Comparative Analysis of Single-Cell RNA Sequencing Methods with and without Sample Multiplexing.

Single-cell RNA sequencing (scRNA-seq) has emerged as a powerful technique for investigating biological heterogeneity at the single-cell level in human systems and model organisms. Recent advances in scRNA-seq have enabled the pooling of cells from multiple samples into single libraries, thereby increasing sample throughput while reducing technical batch effects, library preparation time, and the overall cost. However, a comparative analysis of scRNA-seq methods with and without sample multiplexing is lacking. In this study, we benchmarked methods from two representative platforms: Parse Biosciences (Parse; with sample multiplexing) and 10x Genomics (10x; without sample multiplexing). By using peripheral blood mononuclear cells (PBMCs) obtained from two healthy individuals, we demonstrate that demultiplexed scRNA-seq data obtained from Parse showed similar cell type frequencies compared to 10x data where samples were not multiplexed. Despite relatively lower cell capture affecting library preparation, Parse can detect rare cell types (e.g., plasmablasts and dendritic cells) which is likely due to its relatively higher sensitivity in gene detection. Moreover, a comparative analysis of transcript quantification between the two platforms revealed platform-specific distributions of gene length and GC content. These results offer guidance for researchers in designing high-throughput scRNA-seq studies.

Gut microbiome profiling in systemic sclerosis: a metagenomic approach.

OBJECTIVES: The early gastrointestinal (GI) manifestation of systemic sclerosis (SSc) suggests a possible GI microbiota engagement in the pathophysiology and/or progression of SSc. Previous studies have revealed dysbiosis among Caucasian SSc patients. This study extends these findings to Asian SSc patients. METHODS: Adult SSc patients, stratified according to 1) on immunosuppressive (On-IS) drugs or 2) no immunosuppressive drugs (No-IS), and age-and-sex-matched healthy controls (HC) were recruited. Metagenomic sequencing of stool DNA was compared between SSc patients and HC, and between SSc (On-IS) and (No-IS) patients. Alpha and beta-diversity, taxonomic and functional profiling were evaluated. RESULTS: Twenty-three female SSc patients (12 On-IS; 11 No-IS; 5 diffuse and 18 limited SSc subtype) and 19 female HC, with median age of 54 years and 56 years, respectively, were recruited. Median SSc disease duration was 3.3 years. Alpha diversity was significantly higher in SSc versus HC (p=0.014) and in SSc (No-IS) versus HC (p=0.006). There was no significant difference in beta diversity between SSc and HC (p=0.307). At the phyla level, there were significantly increased abundance of Firmicutes and Actinobacteria in SSc versus HC, and reduced abundance of Bacteroidetes (all p<0.001). At the species level, there were significantly increased abundance of several Lactobacillus, Bifidobacterium, and Coprococcus species in SSc, and increased abundance of Odoribacter, Bacteroides and Prevotella species in HC. KEGG pathway analysis demonstrated distinct differences between SSc versus HC, and between SSc (No-IS) and SSc (On-IS). CONCLUSIONS: Using metagenomic sequencing, our study further underlines distinct alterations in microbiota profiling among Asian SSc patients.

Improvements in work productivity among patients with inflammatory arthritis and osteoarthritis in the first six months after diagnosis: an inception cohort study.

OBJECTIVES: Reduced work productivity (WP), measured by work productivity loss (WPL) and work disability (WD), is common in patients with inflammatory arthritis (IA) and osteoarthritis (OA) but is not well characterised. We aimed to assess if there were any improvements in WP (WPL and WD) from diagnosis (T1) to six months later (T2) and to explore associations between WP at T2 and health status at T1 among these patients. METHODS: Patients were surveyed for work characteristics, work ability, WP and health status including physical functioning and vitality at T1 and T2. Associations between WP at T2 and health status at T1 were explored using regression models. RESULTS: Patients with IA (n=109) were younger than those with OA (n=70) (mean age: 50.5 vs. 57.7 years). The median WPL score decreased from 30.0 to 10.0 in patients with IA and from 20.0 to 0.0 in patients with OA, while the proportion reporting WD decreased from 52.3% to 45.3% in patients with IA and increased from 52.2% to 56.5% in patients with OA from T1 to T2. Physical functioning at T1 (coefficient = -0.35) was significantly associated with WPL at T2. Vitality at T1 (coefficient = 0.03) was associated with WD at T2. CONCLUSIONS: Greater improvements in WP were observed among patients with IA than those with OA in the first six months after diagnosis. This provides a basis for healthcare professionals to aim for greater improvements in work and health status for patients with IA.

