Diagnostic performance of classification criteria for systemic lupus erythematosus: A validation study from Singapore.

Introduction: Classification criteria for systemic lupus erythematosus (SLE) include American College of Rheumatology (ACR) 1997, Systemic Lupus Erythematosus International Collaborating Clinics (SLICC) 2012 and European Alliance of Associations for Rheumatology (EULAR)/ACR 2019 criteria. Their performance in an Asian childhood-onset SLE (cSLE) population remains unclear as the clinical manifestations differ. We aim to evaluate the diagnostic performance in a cSLE cohort in Singapore. Method: Cases were physician-diagnosed cSLE, while controls were children with mixed and undifferentiated connective tissue disease that posed an initial diagnostic challenge. Data were retrospec-tively reviewed to establish the 3 criteria fulfilled at diagnosis and over time. Results: The study population included 120 cSLE cases and 36 controls. At diagnosis, 102 (85%) patients fulfilled all criteria. SLICC-2012 had the highest sensitivity (97.5%, 95% confidence interval [CI] 92.3-99.5), while ACR-1997 had the highest specificity (91.7%, 95% CI 77.5-98.3). All criteria had diagnostic accuracies at more than 85%. Over time, 113 (94%) fulfilled all criteria. SLICC-2012 remained the criteria with the highest sensitivity (99.2%, 95% CI 95.4-99.9), while ACR-1997 had the highest specificity (75.0%, 95% CI 57.8-87.9). Only SLICC-2012 and ACR-1997 had more than 85% diagnostic accuracy over time. Using a cutoff score of ≥13 for EULAR/ACR-2019 criteria resulted in improved diagnostic performance. Conclusion: SLICC-2012 criteria had the highest sensitivity early in the disease course in this first study evaluating the SLE classification criteria performance in a Southeast Asian cSLE cohort, while the ACR-1997 criteria had the highest specificity. Using a cutoff score of ≥13 for EULAR/ACR-2019 improved the diagnostic performance.

Anti-tumor necrosis factor (aTNF) weaning strategy in juvenile idiopathic arthritis (JIA): does duration matter?

BACKGROUND: To compare outcomes of a short and long weaning strategy of anti-tumor necrosis factor (aTNF) in our prospective juvenile idiopathic arthritis (JIA) cohort. RESEARCH DESIGN AND METHODS: JIA patients on subcutaneous adalimumab with at least 6 months of follow-up were recruited (May 2010-Jan 2022). Once clinical remission on medication (CRM) was achieved, adalimumab was weaned according to two protocols-short (every 4-weekly for 6 months and stopped) and long (extending dosing interval by 2 weeks for three cycles until 12-weekly intervals and thereafter stopped) protocols. Outcomes assessed were flare rates, time to flare, and predictors. RESULTS: Of 110 JIA patients, 77 (83% male, 78% Chinese; 82% enthesitis-related arthritis) underwent aTNF weaning with 53% on short and 47% on long weaning protocol. The total flare rate during and after stopping aTNF was not different between the two groups. The time to flare after stopping aTNF was not different (p = 0.639). Positive anti-nuclear antibody increased flare risk during weaning in long weaning group (OR 7.0, 95%CI: 1.2-40.8). Positive HLA-B27 (OR 6.5, 95%CI: 1.1-30.4) increased flare risks after stopping aTNF. CONCLUSION: Duration of weaning aTNF may not minimize flare rate or delay time to flare after stopping treatment in JIA patients. Recapture rates for inactive disease at 6 months remained high for patients who flared after weaning or discontinuing medication.

COVID-19 mRNA vaccine immunogenicity decay and breakthrough illness in adolescents and young adults with childhood-onset rheumatic diseases.

