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.

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.

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 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.

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 in 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 vs 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 SScpatients.

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.

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.

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.

Intravenous epoprostenol therapy in the treatment of pulmonary arterial hypertension: the Singapore experience

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary arterial hypertension (PAH) is a progressive disease with significant morbidity and mortality. While intravenous (IV) Epoprostenol, a prostacyclin analogue, has been shown to improve exercise tolerance, symptoms, hemodynamics and survival, there are challenges with initiation and maintenance of this IV therapy.

Purpose

We aim to describe our local experience of the use of IV Epoprostenol in the treatment of PAH patients in Singapore, highlighting various issues and challenges.

Methods

From 2016, patients at a tertiary cardiac institution diagnosed with Group 1 PAH and remaining in intermediate to high risk class with progressive symptoms (despite being on maximum tolerable doses of PhosphoDiEsterase-5 inhibitors and Endothelin-1 receptor antagonists) were assessed and counselled for initiation of Epoprostenol therapy. With a fixed set of local protocols, comprehensive assessment and support of a multi-disciplinary team including physicians, specialist nurses and pharmacists, suitable patients were started on this treatment.

Results

A total of 12 patients (11 female, mean age 42.8 +/- 11.0 years) were included. The average New York Heart Association class of the patients initiated on Epoprostenol was II-III. The pulmonary artery pressures and pulmonary vascular resistance on right heart catheterization prior to initiation was 52.5 (IQR 47.0-54.0) mmHg and 12.6 (IQR 10.0-14.2) Woods respectively. The duration from diagnosis to time of initiating Epoprostenol was 89 (IQR 62-140) months. Epoprostenol was generally well tolerated. The most common side effect experienced was diarrhea (5/12 patients) followed by headache and musculoskeletal complains (3/12 patients each). Of the 12 patients, 6 passed away after 12 (IQR 10-16) months of Epoprostenol therapy. Of the remaining 6, PAH was diagnosed 110 (IQR 104-136) months ago and Epoprostenol therapy has been continued for 17 (IQR 14-27) months. Of those who survived, right ventricle size and PA pressures on echocardiography remained relatively stable as compared to those who passed on. 2 patients had line related infections requiring a line change 1 and 2 times respectively.

Conclusion

While not without its challenges, the establishment of concrete protocols with the support of a multidisciplinary team allows for the introduction of IV Epoprostenol as an additional potential line of effective therapy for PAH patients in Singapore.

Risk stratification and prognosis in pulmonary arterial hypertension: the Singapore experience

Funding Acknowledgements

Type of funding sources: None.

Aims & Background: Guidelines recommend the risk stratification of patients with pulmonary arterial hypertension (PAH) at baseline and on follow-up, so as to guide the management and titration of therapy in these patients.  This approach has been validated in various pulmonary hypertension registries in the West.  We aim to study the value of risk stratification on the prognosis of PAH patients in Asia.

Methods

A retrospective review of all PAH patients from 2002 to 2018 from a single tertiary cardiac centre was performed. Inclusion criteria was the availability of both initial visit and follow-up data. Patients were classified into low-, medium-, and high-risk groups in both initial and follow-up visits based on the variables in the 2015 ESC/ERS PH risk stratification table  according to the "score and average" method used by SPAHR and COMPERA registries (total score divided by number of variables assessed and rounded to nearest integer). An average score of 1, 2 and 3 was defined as low, medium and high risk respectively. The primary outcomes was all-cause mortality.

Results

 A total of 102 patients (mean age 57 ± 18 years old, 82 females) were included. Survival was significantly affected by PAH subtype and risk profile. On multivariate analysis, baseline risk did not impact on mortality. Follow-up risk stage impacted on prognosis, with significantly poorer prognosis noted in both intermediate- (adj HR 3.12, 95% CI 1.03 – 9.48, p = 0.045) and high-risk (adj HR = 7.84, 95% CI 2.22 – 27.64, p = 0.001) groups. Patients who improved their risk groups to low risk on follow-up had  similar survival to stable low-risk patients, but those patients whose risk group worsened on follow-up had significantly worse prognosis (adj HR = 5.44, 95% CI 1.26 – 13.75, p = 0.02).