The Pathogenesis of Systemic Sclerosis: The Origin of Fibrosis and Interlink with Vasculopathy and Autoimmunity.

Systemic sclerosis (SSc) is an autoimmune disease associated with increased mortality and poor morbidity, impairing the quality of life in patients. Whilst we know that SSc affects multiple organs via vasculopathy, inflammation, and fibrosis, its exact pathophysiology remains elusive. Microvascular injury and vasculopathy are the initial pathological features of the disease. Clinically, the vasculopathy in SSc is manifested as Raynaud's phenomenon (reversible vasospasm in reaction to the cold or emotional stress) and digital ulcers due to ischemic injury. There are several reports that medications for vasculopathy, such as bosentan and soluble guanylate cyclase (sGC) modulators, improve not only vasculopathy but also dermal fibrosis, suggesting that vasculopathy is important in SSc. Although vasculopathy is an important initial step of the pathogenesis for SSc, it is still unclear how vasculopathy is related to inflammation and fibrosis. In this review, we focused on the clinical evidence for vasculopathy, the major cellular players for the pathogenesis, including pericytes, adipocytes, endothelial cells (ECs), and myofibroblasts, and their signaling pathway to elucidate the relationship among vasculopathy, inflammation, and fibrosis in SSc.

Improving sensitivity of the connective tissue disease screening questionnaire: A comparative study of various scoring methods.

OBJECTIVES: Early detection of autoimmune rheumatic diseases is crucial given their high morbidity and mortality and short window of opportunity to improve patient outcomes. Self-administered screening questionnaires such as the connective tissue disease screening questionnaire (CSQ) have been shown to promote early detection of autoimmune rheumatic diseases. However, optimal scoring of screening questionnaires may differ with prevalence of clinical features and changes in classification criteria. We compared the performance of 3 scoring methods for the CSQ for early detection of autoimmune rheumatic diseases in a multi-ethnic Asian population. METHODS: Patients who were newly referred for evaluation of possible autoimmune rheumatic diseases were invited to answer the cross-culturally adapted CSQ. Detection of autoimmune rheumatic diseases using 1) the original CSQ scoring, 2) a modified CSQ scoring and 3) a scoring based on current classification criteria, were compared to classification of autoimmune rheumatic diseases by classification criteria. RESULTS: Of 819 participants, 85 were classified as having autoimmune rheumatic diseases screened for by the adapted CSQ. The original CSQ scoring yielded relatively lower sensitivities in detecting both any and individual autoimmune rheumatic diseases (67% and 20-57%, respectively) compared to the modified CSQ scoring (81% and 60-73%, respectively) and the scoring based on current classification criteria (89% and 50-88%, respectively). CONCLUSION: The adapted CSQ with the classification criteria-based scoring achieved relatively high sensitivities in detecting autoimmune rheumatic diseases, suggesting this could be employed as the first step in population screening.

Comparison of the Charlson Comorbidity Index derived from self-report and medical record review in Asian patients with rheumatic diseases.