OBJECTIVES: To evaluate the humoral immunogenicity for 6 months after the two-dose coronavirus disease 2019 (COVID-19) mRNA vaccination in adolescents and young adults (AYAs) with childhood-onset rheumatic diseases (cRDs). METHODS: This monocentric observational study was conducted between August 2020 and March 2022. Humoral immunogenicity was assessed at 2-3 weeks after first vaccine dose and 1, 3 and 6 months after the second dose by the cPass™ severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralization antibody (nAb) assay. An inhibition signal of ≥30% defined the seroconversion threshold and the readings were calibrated against the World Health Organization International Standard for SARS-CoV-2 antibodies. RESULTS. ONE HUNDRED AND SIXTY-NINE: AYAs with cRDs were recruited [median age 16.8 years (interquartile range, IQR 14.7-19.5), 52% female, 72% Chinese]. JIA (58%) and SLE (18%) comprised the major diagnoses. After second vaccine dose, 99% seroconverted with a median nAb titre of 1779.8 IU/ml (IQR 882.8-2541.9), declining to 935.6 IU/ml (IQR 261.0-1514.9) and 683.2 IU/ml (IQR 163.5-1400.5) at the 3- and 6-month timepoints, respectively. The diagnosis of JIA [odds ratio (OR) 10.1, 95% CI 1.8-58.4, P = 0.010] and treatment with anti-TNF-α (aTNF) (OR 10.1, 95% CI 1.5-70.0, P = 0.019) were independently associated with a >50% drop of nAb titres at 6 months. Withholding MTX or MMF did not affect the vaccine response or decay rate. The COVID-19 breakthrough infection was estimated at 18.2 cases/1000 patient-months with no clinical risk factors identified. CONCLUSION: Over half of AYAs with cRDs had a significant drop in SARS-CoV-2 nAb at 6-month despite an initial robust humoral response. JIA and aTNF usage are predictors of a faster decay rate.

Post-mRNA vaccine flares in autoimmune inflammatory rheumatic diseases: Results from the COronavirus National Vaccine registry for ImmuNe diseases SINGapore (CONVIN-SING).

BACKGROUND: Studies of flares of autoimmune inflammatory rheumatic diseases (AIIRD) after COVID-19 mRNA vaccination are limited by small sample size, short follow up or at risk of selection bias. METHODS: A national retrospective cohort study of consecutive AIIRD patients ≥12 years old, across 8 hospitals who received at least one dose of a COVID-19 mRNA vaccine. Patients were included from the date of 1st vaccine dose and censored at the time of flare or on the date of the clinic visit at least 3 months from cohort entry, whichever came first. Predictors of flare were determined by Cox proportional hazards analysis. FINDINGS: 4627 patients (73% Chinese, 71% female) of median (IQR) age 61 (48, 70) years were included; 42% Rheumatoid arthritis, 14% Systemic lupus erythematosus and 11% Psoriatic arthritis. 47% were in remission, 41% low disease activity, 10% moderate disease activity and 1% in high disease activity. 18% patients flared, of which 11.7% were within the 3-month period of interest. 11.8% patients improved. Median (IQR) time-to-flare was 60 (30, 114) days. 25% flares were self-limiting, 61% mild-moderate and 14% severe. Older patients (53-65 years and >66 years) had a lower risk of flare [HR 0.6 (95% CI 0.5-0.8) and 0.7 (0.6-0.8) respectively]. Patients with inflammatory arthritis and with active disease had a higher risk of flare [HR 1.5 (1.2-2.0) and 1.4 (1.2-1.6), respectively]. Treatment with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), immunosuppression and prednisolone was also associated with an increased risk of flare [HR 1.5 (1.1-2), 1.2 (1.1-1.4) and 1.5 (1.2-1.8) for prednisolone ≤7.5 mg respectively]. INTERPRETATION: There was a moderately high rate of AIIRD flares after mRNA vaccination but also improvement in several patients. Severe flares and hospitalisation were rare. Thus, vaccination remains safe and highly recommended.

Multisystem inflammatory syndrome in children in Singapore.

