Elevated Salivary Alpha-Amylase Level, Association Between Depression and Disease Activity, and Stress as a Predictor of Disease Flare in Systemic Lupus Erythematosus: A Prospective Case-Control Study

The correlation of anxiety and depression with C3 and C4 Levels and systemic lupus erythematosus activity

BACKGROUND

Anxiety and depression are psychosomatic disorders that are frequently observed in chronic conditions such as systemic lupus erythematosus (SLE). Anxiety and depression can be induced by immunological and neurotransmitter dysregulation, which is characterized by hypothalamic-pituitary-adrenal (HPA) axis dysfunction, production of proinflammatory cytokines, and activation of complement in the blood, such as C3 and C4. The causes of anxiety and depression in SLE are complex, ranging from neuropsychiatric involvement to drug adverse effects. Detecting anxiety and depression symptoms in SLE patients is critical to preventing disability from impacting quality of life.

OBJECTIVE

To assess the relationship between anxiety and depression symptomatology, SLE disease activity with levels of C3 and C4 in Cipto Mangunkusumo National Hospital.

METHODS

This study used a cross-sectional design. The study included 120 SLE patients from Cipto Mangunkusumo National Hospital, aged 18 to 60 years. All patients were requested to complete a Hospital Anxiety and Depression Scale (HADS) questionnaire to assess their anxiety and depression symptoms. Subjects with anxiety and depression were assessed for disease activity using the Mexican Systemic Lupus Erythematosus Systemic Disease Activity (Mex-SLEDAI), and blood samples were collected to test complement C3 and C4 levels. Spearman's correlation test was used to examine the relationship between HADS scores, Mex-SLEDAI, and C3 and C4 levels.

RESULTS

The results of the study showed a very weak statistically significant negative correlation between anxiety symptoms based on HADS and C3 levels (r = -0.189; p = 0.038) and a weak correlation between anxiety symptoms and C4 levels (r = -204; p = 0.026). Depressive symptoms based on HADS revealed a very poor connection and no statistical significance with levels of C3 (r = -0.056; p = 0.546) and C4 (r = -0.068; p = 0.461). Anxiety (r = 0.06; p = 0.173) and depression (r = 0.031; p = 0.753) symptoms have a weak and insignificant positive connection with SLE activity.

CONCLUSION

C3 and C4 serum levels appeared to decrease when the presence of anxious symptoms increased. There was no significant correlation in SLE disease activity between anxious and depressed patients.

The association of trauma with self-reported flares and disease activity in systemic lupus erythematosus (SLE)

OBJECTIVES

Trauma has been linked to incident SLE, but its relationship with SLE disease activity is unknown. This analysis examines associations between trauma exposures and patient-reported SLE disease activity and flares.

METHODS

Data were from the California Lupus Epidemiology Study (CLUES). Flares were self-reported as any flare and, of those, flares accompanied by medical care (hospitalization or physician contact). The Systemic Lupus Activity Questionnaire (SLAQ) assessed disease activity. The Brief Trauma Questionnaire (BTQ) assessed all historical trauma exposures. The Adverse Childhood Experiences (ACEs) questionnaire was available for a subset. Multivariable regression analyses (n = 252) examined whether trauma exposure was associated with flares or SLAQ controlling for age, sex, poverty, race/ethnicity, comorbidities, perceived stress, disease duration and self-reported disease damage.

RESULTS

Excluding exposure to serious illness, 63.4% reported ≥1 trauma exposure. Any traumatic event, excluding illness, doubled the odds of a flare [OR 2.27 (95% CI 1.24, 4.17)] and was associated with significantly higher SLAQ scores [β 2.31 (0.86, 3.76)]. Adjusted odds of any flare and flare with medical care were significantly elevated for those with both BTQ and ACE exposures [5.91 (2.21, 15.82) and 4.69 (1.56, 14.07), respectively]. SLAQ scores were also higher for those with both exposures [β 5.22 (3.00, 7.44)].

CONCLUSION

In this cohort, those with a history of trauma reported more flares and greater disease activity. Identifying mechanisms of associations between trauma and disease activity and flares, as well as interventions to mitigate the effects of trauma exposures is critical, given the high rates of trauma exposures.