The aim of the study was to compare the agreement between self-report Charlson Comorbidity Index (SR-CCI) and the medical record-based CCI (MR-CCI) and to examine the impact of both instruments on health-related quality of life (HRQoL) amongst Asian patients with rheumatic diseases. This cross-sectional study surveyed a convenience sample of patients seen at rheumatology specialty outpatient clinics. Patients completed the SR-CCI and Short Form 36, while two research assistants completed the MR-CCI. Item-level agreement between the SR-CCI and MR-CCI was evaluated using kappa coefficients. Adjusted linear regression models evaluated the independent effect of the SR-CCI/MR-CCI on HRQoL. The study included 301 patients (median age 51, range 21-79, 61.5 % female, 68.8 % Chinese, 17.6 % Indian, 6.0 % Malay). Kappa statistics for cerebrovascular disease (0.433), chronic pulmonary disease (0.509), connective tissue disease/rheumatoid arthritis (0.506), ulcer disease (0.461), and tumour (0.541) reflected moderate agreement between the SR-CCI and MR-CCI (all p < 0.0001). There was substantial agreement in the reporting of diabetes (0.764, p < 0.0001) but poor/fair agreement for that of myocardial infarction (0.359, p < 0.0001) and diabetes with end-organ damage (0.189, p = 0.0002). Increases in SR-CCI were associated with significant reductions in both physical (ß coefficient -2.56, p < 0.0001) and mental HRQoL (ß coefficient -1.24, p = 0.044). However, such associations were not observed with the MR-CCI. The SR-CCI demonstrated moderate concordance with the MR-CCI, and the SR-CCI but not MR-CCI scores were associated with lower HRQoL. Assessment of comorbidities amongst rheumatology patients remains complex, and more efficient methods of quantifying these conditions are needed for clinical and research purposes.

Advances in biological and targeted therapies for systemic sclerosis.

INTRODUCTION: Systemic sclerosis (SSc) is a severe, and often life-threatening, autoimmune disease, which causes inflammation and fibrosis of the skin and internal organs. There are currently limited effective therapeutic options for patients with SSc. There are recently completed and ongoing phase 2 and 3 studies looking at biologic therapies for SSc that target the underlying pathogenesis of the disease. AREAS COVERED: The purpose of this review is to describe completed and ongoing trials of different biologic therapies for the treatment of SSc. This review discusses biologic therapy directed at multiple pathways that are believed to contribute to inflammation and fibrosis in SSc including T cell, B cell, direct cytokines, and JAK signaling. Data presented is based on authors' expertise of completed and ongoing trials. EXPERT OPINION: Tocilizumab and rituximab have supporting data to advocate for use in early SSc. Data from tocilizumab showed preservation of forced vital capacity (FVC) and beneficial effects on global composite measure. Recent data from different trials with rituximab in SSc (with and without interstitial lung disease) show beneficial effects on skin and FVC with good tolerability. We highlight the molecular heterogeneity in early SSc phenotype and the need to account for this in future trials.

Systemic sclerosis in Asians: Are there racial differences?

Systemic sclerosis is a multisystemic autoimmune disease characterized by vasculopathy and fibrosis. Racial factors exert a significant influence on the epidemiology, clinical manifestations, antibody profile, mortality and genetic factors in systemic sclerosis. In this review, we examined Asian systemic sclerosis cohorts reported in Asia and multi-racial cohort studies to evaluate the disease characteristics and outcomes of systemic sclerosis in Asians. Asian patients have distinct genetic susceptibility to systemic sclerosis, younger age of systemic sclerosis onset, higher frequency of diffuse skin involvement, different autoantibody profiles such as higher frequency of anti-Scl70 and anti-U1-RNP antibodies, and more severe clinical phenotype. There was a suggestion of poorer survival among Asians that may be contributed by more severe disease, socioeconomic factors and differences in healthcare systems. Recognizing the influence of racial differences in systemic sclerosis disease course is important as it has implications for appropriate treatment, monitoring and prognostication.

Toward Molecular Stratification and Precision Medicine in Systemic Sclerosis.

Systemic sclerosis (SSc), a complex multi-systemic disease characterized by immune dysregulation, vasculopathy and fibrosis, is associated with high mortality. Its pathogenesis is only partially understood. The heterogenous pathological processes that define SSc and its stages present a challenge to targeting appropriate treatment, with differing treatment outcomes of SSc patients despite similar initial clinical presentations. Timing of the appropriate treatments targeted at the underlying disease process is critical. For example, immunomodulatory treatments may be used for patients in a predominantly inflammatory phase, anti-fibrotic treatments for those in the fibrotic phase, or combination therapies for those in the fibro-inflammatory phase. In advancing personalized care through precision medicine, groups of patients with similar disease characteristics and shared pathological processes may be identified through molecular stratification. This would improve current clinical sub-setting systems and guide personalization of therapies. In this review, we will provide updates in SSc clinical and molecular stratification in relation to patient outcomes and treatment responses. Promises of molecular stratification through advances in high-dimensional tools, including omic-based stratification (transcriptomics, genomics, epigenomics, proteomics, cytomics, microbiomics) and machine learning will be discussed. Innovative and more granular stratification systems that integrate molecular characteristics to clinical phenotypes would potentially improve therapeutic approaches through personalized medicine and lead to better patient outcomes.