INTRODUCTION: Multisystem inflammatory syndrome in children (MIS-C) is a rare inflammatory syndrome with multisystem involvement affecting children exposed to COVID-19. This condition is rarely reported in East Asia and was not detected in Singapore until 2021. We present 12 cases of MIS-C diagnosed in KK Women's and Children's Hospital (KKH) from October 2021 to December 2021. METHOD: We conducted an observational study on cases fulfilling the Singapore Ministry of Health criteria for MIS-C from January 2020 to December 2021 in KKH. Medical records were reviewed to obtain information on clinical presentation, disease course, treatment received and outcomes. RESULTS: In the 12 cases detected, the median age was 7.50 years (interquartile range 4.00-9.25); 8 were male. All patients had mucocutaneous symptoms similar to Kawasaki disease. Other commonly involved systems were: haematological (coagulopathy 100%, lymphopaenia 91.70% and thrombocytopaenia 75.00%), gastrointestinal (75.00%) and cardiovascular (83.30%). Six patients (50.00%) had shock and were admitted to the intensive care unit. The majority of patients received treatment within 2 days of hospitalisation with intravenous immunoglobulin (IVIg) and steroids. All survived; the majority had normal echocardiograms and no long-term organ sequelae at 6 months post-discharge. CONCLUSION: MIS-C emerged in Singapore as the incidence of COVID-19 in the community increased in 2021. The clinical presentation of our patients is similar to earlier reports, with some significant differences from Kawasaki disease. Multidisciplinary management, timely diagnosis, and early initiation of treatment with IVIg and steroids likely contributed to comparatively good outcomes. Our cases highlight the need for continued awareness of MIS-C among physicians, and surveillance of its incidence, short- and long-term outcomes.

Sacroiliitis at diagnosis as a protective predictor against disease flare after stopping medication: outcomes of a Southeast Asian enthesitis-related arthritis (ERA) longitudinal cohort.

OBJECTIVES: To assess short- and long-term outcomes of ERA in a large monocentric cohort in Singapore. METHODS: Children diagnosed with ERA according to ILAR criteria from 2002 to 2021 were recruited. Nonparametric statistics were used to describe the data. Outcomes were defined according to modified Wallace criteria, and probabilities and predictors were determined using Kaplan-Meier survival and logistic regression analyses. RESULTS: One hundred fifty-one ERA patients (male 86%; Chinese 81%) were included. The median age at onset was 11.9 years (IQR: 9.4-13.9), and disease duration was 5.3 years (IQR: 2.9-8.4). At diagnosis, 39% of the patients had sacroiliitis. HLA-B27 was positive in 83%, and biologics were used in 72% of the patients. Clinical inactive disease (CID) was achieved in 92% of the patients, of which 27% achieved within 6 months. Sacroiliitis at diagnosis is an unfavorable predictor of early CID at 6 months. Medication was discontinued in one-third of the patients. Favorable predictor of medication withdrawal includes male gender, while unfavorable predictors include positive HLA-B27 and ANA. Two-thirds of the patients with CID had at least one disease flare. Sacroiliitis at diagnosis is a protective predictor of flare after stopping medication. CONCLUSION: Despite a high proportion of ERA patients achieving CID, only one-third could stop medication with high rates of disease flare. Unfavorable predictors include older age at onset, HLA-B27, and ANA positivity. While sacroiliitis at diagnosis is a negative predictor of CID at 6 months, it is associated with less disease flare after discontinuing medication.

Robust neutralizing antibody response to SARS-CoV-2 mRNA vaccination in adolescents and young adults with childhood-onset rheumatic diseases.

