg), e.g. amylase (P</=0. 001), total IgA (P</=0.005) and IgM (P</=0.001) were significantly lower in CD patients than in healthy controls. In CD patients, gluten challenge resulted in a decrease in myeloperoxidase (P</=0. 005) activity, IgA (P</=0.001) and IgM (P</=0.005) concentrations and the relative amounts of secreted IgA (P</=0.001). In healthy individuals, however, gluten challenge caused a decrease in total and relative amylase activity (P</=0.005; P</=0.001) and total IgM (P</=0.005) concentration. It is concluded that CD patients, following a strict gluten-free diet, secrete lower relative amounts of amylase, IgA and IgM into paraffin-stimulated whole saliva than do healthy controls.

Depressive symptoms favor abundant growth of salivary lactobacilli

OBJECTIVE

The purpose was to study the growth of lactobacilli in subjects with depressive symptoms in the total 55-year-old population of Oulu (a medium-sized town in Finland); 780 people participated.

METHODS

The dental examination included measurements of salivary lactobacillus growth with the Dentocult-LB method; measurements of salivary flow rate, pH, and buffering capacity; and assessment of oral health status. Depressive symptoms were determined with the Zung Self-Rating Depression Scale (ZSDS). Participants were also asked about their health, medication, smoking, and dietary habits.

RESULTS

The prevalence of high lactobacillus counts (> or =100,000 CFU/ml) was 22% among women and 31% among men (p = .02). Thirty-seven percent of the subjects with a high rate of depressive symptoms (ZSDS score of > or = 40) and 23% of those with an ZSDS score of < or = 39 had high counts of lactobacilli (p = .003). A logistic regression analysis with improvement of goodness of fit was made to confirm the relation between abundant lactobacilli and a high rate of depressive symptoms. After the confounding factors had been added stepwise into the logistic regression model, depressive symptoms were still significantly associated with abundant lactobacillus growth.

CONCLUSIONS

The association between high lactobacillus counts and depressive symptoms suggests that depressed subjects are at risk of having caries and possibly other dental diseases that should be recognized in the treatment of these patients.

Oral microbial ecology and the role of salivary immunoglobulin A

In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an imbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.

Longitudinal analysis of the association of human salivary antimicrobial agents with caries increment and cariogenic micro-organisms: a two-year cohort study

Previous studies of the possible associations of salivary antimicrobial agents with dental caries have given controversial results, obviously mainly because almost all studies have been cross-sectional. Our aim was to find out, in a two-year longitudinal follow-up study, the associations among selected salivary non-immune and immune antimicrobial variables, cariogenic bacteria, and caries increment. The study population was comprised of 63 subjects, all of whom had their 13th birthday during the first study year. In addition to a comprehensive dental examination at baseline and after 2 yrs, paraffin-stimulated whole saliva samples were collected in a standardized way at six-month intervals. Saliva samples were analyzed for flow rate, buffer effect, lysozyme, lactoferrin, total peroxidase activity, hypothiocyanite, thiocyanate, agglutination rate, and total and specific anti-S. mutans IgA and IgG, as well as for numbers of total and mutans streptococci, lactobacilli, and total anaerobic bacteria. Cluster analysis and Spearman-Rank correlation coefficients were used to explore possible associations between and among the studied variables. During the two-year period, a statistically significant increase was observed in flow rate, thiocyanate, agglutination rate, anti-S. mutans IgA antibodies, lactobacilli, and total anaerobes, whereas lysozyme, lactoferrin, and total and anti-S. mutans IgG antibodies declined significantly. Based on various analyses, it can be concluded that, at baseline, total IgG and hypothiocyanite had an inverse relationship with subsequent two-year caries increment, anti-S. mutans IgG antibodies increased with caries development, and mutans streptococci and lactobacilli correlated positively with both baseline caries and caries increment. Total anaerobic microflora was consistently more abundant among caries-free individuals. In spite of the above associations, we conclude that none of the single antimicrobial agents as such has sufficiently strong power to have diagnostic significance in vivo with respect to future caries.