Patient and learner experience in a new set up of a multidisciplinary dermatology-rheumatology clinic care model for psoriatic arthritis.

OBJECTIVES: We described the set-up of a new multidisciplinary psoriatic arthritis-psoriasis (PsA-PsO) clinic incorporating service, education, and research between rheumatologists and dermatologists for PsA. We describe the patients' and learners' experience of this shared-care model. METHODS: A PsA-PsO clinic was newly set up in 2019. Each patient was first seen by a trainee, followed by both a dermatologist and a rheumatologist simultaneously in the same consultation room. We collected patients' and learners' experience through self-administered surveys. RESULTS: From May 2019 to January 2020, we collected data from 44 visits (55% new referrals, 45% follow up) from 30 patients: 22.7% were referred for diagnostic doubts, 77.3% were for therapeutic issues. Eight of the 10 patients referred for diagnosis had PsA confirmed. Medication changes occurred in 63.6% of visits; 63.6% of patients continued follow up in the PsA-PsO clinic, and 36.4% were discharged back to the original respective care. The median (interquartile range) rating of patient satisfaction of the care was 8 (7-8) out of 10; 96.1% of patients would "probably" or "definitely recommend" the care to others. From 20 learners, 95% reported the experience as "extremely" or "very" beneficial to training. The PsA-PsO clinic was suspended during the COVID-19 pandemic from February 2020 because of lack of available staff. The service was resumed gradually from May 2021. CONCLUSION: Despite challenges, we report the set-up of a new care model between dermatologists and rheumatologists for care of patients with psoriatic disease. The care model was well received by patients. Learners from various levels reported benefit from the learning experience.

Early identification of axial spondyloarthritis in a multi-ethnic Asian population.

INTRODUCTION/OBJECTIVES: To address the diagnostic delay in axial spondyloarthritis (axSpA), we have cross-culturally adapted the Hamilton axSpA questionnaire, a self-administered screening questionnaire, in the Singapore population. In this study, we compared the performance of various scoring methods for this questionnaire in detecting axSpA. METHOD: The questionnaire was self-administered by eligible subjects. Scoring methods included method A, the original questionnaire scoring, and methods B-E, scoring developed based on the Assessment of SpondyloArthritis International Society (ASAS) criteria for inflammatory back pain (IBP) and the referral, classification and both referral and classification of axSpA, respectively. The reference standard was diagnosis by a rheumatologist. Since the ASAS criteria-based scoring methods were mainly based on clinical axSpA features, self-report and rheumatologist-assessment of clinical axSpA features were also compared in subjects with axSpA. RESULTS: Of 1418 subjects (age: 54 ± 14 years, female: 73%) recruited, 46 were diagnosed with axSpA by a rheumatologist. Sensitivities of methods A-E were 35%, 61%, 63%, 48% and 83%, respectively. Self-report of clinical axSpA features exceeded rheumatologist-assessment for arthritis (83 vs 26%), good response to NSAIDs (37 vs 30%), enthesitis (35 vs 30%), dactylitis (20 vs 2%) and family history for axSpA (13 vs 4%). The reverse was true for IBP (41 vs 63%) and uveitis (4 vs 15%). CONCLUSIONS: A self-administered questionnaire using the ASAS referral and classification criteria-based scoring yielded relatively high sensitivity in detecting axSpA in subjects newly referred to rheumatology clinics. This supports its evaluation as a screening and referral tool in the general population in future studies. Key Points • A self-administered questionnaire could be used as a screening and referral tool. • ASAS referral and classification criteria-based scoring yielded relatively high sensitivity. • Inaccurate perception of clinical axSpA features was observed in axSpA patients.

The microbiome and systemic sclerosis: A review of current evidence.