OBJECTIVES: Immunogenicity to the SARS-CoV-2 mRNA vaccines in adolescents and young adults (AYA) with childhood-onset rheumatic diseases (cRD) is unknown. We aimed to evaluate the humoral immunogenicity and safety of the vaccines in our AYA with cRD. METHODS: A monocentric observational study with 159 AYA (50.3% female and 70.4% Chinese). Humoral immunogenicity was assessed at 2-3 and 4-6 weeks following first and second vaccination by cPass™ SARS-CoV-2 Neutralization Antibody Assay. Inhibition signal of ≥30% defined the cut-off for positive detection of the SARS-CoV-2 neutralizing antibodies. Vaccine safety and disease activity were assessed within 6 weeks after second vaccination. RESULTS: A total of 64.9% and 99.1% of 159 patients (median age: 16.9, IQR: 14.7-19.5) mounted positive SARS-CoV-2 neutralizing responses after first and second vaccination, respectively. Most patients (89.8%) had ≥90% inhibition signal after second vaccination. Methotrexate and mycophenolate mofetil increased the risk associated with negative cPass neutralization responses following the first vaccination. Holding both medications after each vaccination did not affect immunogenicity. There was no symptomatic COVID-19 infection. Local reaction remained the most common (23.3-25.2%) adverse event, without serious complication. Two and seven patients flared following the first and second vaccination, respectively. Subgroup analyses of the 12-18-year-old cohort did not show any differences in vaccine efficacy, predictors of poor response and general safety, but higher proportion of disease flares. CONCLUSIONS: SARS-CoV-2 mRNA vaccines were efficacious after the two-dose regimen in almost all AYA with cRD without serious adverse event. The rate of disease flare observed is 4.4% after the second mRNA vaccine dose.

Transition readiness assessment in adolescents and young adults with rheumatic diseases: The Singapore experience.

BACKGROUND: Transition from pediatric to adult care is a challenging time for adolescents and young adults (AYA) with rheumatic diseases. Validated tools have been developed to assess transition readiness. AIM: To evaluate transition readiness among AYA with rheumatic diseases and to identify factors associated with transition readiness. METHODS: Patients ≥15 years old were enrolled into our transition program and administered a Transition Readiness Assessment Tool (TRAT) from July 2017. The TRAT consists of 3 components: (a) patient's perception on importance of transition and confidence toward transition on a Likert scale 0-10; (b) assessment of knowledge on medical and healthcare usage using a set of 23 questions; (c) transition readiness using the Transition Readiness Assessment Questionnaire (TRAQ). Differences between groups were compared to identify factors associated with transition readiness. RESULTS: Transition readiness assessment was performed in 152 patients. The median score for perception on transition importance was 7.0 (5.0-8.8) and the median score for confidence in transition was 7.0 (5.0-9.0). Majority of the patients (>50%) lack knowledge in health insurance, carrying health information, healthcare privacy changes and making own healthcare decision. Patients <20 years old were also deficient in knowledge in navigating healthcare systems. TRAQ scores were lowest in areas pertaining to healthcare insurance and obtaining financial help. CONCLUSION: Healthcare insurance literacy and self-management skills were lacking in the assessment of transition readiness in AYA with rheumatic diseases. Targeted intervention in these areas will improve transition readiness and promote successful transition processes.

The Coming-of-Age Transition Care for Adolescents with Rheumatic Disease-Where Are We and What Have We Done in Asia?

The transition from pediatric to adult health care is a challenging yet important process in rheumatology as most childhood-onset rheumatic diseases persist into adulthood. Numerous reports on unmet needs as well as evidence of negative impact from poor transition have led to increased efforts to improve transition care, including international guidelines and recommendations. In line with these recommendations, transition programs along with transition readiness assessment tools have been established. Despite these efforts, there are still a lot of work to be done for transition care in rheumatology. This review article focuses on how transition care in rheumatology has developed in recent years and highlights the gaps in current practices.

Enthesitis Related Arthritis in a Longitudinal Southeast Asian Registry: High Prevalence of HLA-B27, Different Sacroiliitis Risk Factors and Less Common Drug-Free Remission.

