Influence of environmental factors on disease activity in spondyloarthritis: a prospective cohort study

Exploring the Pathogenesis of Spondylarthritis beyond HLA-B27: A Descriptive Review

Spondylarthritis (SpA) is a chronic inflammatory condition that encompasses damage to the axial or peripheral skeleton, accompanied by specific extra-articular symptoms. Within this group, Ankylosing Spondylitis stands out as the hallmark member. Although the heritability of Ankylosing Spondylitis is estimated to be over 95%, only a portion of the heritability has been explained, with HLA-B27 accounting for 20.1% of it; therefore, ongoing research endeavors are currently concentrated on investigating the potential participation of different entities in the development of the disease. Genome-wide association studies have led to significant advances in our understanding of the genetics of SpA. In this descriptive review, we delve into the pathogenesis of Spondylarthritis beyond HLA-B27. We summarize the latest research on the potential participation of various entities in the development of the disease, including other genetic loci, immune dysregulation, microbiota, and environmental factors. The multifactorial nature of SpA and the complex interplay of genetic, immunological, and environmental factors are being increasingly recognized; therefore, it is of paramount importance to consider a holistic approach to comprehend the pathogenesis of SpA in order to identify novel therapeutic targets.

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity

BACKGROUND

Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs.

METHODS

IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies.

RESULTS

In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p < 0.001). Seropositivity rates were lowest in patients on anti-CD20 (40.0%) and anti-tumor necrosis factor (TNF) agents (60.5%), as compared to other ISPs (p < 0.001 and p < 0.001, respectively). Increased disease activity after infection was reported by 68 of 260 patients (26.2%; 95% CI 21.2-31.8%), leading to ISP intensification in 6 out of these 68 patients (8.8%).

CONCLUSION

IMID patients using ISPs showed reduced long-term humoral immune responses after primary SARS-CoV-2 infection, which was mainly attributed to treatment with anti-CD20 and anti-TNF agents. Increased disease activity after SARS-CoV-2 infection was reported commonly, but was mostly mild.

TRIAL REGISTRATION

NL74974.018.20, Trial ID: NL8900. Registered on 9 September 2020.

Association between air pollutants and initiation of biological therapy in patients with ankylosing spondylitis: a nationwide, population-based, nested case-control study

BACKGROUND

Outdoor air pollution has been found to trigger systemic inflammatory responses and aggravate the activity of certain rheumatic diseases. However, few studies have explored the influence of air pollution on the activity of ankylosing spondylitis (AS). As patients with active AS in Taiwan can be reimbursed through the National Health Insurance programme for biological therapy, we investigated the association between air pollutants and the initiation of reimbursed biologics for active AS.

METHODS

Since 2011, hourly concentrations of ambient air pollutants, including PM2.5, PM10, NO2, CO, SO2, and O3, have been estimated in Taiwan. Using Taiwanese National Health Insurance Research Database, we identified patients with newly diagnosed AS from 2003 to 2013. We selected 584 patients initiating biologics from 2012 to 2013 and 2336 gender-, age at biologic initiation-, year of AS diagnosis- and disease duration-matched controls. We examined the associations of biologics initiation with air pollutants exposure within 1 year prior to biologic use whilst adjusting for potential confounders, including disease duration, urbanisation level, monthly income, Charlson comorbidity index (CCI), uveitis, psoriasis and the use of medications for AS. Results are shown as adjusted odds ratio (aOR) with 95% confidence intervals (CIs).

RESULTS

The initiation of biologics was associated with exposure to CO (per 1 ppm) (aOR, 8.57; 95% CI, 2.02-36.32) and NO2 (per 10 ppb) (aOR, 0.23; 95% CI, 0.11-0.50). Other independent predictors included disease duration (incremental year, aOR, 8.95), CCI (aOR, 1.31), psoriasis (aOR, 25.19), use of non-steroidal anti-inflammatory drugs (aOR, 23.66), methotrexate use (aOR, 4.50; 95% CI, 2.93-7.00), sulfasalazine use (aOR, 12.16; 95% CI, 8.98-15.45) and prednisolone equivalent dosages (mg/day, aOR, 1.12).