Conclusion

Risk stratification is useful in prognosticating Asian PAH patients. There is potential survival benefit in optimising treatment to achieve a low-risk profile.

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.

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.

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.

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.

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.

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.

A double-blind randomized placebo-controlled trial of probiotics in systemic sclerosis associated gastrointestinal disease

OBJECTIVE

Assess whether treatment with probiotics improve gastrointestinal symptoms in patients with systemic sclerosis (SSc).

METHODS

In this double-blind randomized placebo-controlled parallel-group phase II trial, SSc subjects with total score ≥ 0.1 on a validated SSc-specific gastrointestinal tract (GIT) questionnaire were randomized (1:1) to receive 60 days of high dose multi-strain probiotics (Vivomixx® 1800 billion units/day) or identical placebo, followed by an additional 60 days of probiotics in both groups. Between group differences in GIT score change were assessed after 60 days (primary outcome, time-point T1) and 120 days (secondary outcome, time-point, T2) by an intention-to-treat approach. Stool samples at three time-points were subjected to 16S next generation sequencing.

RESULTS

Forty subjects were randomized to placebo-probiotics (n = 21) or probiotics-probiotics (n = 19). At T1, no significant improvement was observed between the two groups, reported as mean ± SE for total GIT score (placebo 0.14 ± 0.06 versus probiotics 0.13 ± 0.07; p = 0.85) or its subdomains. At T2, whilst there was no significant improvement in total GIT score (placebo-probiotics -0.05±0.06; probiotics-probiotics -0.18 ± 0.07; p = 0.14), there was significant improvement of GIT-reflux in the probiotic group (-0.22 ± 0.05 versus placebo-probiotics 0.05 ± 0.07; p = 0.004). Subjects on probiotics exhibited increasing stool microbiota alpha diversity compared to the placebo-probiotics group. Adverse events (AEs) were mild, with similar proportion of subjects with AEs and serious AEs in both groups.

CONCLUSION

Whilst there was no clear improvement in overall GI symptoms after 60 days, we observed significantly improved GI reflux after 120 days of probiotics. The trial confirmed safety of multi-strain probiotics in SSc patients.

TRIAL REGISTRATION

Clinicaltrials.gov; NCT01804959.

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 (β coefficient -2.56, p < 0.0001) and mental HRQoL (β 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.

Disease patterns of rheumatology outpatients seen in a tertiary hospital serving a multi-ethnic, urban Asian population in Singapore

AIMS

To describe the spectrum of diseases seen in an outpatient setting in the Singapore General Hospital, the largest tertiary referral centre in Singapore.

METHODS

In this cross-sectional study, medical records of patients scheduled for an appointment at the rheumatology specialist outpatient clinics over a 4-month period (10 August 2010-31 December 2010) were reviewed. Primary diagnoses documented by the attending physician at the latest visit were recorded.

RESULTS

Among 4180 patients (29.5% male; mean [SD] age: 53.5 [15.1] years; 77.0% Chinese, 8.0% Malay, 8.8% Indian and 6.2% others), the spectrum of diseases seen was as follows [disease - definite n (%), probable n (%)]: Arthritis: rheumatoid arthritis - 958 (22.9%), 68 (1.6%); osteoarthritis - 452 (10.8%), 39 (0.9%); crystal arthritis - 417 (10.0%), 18 (0.4%); spondyloarthritis - 227 (5.4%), 61 (1.5%); psoriatic arthritis - 158 (3.8%), 9 (0.2%); other inflammatory arthritis - 153 (3.7%), 94 (2.2%); Connective tissues diseases: systemic lupus erythematosus - 412 (9.9%), 26 (0.6%); vasculitis - 105 (2.5%), 22 (0.5%); Sjögren's syndrome - 81 (1.9%), 32 (0.8%); overlap syndromes - 73 (1.8%); scleroderma - 50 (1.2%), 4 (0.1%); undifferentiated connective tissue diseases - 45 (1.1%), 106 (2.5%); myositis - 41 (1.0%), 12 (0.3%); antiphospholipid syndrome - 22 (0.5%), 7 (0.2%); polymyalgia rheumatica - 16 (0.4%); Others: soft tissue rheumatism - 155 (3.7%); osteoporosis - 61 (1.5%); other non-rheumatologic conditions - 189 (4.5%); other rheumatologic conditions - 67 (1.6%).