Salivary IgA responses to bacteria in dental plaque as related to periodontal and HIV infection status

Levels of total IgA and specific IgA reactive with Streptococcus mutans, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Fusobacterium nucleatum were measured by ELISA in parotid saliva from HIV+ and HIV- persons with healthy gingiva (HG), chronic gingivitis, chronic marginal periodontitis (CMP), or necrotizing ulcerative periodontitis (NUP). When the HIV+ group was compared with the HIV- group regardless of periodontal status, total salivary IgA concentration was higher in HIV+ patients, but no such difference was observed for total IgA output. HIV+ CMP displayed higher total IgA concentration as compared with HIV- CMP. No significant differences in specific IgA outputs and ratios were detected between HIV+ and HIV- subgroups with similar periodontal status. HIV+ NUP displayed increased specific IgA output towards S. mutans and increased specific IgA ratio values towards S. mutans, P. gingivalis and P. nigrescens as compared with HIV+ CMP, and increased specific IgA ratio values towards S. mutans and P. nigrescens as compared with HIV+ HG. No such differences were observed between the HIV- subgroups. In sum, salivary IgA responses to bacteria in dental plaque seem not to be related to chronic periodontal disease and HIV infection, but are possibly influenced by acute periodontal infection.

Salivary parameters of relevance for assessing caries activity in individuals and populations

A review of the non-microbial salivary parameters with respect to their possible association with caries activity is presented. The parameters are limited to those which already are or at least in the near future will obviously be simple enough, also for clinical purposes. Salivary flow rate is undoubtedly the most important single parameter since the cariostatic activity or efficacy of practically all other salivary parameters depends on the flow rate. Flow rate as such has no linear association with dental caries but there seems to exist an individual "threshold" limit which is decisive for enhanced caries activity. This threshold limit varies among different individuals and therefore the so-called normal values for unstimulated or stimulated flow rate are more reliable on a population level than among individuals for screening purposes. In any individual a regular and longitudinal follow-up of the flow rate is of higher clinical value than only a single cross-sectional measurement. Salivary buffer effect has only a weak negative association with caries activity and again, this effect is of greater clinical significance on a population level. Since the decisive processes in caries attack occur within or under the dental plaque, the buffering effect of saliva is limited and obviously more important to screen for erosion-than caries-prone individuals. Although important for dental health, none of the salivary antimicrobial agents as such has shown any strong association with caries activity. The only ones with some evidence of a regulatory role are secretory IgA antibodies, hypothiocyanite ions, and agglutinins. However, the data are controversial and it seems that instead of measuring individual parameters, the assessment of saliva's functional properties (such as the ability to aggregate bacteria, prevent their adhesion to hydroxyapatite or sugar metabolism etc.) is more important for clinical purposes. Of the parameters involved in de- and remineralization process, only salivary fluoride content has some association with caries susceptibility but its diagnostic or predictive value is questionable.

Matrix metalloproteinases-1, -3 and -8 and myeloperoxidase in saliva of patients with human immunodeficiency virus infection

OBJECTIVE

Human immunodeficiency virus (HIV)-seropositive patients have frequently severe gingival inflammation and/or attachment loss. In addition many infectious diseases affect their periodontium with varying clinical manifestations. Matrix metalloproteinases seem to play a key role in physiological periodontal remodelling and pathological tissue destruction. The aim of the present study was to characterize the presence, molecular forms, cellular sources, activities, and relative amounts of fibroblast-type (matrix metalloproteinase [MMP]-1) and neutrophil (MMP-8) collagenases, as well as their potential activator stromelysin-I (MMP-3) and myeloperoxidase in saliva of HIV-seropositive patients at different phases of HIV-infection. HIV-seronegative, healthy, age-matched patients served as controls.

PATIENTS AND METHODS

Saliva samples were characterized by Western blotting using antibodies specific for MMP-1, MMP-3 and MMP-8. Interstitial collagenase activities were measured using quantitative sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis/laser densitometry assay. Myeloperoxidase was analysed using quantitative dot blotting.