CONCLUSIONS

This nationwide, population-based study revealed the initiation of reimbursed biologics was positively associated with CO levels, but negatively associated with NO₂ levels. Major limitations included lack of information on individual smoking status and multicollinearity amongst air pollutants.

Air pollution exposure and auto-inflammatory and autoimmune diseases of the musculoskeletal system: a review of epidemiologic and mechanistic evidence

Auto-inflammatory and autoimmune diseases of the musculoskeletal system can be perceived as a spectrum of rheumatic diseases, with the joints and connective tissues are eroded severely that progressively develop chronic inflammation and lesion. A wide range of risk factors represented by genetic and environmental factors have been uncovered by population-based surveys and experimental studies. Lately, the exposure to air pollution has been found to be potentially involved in the mechanisms of occurrence or development of such diseases, principally manifest in oxidative stress, local and systemic inflammation, and epigenetic modifications, as well as the mitochondrial dysfunction, which has been reported to participate in the intermediate links. The lungs might serve as a starting area of air pollutants, which would cause oxidative stress-induced bronchial-associated lymphoid tissue (iBALT) to further to influence T, B cells, and the secretion of pro-inflammatory cytokines. The binding of aromatic hydrocarbon receptor (AhR) to the corresponding contaminant ligands tends to regulate the reaction of Th17 and Tregs. Furthermore, air pollution components might spur on immune and inflammatory responses by damaging mitochondria that could interact with and exacerbate oxidative stress and pro-inflammatory cytokines. In this review, we focused on the association between air pollution and typical auto-inflammatory and autoimmune diseases of the musculoskeletal system, mainly including osteoarthritis (OA), rheumatoid arthritis (RA), spondyloarthritis (SpA) and juvenile idiopathic arthritis (JIA), and aim to collate the mechanisms involved and the potential channels. A complete summary and in-depth understanding of the autoimmune and inflammatory effects of air pollution exposure should hopefully contribute new perspectives on how to formulate better public health policies to alleviate the adverse health effects of air pollutants.

The Potential Role of Genetics, Environmental Factors, and Gut Dysbiosis in the Aberrant Non-Coding RNA Expression to Mediate Inflammation and Osteoclastogenic/Osteogenic Differentiation in Ankylosing Spondylitis

Ankylosing spondylitis (AS) or radiographic axial spondyloarthritis is a chronic immune-mediated rheumatic disorder characterized by the inflammation in the axial skeleton, peripheral joints, and soft tissues (enthesis, fascia, and ligament). In addition, the extra-skeletal complications including anterior uveitis, interstitial lung diseases and aortitis are found. The pathogenesis of AS implicates an intricate interaction among HLA (HLA-B27) and non-HLA loci [endoplasmic reticulum aminopeptidase 1 (ERAP1), and interleukin-23 receptor (IL23R), gut dysbiosis, immune plasticity, and numerous environmental factors (infections, heavy metals, stress, cigarette smoking, etc.) The latter multiple non-genetic factors may exert a powerful stress on epigenetic regulations. These epigenetic regulations of gene expression contain DNA methylation/demethylation, histone modifications and aberrant non-coding RNAs (ncRNAs) expression, leading to inflammation and immune dysfunctions. In the present review, we shall discuss these contributory factors that are involved in AS pathogenesis, especially the aberrant ncRNA expression and its effects on the proinflammatory cytokine productions (TNF-α, IL-17 and IL-23), T cell skewing to Th1/Th17, and osteoclastogenic/osteogenic differentiation. Finally, some potential investigatory approaches are raised for solving the puzzles in AS pathogenesis.