Systemic sclerosis (SSc) is characterized by immune dysregulation, vasculopathy, and fibrosis of multiple organs. The gastrointestinal (GI) tract is the most common internal organ manifestation, which contributes to significant morbidity and mortality in patients with SSc. Emerging reports have identified unique microbial taxa alterations in the GI microbiome of patients with SSc as compared to healthy controls (HC). These taxa alterations include differences at the phyla (e.g., Bacteroidetes) and genera (e.g., Bacteroides, Clostridium, Faecalibacterium, and Lactobacillus) level. In addition, some genera have been associated with more severe GI symptoms (e.g., Prevotella and Akkermansia). This review summarizes the current evidence on factors influencing the GI microbiome, GI microbiome alterations in SSc as compared to HC, and in SSc subgroups according to disease manifestations. Current exploration in therapeutic interventions that target the GI microbiome is discussed.

Microbiome and osteoarthritis: New insights from animal and human studies.

Osteoarthritis (OA) is a common cause of disability, especially among the elderly. With an ageing and increasingly obese population, OA will become more prevalent. Obesity and metabolic syndrome are risk factors for OA and have been implicated in its pathogenesis. The gut microbiome may shed light on this possible common pathogenesis. Recent animal and human studies have gained important insights into the relationship between OA, obesity, and the gut microbiome. Animal studies have demonstrated links between obesity and increased severity of OA and altered gut microbial DNA profile. Use of prebiotics and probiotics in animal trials provides proof-of-concept that interventional options to the gut microbiome can modulate the progression of OA favorably. Current evidence in human studies is limited. Shifts in gut microbial profile and reduced gut microbial diversity have been associated with people with OA, as well as blood and synovial fluid lipopolysaccharide endotoxemia. Linkages between microbiome dysbiosis and host responses may help in the understanding of OA pathogenesis and the discovery of therapeutic targets. This narrative review provides a summary of up-to-date animal and human studies on the gut microbiome and its link with OA.

Interval between symptom onset and diagnosis among patients with autoimmune rheumatic diseases in a multi-ethnic Asian population.

AIM: The interval between symptom onset and diagnosis (pre-diagnosis interval) can at times be longer than is ideal in patients with autoimmune rheumatic diseases (ARDs). In this study, we aimed to characterize this interval and to identify its associated factors. METHOD: We characterized pre-diagnosis interval into 4 intervals: Interval #1 between symptom onset and first visit to healthcare professionals; Interval #2 between first visit to healthcare professionals and rheumatology referral; Interval #3 between rheumatology referral and first rheumatology assessment; and Interval #4 between first rheumatology assessment and diagnosis. Median regression models were used to identify factors associated with longer pre-diagnosis interval and Interval #1. RESULTS: Among 259 patients (median age = 52.0 [41.6-61.9] years, 71% female, rheumatoid arthritis [n = 75], axial spondyloarthritis [axSpA] [n = 40] and psoriatic arthritis [n = 35]), median pre-diagnosis interval was 11.5 (4.7-36.0) months. Interval #1 (median = 4.9 months) was significantly longer than Intervals #2-#4 (median = 0.3, 1.5, and 0.0 months, respectively). Patients with axSpA had significantly longer pre-diagnosis interval (median = 38.7 months) and Interval #1 (median = 26.6 months) than patients with the other ARDs. Median regression suggested that patients referred from specialty care had significantly longer pre-diagnosis interval (median difference = 7.7 months) and Interval #1 (median difference = 6.4 months) compared to those referred from primary care. CONCLUSION: A long pre-diagnosis interval was observed among patients with ARDs (especially axSpA), due largely to a long interval between symptom onset and the first visit to healthcare professionals. This highlights the importance of interventions targeting patients prior to their first visit to healthcare professionals in reducing pre-diagnosis interval.

Recommendations for COVID-19 vaccination in people with rheumatic disease: Developed by the Singapore Chapter of Rheumatologists.