Changes in salivary biomarkers of stress, inflammation, redox status, and muscle damage due to Streptococcus suis infection in pigs

BACKGROUND

Streptococcus suis (S. suis) is a Gram-positive bacteria that infects pigs causing meningitis, arthritis, pneumonia, or endocarditis. This increases the mortality in pig farms deriving in severe economic losses. The use of saliva as a diagnostic fluid has various advantages compared to blood, especially in pigs. In this study, it was hypothesized that saliva could reflect changes in different biomarkers related to stress, inflammation, redox status, and muscle damage in pigs with S. suis infection and that changes in these biomarkers could be related to the severity of the disease.

RESULTS

A total of 56 growing pigs from a farm were selected as infected pigs (n = 28) and healthy pigs (n = 28). Results showed increases in biomarkers related to stress (alpha-amylase and oxytocin), inflammation (haptoglobin, inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), total protein, S100A8-A9 and S100A12), redox status (advanced oxidation protein producs (AOPP)) and muscle damage (creatine kinase (CK), CK-MB, troponin I, lactate, aspartate aminotransferase, and lactate dehydrogenase). An increase in adenosine deaminase (ADA), procalcitonin, and aldolase in infected animals were also observed, as previously described. The grade of severity of the disease indicated a significant positive correlation with total protein concentrations, aspartate aminotransferase, aldolase, and AOPP.

CONCLUSIONS

This report revealed that S. suis infection caused variations in analytes related to stress, inflammation, redox status, and muscle damage in the saliva of pigs and these can be considered potential biomarkers for this disease.

The salivary alpha-amylase concentration in patients with rheumatoid arthritis: A case-control study

Background

Rheumatoid arthritis (RA) is one of the most common chronic inflammatory diseases. Previous studies have reported an association between stress and salivary alpha-amylase. The aim of this study was to investigate the concentration of salivary alpha-amylase in patients with RA (by elimination of stress factor).

Materials and Methods

In this case-control study, we enrolled 50 patients with RA and 48 healthy patients as the control group. The perceived stress scale questionnaire was used to evaluate scores of stress in both case and control groups, and then the participants with high scores of stress were excluded from the study. Moreover, the alpha-amylase activity kit was used for the assessment of the levels of salivary alpha-amylase. In all analyses, the significance level was considered to be < 0.05. Finally, the obtained data were analyzed by SPSS22.

Results

Our results indicated a high score of stress in the case group (19.42 ± 5.83 units) compared with the control group (18.02 ± 6.07 units) which was not statistically significant (P < 0.248). Moreover, we demonstrated a high salivary alpha-amylase concentration in the case group (340.65 ± 38.04 units) compared to the control group (302.62 ± 58.72 units), which was statistically significant (P < 0.001). The sensitivity and specificity of this method, at >312 alpha-amylase concentrations, were 80% and 46%, respectively.

Conclusion

In general, we indicated that the alpha-amylase concentration in patients with RA is higher than the healthy controls, and can be used as a codiagnostic factor.

The link between post-traumatic stress disorder and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous, multisystem autoimmune disorder characterized by unpredictable disease flares. Although the pathogenesis of SLE is complex, an epidemiologic link between posttraumatic stress disorder (PTSD) and the development of SLE has been identified, suggesting that stress-related disorders alter the susceptibility to SLE. Despite the strong epidemiologic evidence connecting PTSD and SLE, gaps remain in our understanding of how the two may be connected. Perturbations in the autonomic nervous system, neuroendocrine system, and at the genomic level may cause and sustain immune dysregulation that could lower the threshold for the development and propagation of SLE. We first describe shared risk factors for SLE and PTSD. We then describe potential biological pathways which may facilitate excessive inflammation in the context of PTSD. Among those genetically predisposed to SLE, systemic inflammation that accompanies chronic stress may fan the flames of smoldering SLE by priming immune pathways. Further studies on the connection between trauma and inflammation will provide important data on pathogenesis, risk factors, and novel treatments for SLE.

Establishment of quantitative indicators for an efficient treatment on masticatory muscle pain

BACKGROUND

Although several studies have investigated effective treatments for masticatory muscle pain (MMP), no unified conclusion has been drawn regarding the effectiveness of these treatments.

OBJECTIVES

This study aimed to define quantitative indicators for predicting the outcome of MMP treatment.

