Publications by authors named "Ee-Tzun Koh"

Introduction: Traditional risk factors do not fully explain the increased risk of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA). The 2-2 genotype confers a lower anti-oxidant and higher inflammatory effect on the vasculature compared to the non- 2-2 genotype. This study investigates the association of the genotype with CVD in patients with RA.

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Objective: More than 130 susceptibility loci for rheumatoid arthritis (RA) have been identified with genome-wide association studies. To investigate the genetic predisposition of Chinese patients to anticitrullinated protein antibody (ACPA)-positive RA, we carried out an exome sequencing study.

Methods: Patients were recruited from 3 major public hospitals in Singapore: Tan Tock Seng Hospital (TTSH), Singapore General Hospital, and the National University Hospital.

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Background/objective: Tumoral calcinosis (TC) is a rare, arcane, and debilitating disorder of phosphate metabolism manifesting as hard masses in soft tissues. Primary hyperphosphatemic TC has been shown to be caused by pathogenic variants in the genes encoding FGF23, GALNT3, and KLOTHO. We report a case of massive TC mechanistically associated with phosphatonin resistance associated with heterozygous alterations in the sterile alfa motif domain-containing protein-9 gene (), alfa 2-Heremans-Schmid glycoprotein gene (), FSHD region gene 2-family member-C gene (), and fibroblast growth factor receptor-4 gene ().

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Introduction: Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (ACPA) are used in the diagnosis and prognostication of rheumatoid arthritis (RA). We wanted to determine the specific contributions of RF and ACPA to the biological nature of RA and whether they act synergistically.

Methods: We identified 731 patients from our prospective multi-ethnic RA cohort and categorised them into four groups: ACPA-positive, RF-positive, doubly positive and doubly negative.

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Article Synopsis
  • This study addresses the limitations of traditional Genome-wide association studies (GWAS) by employing a machine-learning approach to optimize polygenic risk scores (PRS) for predicting complex disorders, specifically using rheumatoid arthritis (RA) as a model.
  • A feature selection algorithm identified 9 key single nucleotide polymorphisms (SNPs) that provided excellent predictive performance for RA across three independent datasets, achieving an Area Under the Curve (AUC) higher than 0.9.
  • A RA ML-PRS calculator was developed to enhance clinical applicability by allowing personalized risk assessments, highlighting that most identified SNPs are protective and located in non-coding regions, with potential functional implications.
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Objectives: The Montreal Cognitive Assessment (MoCA) is an increasingly used screening tool for cognitive impairment. The aim of this study was to examine how MoCA performed in identifying cognitive impairment (CI) domains in SLE patients compared with formal standardized neuropsychological testing (NPT). Factors related to SLE disease, immunologic and psychological state associated with CI were also explored.

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Objectives: This study aims to uncover variants of large effect size and allele frequency below 5% by sequencing all extant genes associated with rheumatoid arthritis (RA) in a homogeneous patient cohort.

Patients And Methods: This retrospective study was conducted between January 2001 and December 2017. We selected Chinese RA patients positive for anti-citrullinated peptide antibody (ACPA).

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Objective: To develop a hypothesis-free model that best predicts response to MTX drug in RA patients utilizing biologically meaningful genetic feature selection of potentially functional single nucleotide polymorphisms (pfSNPs) through robust machine learning (ML) feature selection methods.

Methods: MTX-treated RA patients with known response were divided in a 4:1 ratio into training and test sets. From the patients' exomes, potential features for classifier prediction were identified from pfSNPs and non-genetic factors through ML using recursive feature elimination with cross-validation incorporating the random forest classifier.

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Article Synopsis
  • - This study tackles the challenges of identifying important genetic variations and their interactions in large-scale research to better predict how patients with rheumatoid arthritis (RA) will respond to the drug methotrexate (MTX), utilizing a new machine-learning technique that combines genetic and non-genetic data.
  • - Researchers analyzed genetic data from 349 RA patients, separating them into training and test sets, and applied machine learning methods to select 100 predictive features, with a focus on potentially functional coding haplotypes (pfcHaps).
  • - The findings showed that the identified features, mostly pfcHaps, had strong predictive capabilities for MTX response, indicating a link between these genetic factors and known RA treatment pathways, with robust performance across various
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Objectives: We evaluated the impact of type 2 diabetes mellitus (T2DM) on RA treatment and outcomes in a longitudinal RA cohort.

Methods: We analysed data collected in the period 2001-2013 involving 583 RA patients, including demographics, diabetes diagnosis, clinical features, treatment, ACR functional class, HAQ, and quality-of-life measurement using the Short-Form 36.

Results: Seventy-seven (13.

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Introduction: Over-expression of common inflammatory mediators in the metabolic syndrome (MetS) and in rheumatoid arthritis (RA) may lead to mutually adverse outcomes.

Aim: We investigate the prevalence of MetS in a multi-ethnic population of RA patients and its effect on clinical and patient-reported outcomes.

