Tonsillectomy as a risk factor of periodontitis: a population-based cohort study

Association between Tonsillectomy and Cardiovascular Diseases in Adults

This study aimed to evaluate the association between tonsillectomy and cardiovascular diseases (CVDs) in the Korean adult population. Using data from the 2002-2015 Korean National Health Insurance Service-Health Screening Cohort, a total of 1082 participants aged 40 years or older who had undergone tonsillectomy were matched with 4328 control individuals for age, sex, income, and region of residence. We evaluated the incidence of CVDs in both the tonsillectomy and control groups and calculated the hazard ratios (HRs) of stroke, ischemic heart disease (IHD), and heart failure (HF) for participants who underwent tonsillectomy using a stratified Cox proportional hazard model. The incidence rates of stroke (81.3 vs. 46.6 per 10,000 person-years) and IHD (112.3 vs. 64.9 per 10,000 person-years) were significantly higher in patients who had undergone tonsillectomy than in the control group. After adjustment, the tonsillectomy group exhibited a 1.78-fold and 1.60-fold higher occurrence of stroke (CI = 1.32-2.42, p < 0.001) and IHD (CI = 1.24-2.08, p < 0.001), respectively, compared to the control group. However, there was no significant difference in the incidence rate of tonsillectomy and control groups (11.1 vs. 6.1 per 10,000 person-years). The HR of HF did not differ significantly between the tonsillectomy and control groups in the adjusted model (p = 0.513). We identified a significant relationship between a history of tonsillectomy and occurrence of stroke/IHD in the Korean adult population.

Association Between Maternal Mood Disorders and Schizophrenia and the Risk of Type 1 Diabetes in Offspring: A Nationwide Cohort Study

Objective

Our study aimed to determine whether mothers with bipolar disorder, major depressive disorder, schizophrenia, or schizoaffective disorder affected the risk of type 1 diabetes (T1D) in their offspring.

Methods

We conducted a nationwide cohort study by using data from Taiwan's National Health Insurance Research Database and the Maternal and Child Health Database from 2004 to 2018. A total of 2,556,640 mother-child pairs were identified. Cox proportional hazards models were used to compare the risk of T1D between children born to mothers with mood disorders and schizophrenia and those without.

Results

No significant difference in risk of T1D was observed between the offspring of mothers with major psychiatric disorders and those without (adjusted hazard ratio (aHR) of 0.86 with a 95% confidence interval (CI) of 0.58-1.24). In subgroup analysis, we found an aHR of 1.81 with a 95% CI of 0.83-3.82 in the maternal bipolar disorder on the risk of T1D in offspring and an aHR of 0.87 (95% CI: 0.59-1.25) in maternal major depressive disorder. In the schizophrenia/schizoaffective disorder group, aHR cannot be obtained due to lesser than three events in the analysis.

Conclusion

The risk of T1D in offspring of mothers with mood disorders and schizophrenia was not significant. However, children born to mothers with bipolar disorder may have a tendency to develop T1D. The relationship between maternal psychiatric disorders and the risk of T1D in offspring warrants further investigation in studies with longer follow-up periods.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2022 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertise in their subject areas that include (in order of the appearance in this report): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence the daily dental treatment decisions of the reader with an emphasis on innovations, new materials and processes, and future trends in dentistry. With the tremendous volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope that readers find this work helpful in managing patients.

Human Papillomavirus Infections and Increased Risk of Incident Osteoporosis: A Nationwide Population-Based Cohort Study