MATERIALS AND METHODS

In total, patients aged 20-70 years were recruited and divided into the MMP (n = 24) and control (n = 36) groups, based on the presence of MMP according to the Diagnostic Criteria for Temporomandibular Disorders. At pretreatment, the MMP group was assessed using quantitative indicators such as subjective pain levels, pain duration, graded chronic pain scale (GCPS), and perceived stress scale (PSS). Salivary alpha-amylase (sAA) and interleukin-6 (IL-6) levels were analyzed. The masticatory muscle palpation score and the range of mouth opening were measured. At posttreatment, subjective pain levels, mouth opening, and treatment/medication duration were examined. The PSS and sAA levels were assessed in the control group.

RESULTS

sAA levels in the MMP group were significantly higher than those in the control group (p < .05). The masseter muscle palpation score (MPS) showed a positive correlation with IL-6 levels (ρ = 0.503, p < .05) and a negative correlation with nonsteroidal anti-inflammatory drug (NSAID) treatment period (ρ = -0.462, p < .05). The temporalis muscle palpation score (TPS) was positively correlated with pain duration and GCPS grade (ρ = 0.483, p < .05, and ρ = 0.445, p < .05, respectively).

CONCLUSIONS

Treatment with NSAIDs was effective in the MMP group with high MPS and IL-6 levels, but not in the MMP group with high TPS, pain duration, and GCPS grade.

Perceived Stress and Prediction of Worse Disease Activity and Symptoms in a Multiracial, Multiethnic Systemic Lupus Erythematosus Cohort

OBJECTIVE

Studies have suggested a potential link between traumatic experiences, psychological stress, and autoimmunity, but the impact of stress on disease activity and symptom severity in systemic lupus erythematosus (SLE) remains unclear. The present study was undertaken to examine whether increases in perceived stress independently associate with worse SLE disease outcomes over 3 years of follow-up.

METHODS

Participants were drawn from the California Lupus Epidemiology Study (CLUES). Stress was measured annually using the 4-item Perceived Stress Scale (PSS). Participants with increases of ≥0.5 SD in PSS score were defined as having an increase in stress. Four outcomes were measured at the year 3 follow-up visit: physician-assessed disease activity (Systemic Lupus Erythematosus Disease Activity Index); patient-reported disease activity (Systemic Lupus Activity Questionnaire); pain (Patient-Reported Outcomes Measurement Information System [PROMIS] pain interference scale); and fatigue (PROMIS fatigue scale). Multivariable linear regression evaluated longitudinal associations of increase in stress with all 4 outcomes while controlling for potential confounders.

RESULTS

The sample (n = 260) was 91% female, 36% Asian, 30% White, 22% Hispanic, and 11% African American; the mean ± SD age was 46 ± 14 years. In adjusted longitudinal analyses, increase in stress was independently associated with greater physician-assessed disease activity (P = 0.015), greater self-reported disease activity (P < 0.001), more pain (P = 0.019), and more fatigue (P < 0.001).

CONCLUSION

In a racially diverse sample of individuals with SLE, those who experienced an increase in stress had significantly worse disease activity and greater symptom burden at follow-up compared to those with stress levels that remained stable or declined. Findings underscore the need for interventions to bolster stress resilience and support effective coping strategies among individuals living with lupus.

T2DM patients with depression have higher levels of hyperglycemia and cognitive decline than T2DM patients

The cognitive impairment, depression, a decrease in the ability to perform activities of daily living (ADLs), and salivary gland dysfunction, as indicated by the reduction of alpha-amylase activity, have been reported in patients with type 2 diabetes (T2DM). However, the effects of depression on cognitive function, salivary alpha-amylase activity, and ADLs in T2DM patients have never been investigated. In this study, 115 participants were divided into three groups, including 30 healthy people, 50 T2DM patients without depression, and 35 T2DM patients with depression. Then, the cognitive function, the level of depression, salivary-alpha amylase activity, ADLs, and metabolic parameters were determined. Results showed that T2DM patients had hyperglycemia and cognitive impairment. A decrease in the salivary alpha-amylase activity was observed in T2DM patients. Interestingly, T2DM patients with depression had higher level of hyperglycemia and cognitive impairment than T2DM patients. Additionally, cognitive function was associated with the salivary-alpha amylase activity in T2DM without depression, while the severity of depression was associated with the salivary-alpha amylase activity in T2DM patients with depression. Therefore, we concluded that T2DM caused the impairment of metabolism, decreased salivary alpha-amylase activity, and cognitive impairment. Furthermore, T2DM patients with depression had higher level of hyperglycemia and cognitive decline than T2DM patients.

