Muscarinic cholinergic receptors (MR3) in saliva of patients with oral lichen planus

Patients with oral lichen planus display lower levels of salivary acidic glycoproteins than individuals without oral mucosal disease

OBJECTIVES

Salivary proteins, acidic glycoproteins, and free calcium might take part in oral mucosal defence against inflammation in oral lichen planus (OLP). The study aimed to investigate whether the levels of sulfated and sialylated glycoproteins, total protein, and free calcium in saliva from patients with OLP differ from those of individuals without oral mucosal diseases.

MATERIAL AND METHODS

Patients diagnosed with OLP (n = 25) and two control groups without any oral mucosal disease; age- and gender-matched controls (n = 25, 65.6 ± 2.9 years), and younger controls (n = 25, 41.8 ± 2.5 years) were included. Subjective dry mouth (xerostomia) was assessed by asking a single-item question. Chew-stimulated whole saliva was collected to measure sulfated and sialylated glycoproteins by the Alcian Blue method. The total protein was determined spectrophotometrically, and the free calcium measured using an electrode.

RESULTS

The output of salivary sulfated and sialylated glycoproteins in the OLP group (21.8 ± 2.4 µg/min) was lower than in the age- and gender-matched controls (43.0 ± 2.9 µg/min, p = 0.0002), whereas the total protein and calcium output did not differ between the three groups (p > 0.05). The prevalence of xerostomia was significantly higher in the OLP group compared to both control groups (p = 0.038).

CONCLUSIONS

Patients with OLP showed a high prevalence of xerostomia and lower levels of salivary acidic type glycoproteins compared to the individuals without oral mucosa disease.

CLINICAL RELEVANCE

It is relevant to investigate the role of acidic glycoproteins in the pathogenesis of OLP.

Evaluation of Oral Dryness and the Salivary-flow Rate in Patients with Oral Lichen Planus

Background and Objectives:

Oral lichen planus (OLP) is a common T-cell-mediated inflammatory oral mucosal disease. One of the complaints among OLP patients is xerostomia. However, the relationship between oral dryness and a decreased salivary-flow rate in these patients is not yet conclusive. So, we investigated oral dryness and the salivary-flow rate in OLP patients using various measurements.

Material and Methods:

Thirty OLP patients and 30 controls were included. The oral-dryness symptoms were collected using the Xerostomia Inventory (XI) and Bother Index (BI). The salivary-flow rate was measured using a Modified Schirmer Test (MST) and the spitting method. The clinical signs of dry mouth were determined by the clinical oral-dryness score (CODS). The Thongprasom score was used to evaluate the severity of OLP. The data were analyzed using the Mann-Whitney U test and Spearman’s rank correlation coefficient.

Results:

The XI score and BI score in the OLP group were significantly higher than in the control group. However, CODS, MST, the unstimulated salivary-flow rate, and the stimulated salivary-flow rate were not significantly different between the two groups. There was no correlation between oral dryness and the salivary-flow rate in OLP patients. The severity of OLP was also not correlated to oral dryness and the salivary-flow rate.

Conclusion:

OLP patients had more complaints about mouth dryness than the controls. However, the salivary-flow rates between the two groups were not different. Additionally, the severity of OLP was not related to dry mouth or the salivary-flow rate. The possible reasons for oral dryness among people with OLP require further investigation.

Serum and Saliva Myelin Basic Protein as Multiple Sclerosis Biomarker

Introduction:

Multiple Sclerosis (MS) is presented with motor and sensory function loss. It is caused by demyelination and following axonal lesion. As Myelin Basic Protein (MBP) is one of the key elements of the myelin cover, we examined the level of MBP in serum, stimulated, and unstimulated saliva as a suitable biomarker for detecting MS.

Methods:

A case-control study was performed in 29 healthy women and 32 definitive relapsing-remitting MS patients hospitalized in Imam Reza hospital, Tehran, Iran. MBP level was assayed in serum and stimulated and unstimulated whole saliva.

Results:

MBP was expressed at a lower level in serum and stimulated saliva of MS patients compared to the control group. The serum MBP level had a considerable correlation with its stimulated saliva level. The receiver operating characteristic analysis showed significant diagnostic ability for MBP to discriminate MS patients with serum and stimulated saliva from controls.

Conclusion:

Serum and saliva level of MBP is lower in MS, so it may be considered a potential biomarker in MS.

Muscarinic cholinergic receptors in minor salivary gland tissues of patients with oral lichen planus: A case-control study

BACKGROUND

Oral lichen planus (OLP) is a common, chronic immunological and inflammatory condition. Many of the OLP patients complain of xerostomia. The M3 muscarinic cholinergic receptors (MR3) are the main receptors in the salivary glands responsible for water secretion into the saliva. This study aimed to assess the level of M3 muscarinic cholinergic receptors in minor salivary glands of OLP patients.

METHODS

This case-control cross-sectional study evaluated 40 OLP patients and 22 controls. All participants completed two questionnaires (xerostomia and xerostomia inventory). Stimulated and unstimulated saliva samples were collected. The saliva flow rate was calculated by dividing the saliva volume (in milliliters) by time (in minutes). Six minor salivary glands were also surgically removed from the lower lip of patients and controls, and weighed using a digital scale with 10^-4  g accuracy. They were then frozen at -80°C, and the level of M3 receptors of the glands was determined using the ELISA kit.