Patients with viral infections are susceptible to osteoporosis. This cohort study investigated the correlation between human papillomavirus (HPV) infections and the risk of osteoporosis via 12,936 patients with new-onset HPV infections and propensity score-matched non-HPV controls enrolled in Taiwan. The primary endpoint was incident osteoporosis following HPV infections. Cox proportional hazards regression analysis and the Kaplan-Meier method was used to determine the effect of HPV infections on the risk of osteoporosis. Patients with HPV infections presented with a significantly high risk of osteoporosis (adjusted hazard ratio, aHR = 1.32, 95% CI = 1.06-1.65) after adjusting for sex, age, comorbidities and co-medications. Subgroup analysis provided that populations at risk of HPV-associated osteoporosis were females (aHR = 1.33; 95% CI = 1.04-1.71), those aged between 60 and 80 years (aHR = 1.45, 95% CI = 1.01-2.08 for patients aged 60-70; aHR = 1.51; 95% CI = 1.07-2.12 for patients aged 70-80), and patients with long-term use of glucocorticoids (aHR = 2.17; 95% CI = 1.11-4.22). HPV-infected patients who did not receive treatments for HPV infections were at a greater risk (aHR = 1.40; 95% CI = 1.09-1.80) of osteoporosis, while the risk of osteoporosis in those who received treatments for HPV infections did not reach statistical significance (aHR = 1.14; 95% CI = 0.78-1.66). Patients with HPV infections presented with a high risk of subsequent osteoporosis. Treatments for HPV infections attenuated the risk of HPV-associated osteoporosis.

Onset of oral lichen planus following dental treatments: A nested case-control study

INTRODUCTION

The exposure to amalgam restorations has been reported to bring about altered immunity followed by inflammation and infection.

AIMS

This study aimed at identifying whether patients who received restorative or endodontic treatments, or tooth extraction, would have altered odds of developing oral lichen planus (OLP).

MATERIAL AND METHODS

In this population-based nested case-control study, 421 cases of OLP and 1,684 controls were included after propensity score matching. Logistic regression was used to estimate the adjusted odds ratio (aOR) of OLP in individuals who had received amalgam and composite resin restorations, root canal therapy, and tooth extraction over a follow-up duration of five years.

RESULTS

There were no significantly different odds of OLP for those who underwent either amalgam (aOR = 0.948, 95% CI = 0.853-1.053, p = 0.3170) or resin restorations (aOR = 1.007, 95% CI = 0.978-1.037, p = 0.6557) in both anterior and posterior teeth in an observational period of five  years after restorations. Root canal therapy was associated with significantly lower odds of OLP, with each additional root canal therapy attenuating the risk of OLP at an aOR of 0.771 (95% CI = 0.680-0.874, p = 0.0001) for both anterior (aOR = 0.786, 95% CI = 0.626-0.986, p = 0.0372) and posterior teeth (aOR = 0.762, 95% CI = 0.650-0.893, p = 0.0008). Likewise, each tooth extraction reduced the risk of OLP, with an aOR of 0.846 (95% CI = 0.772-0.927, p = 0.0003), especially for anterior teeth (aOR = 0.733, 95% CI = 0.595-0.904, p = 0.0037).

CONCLUSIONS

We reported no significant association between dental restorations and consequent OLP, and significantly lower odds of OLP following both root canal therapy and tooth extraction.

Awareness and Perceptions of the Impact of Tonsillectomy on the Level of Immunity and Autoimmune Diseases among the Adult Population in Abha City, Kingdom of Saudi Arabia

The widespread misconception that tonsillectomy leads to a decrease in immunity may lead to fear and avoidance of the operation. This can result in a deterioration of the situation, such as sleep-related breathing issues, frequent infections, and an increase in complications. The current research was conducted to assess the awareness and perception with respect to the impact of tonsillectomy on the immune system and to assess the awareness and perception of the relationship between autoimmune diseases and tonsillectomy. This 6-month descriptive cross-sectional online questionnaire survey was conducted among individuals who were 18 years and above living in Abha city, Saudi Arabia. Out of the 800 study subjects, 104 (13%) had undergone tonsillectomy. Statistically significant associations were found between age group, education, income, and occupation among those who had undergone tonsillectomy. Multivariate logistic regression analysis showed that ages 18-30 years and 31-40 years (OR: 2.36, 95% CI: 1.18-4.71, and OR: 1.46, 95% CI: 0.53-3.97) and education levels of high school, bachelors, and above (OR: 8.30, 95% CI: 3.05-22.58 and OR: 10.89, 95% CI: 4.23-28.05) were found to be associated with tonsillectomy status of the subjects. On the contrary, income levels of 5000-9000 and >9000 (OR: 0.65, 95% CI: 0.36-1.17 and OR: 0.78, 95%CI: 0.42-1.42) and male gender (OR: 0.79, 95% CI: 0.52-1.19) were found to be associated with non-tonsillectomy status of subjects. Almost 36% of study subjects thought that tonsillectomy affects immunity. Only 18% of study subjects thought that there is a relationship between tonsillectomy and autoimmune diseases. About one-third of the respondents had received this information from community members and social media. A small number of study subjects relied on public awareness programs. Therefore, social media can play a vital role in the community to remove misconceptions regarding tonsillectomy and its effect on immunity and autoimmune disease. Further educational interventional studies are required to see the correction to the public perception of tonsillectomy and its effect on immunity and autoimmune diseases.