The Relationship of Lifestyle with Disease Activity among Patients with Systemic Lupus Erythematosus: A Descriptive-Correlational Study

Objective:

The objective of this study was to evaluate the relationship of lifestyle with disease activity among patients with systemic lupus erythematosus.

Methods:

This cross-sectional descriptive-correlational study was conducted in 2019 on 209 patients with systemic lupus erythematosus. Data were collected using a demographic and clinical characteristics questionnaire, the Health-Promoting Lifestyle Profile II, and the systemic lupus erythematosus disease activity Index. The data were analysed through the mixed model and the logistic regression analyses.

Results:

In total, 67.5% of participants had active disease. The mean score of lifestyle was 2.49±0.30 and the lowest and the highest lifestyle dimensional mean scores were respectively related to the physical activity and the health responsibility dimensions (1.55±0.60 and 3.25±0.45). The analysis showed that each one point increase in the mean score of lifestyle was associated with 0.79 point decrease in the odds of disease activity (P = 0.006). Moreover, disease activity had significant positive relationship with body mass index (P = 0.015).

Conclusion:

Interventions for promoting lifestyle among these patients and improving healthcare providers’ knowledge about Systemic lupus erythematosus and lifestyle modification are recommended to reduce disease activity.

Salivary Markers of Stress in Grandparents Rearing Grandchildren in Rural Appalachia: The Role of Mental Health, Religiosity, and Social Support

This study examines changes in salivary cortisol and alpha-amylase among grandparents rearing grandchildren in rural Appalachia. Grandparent-caregivers experience greater stress than non-grandparent-caregivers. Participants included 20 grandparent-caregivers and a child for which they cared, who completed questionnaires assessing family functioning and mental health via interview. Grandparent-caregivers provided morning saliva samples once a year for two years. For grandparent-caregivers low in social support and religiosity, grandparent-caregiver depressive symptoms, child depressive symptoms, and child stress were associated with increased grandparent-caregiver salivary alpha-amylase. For grandparent-caregivers high in social support and religiosity, child depressive symptoms, child stress, and child aggression were associated with increased grandparent-caregiver cortisol.

Salivary Cytokines as Potential Diagnostic Biomarkers for Systemic Lupus Erythematosus Disease

Systemic lupus erythematosus (SLE) is a complex autoimmune inflammatory disease characterized by an unknown etiology and a highly variable clinical presentation. This clinical heterogeneity might be explained by dysregulation of tolerance to self and apoptotic mechanisms, overproduction of autoantibodies, and abnormal cytokine levels. Cytokine imbalance levels have been associated with disease activity and severity in SLE patients. In the last years, salivary cytokines related to SLE have gained significant attention and researchers have begun to focus on the identification of cytokines in the saliva of SLE patients using it as a diagnostic fluid for the inflammatory process underlying SLE. This review highlights and summarizes recent studies revealing the cytokines that have been identified in the saliva of individuals with SLE. Data reported and discussed in this report may provide useful additional information to better understand the mechanisms associated with the disease.

Association between depression and anxiety with skin and musculoskeletal clinical phenotypes in systemic lupus erythematosus

Objectives

To study the clinical phenotypes, determined based on cumulative disease activity manifestations, and sociodemographic factors associated with depression and anxiety in SLE.

Methods

Patients attending a single centre were assessed for depression and anxiety. SLE clinical phenotypes were based on the organ systems of cumulative 10-year SLE Disease Activity Index 2000 (SLEDAI-2K), prior to visit. Multivariable logistic regression analyses for depression, anxiety, and coexisting anxiety and depression were performed to study associated SLE clinical phenotypes and other factors.