RESULTS

The unstimulated and stimulated saliva flow rate was significantly lower in OLP patients. The xerostomia inventory score was significantly higher in the OLP group. The level of M3 muscarinic receptors in minor salivary glands of OLP patients was significantly higher than that in controls.

CONCLUSIONS

It may be concluded that the reduction in saliva flow significantly increases the number of M3 receptors in an attempt to compensate for this shortage and prevent xerostomia (compensatory upregulation).

Aquaporin3 (AQP3) expression in oral epithelium in oral lichen planus

Lichen Planus is an autoimmune disease of skin and mucous membranes, including oral mucosa and genital organs, with the potential to undergo a malignant transformation. Xerostomia and the salivary gland hypofunction are common manifestations and complications in oral lichen planus (OLP), whose exact cause has not been well defined yet. Aquaporins (AQP) are a family of membrane channel cell proteins which play an important role in the intercellular water permeability. This study for the first time compares the expression of the aquaporin-3 (AQP3) gene in oral tissues of a group of OLP patients and a control group. In this study, 30 OLP patients and 30 healthy individuals were selected. The expression of AQP3 gene was measured using Real-Time PCR method. The expression of the gene in the OLP patients was more than the control group. It could be argued that decreased salivation increases the level of expression of the AQP3 gene in an effort to compensate for this deficiency and prevent the onset of xerostomia (compensatory up-regulation).

Salivary gland performance in autoimmune diseases: review and meta-analysis

Objectives: Autoimmune diseases include a spectrum of disorders in which immune response to the autoantigens leads to tissue damage or dysfunction. Xerostomia, salivary gland dysfunction and lack of saliva are some common symptoms associated with many autoimmune diseases.Methods: In this review study, the meta-analysis technique is used to objectively review the relationship between autoimmune diseases and salivary gland dysfunction. We have searched Medline and Embase and Google Scholar. By Revman 5.3, meta-analysis was performed to investigate the salivary flow rate in both stimulatory and non-stimulatory saliva. The sample size obtained from these studies was 130 people with autoimmune diseases and 100 healthy individuals.Results: The results showed a significant decrease in the level of non-stimulatory saliva in people with autoimmune diseases.Conclusions: A complete and comprehensive understanding of the clinical manifestation of systemic diseases is crucial in early diagnosis of diseases and identifying the mechanisms that develop the disease. Other than xerostomia, there is a significant reduction in salivary flow rate in patients with autoimmune diseases. As saliva plays a very important role in oral health and has significant functions, more attention is needed for monitoring and managing of hyposalivation in autoimmune patients.

Mucin 5B in saliva and serum of patients with oral lichen planus

Oral lichen planus (OLP) is among the most common oral diseases. Its etiopathogenesis has yet to be clearly identified. OLP patients complain of mouth dryness. This study aimed to assess the level of Mucin 5B in OLP patients with xerostomia. This study was conducted on 30 OLP patients and 30 healthy individuals. In addition to patient complaint of mouth dryness, xerostomia was assessed by tongue blade and lipstick tests. Stimulated and unstimulated saliva were collected in plastic vials by spitting method. Level of Mucin 5B was measured by ELISA. Unstimulated saliva flow was significantly lower in OLP patients (P = 0.0001). Stimulated saliva flow was not significantly different between the two groups (P > 0.05). Level of Mucin 5B in unstimulated saliva was significantly lower in OLP group (P = 0.0001) while it was not significantly different in stimulated saliva of the two groups (P > 0.05). Level of Mucin 5B was significantly higher in serum of OLP patients (P = 0.016). Both saliva flow and level of Mucin 5B decrease in OLP patients. Since Mucin 5B is effective for wetting and lubrication of the oral cavity, this result can suggest a possible reason for mouth dryness in OLP patients.

Evaluation of salivary oxidate stress biomarkers, nitric oxide and C-reactive protein in patients with oral lichen planus and burning mouth syndrome

OBJECTIVES

The aim of this study was to evaluate oxidative stress factors and C-reactive protein in the saliva of patients with oral lichen planus (OLP) and burning mouth syndrome (BMS).

METHODS

This consecutive, cross-sectional study included 20 patients with OLP, 19 with burning mouth syndrome (BMS), and 31 control subjects. The oral cavity of each patient was examined and patients responded to a quality of life questionnaire (OHIP-14) and the xerostomia inventory. The following parameters were measured in whole non-stimulated saliva: trolox equivalent antioxidant capacity (TEAC); total antioxidant capacity (TAC); cupric reducing antioxidant capacity (CUPRAC); ferric reducing ability of plasma (FRAP); C-reactive protein (CRP); nitric oxide; nitrates; and nitrites.

RESULTS

The OLP group presented statistically significant differences in reactive oxygen species (ROS) (29 600 cps) in comparison with the control group (39 679 cps) (P < 0.05). In the BMS group, ROS was 29 707 cps with significant difference in comparison with the control group (P < 0.05). Significantly higher salivary nitric oxide (145.7 μmol) and nitrite (141.0 μmol) levels were found in OLP patients in comparison with control group (P < 0.05).

CONCLUSION

Increases in nitric oxide and C-reactive protein were found in the saliva of OLP patients in comparison with BMS and control patients. Further studies are required to confirm these findings.