Dental caries and risk of newly-onset systemic lupus erythematosus: a nationwide population-based cohort study

OBJECTIVE

This study investigated whether patients with history of dental caries are associated with an increased risk of newly-onset systemic lupus erythematosus (SLE).

METHODS

A total of 501,461 carious patients and 258,918 controls without carious teeth were enrolled between 1997 and 2013 from the National Health Insurance Research Database. Subgroup analyses were conducted based on restorative materials including amalgam, composite resins, or both. The cumulative incidence and hazard ratios (HRs) of SLE development were derived after adjusting for age, sex, socioeconomic status, income, insured classification, comorbidities, and frequency of dental visit in a multivariable model.

RESULTS

The risk of SLE was significantly higher in carious patients (HR = 1.98, 95% confidence interval [CI] = 1.65-2.38) compared to controls. Dose-dependent relationship between caries and risk of SLE was identified. The risk of SLE was higher among those who had dental visits ≧11 (HR = 2.53, 95% CI = 1.86-3.43), followed by those with 3-10 dental visits (HR = 1.86, 95% CI = 1.36-2.54), when compared to those with 1-2 visits, and was higher among those who had carious teeth extractions ≧5 (HR = 1.88, 95% CI = 1.19-2.97), followed by those with 1-4 carious teeth extractions (HR = 1.36, 95% CI = 1.17-1.59) than those without extraction. The risk of SLE for dental caries management among different restorative materials, including amalgam, composite resins, or both, was not statistically different.

CONCLUSIONS

Patients with dental caries were associated with higher SLE risks. The relationship between dental caries and risk of SLE was dose-dependent, regardless of the material used for the restoration.

Patients with obstructive sleep apnea are at great risk of flavor disorders: a 15-year population-based cohort study

OBJECTIVE

Obstructive sleep apnea (OSA) results from upper airway remodeling, which has been suggested to alter sensory and motor neuron function due to hypoxia or snore vibration. This study investigated whether OSA was associated with the risk of flavor disorder (FD).

MATERIALS AND METHODS

Seven thousand and eight hundred sixty-five patients with OSA and 7865 propensity score-matched controls without OSA were enrolled between 1999 and 2013 through a nationwide cohort study. The propensity score matching was based on age, sex, comorbidities including hypertension, hyperlipidemia, chronic obstructive pulmonary disease (COPD), asthma, ankylosing spondylitis, and Charlson comorbidity index, and co-medications during the study period, including statins and angiotensin-converting enzyme (ACE) inhibitors. The adjusted hazard ratio (aHR) of incident FD following OSA was derived using a Cox proportional hazard model. A log-rank test was used to evaluate the time-dependent effect of OSA on FD. Age, sex, comorbidities, and co-medications were stratified to identify subgroups susceptible to OSA-associated FD.

RESULTS

Patients with OSA were at a significantly great risk of FD (aHR = 1.91, 95% CI = 1.08-3.38), which was time-dependent (log-rank test p = 0.013). Likewise, patients with hyperlipidemia were at a significant great risk of FD (aHR = 2.99, 95% CI = 1.33-6.69). Subgroup analysis revealed that female patients with OSA were at higher risks of FD (aHR = 2.39, 95%CI = 1.05-5.47).

CONCLUSIONS

Patients with OSA were at significantly great risk of incident FD during the 15-year follow-up period, especially in female patients with OSA.

CLINICAL RELEVANCE

Timely interventions for OSA may prevent OSA-associated FD.

