Specific antibodies against Actinobacillus actinomycetemcomitans in serum and saliva of patients with advanced periodontitis

Salivary immunoglobulins (A, G, and M) in type 1 diabetes mellitus patients: A PROSPERO-registered systematic review and meta-analysis

OBJECTIVE

To assess the difference in the salivary levels of immunoglobulins between patients with type 1 diabetes mellitus (DM1) and healthy controls.

DESIGN

This systematic review was registered on the PROSPERO (CRD42020159198) database. All references were cross-checked and the risk of bias assessment was conducted using the Newcastle-Ottawa Scale. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to appraise the quality of evidence. The standardized mean difference and Cohen's d as the effect size were used in the meta-analysis. I-square statistics was used to estimate heterogeneity. Analysis was performed using the RevMan® software (p < 0.05) with a 95 % confidence interval.

RESULTS

Of the total 92 articles, 9 were selected for this study. The meta-analysis included 333 DM1 patients and 325 healthy controls. DM1 patients showed a significant reduction in salivary flow (p = 0.0008; Cohen's d= -0.19, CI 95 %= -0.33, -0.05), although not significant enough to modify the IgA concentration (p = 0.120; Cohen's d = 0.58, CI 95 %= -0.15, 1.32). However, DM1 increased IgA concentration by reducing salivary flow (Cohen's d = 0.84; CI 95 % = 0.36, 1.32), with a strong estimate of effect (p = 0.0006). Regarding IgG, no significant change was noted with DM1 in the patient's saliva (p = 0.420). Furthermore, there was no significant variation in the salivary IgM levels (p = 0.300).

CONCLUSIONS

The data suggest that the salivary levels of the evaluated immunoglobulins do not seem to be altered in DM1 patients when compared to that in healthy controls. However, the increase in IgA salivary concentration was dependent on total protein estimation.

The Application of Magnetic Bead Selection to Investigate Interactions between the Oral Microbiota and Salivary Immunoglobulins

The effect of humoral immunity on the composition of the oral microbiota is less intensively investigated than hygiene and diet, in part due to a lack of simple and robust systems for investigating interactions between salivary immunoglobulins and oral bacteria. Here we report the application of an ex situ method to investigate the specificity of salivary immunoglobulins for salivary bacteria. Saliva collected from six volunteers was separated into immunoglobulin and microbial fractions, and the microbial fractions were then directly exposed to salivary immunoglobulins of "self" and "non-self" origin. Antibody-selected bacteria were separated from their congeners using a magnetic bead system, selective for IgA or IgG isotypes. The positively selected fractions were then characterized using gel-based eubacterial-specific DNA profiling. The eubacterial profiles of positively selected fractions diverged significantly from profiles of whole salivary consortia based on volunteer (P≤ 0.001%) and immunoglobulin origin (P≤ 0.001%), but not immunoglobulin isotype (P = 0.2). DNA profiles of separated microbial fractions were significantly (p≤ 0.05) less diverse than whole salivary consortia and included oral and environmental bacteria. Consortia selected using self immunoglobulins were generally less diverse than those selected with immunoglobulins of non-self origin. Magnetic bead separation facilitated the testing of interactions between salivary antibodies and oral bacteria, showing that these interactions are specific and may reflect differences in recognition by self and non-self immunoglobulins. Further development of this system could improve understanding of the relationship between the oral microbiota and the host immune system and of mechanisms underlying the compositional stability of the oral microbiota.

Diagnostic biomarkers for oral and periodontal diseases

This article provides an overview of periodontal disease diagnosis that uses clinical parameters and biomarkers of the disease process.This article discusses the use of biomarkers of disease that can be identified at the tissue, cellular, and molecular levels and that are measurable in oral fluids such as saliva and gingival crevicular fluid. Biomarkers identified from these biologic fluids include microbial, host response, and connective tissue-related molecules that can target specific pathways of local alveolar bone resorption. Future prospects for oral fluid-based diagnostics that use micro-array and microfluidic technologies are presented.

Rapid identification of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus by restriction enzyme analysis of PCR-amplified 16S rRNA genes

Restriction enzyme analysis of PCR-amplified 16S rRNA genes was used to distinguish among clinical isolates of Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus which were originally identified by conventional phenotypic methods. This PCR-based method is a reliable and rapid alternative to conventional methods for identification of these bacterial species.