AIM: People with rheumatic diseases (PRD) remain vulnerable in the era of the COVID-19 pandemic. We formulated recommendations to meet the urgent need for a consensus for vaccination against SARS-CoV-2 in PRD. METHODS: Systematic literature reviews were performed to evaluate: (a) outcomes in PRD with COVID-19; (b) efficacy, immunogenicity and safety of COVID-19 vaccination; and (c) published guidelines/recommendations for non-live, non-COVID-19 vaccinations in PRD. Recommendations were formulated based on the evidence and expert opinion according to the Grading of Recommendations Assessment, Development and Evaluation methodology. RESULTS: The consensus comprises 2 overarching principles and 7 recommendations. Vaccination against SARS-CoV-2 in PRD should be aligned with prevailing national policy and should be individualized through shared decision between the healthcare provider and patient. We strongly recommend that eligible PRD and household contacts be vaccinated against SARS-CoV-2. We conditionally recommended that the COVID-19 vaccine be administered during quiescent disease if possible. Immunomodulatory drugs, other than rituximab, can be continued alongside vaccination. We conditionally recommend that the COVID-19 vaccine be administered prior to commencing rituximab if possible. For patients on rituximab, the vaccine should be administered a minimum of 6 months after the last dose and/or 4 weeks prior to the next dose of rituximab. Post-vaccination antibody titers against SARS-CoV-2 need not be measured. Any of the approved COVID-19 vaccines may be used, with no particular preference. CONCLUSION: These recommendations provide guidance for COVID-19 vaccination in PRD. Most recommendations in this consensus are conditional, reflecting a lack of evidence or low-level evidence.

Systemic Sclerosis Perturbs the Architecture of the Immunome.

Systemic sclerosis (SSc) is an autoimmune disease characterized by excessive fibrosis of skin and internal organs, and vascular dysfunction. Association of T and B cell subsets has been reported in SSc; however, there is lack of systematic studies of functional relations between immune cell subsets in this disease. This lack of mechanistic knowledge hampers targeted intervention. In the current study we sought to determine differential immune cell composition and their interactions in peripheral blood of SSc patients. Mononuclear cells from blood of SSc patients (n = 20) and healthy controls (n = 10) were analyzed by mass cytometry using a 36-marker (cell surface and intracellular) panel. Transcriptome analysis (m-RNA sequencing) was performed on sorted T and B cell subsets. Unsupervised clustering analysis revealed significant differences in the frequencies of T and B cell subsets in patients. Correlation network analysis highlighted an overall dysregulated immune architecture coupled with domination of inflammatory senescent T cell modules in SSc patients. Transcriptome analysis of sorted immune cells revealed an activated phenotype of CD4 and mucosal associated invariant T (MAIT) cells in patients, accompanied by increased expression of inhibitory molecules, reminiscent of phenotype exhibited by functionally adapted, exhausted T cells in response to chronic stimulation. Overall, this study provides an in-depth analysis of the systemic immunome in SSc, highlighting the potential pathogenic role of inflammation and chronic stimulation-mediated "functional adaptation" of immune cells.

Mortality and hospitalization outcomes of interstitial lung disease and pulmonary hypertension in the Singapore systemic sclerosis cohort.

OBJECTIVES: We compared mortality and hospitalization rates in four groups of patients with systemic sclerosis (SSc) [isolated pulmonary arterial hypertension (PAH) or interstitial lung disease (ILD), concomitant ILD-pulmonary hypertension (PH), and no/mild pulmonary involvement]. METHODS: In the Systemic Sclerosis Cohort Singapore (SCORE), ILD was diagnosed by HRCT and significant ILD was defined by forced vital capacity <70% predicted. Patients were classified as PAH if echocardiographic systolic pulmonary artery pressure (sPAP) ≥50 mmHg or right heart catheterization (RHC) mean PAP ≥25 mmHg. Multivariable regression analyses were performed to determine factors associated with mortality and hospital admissions per year. Cox proportional hazard model was used to analyze survival. RESULTS: Of 490 SSc patients, 50 patients had PAH, 92 patients had ILD and 43 patients had ILD-PH. Of 93 patients with PAH or ILD-PH, 56 were based on echocardiography and 37 on RHC. Patients with ILD-PH (HR 3.77, 95% CI: 2.05-6.93) had the highest risk of death, followed by PAH (HR 3.03, 95% CI: 1.60-5.76) and ILD (HR 1.84, 95% CI: 1.04-3.28). After adjustment for confounders, PAH (HR 2.39, 95% CI: 1.13-5.07) remained independently associated with mortality, but not ILD-PH or ILD. Other factors associated with mortality were male gender, age at SSc diagnosis, malabsorption and digital ulcer/ gangrene. Increased hospitalization rate was associated with renal crisis, right heart failure and PAH medications, but not SSc groups. CONCLUSION: PAH is an independent risk factor of mortality in SSc. Increased hospitalization rate was not associated with SSc groups. Other factors associated with increased mortality and hospital admissions were identified.