Results

Among 341 patients, the prevalence of anxiety and depression was 34% and 27%, respectively, while 21% had coexisting anxiety and depression. Patients with skin involvement had significantly higher likelihood of anxiety compared with patients with no skin involvement [adjusted odds ratio (aOR) = 1.8; 95% CI: 1.1, 3.0]. Patients with skin involvement also had higher likelihood of having coexisting anxiety and depression (aOR = 2.0, 95% CI: 1.2, 3.9). Patients with musculoskeletal (MSK) (aOR = 1.9; 95% CI: 1.1, 3.5) and skin system (aOR = 1.8; 95% CI: 1.04, 3.2) involvement had higher likelihood of depression compared with patients without skin or musculoskeletal involvement. Employment status and fibromyalgia at the time of the visit, and inception status were significantly associated with anxiety, depression, and coexisting anxiety and depression, respectively.

Conclusion

SLE clinical phenotypes, specifically skin or MSK systems, along with fibromyalgia, employment and shorter disease duration were associated with anxiety or depression. Routine patient screening, especially among patients with shorter disease duration, for these associations may facilitate the diagnosis of these mental health disorders, and allow for more timely diagnosis.

Relationship of psychological factors with salivary flow rate and cortisol levels in individuals with oral lichen planus: A case-control study

OBJECTIVE

The objective of this study was to analyze the relationship between psychological factors and salivary flow rate and cortisol levels in individuals with oral lichen planus.

STUDY DESIGN

A case-control study of 21 individuals with clinical and histopathological diagnosis of oral lichen planus and 21 individuals without the disease (controls), matched by sex and age, was performed. The Beck Anxiety and Depression Inventories and Perceived Stress Scale were administered, and the salivary flow rate and salivary cortisol secretion pattern were determined. Data were statistically analyzed using Mann-Whitney U, McNemar's χ², and Student's t tests and the Spearman correlation coefficient. The significance level adopted was 5%.

RESULTS

Individuals with oral lichen planus had higher anxiety (P = .001), depression (P = .005), and perceived stress (P = .026) scores, but no association was found between the disease and salivary flow rate (P = .29) or with the pattern of salivary cortisol secretion (at awakening: P = .98; 30 min post-awakening: P = .95; at bedtime: P = .97).

CONCLUSION

An association was observed between oral lichen planus and anxiety, depression, and stress scores through psychological tests but not in relation to salivary flow rate and the pattern of salivary cortisol secretion.

Sjögren's syndrome and systemic lupus erythematosus: links and risks

Systemic lupus erythematosus (SLE) and Sjögren’s syndrome (SS) may coexist, and they are chronic complex disorders, with an autoimmune background, multifactorial etiology, multiple circulating autoantibodies, and variable prognosis. The prominent feature of SS is the impairment of the lacrimal and salivary glands leading to sicca symptoms. This disease may be classified as primary Sjögren’s syndrome (pSS), or secondary Sjögren’s syndrome (sSS) since it is often associated to other autoimmune disorders, principally SLE, rheumatoid arthritis, and systemic sclerosis. Systematic reviews and meta-analyses show an sSS prevalence in SLE patients of about 14%–17.8%. Herein, we updated important aspects of the clinical association between SLE and sSS through a narrative review of the PubMed database in the last 5 years (from July 2013 to October 2018) with the terms “Sjogren syndrome and systemic lupus erythematosus”. The following aspects are addressed: the classification criteria for sSS; differences and similarities between SLE and pSS regarding demographic, clinical, and serological characteristics (including new autoantibodies), as well as comorbidities; the etiopathogenic links between SLE and pSS (including genetic and environmental factors, B-cell activation, and autoantibodies); the predictive factors for sSS onset in SLE patients; the ocular and oral involvements due to sSS in SLE; and the main distinctive demographic, clinical, and serological features of SLE with and without associated SS.

Fatigue in systemic lupus: the role of disease activity and its correlates

OBJECTIVES

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that leads to a variety of negative health outcomes resulting from inflammation in various organ systems. Although treatment continues to advance, fatigue remains one of the most salient, poorly understood and addressed patient complaints. Understanding the mechanisms of fatigue can help guide the development of interventions to improve health outcomes. The aim of this research was to evaluate the contribution of six variables (disease activity, insomnia, depression, stress, pain and physical health) to fatigue in SLE without concomitant fibromyalgia (FM).