Risk of primary Sjogren's Syndrome following human papillomavirus infections: a nationwide population-based cohort study

Introduction

Viral infection is an exogeneous factor for primary Sjogren's syndrome (pSS). This study investigated the association between human papillomavirus (HPV) infections and pSS through a nationwide population based cohort study.

Methods

Patients with HPV infections between January, 1999 and December, 2013 were included. The incidence of new-onset pSS in patients with HPV infections and non-HPV controls were derived. The multiple Cox regression model derived the risk of pSS in patients with HPV infections. Subgroup analysis and sensitivity analysis were performed to validate the association.

Results

During a follow-up period of 12 years, the adjusted hazard ratio (aHR) of pSS in patients with HPV infections was significantly higher than that in non-HPV controls (aHR=1.64, 95% CI=1.47-1.83, P<0.001). The risk of pSS increased with age and the risk increased by 2.64-fold (95% CI= 2.37-2.93) for those older than 45 years. The significant association between HPV infections and the risk of pSS persisted in the sensitivity analysis restricted in HPV infections that lasted over 12 months (aHR=1.63, 95%CI=1.45-1.83, P<0.0001). Subgroup analyses revealed that both male (aHR=1.83, 95%CI=1.47-2.28, P<0.0001) and female (aHR=1.58, 95%CI=1.40-1.79, P<0.0001) patients with HPV infections and HPV-infected patients aged between 16 and 45 years (aHR=1.60, 95%CI=1.34-1.91, P<0.0001) and over 45 years (aHR=1.67, 95%CI=1.46-1.91, P<0.0001) were associated with a significantly greater risk of pSS.

Conclusion

Patients with HPV infections presented with a significantly higher risk of pSS, regardless of age and sex.

Bidirectional Relationship Between Osteoarthritis and Periodontitis: A Population-Based Cohort Study Over a 15-year Follow-Up

Objective

To identify the relationship between osteoarthritis and periodontitis.

Methods

144,788 periodontitis patients and 144,788 propensity score-matched controls without history of periodontitis were enrolled in this cohort study. A Cox proportional hazard model was used to estimate the risk of osteoarthritis. Survival analysis was utilized to assess the time-dependent effect of periodontitis on osteoarthritis. Age and gender were stratified to identify subgroups at risk. A symmetrical case-control analysis was designed to determine the relationship between present periodontitis and history of osteoarthritis.

Results

Patients with periodontitis had higher risk of osteoarthritis (hazard ratio, HR =1.15, 95% CI =1.12-1.17, p < 0.001) and severe osteoarthritis that led to total knee replacement or total hip replacement (TKR/THR) (HR =1.12, 95% CI =1.03-1.21, p < 0.01) than controls, which was time-dependent (log-rank test p < 0.01). The effect of periodontitis on osteoarthritis was significant in both genders and age subgroups over 30 years-old (all p < 0.001). Among them, females (HR=1.27, 95% CI = 1.13-1.42, p < 0.001) and patients aged over 51 (HR= 1.21, 95% CI =1.10-1.33, p < 0.001) with periodontitis were predisposed to severe osteoarthritis. In addition, periodontitis patients were more likely to have a history of osteoarthritis (odds ratio = 1.11, 95% CI = 1.06 - 1.17, p < 0.001).

Conclusions

These findings suggest an association between periodontitis and a higher risk of osteoarthritis, including severe osteoarthritis that led to TKR/THR. Likewise, periodontitis is more likely to develop following osteoarthritis. A bidirectional relationship between osteoarthritis and periodontitis was observed.

Nutritional support for successful weaning in patients undergoing prolonged mechanical ventilation

