1.Dual rheumatoid factor and anti-cyclic citrullinated peptide antibody positivity affects the manifestations of rheumatoid arthritis.
Li Huan Angela Marie CHAN ; Khai Pang LEONG ; Justina Wei Lynn TAN ; Xiao GAO ; Wei Qiang SEE ; Ee Tzun KOH
Singapore medical journal 2025;66(9):486-491
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. We compared the demographics, Disease Activity Score-28, Health Assessment Questionnaire score, quality of life using Short Form 36 and the use of prednisolone and disease-modifying antirheumatic drugs (DMARDs) of these patient groups.
RESULTS:
Four hundred and ninety-one patients (67.2%) were ACPA+RF+, 54 (7.4%) were ACPA+RF-, 82 (11.2%) were ACPA-RF+ and 104 (14.2%) were ACPA-RF-. Mean disease duration before the study entry was not different in the four groups. Patients with older age of onset were less likely to be positive for RF and ACPA. Fewer ACPA+RF+ patients were in remission compared to those in the other groups ( P < 0.05). Erythrocyte sedimentation rate (ESR) was higher at study entry in the ACPA+RF+ group (40.4 mm/h vs. 30.6-30.9 mm/h, P < 0.05). Prednisolone and number of DMARDs used were higher in the ACPA+RF+ group compared to the doubly negative group. There were no differences in the functional status and quality of life.
CONCLUSIONS
RA patients who were positive for both ACPA and RF had lower remission rate, higher baseline ESR and required more corticosteroid and DMARD treatment compared to those who were singly positive or doubly negative. Being doubly positive confers a worse outcome to RA patients.
Humans
;
Arthritis, Rheumatoid/diagnosis*
;
Male
;
Female
;
Middle Aged
;
Rheumatoid Factor/blood*
;
Anti-Citrullinated Protein Antibodies/blood*
;
Adult
;
Quality of Life
;
Prospective Studies
;
Antirheumatic Agents/therapeutic use*
;
Aged
;
Peptides, Cyclic/immunology*
;
Prednisolone/therapeutic use*
;
Surveys and Questionnaires
;
Severity of Illness Index
;
Prognosis
2.Association between bone mineral density and vascular health in rheumatoid arthritis.
Chuanhui XU ; Yi Wye LAI ; Shih-Huan CHOU ; Xiaoe ZHANG ; Ee Tzun KOH ; Rinkoo DALAN ; Khai Pang LEONG
Singapore medical journal 2025;66(3):147-153
INTRODUCTION:
Rheumatoid arthritis (RA) is associated with heightened cardiovascular disease and increased susceptibility to osteoporosis, with shared underlying mechanisms. This study aimed to investigate the association between vascular function and bone mineral density (BMD).
METHODS:
We conducted a cross-sectional study of 49 patients with RA at Tan Tock Seng Hospital, Singapore. Endothelial function was measured as reactive hyperaemia index (RHI)-endothelial peripheral arterial tonometry and aortic stiffness as carotid-femoral pulse wave velocity (cf-PWV) using SphygmoCor. Univariable and multivariable linear regression analyses were performed to evaluate the associations between BMD and vascular function. We used natural logarithm RHI (lnRHI) and cf-PWV as response variables, and each BMD as covariate, adjusting for body mass index, positive anti-cyclic citrullinated peptide, cumulative prednisolone dose, hydroxychloroquine use and Systematic COronary Risk Evaluation 2.
RESULTS:
We recruited 49 patients (mean age 61.08 ± 8.20 years), of whom 44 (89.80%) were women and 39 (81.25%) were Chinese. Significant associations were found between lnRHI and BMD at the lumbar spine (β = 0.4289, P = 0.037) and total hip (β = 0.7544, P = 0.014) in univariable analyses. Multivariable analyses confirmed these associations, showing that lower BMD at the lumbar spine (β = 0.7303, P = 0.001), femoral neck (β = 0.8694, P = 0.030) and total hip (β = 0.8909, P = 0.010) were significantly associated with worse lnRHI. No significant associations were found between BMD and cf-PWV.
CONCLUSION
Lower BMD is associated with endothelial dysfunction, but not aortic stiffness in patients with RA. Further longitudinal studies are needed to confirm these associations and understand the underlying mechanisms.
Humans
;
Arthritis, Rheumatoid/complications*
;
Female
;
Male
;
Bone Density
;
Middle Aged
;
Cross-Sectional Studies
;
Vascular Stiffness
;
Aged
;
Singapore
;
Pulse Wave Analysis
;
Osteoporosis/complications*
;
Endothelium, Vascular/physiopathology*
;
Cardiovascular Diseases/complications*
;
Carotid-Femoral Pulse Wave Velocity
;
Hyperemia
3.Clinical utility of anti-DFS70 for identifying antinuclear antibody-positive patients without systemic autoimmune rheumatic disease.