Method: Six hundred sixty RA (561 women) patients from a public-sector specialist clinic in a hospital in Singapore were assessed for MetS according to the 2009 Joint Consensus (JC) and the 2004 National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) definitions.

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Feature selection (marker gene selection) is widely believed to improve clustering accuracy, and is thus a key component of single cell clustering pipelines. Existing feature selection methods perform inconsistently across datasets, occasionally even resulting in poorer clustering accuracy than without feature selection. Moreover, existing methods ignore information contained in gene-gene correlations.

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Objective: Disease activity indices for rheumatoid arthritis (RA) are important in clinical practice and research. Although they are closely correlated, they are not in good agreement. We derived formulae to convert values from one of the four 28-joint count indices (disease activity score using erythrocyte sedimentation rate [DAS28-ESR], disease activity score using C-reactive protein [DAS28-CRP], clinical disease activity index [CDAI], and simple disease activity index [SDAI]) to any of the others.

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Article Synopsis
  • This study aimed to assess the incidence and types of cancers in patients with rheumatoid arthritis (RA) over a 12-year period at Tan Tock Seng Hospital.
  • Researchers analyzed data from 1,117 RA patients and found a total of 132 new malignancies, primarily solid-organ tumors (86.4%) and a significant number of lymphomas, with increased risks compared to the general population.
  • The findings suggest that RA patients have a higher overall risk of developing malignancies, particularly lymphomas among all patients, lung cancer in males, and cervical cancer in females.
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Studies have shown that the genetic risk factors for rheumatoid arthritis (RA) differ substantially between Asian and Caucasian populations. Even among Asian populations, the genetic contributions of NLRP1, PTPN22 and PADI4 have been controversial. Consequently, we sought to address these separate findings and determine whether any of these proposed risk variants are associated with RA susceptibility, onset, DAS activity and erosion in a Singaporean Chinese cohort.

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Objective: To describe the demographic characteristics, clinical features, functional status and quality of life of elderly-onset (EORA) and young-onset (YORA) rheumatoid arthritis (RA) patients in an Asian cohort.

Methods: We studied all RA patients in our prospective disease registry, utilizing baseline data. EORA was defined as disease onset at 60 years or older.

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Introduction: Up to 30% of patients with rheumatoid arthritis (RA) respond inadequately to conventional non-biologic disease modifying antirheumatic drugs (nbDMARDs), and may benefit from therapy with biologic DMARDs (bDMARDs). However, the high cost of bDMARDs limits their widespread use. The Chapter of Rheumatologists, College of Physicians, Academy of Medicine, Singapore aims to define clinical eligibility for government-assisted funding of bDMARDs for local RA patients.

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Background: The aim of this study was to determine the risk factors of MTX-associated nonalcoholic fatty liver disease (NAFLD) with transaminitis in a cohort of rheumatoid arthritis (RA) patients from Singapore.

Methods: Patients who developed ultrasound proven NAFLD with transaminitis while on MTX therapy were identified. The demographic and clinical characteristics of the above patients (cases) were compiled and compared with age- and gender-matched controls who were RA patients on long standing MTX therapy without any episode of transaminitis.

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To investigate the association between helplessness, disability, and disease activity with health-related quality of life (HRQoL) in a multiethnic cohort of rheumatoid arthritis (RA) patients in Singapore. This cross-sectional study was conducted at Tan Tock Seng Hospital, Department of Rheumatology, Allergy and Immunology, from October 2010 to October 2011. All patients fulfilled the American College of Rheumatology 1987 criteria for RA.

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We analyzed the epidemiological changes of rheumatoid arthritis (RA) over three decades using patients from a single center in Singapore. All patients who fulfill the 1987 American College of Rheumatology criteria for RA were invited to enroll in a prospective disease registry. We analyzed the patient demographics, disease manifestation, management and patient-reported outcomes, including quality of life (QoL), in the three categories according to the year of disease onset: before 1989 (group I), 1990-1999 (group II) and after 2000 (group III).

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Objective: To evaluate the efficacy and safety of oral alendronate sodium therapy once daily in preventing glucocorticoid-induced bone loss in patients with immunobullous skin diseases treated with long-term glucocorticoid therapy.

Design: A 12-month randomized, double-blind, placebo-controlled trial.

Setting: A tertiary referral dermatology center in Singapore.

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A genome-wide association study in Japan identified the C-C chemokine receptor type 6 gene (CCR6) as associated with rheumatoid arthritis (RA). This finding has not been validated in other Asian populations. A case-control study involving 996 subjects, comprising 440 controls and 556 RA patients, was done to determine their anticyclic citrullinated peptide (anti-CCP) antibody status and CCR6 polymorphism (rs3093024) genotype.

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Introduction: The aim of this study was to ascertain the outcomes of chronic hepatitis B (CHB) infection following immunosuppressive therapy in 38 consecutive oriental patients with systemic rheumatic diseases.

Materials And Methods: This is a retrospective consecutive, non-comparative study.

Results: The majority of patients were female (26, 68.

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