RESULTS

Clinical and microbiological evaluation of HIV-seropositive patients' periodontium showed the presence of putative periodontopathogens ie Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Peptostreptococcus micros (Psm) and Campylobacter rectus (Cr) in their periodontal pockets. The amount of Candida increased with the severity of HIV-infection. Clinical and microbiological findings of HIV-seropositive patients suggested that they have a tendency to develop periodontal disease. Interstitial collagenase activities were found to be increased in saliva of different phases of HIV-infected patients compared to the controls. Independent of the phase of HIV-infection saliva samples contained pro- and active forms of MMP-1, -3 and -8 using Western blotting. Saliva samples from healthy controls were found to contain hardly any immunoreactivities for MMP-1 or MMP-8, but considerable amounts of MMP-3 were detected. Quantitative dot blotting demonstrated increased amounts of myeloperoxidase in HIV-patients' saliva relative to controls.

CONCLUSION

The present results showed increased amounts of MMP-1, -3, -8 and myeloperoxidase in HIV-patients' saliva. MMP-1 and -8 may have been activated by MMP-3 and/or oxidants generated by myeloperoxidase. The increased amounts of MMPs and myeloperoxidase may reflect and directly participate in HIV-infection associated periodontitis.

Does variability in salivary protein concentrations influence oral microbial ecology and oral health?

Salivary protein interactions with oral microbes in vitro include aggregation, adherence, cell-killing, inhibition of metabolism, and nutrition. Such interactions might be expected to influence oral ecology. However, inconsistent results have been obtained from in vivo tests of the hypothesis that quantitative variation in salivary protein concentrations will affect oral disease prevalence. Results may have been influenced by choices made during study design, including saliva source, stimulation status, control for flow rate, and assay methods. Salivary protein concentrations also may be subject to circadian variation. Values for saliva collected at the same time of day tend to remain consistent within subjects, but events such as stress, inflammation, infection, menstruation, or pregnancy may induce short-term changes. Long-term factors such as aging, systemic disease, or medication likewise may influence salivary protein concentrations. Such sources of variation may increase the sample size needed to find statistically significant differences. Clinical studies also must consider factors such as human population variation, strain and species differences in protein-microbe interactions, protein polymorphism, and synergistic or antagonistic interaction between proteins. Salivary proteins may form heterotypic complexes with unique effects, and different proteins may exert redundant effects. Patterns of protein-microbe interaction also may differ between oral sites. Future clinical studies must take those factors into account. Promising approaches might involve meta-analysis or multi-center studies, retrospective and prospective longitudinal designs, short-term measurement of salivary protein effects, and consideration of individual variation in multiple protein effects such as aggregation, adherence, and cell-killing.

Biochemical composition of human saliva in relation to other mucosal fluids

This paper describes several salivary components and their distribution in other mucosal secretions. Histatins are polypeptides which possess exceptional anti-fungal and anti-bacterial activities, but are nevertheless present only in saliva. Proline-rich proteins (PRPs) are members of a closely related family, of which the acidic PRPs are found solely in saliva, whereas the basic PRPs are also found in other secretions. Mucins are a group of glycoproteins that contribute to the visco-elastic character of the mucosal secretions. Despite the similarities in their structure and behavior, mucins have distinct tissue distributions and amino acid sequences. Other salivary proteins are present in one or more mucosal secretions. Lysozyme is an example of a component belonging to an ancient self-defense system, whereas secretory immunoglobulin A (sIgA) is the secreted part of a sophisticated adaptive immune system. Cystatins are closely related proteins which belong to a multigene family. Alpha-Amylase is a component that is believed to play a specific role in digestion, but is nevertheless present in several body fluids. Kallikrein and albumin are components of blood plasma. But whereas albumin diffuses into the different mucosal secretions, kallikrein is secreted specifically by the mucosal glands. The presence of these proteins specifically in saliva, or their distribution in other mucosal secretions as well, may provide important clues with respect to the physiology of those proteins in the oral cavity.