Teck Choon TAN ; Carol Yee Leng NG ; Khai Pang LEONG
Singapore medical journal 2022;63(3):147-151
INTRODUCTION:
The antinuclear antibody (ANA) test is a screening test for systemic autoimmune rheumatic disease (SARD). We hypothesised that the presence of anti-DFS70 in ANA-positive samples was associated with a false-positive ANA test and negatively associated with SARD.
METHODS:
A retrospective analysis of patient samples received for ANA testing from 1 January 2016 to 30 June 2016 was performed. Patient samples underwent ANA testing via indirect immunofluorescence method and anti-DFS70 testing using enzyme-linked immunosorbent assay.
RESULTS:
Among a total of 645 ANA-positive samples, the majority (41.7%) were positive at a titre of 1:80. The commonest nuclear staining pattern (65.5%) was speckled. Only 9.5% of ANA-positive patients were diagnosed with SARD. Anti-DFS70 was found to be present in 10.0% of ANA-positive patients. The majority (51/59, 86.4%) of patients did not have SARD. Seven patients had positive ANA titre > 1:640, the presence of anti-double stranded DNA and/or anti-Ro60. The presence of anti-DFS70 in ANA-positive patients was not associated with the absence of SARD (Fisher's exact test, p = 0.245).
CONCLUSION
The presence of anti-DFS70 was associated with a false-positive ANA test in 8.6% of our patients. Anti-DFS70 was not associated with the absence of SARD.
Adaptor Proteins, Signal Transducing
;
Antibodies, Antinuclear
;
Autoimmune Diseases/diagnosis*
;
Humans
;
Retrospective Studies
;
Rheumatic Diseases/diagnosis*
;
Transcription Factors
4.Antiphospholipid and other autoantibodies in COVID-19 patients: A Singapore series.
Khai Pang LEONG ; Carol Yee Leng NG ; Bingwen Eugene FAN ; Chien Mei LOH ; Lok To WONG ; Valerie Hui Hian GOH ; Gwen Li Xuan TAN ; Chong Rui CHUA ; Janet Suyun TAN ; Samuel Shang Ming LEE ; Xin Rong LIM ; Teck Choon TAN
Annals of the Academy of Medicine, Singapore 2022;51(9):586-588
5.A SIX-YEAR TREND OF YOUTH DEPRESSION IN A HEALTHCARE GROUP IN SINGAPORE
Xiao Wei Tan ; Rajagopalan Arvind ; Eng Sing Lee ; Matthias Paul Han Sim To ; Khai Pang Leong ; Phern Chern Tor ; Daniel Shuen Sheng Fung
ASEAN Journal of Psychiatry 2021;22(8):1-8
Aim:
To examine the trend of youth depression diagnosed in a healthcare group in Singapore over a 6-year period.
Methods:
This is a retrospective analysis of the medical records of patients who had been diagnosed with depression from Jan 2013 to Dec 2018 in a healthcare group in Singapore. The yearly trend of depression diagnosis among the youths (10-24 years of age) was compared with adults (25-64 years of age) and the elderly (≥ 65 years of age). The mean age at diagnosis, distribution of gender, ethnicity and clinical care settings among the subgroup of youth patients were compared across the years using analysis of variance or Pearson’s chi-square test.
Results:
A total of 4701 youths, 15243 adults and 6908 elderly patients were included in the analysis. Between 2013 and 2018, the rise in depression diagnosis in the youth was greater than in the adult and elderly populations, and the mean age at diagnosis decreased from 49.7 ± 0.3 (mean ± SE) years in 2013 to 39.6 ± 0.3 years in 2018. Among the youths, more females had been diagnosed with depression than males and females displayed a larger increase in diagnosis of depression. There was also a larger
increase in the diagnosis of depression in primary care compared to emergency departments, outpatient specialist clinics and in-hospital wards.
Conclusion
Youth depression is a major health problem in Singapore. There is a need for the expansion of resources in a variety of avenues for depressed youths to seek help.