Cross-cultural adaptation of the Hamilton axial spondyloarthritis questionnaire and development of a Chinese version in a multi-ethnic Asian population.

OBJECTIVE: To cross-culturally adapt the Hamilton axial spondyloarthritis (axial SpA) screening questionnaire and develop a Chinese version for use in a multi-ethnic Asian population in Singapore. METHODS: Consenting participants newly referred from primary care to a rheumatology specialist outpatient clinic for evaluation of possible axial SpA were studied. The original axial SpA questionnaire was revised based on inputs from cognitive debriefing interviews (CDIs) and discussions with an expert panel of rheumatologists and the developer. Forward and back translations of the adapted English version were also reviewed by the expert panel and the developer. The common translation produced was tested in CDIs with Chinese-speaking participants. Adapted English and Chinese versions were pilot-tested in a separate group of similar participants. RESULTS: Participants were recruited for English (n = 25) and Chinese CDIs (n = 15, relatively older and less frequently presented with axial SpA symptoms), respectively. Alternative terms and explanatory notes were added to difficult medical terms to improve the understandability of the adapted English version. English medical terms were retained in the Chinese version. Pilot-testing of the adapted axial SpA questionnaire was performed on 116 participants, all of whom reported ease of comprehension with both adapted versions. Only one participant was diagnosed with axial SpA, who also scored positive on the adapted axial SpA questionnaire. CONCLUSION: The adapted axial SpA questionnaire demonstrated good sensitivity in the pilot-testing and appears to be a promising tool for facilitating early identification of axial SpA cases in the multi-ethnic Asian population.

Cross-cultural adaptation of the connective tissue disease screening questionnaire and development of a Chinese version in a multi-ethnic Asian population.

OBJECTIVES: To cross-culturally adapt the Connective Tissue Disease (CTD) Screening Questionnaire (CSQ) in a multi-ethnic Asian population in Singapore. METHODS: An expert panel of accredited rheumatologists evaluated the content validity of the original CSQ. Consenting participants newly referred from primary care to a rheumatology specialist outpatient clinic for evaluation of possible CTDs were studied. Cognitive debriefing interviews (CDIs) using the original CSQ were conducted with English-speaking participants, with modifications made based on their inputs and in discussion with a second expert panel (rheumatologists and the CSQ developers). Forward and back translations of the adapted English version were reviewed by the second expert panel. The common translation produced was tested in CDIs with Chinese-speaking participants. Adapted English and Chinese versions were pilot tested in a separate group of newly referred patients. RESULTS: Content validity of the original CSQ was confirmed by the expert panel. A total of 30 and 15 participants were recruited for English and Chinese CDIs, respectively. Alternative terms and explanatory notes were added to difficult medical terms in the adapted English CSQ. A further explanatory note was added to one difficult item, and English medical terms were retained in the Chinese version. Pilot testing of the adapted CSQ was performed on 116 participants, which exhibited an overall sensitivity and specificity of 71% and 58%, respectively, in identifying CTDs. CONCLUSIONS: The adapted CSQ demonstrated satisfactory sensitivity in the pilot testing and appears to be a promising tool for facilitating early identification of CTDs in the multi-ethnic Asian population. KEY POINTS: • Early identification and management of patients with CTDs is crucial given their high disease burden and short "windows of opportunity." • High reliability and validity of original CSQ and its cross-culturally adapted versions have been reported; however, the CSQ has not been validated in Southeast Asia where CTDs are associated with higher morbidity and mortality compared to other countries. • Our cross-culturally adapted CSQ demonstrated satisfactory sensitivity in identifying CTDs in the multi-ethnic Asian population.