Successful weaning from ventilators not only improves the quality of life of patients, but also reduces medical expenses. The aim of this study was to explore the association between nutritional provision and successful ventilator weaning. In this retrospective study data from the Respiratory Care Center of Chung Shan Medical University Hospital between October, 2017 and July, 2019 on patient characteristics, amount of nutrition delivered, and clinical outcomes were retrieved. A total of 280 ventilated patients were enrolled and divided into successful extubation and failed weaning groups. There were 178 males (63.6%) and 102 females (36.4%) with a mean age of 67.3 ± 16.9 years. The successful extubation group consisted of patients who tended towards ideal body weight during the weaning process (BMI 23.9 ± 5.0 versus 22.7 ± 4.8 kg/m², p < 0.001). Patients from both groups initially received the same nutritional intervention, while patients of successful extubation received significantly more calories and protein after weaning (23.8 ± 7.8 kcal versus 27.8 ± 9.1 kcal, p < 0.001 and 0.97 ± 0.36 g versus 1.14 ± 0.42 g, p < 0.001). Successful weaning was associated with higher survival rate (p = 0.016), shortened hospital stay (p = 0.001), and reduced medical costs (p < 0.001). Overall, nutritional support with high calories and protein was associated with the probability of successful ventilator weaning in patients undergoing prolonged mechanical ventilation. Adequate nutrition is a determinant of successful ventilator weaning.

Risk of Autoimmune Diseases Following Optic Neuritis: A Nationwide Population-Based Cohort Study

Objectives

Optic neuritis is (ON) is believed to be an immune-mediated disease; however, the association between optic neuritis and autoimmune diseases remains unclear. This study aimed to identify the incidence rate and adjusted hazard ratio (aHR) of autoimmune diseases in patients with optic neuritis.

Methods

This nationwide, population-based, retrospective cohort study collected patients’ data between 1999 and 2013 from the National Health Insurance Research Database in Taiwan. A total of 9,235 patients were included. Using 1:4 propensity scoring, 1,847 patients were enrolled in the optic neuritis group and 7,388 in the non-optic neuritis group according to age, sex, comorbidities, and corticosteroid use. Follow-up was started from the index date and the endpoint was a diagnosis of new-onset autoimmune diseases including, myasthenia gravis (MG), psoriatic arthritis (PsA), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and ankylosing spondylitis (AS).

Results

The Kaplan-Meier curves depicted that patients with optic neuritis had a higher cumulative incidence of autoimmune diseases than patients without optic neuritis. Cox proportional hazard regression showed that patients with optic neuritis were at a high risk of autoimmune diseases (aHR: 1.40; 95% C.I., 1.05–1.87), including MG (aHR: 4.16, 95% C.I.: 1.33–12.94), SLE (aHR: 3.33, 95% C.I.: 1.24–8.97), and AS (aHR: 2.86, 95% C.I.: 1.54–5.31). Subgroup analysis provided that patients with optic neuritis aged below 65 years (aHR: 1.42, 95% C.I.: 1.03–1.96) or who were females (aHR: 1.59, 95% C.I.: 1.11–2.27) had a significantly increased risk of autoimmune diseases compared to respective controls. The use of corticosteroids reduced the risk of autoimmune diseases in patients with optic neuritis (aHR for corticosteroids non-users: 1.46, 95% C.I.: 1.03–2.07).

Conclusion

Patients with optic neuritis presented with a high risk of autoimmune diseases such as MG, SLE, and AS, especially patients with optic neuritis who were young or females. Corticosteroids attenuated the link between optic neuritis and subsequent autoimmune diseases.

Human Papillomavirus Infection and the Risk of Erectile Dysfunction: A Nationwide Population-Based Matched Cohort Study

BACKGROUND

Male patients with genital warts are known for higher rates of sexual dysfunction. This study was conducted to investigate whether human papillomaviruses (HPV) infection is associated with an increased risk of erectile dysfunction (ED).

METHODS

Patients aged over 18 with HPV infection (n = 13,296) and propensity score-matched controls (n = 53,184) were recruited from the Longitudinal Health Insurance Database (LHID). The primary endpoint was the diagnosis of ED. Chi-square tests were used to analyze the distribution of demographic characteristics. The Cox proportional hazards regression was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the development of ED in both groups, after adjusting for sex, age, relevant comorbidities, co-medication, and surgery.

RESULTS

ED developed in 181 patients of the study group. The incidence density of ED was 2.53 per 1000 person-years for the HPV group and 1.51 per 1000 person-years for the non-HPV group, with an adjusted HR (95% CI) of 1.63 (1.37-1.94). In stratification analysis, adjusted HR of diabetes-, chronic obstructive pulmonary disease (COPD-), and stroke-subgroup were 2.39, 2.51, and 4.82, with significant p values for interaction, respectively. Sensitivity analysis yields consistent findings.