7.Shellfish/crustacean oral allergy syndrome among national service pre-enlistees in Singapore
Bernard Yu Hor THONG ; Shalini ARULANANDAM ; Sze Chin TAN ; Teck Choon TAN ; Grace Yin Lai CHAN ; Justina Wei Lyn TAN ; Mark Chong Wei YEOW ; Chwee Ying TANG ; Jinfeng HOU ; Khai Pang LEONG
Asia Pacific Allergy 2018;8(2):e18-
BACKGROUND: All Singaporean males undergo medical screening prior to compulsory military service. A history of possible food allergy may require referral to a specialist Allergy clinic to ensure that special dietary needs can be taken into account during field training and deployment. OBJECTIVE: To study the pattern of food allergy among pre-enlistees who were referred to a specialist allergy clinic to work up suspected food allergy. METHODS: Retrospective study of all pre-enlistees registered in the Clinical Immunology/Allergy New Case Registry referred to the Allergy Clinic from 1 August 2015 to 31 May 2016 for suspected food allergy. RESULTS: One hundred twenty pre-enlistees reporting food allergy symptoms other than rash alone were referred to the Allergy Clinic during the study period. Of these, 77 (64.2%) had food allergy. Among those with food allergy, mean age was 19.1 ± 1.5 years. They comprised predominantly Chinese (66.2%) and Malays (20.8%). The most commonly reported foods were shellfish/crustaceans (78%), peanut (15.6%), and egg (6.5%). Self-limiting oral allergy syndrome, OAS (itchy lips and throat with/without lip angioedema) was the most common manifestation (n = 33, 42.9%) followed by anaphylaxis (n = 23, 29.9%). Majority of OAS was from shellfish/crustacean (90.6%); of which shrimp (30.3%), crab (15.2%), and lobster (3.0%) were the most common. Mild childhood asthma (69.7%), allergic rhinitis (6.3%), and eczema (6.1%) were the most common atopic conditions among individuals with shellfish/crustacean OAS. This pattern was similar for shellfish/crustacean anaphylaxis. Skin prick tests were most commonly positive for shrimp (OAS 87.1% vs. anaphylaxis 100%), crab (OAS 95.8% vs. 90.9%), and lobster (OAS 91.7% vs. 63.6%). CONCLUSION: OAS to shellfish/crustaceans was more common than anaphylaxis among this study population of young males referred for food allergy symptoms other than rash alone.
Anaphylaxis
;
Arachis
;
Asian Continental Ancestry Group
;
Asthma
;
Eczema
;
Exanthema
;
Food Hypersensitivity
;
Humans
;
Hypersensitivity
;
Lip
;
Male
;
Mass Screening
;
Military Personnel
;
Ovum
;
Pharynx
;
Referral and Consultation
;
Retrospective Studies
;
Rhinitis, Allergic
;
Shellfish
;
Singapore
;
Skin
;
Specialization
9.A retrospective study on sequential desensitization-rechallenge for antituberculosis drug allergy
Bernard Yu Hor THONG ; Faith Li Ann CHIA ; Sze Chin TAN ; Teck Choon TAN ; Khai Pang LEONG ; Justina Wei Lyn TAN ; Chwee Ying TANG ; Jin Feng HOU ; Grace Yin Lai CHAN ; Hiok Hee CHNG
Asia Pacific Allergy 2014;4(3):156-163
BACKGROUND: Antituberculosis (anti-TB) drug allergy often involves multiple concurrently administered drugs which subsequently need to be reinitiated as no better alternatives exist. OBJECTIVE: To describe the results of tailored sequential desensitization-rechallenge (D-R) for anti-TB drug allergy. METHODS: Consecutive patients who had undergone D-R to anti-TB drugs between 1 September 1997 and 31 January 2012 were recruited. Following resolution of the acute reaction, anti-TB drug was restarted at 1:6,000 to 1:3 of the final daily dose (FDD), with gradual single or multiple step daily dose escalation to the FDD. Subsequent drugs were sequentially added ≥3 days later when the preceding drug was tolerated. Full blood count and liver function tests were monitored prior to addition of each new drug. RESULTS: There were 11 patients of whom 10 were male, predominantly Chinese (8 patients). Regimens comprised at least 3 drugs: isoniazid (INH), rifampicin (RIF), ethambutol (EMB), pyrazinamide (PZA), or streptomycin. All patients had nonimmediate reactions, with cutaneous eruptions, where maculopapular exanthema (MPE) was the most common (8 patients). Drug-induced hypersensitivity syndrome (DIHS) occurred in 6 patients, and Stevens Johnson syndrome (SJS) in 2 patients. D-R to INH was successful in 7/9 patients (77.8%) and to RIF/EMB/PZA/streptomycin in all. Of the 2 patients who failed INH D-R, 1 developed fever and MPE on day 3, the other MPE on day 8. D-R with INH and RIF respectively was successful in 2 patients with SJS. Among DIHS patients, 1 failed D-R with INH (fever and MPE on day 3). There were 23/25 (92%) successful D-R among the 11 patients. All patients completed TB treatment of ≥5 months' duration with no cases of drug-resistant TB. CONCLUSION: Tailored sequential TB drug D-R is successful where no better alternative therapies are available, with careful dose escalation and close monitoring, and after a careful risk-benefit assessment.
Asian Continental Ancestry Group
;
Complementary Therapies
;
Drug Eruptions
;
Drug Hypersensitivity Syndrome
;
Drug Hypersensitivity
;
Ethambutol
;
Exanthema
;
Fever
;
Humans
;
Hypersensitivity
;
Isoniazid
;
Liver Function Tests
;
Male
;
Pyrazinamide
;
Retrospective Studies
;
Rifampin
;
Risk Assessment
;
Stevens-Johnson Syndrome
;
Streptomycin


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