Abrupt and unexpected stressful life events are followed with increased disease activity in spondyloarthritis: A two years web-based cohort study

OBJECTIVE

The contribution of environmental factors to spondyloarthritis (SpA) course remains poorly characterized. We previously reported a possible triggering of disease flares by stressful life events and vaccination. The objective of the present study was to specify the types of vaccine and life event that may influence disease activity.

METHODS

A prospective cohort of adult SpA was followed for two years. Patients logged on to a secured website every month to complete a standardized auto-questionnaire. They reported whether they had been exposed to stressful life events, vaccinations or other environmental factors. Patients were asked to rate the distress resulting from exposure to life events on a numerical rating scale (NRS: 0-10). Primary outcome variable was the variation of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) measured on two consecutive connections. Months where an event occurred were compared to months without events. The cut-off value of 1 is defined as the minimal clinically important variation for the BASDAI.

RESULTS

The 272 enrolled SpA patients returned 3,388 questionnaires. Months where an abrupt and unexpected traumatic event occurred were associated with a significant increase of BASDAI of 0.57 [95%CI: 0.29; 0.85] (P<0.001). The higher the rating of distress, the larger the impact on BASDAI, reaching a clinically meaningful increase of 0.99 [0.17; 1.82] for a VNS≥9. The effect of stressful events on BASDAI persisted during a median of 3 months. No other environmental factor was significantly associated with BASDAI variations.

CONCLUSION

Among stressful life events, abrupt and unexpected events were associated with transient worsening of disease activity in SpA, which reached a clinically meaningful increase for the highest rating of distress. Association between vaccines and disease flare was not confirmed.

Post-Traumatic Stress Disorder and Risk for Incident Rheumatoid Arthritis

OBJECTIVE

To examine the association between symptoms of post-traumatic stress disorder (PTSD) and rheumatoid arthritis (RA) risk in a prospective cohort and to characterize the role of smoking in this relationship.

METHODS

A subset (n = 54,224) of the Nurses' Health Study II, a prospective cohort of female nurses, completed the Brief Trauma Questionnaire and a screen for PTSD symptoms. Participants were categorized based on trauma exposure and number of PTSD symptoms. Incident RA cases (n = 239) from 1989 to 2011 were identified. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) between PTSD symptoms and incident RA. To identify the impact of smoking, secondary and subgroup analyses were performed. In all analyses, PTSD and smoking were lagged 2 years before the development of RA.

RESULTS

Compared to no history of trauma/PTSD symptoms, the HR for ≥4 PTSD symptoms and incident RA was 1.76 (95% CI 1.16-2.67) in models adjusted for age, race, and socioeconomic status. The risk for RA increased with an increasing number of PTSD symptoms (P = 0.01). When smoking was added to the model, the HR for RA remained elevated (HR 1.60 [95% CI 1.05-2.43]). In a subgroup analysis, excluding women who smoked before PTSD onset, results were unchanged (HR 1.68 [95% CI 1.04-2.70]).

CONCLUSION

This study suggests that women with high PTSD symptomatology have an elevated risk for RA, independent of smoking, adding to emerging evidence that stress is an important determinant of physical health.

Ankylosing Spondylitis patients with Type D personality have worse clinical status

OBJECTIVES

Type D personality was identified as an important factor that can explain the differences in clinical outcomes in various diseases. The aim of this study is to clarify the relationships between Type D personality and clinical status of patients with Ankylosing Spondylitis (AS).

METHODS

The scores of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), the Bath Ankylosing Spondylitis Functional Index (BASFI), the 36-Item Short-Form Health Survey (SF-36), and 14-item Type D Scale (DS-14) were noted.

RESULTS

We found significantly higher levels of the BASDAI, the BASFI, and the SF-36 mental subscale scores in patients with Type D personalities compared to those who were Non-Type D (p < 0.05). The total DS-14 scores were found to be correlated with the scores of physical and mental subscales of SF-36, the BASDAI, the BASFI, ASDAS-CRP, and ESR (p < 0.05). In logistic regression analysis, the occurrence of Type D personality was found to be an independent predictor for disease activity of AS due to BASDAI and ASDAS-ESR (p = 0.016, OR, 95% CI = 2.98,1.23-7.22; p = 0.022, OR, 95% CI = 2.78,1.16-6.63 respectively).