CONCLUSIONS

The patients with HPV infection had a higher risk of subsequent ED in comparison to the non-HPV controls. The mechanism behind such association and its possible role in ED prevention deserves further study in the future.

Age-dependent oral manifestations of neurofibromatosis type 1: a case-control study

INTRODUCTION

Most craniofacial manifestations of neurofibromatosis type 1 (NF1) are considered as a result of tumor compression. We sought to determine salivary changes, caries, and periodontal complications in NF1 patients without tumors in the oral cavity.

OBJECTIVE AND METHODS

Eleven NF1 patients without tumors in the oral cavity and 29 matched controls without NF1 were enrolled in this case-control study. Demographic information, medical history, and data of intraoral examinations, including the Decayed, Missing, and Filled Teeth (DMFT) scores and Russel's periodontal index (PI), were recorded. The functional salivary analysis was performed for sialometry, salivary pH values, and amylase activity. Ingenuity Systems Pathway Analysis (IPA) was conducted to identify mutually activated pathways for NF1-associated oral complications.

RESULTS

NF1 patients were associated with periodontitis (OR = 1.40, 95% CI = 1.06-1.73, P = 0.04), gingivitis (OR = 1.55, 95% CI = 1.09-2.01, P = 0.0002), and decreased salivary flow rates (OR = 1.40, 95% CI = 1.05-1.76, P = 0.005). Periodontal destruction, salivary changes, and dental caries in NF1 patients were age-dependent. Subgroup analyses based on age stratification suggested that salivary flow rates and salivary amylase activities were significantly low in NF1 patients aged over 20 years and that salivary pH values, PI and DMFT scores were significantly high among NF1- controls aged over 20. All oral complications were not significantly presented in NF1 patients aged below 20 years. IPA analyses suggested that cellular mechanisms underlying NF1-associated oral complications involved chronic inflammatory pathways and fibrosis signaling pathway.

CONCLUSION

NF1 patients without tumors in the oral cavity presented a comparatively high prevalence of age-dependent oral complications, including periodontal destruction and salivary gland dysfunction, which were associated with chronic inflammatory pathogenesis.

Exposure to environmental air pollutants as a risk factor for primary Sjögren's syndrome

Background

Environmental etiology of primary Sjögren's syndrome (pSS), an autoimmune disease, has been proposed. This study determined whether the exposure to air pollutants was an independent risk factor for pSS.

Methods

Participants were enrolled from a population-based cohort registry. Daily average concentrations of air pollutants from 2000 to 2011 were divided into 4 quartiles. Adjusted hazard ratios (aHRs) of pSS for exposure to air pollutants were estimated in a Cox proportional regression model adjusting for age, sex, socioeconomic status, and residential areas. A subgroup analysis stratified by sex was conducted to validate the findings. Windows of susceptibility indicated years of exposure which contributed the most to the observed association. Ingenuity Pathway Analysis was used to identify underlying pathways of air pollutant-associated pSS pathogenesis, using Z-score visualization.

Results

Two hundred patients among 177,307 participants developed pSS, with a mean age of 53.1 years at acumulative incidence of 0.11% from 2000 to 2011. Exposure to carbon monoxide (CO), nitric oxide (NO), and methane (CH4) was associated with a higher risk of pSS. Compared to those exposed to the lowest concentration level, the aHRs for pSS were 2.04 (95%CI=1.29-3.25), 1.86 (95%CI=1.22-2.85), and 2.21 (95%CI=1.47-3.31) for those exposed to high levels of CO, NO, and CH4, respectively. The findings persisted in the subgroup analysis, in which females exposed to high levels of CO, NO, and CH4 and males exposed to high levels of CO were associated with significantly great risk of pSS. The cumulative effect of air pollution on pSS was time-dependent. The underlying cellular mechanisms involved chronic inflammatory pathways including the interleukin-6 signaling pathway.

Conclusion

Exposure to CO, NO, and CH4 was associated with a high risk of pSS, which was biologically plausible.