CONCLUSION

Rheumatoid arthritis, osteoarthritis and crystal arthritis were the three most common rheumatological diseases seen in a tertiary referral centre serving a multi-ethnic urban Asian population in Singapore.

Cogan's syndrome with recurrent carotid and aortic aneurysms: a potentially fatal disorder mimicking Marfan syndrome

Cogan's syndrome (CS) is a rare multisystemic disease characterized by vestibuloauditory dysfunction, inflammatory eye disease and vasculitis. Aortic aneurysms due to aortitis are under-recognized in CS, and are potentially fatal, with two of eight reported cases dying from aneurysm/arterial rupture. The presence of aneurysms was not recognized antemortem in both cases, highlighting the importance of early detection to prevent this potentially fatal outcome. We report a 17-year-old Chinese male with recurrent carotid and aortic aneurysms, bilateral sensorineural hearing loss, and recurrent scleritis who was initially thought to have Marfan syndrome. The diagnosis of CS was made 4.5 years after initial presentation, during which time recurrent aneurysms due to active aortitis (with aneurysmal rupture on one occasion) necessitated four surgical procedures. Treatment with methotrexate and corticosteroids resulted in no recurrence of aneurysms over 2 years of follow-up. This case illustrates (i) the challenges in diagnosing CS when various manifestations occur separately over a relatively long time period, (ii) that detection of aortic aneurysms in young patients, especially if recurrent, should prompt investigations for vasculitis/aortitis to prevent potentially fatal aneurysm rupture, and (iii) that methotrexate and high-dose corticosteroids may be effective in preventing development of further aneurysms in CS patients.

Recurrent aortic aneurysms following thoracic aortic stent-graft repair in a patient with Cogan syndrome

PURPOSE

To report the need for multiple surgical interventions to treat recurrent aortic aneurysms in a patient with Cogan syndrome.

CASE REPORT

A 17-year-old Chinese man with clinical Marfanoid features had a left common carotid artery pseudoaneurysm electively repaired with an autologous saphenous vein graft. Four months later, he presented with acute chest pain. Computed tomography (CT) revealed a 1-cm pseudoaneurysm at the mid descending aorta; a 24 x 100-mm Talent stent-graft was implanted to exclude the pseudoaneurysm. He was also found to have increasing left-sided hearing loss. A month later, the patient was re-admitted with vertigo and keratitis, which were treated appropriately. Nine months following stent-graft insertion, he was admitted with acute hemoptysis. Urgent CT showed a rupture at the proximal end of the stent-graft, with hemorrhage into the lung parenchyma. In an emergent procedure, the stent-graft was removed, and the descending thoracic aorta was repaired. Intraoperatively, a large pseudoaneurysm was found arising from the proximal part of the stented aorta, which appeared thickened. His postoperative recovery was uneventful. Nine months after the thoracotomy, a routine CT revealed an aneurysm at the distal descending thoracic aorta. On re-thoracotomy, a de novo saccular aneurysm was found 2.5 cm from the distal anastomosis. The affected segment was replaced with a Dacron graft. The distal aorta appeared thickened and edematous; histology confirmed aortitis. The patient was subsequently diagnosed with Cogan syndrome and given corticosteroids and methotrexate. There is no evidence of recurrence at nearly 2 years after the last intervention.

CONCLUSION

This case highlights the pitfalls of stent-graft repair in a patient with presumed connective tissue disease.