Unique Characteristics of Prepubertal Onset Systemic Lupus Erythematosus

Childhood-onset systemic lupus erythematosus in China, 2016-21: a nationwide study

BACKGROUND

Childhood-onset systemic lupus erythematosus (SLE) is a complex autoimmune disorder that can lead to serious organ damage. Despite the prevalence of SLE among children in Asian countries, treatment guidelines, prognosis, and clinical decision making for children with SLE are limited by gaps in region-specific epidemiological data. The aim of this study was to analyse epidemiological characteristics of childhood-onset SLE and associated organ involvement and in-hospital mortality in China.

METHODS

In this nationwide study, we searched standardised hospital discharge records submitted to the Hospital Quality Monitoring System (HQMS) between Jan 1, 2016, and Dec 31, 2021, for patients with a diagnosis of childhood-onset SLE based on the 2019 American College of Rheumatology or 2012 Systemic Lupus International Collaborating Clinics classification criteria. We selected records for patients aged 18 years and younger containing relevant ICD 10th revision diagnostic codes (specifically M32) among discharge diagnostic codes. We excluded records for patients younger than 5 years, whose SLE diagnosis was presumed to be monogenic lupus, and for patients with overlap syndromes or unidentified sex. Date of diagnosis (equal to the first hospital discharge date), age, organ involvement, intensive care unit (ICU) treatment, and in-hospital mortality were extracted from the records. Incidence rates for 2017, 2018, 2019, 2020, and 2021 were identified with five washout periods ranging from 12 months (Jan 1-Dec 31, 2016) to 60 months (Jan 1, 2016-Dec 31, 2020). Data were stratified by sex, age relative to puberty onset, organ involvement and concurrent infection at time of diagnosis, human development index of region of residence, hospital level, and hospital type. Incidence trends by sex, age relative to puberty onset, and year were derived by joinpoint regression analysis, with 95% CIs calculated by the Poisson exact method. Major organ involvement was assessed according to definitions in the British Isles Lupus Assessment Group 2004 disease activity index. Outcomes of ICU admission after first diagnosis and in-hospital death after ICU admission were analysed in Cox proportional hazards models, with p values and 95% CIs calculated with the parametric method.

FINDINGS

Between Jan 1, 2016, and Dec 31, 2021, the HQMS received 134 956 hospital discharge records containing the M32 discharge diagnostic code for patients aged 18 years or younger. 6286 records were excluded, leaving 128 670 records representing 54 338 patients aged 5-18 years; of these, 43 756 patients (36 153 girls and 7603 boys) received their childhood-onset SLE diagnosis on or after Jan 1, 2017. Between Jan 1, 2017, and Dec 31, 2021, the SLE incidence rate was 3·97 (95% CI 3·93-4·01) per 100 000 person-years, with a declining trend during the 5-year period. Joinpoint analysis showed sex-dependent and age-dependent incidence patterns. After a relatively stable incidence rate among prepubertal children aged 5-7 years, the incidence rate increased among peripubertal children aged 8-12 years by 0·92 cases per 100 000 person-years with each 1-year increase in age (p<0·0001). Among peripubertal children aged 8-12 years, girls showed the largest change in incidence rate, with an increase of 1·64 per 100 000 person-years with each 1-year increase in age (p<0·0001), compared with 0·40 per 100 000 person-years with each 1-year increase in age among boys (p=0·013). The organ systems most affected in patients with childhood-onset SLE were the kidneys (56·8%) and the haematological system (27·8%). Among the 2471 patients admitted to the ICU, 213 (9%) of whom died in ICU, the three organ-related risk factors at initial diagnosis that showed greatest association with progression to critical illness were cardiovascular involvement (adjusted hazard ratio 2·50 [95% CI 2·18-2·87]; p<0·0001), neuropsychiatric SLE (2·10 [1·87-2·37]; p<0·0001), and serositis (2·03 [1·78-2·30]; p<0·0001). Other prominent risk factors for progression to critical illness were concurrent infections with Epstein-Barr virus (1·52 [1·16-1·98]; p=0·0020) or fungi (1·49 [1·22-1·83]; p=0·0001). In total, 396 (0·7%) of 54 338 patients with childhood-onset SLE died in hospital; the most common causes of death were pneumonia (146 [37%]), multi-organ dysfunction syndrome (99 [25%]), and renal failure (75 [19%]). Risk of in-hospital mortality was highest among pubertal children (hazard ratio 2·16 [95% 1·14-4·09]) compared with prepubertal children, and risk of ICU admission was highest among prepubertal children (2·95 [2·16-4·03]) compared with postpubertal children.