Objective. To describe the clinical characteristics, predictors and treatment of children with Enthesitis Related Arthritis (ERA) in a Singapore longitudinal cohort over 11 years. Methods. ERA patients were recruited from our registry (2009-2019). Nonparametric descriptive statistics including median (interquartile range, IQR) were used to describe data. Kaplan-Meier survival and logistic/Cox regression analyses were used to estimate the probabilities and determine predictors of clinical variables, respectively. The significance level was set at <0.05. Results. One hundred and forty-six ERA patients (87% male, 82% Chinese) were included. Median onset age was 11.9 years (IQR 9.4-14.0) and median disease duration was 4.9 years (IQR 2.6-8.3). Family history of Human Leukocyte Antigen (HLA)-B27 associated diseases was positive in 7.5%. Acute uveitis occurred in 3.4%. Oligoarthritis was present in 89.7%. Hip, knee and ankle joints were among the most common joints involved. One-fourth had enthesitis at diagnosis (Achilles tendon entheses, 82.9%). Sacroiliitis occurred in 61%. Probabilities of sacroiliitis development were 0.364, 0.448 and 0.578 at 1, 2 and 5 years after onset, respectively. Negative HLA-B27, female, older age at onset and hip arthritis at diagnosis were associated with shorter time for sacroiliitis development (p = 0.001-0.049). Methotrexate (MTX) remained the most common disease modifying anti-rheumatic drug (DMARD) used (77.4%). However, 77.9% required anti-TNF (aTNF) therapy secondary to MTX failure. Among MTX-treated sacroiliitis patients, 85.3% failed, requiring aTNF, as compared to 63.2%patients without axial disease. Longer duration to diagnosis (p = 0.038) and MTX use (p = 0.007) predicted aTNF therapy. None had joint deformity. Conclusions. This study underscores differences in ERA clinical characteristics, predictors and treatment responses. Our ERA population had many unique findings but good functional outcomes.

Implementation of Universal Newborn Screening for Severe Combined Immunodeficiency in Singapore While Continuing Routine Bacille-Calmette-Guerin Vaccination Given at Birth.

Introduction: Severe Combined Immunodeficiency (SCID) is generally fatal if untreated; it predisposes to severe infections, including disseminated Bacille-Calmette-Guerin (BCG) disease from BCG vaccination at birth. However, delaying BCG vaccination can be detrimental to the population in tuberculosis-endemic regions. Early diagnosis of SCID through newborn screening followed by pre-emptive treatment with anti-mycobacterial therapy may be an alternative strategy to delaying routine BCG vaccination. We report the results of the first year of newborn SCID screening in Singapore while continuing routine BCG vaccination at birth. Method: Newborn screening using a T-cell receptor excision circle (TREC) assay was performed in dried blood spots received between 10 October 2019 to 9 October 2020 using the Enlite Neonatal TREC kit. Patients with low TREC had lymphocyte subset analysis and full blood count performed to determine the severity of lymphopenia and likelihood of SCID to guide further management. Results: Of the 35888 newborns screened in 1 year, no SCID cases were detected, while 13 cases of non-SCID T-cell lymphopenia (TCL) were picked up. Using a threshold for normal TREC to be >18 copies/µL, the retest rate was 0.1% and referral rate to immunologist was 0.04%. Initial low TREC correlated with low absolute lymphocyte counts (ALC), and subsequent normal ALC corresponded with increases in TREC, thus patients with normal first CD3+ T cell counts were considered to have transient idiopathic TCL instead of false positive results. 7/13 (54%) had secondary TCL (from sepsis, Trisomy 21 with hydrops and stoma losses or chylothorax, extreme prematurity, or partial DiGeorge Syndrome) and 6/13 (46%) had idiopathic TCL. No cases of SCID were diagnosed clinically in Singapore during this period and for 10 months after, indicating that no cases were missed by the screening program. 8/9 (89%) of term infants with abnormal TREC results received BCG vaccination within the first 6 days of life when TREC and ALC were low. No patients developed BCG complications after a median follow-up of 17 months. Conclusion: Newborn screening for SCID can be implemented while continuing routine BCG vaccination at birth. Patients with transient TCL and no underlying primary immunodeficiency are able to tolerate BCG vaccination.

Outcomes and predictors of juvenile idiopathic arthritis in Southeast Asia: a Singapore longitudinal study over a decade.

