Publications by authors named "Justina W-L Tan"

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

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

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The underlying immunological mechanisms of immediate-type hypersensitivity reactions (HSR) to COVID-19 vaccines are poorly understood. We investigate the mechanisms of immediate-type hypersensitivity reactions to the Pfizer BNT162b2 vaccine and the response of antibodies to the polyethylene glycol (PEG)ylated lipid nanoparticle after two doses of vaccination. Sixty-seven participants, median age 35 and 77.

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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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During the initial rollout of coronavirus disease 2019 (COVID-19) vaccination in Singapore, the Ministry of Health (MOH) issued a recommendation that patients with a history of any previous vaccine allergy be referred to an allergist for further review of their suitability to proceed with mRNA-based COVID-19 vaccines. Patients fulfilling the above criterion were divided into three groups: immediate reaction (Group A), delayed reaction (Group B) and no/irrelevant reaction (Group C). They were subjected to either a skin prick test (SPT) and intradermal test (IDT) with polyethylene glycol (PEG) or polysorbate-containing products; direct injection with the Pfizer BNT162b2 vaccine in the allergy clinic; or injection at community vaccination centres, respectively.

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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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Anaphylactic reactions were observed after Singapore's national coronavirus disease 2019 (COVID-19) vaccination programme started in December 2020. We report the clinical and laboratory features of three patients in our institution who developed anaphylactic reactions after receiving the Pifzer BNT162b2 vaccine. IgM and IgG antibodies, but not IgE antibodies to the Pfizer BNT162b2 vaccine, were detected in all subjects.

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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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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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Rice body formation is a nonspecific response to chronic synovial inflammation associated with tuberculous arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, seronegative inflammatory arthritis, and even osteoarthritis. Such bodies were termed rice bodies because of their close resemblance to grains of polished white rice. We present a case report of a middle-aged woman with right shoulder subacromial/subdeltoid bursitis with giant rice body formation as her initial presentation of rheumatoid arthritis.

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We describe a 35-year-old Chinese woman with Behçet disease complicated by recurrent gastrointestinal flares. During admission for acute lower abdominal pain, a computed tomographic scan of the abdomen showed thrombosis of the left ovarian vein. She was treated with increased immunosuppressant and oral anticoagulant.

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Purpose Of Review: Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE), previously termed drug-related baboon syndrome, is a benign and self-limiting type IV hypersensitivity reaction characterized by symmetrical erythema involving the gluteal and intertriginous areas in the absence of systemic involvement. It may also occur in the absence of previous drug exposure.

Recent Findings: Antibiotics, in particular beta-lactams, comprise the majority of causes of SDRIFE.

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The purpose of study was to assess the validity, reliability and acceptability of the English version of the Asthma Quality of Life Questionnaire in a multi-ethnic Asian population. The English version of the Standardized Asthma Quality of Life Questionnaire (AQLQ-S) and the Asthma Control Questionnaire (ACQ) were self-completed by 119 English-speaking Chinese, Malay and Indian asthmatic subjects, aged 17-78. Spirometric measurements, peak expiratory flow rate, current clinical symptoms and treatment requirements were documented.

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