CONCLUSIONS

Patients may over-rate self-reported measurements such as the BASDAI, BASFI, and SF-36 related to their interpersonal characteristics. Therefore, including the Type D personality, which is a stable construct in evaluating AS patients with brief and valid DS-14, may be noteworthy.

Quantitative Proteomic Analysis of Peripheral Blood Mononuclear Cells in Ankylosing Spondylitis by iTRAQ

This study was designed to identify and quantify the different proteins expression levels in ankylosing spondylitis (AS) and to explore the pathogenesis of AS. We performed isobaric tags for relative and absolute quantitation (iTRAQ) coupled with multiple chromatographic fractionation and tandem mass spectrometry to detect the proteins profiling in peripheral blood mononuclear cells (PBMCs) from AS patients and healthy controls. Mascot software and the International Protein Index and the Gene Ontology (GO) database were used to conduct the bioinformatics analysis. The differentially expressed proteins were validated by enzyme-linked immunosorbent assay (ELISA). A total of 1,232 proteins were identified by iTRAQ, of which 183 showed differential expression and 18 differentially expressed proteins were acute phase reactants. Upon mapping of the differentially expressed proteins to GO database, we found four differentially expressed proteins involved in the biological process of cell killing, including up-regulated cathepsin G (CTSG), neutrophil defensin3 (DEFA3), protein tyrosine phosphatase receptor type C (PTPRC), and down-regulated peroxiredoxin-1(PRDX1),which were consistent with the verified results of ELISA. Our proteomic analyses suggested that the proteins involved in the biological process of cell killing might play an important role in the pathogenesis of AS.

Nonpharmacologic therapies in spondyloarthritis

It is accepted that the optimal management of spondyloarthritis requires a combination of non-pharmacological and pharmacological interventions. Non-pharmacologic therapy in spondyloarthritis has generally focused on the exercise regimens whose purpose is to maintain mobility and strength, relieve symptoms, prevent or decrease spinal deformity, contribute to long-term cardiopulmonary health, and improve overall function and quality of life. Exercise programs such as home exercise, group exercise, inpatient programs, and spa exercise have all been the subject of multiple reports that are reviewed here. Studies reviewed support the use of exercise, spa therapy, manual therapy, and electrotherapeutic modalities. Additional topics that are finding relevance in spondyloarthritis are the behavioral interventions that maximize knowledge, motivation for compliance, and healthy lifestyle choices including smoking cessation, weight management, diet, and probiotics. However, the quality and generalizability of the studies are limited.

Hip replacement surgery in patients with ankylosing spondylitis

OBJECTIVES

Although TNF-α inhibitors' striking effect on clinical symptoms have revolutionised the treatment of ankylosing spondylitis (AS), no certain influence on the development of spinal ankylosis and joint destruction has been documented. We wished to investigate whether improved treatment has affected the use of hip arthroplasty surgery.

METHODS

Using the Norwegian Arthroplasty Register, we selected hip prosthesis procedures performed in patients with AS in 1988-2010 (n=534), and compared the trend in the number of procedures being performed annually in 1988-2002 versus 2003-2010. Patients with osteoarthritis (OA) (n=95094) were used as a control group.

RESULTS

The frequency of hip prosthesis surgery increased significantly in both groups up until 2002. In 2003-2010, although not statistically significant (p=0.087), there was a trend towards a reduced frequency in the AS group when compared with the expected continued increase as was seen among patients with OA. Mean age at surgery increased significantly (p<0.001) from 49.9 years to 56.4 years when comparing patients with AS up until and after 2002.

CONCLUSIONS

TNF-α inhibitors were introduced to patients with AS in Norway in 2000-2003, and our findings suggest that they may have altered the prognosis by inhibiting or slowing large joint arthritis and thus reducing the need for hip replacement surgery.