OBJECTIVE: To assess short- and long-term outcomes and predictors of juvenile idiopathic arthritis (JIA) children treated with contemporary therapy and compare those with reports elsewhere. METHODS: Children with JIA were recruited from our web-based REgistry for Childhood Onset Rheumatic Diseases (RECORD) from 1997 to 2015. Disease status was defined using modified Wallace criteria. Nonparametric statistics described the data. Kaplan-Meier survival and logistic regression analyses were used to estimate probabilities and to determine predictors of outcomes. RESULTS: A total of 251 children with JIA (62% males, 71% Chinese) were included. Median follow-up duration was 2.9 years (range 0.1-17.5). Short-term clinical inactive disease (CID) was attained in 37% with 62% systemic JIA (sJIA) and 47% persistent oligoarthritis (oJIA). Methotrexate (OR 0.34) decreased but sJIA (OR 3.25) increased chance of attaining CID at 6 months. Overall, 79% of patients achieved CID within 2 years (sJIA 92%, the highest, and RF+ polyarthritis 50%, the lowest probability). Biologics were associated with CID attainment (OR 2.73). One-half of patients flare after CID, median 1.2 years (IQR 0.71-1.97). Late CID achievement predicted flare (OR 2.15). Only 15% had clinical remission off medication (none RF+ polyarthritis and 7% ERA). Only 13% of patients had active arthritis as young adults and 22% had active arthritis at last visit. CONCLUSION: Despite high proportion of JIA patients attaining CID, only one-fourth could stop all medications for at least 1 year. Persistent oJIA patients were less likely to achieve clinical remission on medication and ERA patients had the least chance stopping medications. One-tenth of patients had active arthritis as young adults. Key Points • Majority of Asian children with JIA attained inactive disease within 2 years after diagnosis. • Outcome predictors were different from reports from the West. • Despite high inactive disease numbers, only one-in-four JIA patients discontinued treatment within 5 years.

Juvenile idiopathic arthritis in Southeast Asia: the Singapore experience over two decades.

OBJECTIVES: To examine the clinical characteristics, treatment and outcomes of juvenile idiopathic arthritis (JIA) patients evaluated in Singapore and compare those with reports elsewhere. METHODS: Patients with JIA were recruited from our Singapore pediatric rheumatology registry from January 1997 to December 2015. Demographic, clinical, treatment, and outcome data were retrospectively collected. Nonparametric statistics were used to describe the data. Chi-squared, Mann-Whitney U, or Kruskal-Wallis tests were applied to compare differences between groups where appropriate. Multivariate logistic regression analyses were used to identify predictors for clinical parameters. RESULTS: Two hundred eighty-seven JIA patients with 60.6% males of predominantly Chinese descent were included in the study. The median onset age was 9 years (IQR 5.3-12.6), and the median follow-up duration was 30.1 months (IQR 9.1-61.7). Enthesitis-related arthritis (ERA, 32.8%) followed by persistent oligoarthritis (31.0%) was the most common. Elbow or ankle involvement predicted oligoarthritis extension (OR 15.8 (95% CI: 2.3-108.3, p = 0.005), 8.1 (95% CI: 1.5-45.3, p = 0.017)). JIA-associated uveitis was rare (2.8%) which paralleled the less common positive-ANA rate. Majority of our ERA patients had HLA-B27 (79.8%), together with older age predicted sacroiliitis (OR 4.7 (95% CI: 2.0-11.1, p < 0.05), OR 1.2 (95% CI: 1.1-1.3, p = 0.002)). TMJ involvement was under-reported. Methotrexate remained the most common DMARD used, but 36% of patients required biologics for which ERA and polyarthritis were the majority. Joint damage was rare. CONCLUSION: This study highlights geographical and ethnic differences in JIA epidemiology. Compared with reports elsewhere, our JIA population had many unique findings and good functional outcomes requiring regional study validation. Key points • ERA is the most prominent JIA subtype in Singapore with high prevalence of HLA-B27. • JIA-associated uveitis is rare in SEA and is not associated with ANA or JIA-subtypes. • Elbow and/or ankle involvement at presentation is associated with oligoarthritis extension in our JIA cohort.