METHODS

A total of 116 ethnically diverse, primarily female participants (91%) with SLE, receiving care at university medical centers, completed assessments of disease activity and quality of life outcomes (FACIT-FT, Insomnia Severity Index, Perceived Stress Scale (PSS-4), Pain Inventory, Depression-PHQ-9, and LupusPRO-physical function). All patients met the American College of Rheumatology classification criteria for SLE and did not have a known diagnosis of FM. Multivariate linear and stepwise regression analyses were conducted with fatigue (FACIT-FT) as the dependent variable, and the above six variables as independent variables.

RESULTS

Mean (SD) age was 39.80 (13.87) years; 50% were African American, 21% Caucasian, 13% Hispanic, 9% Asian and 8% other. Mean (SD) FACIT-FT was 20.09 (12.76). Collectively, these six variables explained 57% of the variance in fatigue. In the multivariate model, depression, stress and pain were significantly and independently associated with fatigue, but not disease activity, sleep or physical health. Stress had the largest effect on fatigue (β 0.77, 95% CI 0.17-1.38, p = 0.01), followed by depression (β 0.66, 95% CI 0.21-1.10, p = 0.005). On stepwise regression analysis, only stress, depression and pain were retained in the model, and collectively explained 56% of the variance in fatigue. All three remained independent correlates of fatigue, with the largest contribution being stress (β 0.84, 95% CI 0.27-1.42, p = 0.005), followed by depression (β 0.79, 95% CI 0.44-1.14, p < 0.001) with fatigue.

CONCLUSION

Stress, depression and pain are the largest independent contributors to fatigue among patients with SLE, without concurrent FM. Disease activity, sleep and physical health were not associated with fatigue. The evaluation of stress, depression and pain needs to be incorporated during assessments and clinical trials of individuals with SLE, especially within fatigue. This stress-depression-fatigue model requires further validation in longitudinal studies and clinical trials. Significance and innovation: • Disease activity, sleep, pain, stress, depression, and physical health have been reported individually to be associated with fatigue in lupus. This analysis evaluated the role of each and all of these six variables collectively in fatigue among patients with SLE without a known diagnosis of FM. • Disease activity, sleep and physical health were not significantly related to fatigue, but depression, stress and pain were. • The results emphasize the need to evaluate and treat fatigue in individuals with SLE utilizing a biopsychosocial approach, particularly in the realm of clinical trials. Behavioral medicine interventions are shown to be most effective for the treatment of depression, stress and pain.

Analyses of hair and salivary cortisol for evaluating hypothalamic-pituitary-adrenal axis activation in patients with autoimmune disease

Although many studies have shown that patients with autoimmune disease present a hypoactive hypothalamic-pituitary-adrenal axis (HPA), controversial results have been described. Our objective was to study HPA axis activity in women with autoimmune disease compared to healthy women. Therefore, we analyzed salivary cortisol over the course of a day, and hair cortisol concentrations from the three preceding months, from 65 women divided into two groups: healthy women (n = 30), with a mean age of 44.70 ± 11.65 years; and women with autoimmune disease (n = 35), with a mean age of 48.26 ± 9.04 years. The latter group comprises women with systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), and systemic sclerosis (SSc). Perceived stress and psychopathological symptomatology were also evaluated. Autoimmune disease group scored higher on the somatization subscale SCL-90-R and lower on the anxiety subscale than the control group. Regarding HPA axis activation, the area under curve for cortisol levels during the day was higher for the autoimmune disease group. In addition, higher cortisol levels in hair were found in the group with autoimmune disease. Our findings show greater short and long-term HPA axis activity in women with autoimmune disease than in healthy women.

Oral mucosa biology and salivary biomarkers

Although the surfaces of both the skin and oral mucosa are protected by squamous epithelial cells and fall within the scope of dermatologic practice, the oral cavity contains highly specialized structures and functions distinct from other skin biology and pathologic conditions and are also the purview of clinicians who care for patients with skin and mucosal diseases. We describe the distinct features of the tongue, mucosa, and salivary glands. In particular, we examine the composition and function of the saliva, with special focus on salivary biomarkers. Within the oral cavity, saliva shows great promise as a noninvasive and sensitive marker for many systemic diseases. Biomarkers are being used as diagnostic or monitoring tools for a wide variety of diseases, including systemic lupus erythematosus, Sjögren disease, Behçet disease, and autoimmune blistering disorders, as well as premalignant and malignant lesions of the mouth.