INTERPRETATION

These nationwide data on the epidemiology of childhood-onset SLE in the Chinese paediatric population show for the first time a declining trend in incidence rates, rapid rise in puberty-onset rates, and the distinct involvement of vital organs from disease onset to mortality in China. They underscore the complexity of childhood-onset SLE pathogenesis and emphasise the imperative for stratified precision treatment, informed interventions, and health-care planning for childhood-onset SLE.

FUNDING

National Key Research & Development Program of China.

The inequity of global healthcare in pediatric rheumatology

In pediatric rheumatology, global health inequity relates to the uneven distribution of healthcare resources, accessibility, and health outcomes among children with rheumatic conditions across various countries, regions, and socioeconomic groups. This inequity can manifest in various ways. This review article provides an overview of common rheumatic diseases, such as juvenile idiopathic arthritis and systemic lupus erythematosus, which significantly contribute to and are affected by disparities in global healthcare. Subsequently, we delve into the inequalities in accessing patient care, encompassing issues related to diagnosis and treatment. Additionally, we address challenges in educational advancement and identify research gaps within the field of pediatric rheumatology. We also reveal successful global collaborations, such as a Global Task Force for Pediatric Musculoskeletal Health and special working groups among international organizations, aimed at bridging the disparities gap. Through these efforts, we try to enhance understanding, cooperation, and resource allocation to ensure equal access to quality care worldwide for children with rheumatic conditions. Futhermore, we present a case study from Thailand, highlighting their successful initiatives in developing pediatric rheumatology within their healthcare system.

Clinical characteristics of early-onset paediatric systemic lupus erythematosus in a single centre in China

OBJECTIVES

We sought to investigate the sex distribution, clinical presentations, disease outcomes and genetic background of early-onset paediatric SLE (eo-pSLE) in a single centre in China to help enable early diagnosis and timely treatment.

METHODS

The clinical data of children aged less than 5 years old with SLE (n = 19) from January 2012 to December 2021 were reviewed and analysed. We performed DNA sequencing in 11 out of 19 patients to survey the genetic aetiologies.

RESULTS

Our study included 6 males and 13 females. The mean age at onset was 3.73 years. The median diagnostic delay was 9 months and was longer in male patients (P = 0.02). Four patients had an SLE-relevant family history. The most common clinical manifestations at diagnosis were fever, rash and hepatosplenomegaly. ANA positivity and low C3 were identified in all children. The renal (94.74%), mucocutaneous (94.74%), haematological (89.47%), respiratory (89.47%), digestive (84.21%), cardiovascular (57.89%) and neuropsychiatric (52.63%) systems were involved to varying degrees. We identified 13 SLE-associated gene mutations in 9 out of 11 patients: TREX1, PIK3CD, LRBA, KRAS, STAT4, C3, ITGAM, CYBB, TLR5, RIPK1, BACH2, CFHR5 and SYK. One male patient showed a 47, XXY chromosomal abnormality.

CONCLUSION

Early-onset (<5 years) pSLE is characterized by an insidious onset, typical immunological patterns, and the involvement of multiple organs. Immunological screening and genetic testing should be performed as soon as feasible in patients with an early onset of multisystemic autoimmune diseases to confirm the diagnosis.

Aquaporin-4 IgG antibodies: predictors of positivity and their relationship with neuropsychiatric disorders and white matter lesions in Juvenile systemic lupus erythematosus

BACKGROUND

This study aimed to describe the prevalence of the various clinical features and severity of juvenile systemic lupus erythematosus (jSLE) and to assess predictors of AQP4-Ab positivity in jSLE. In addition, we assessed the relationship of AQP4-Abs with neuropsychiatric disorders and white matter lesions in jSLE.

METHOD

For 90 patients with jSLE, demographic data, clinical manifestations, and treatments received were recorded, and all of the patients were underwent clinical examinations, including assessments for the neurological manifestations of jSLE and neuropsychiatric disorders; Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score evaluations; laboratory investigations, including serum AQP4-Ab assays; and 1.5 Tesla brain MRI. Echocardiography and renal biopsy were performed for the indicated patients.

RESULT

Fifty-six patients (62.2%) tested positive for AQP4-Abs. These patients were more likely to have higher disease activity scores (p < 0.001); discoid lesions (p = 0.039); neurological disorders (p = 0.001), mainly psychosis and seizures (p = 0.009 and p = 0.032, respectively); renal and cardiac involvement (p = 0.004 and p = 0.013, respectively); lower C3 levels (p = 0.006); white matter hyperintensities (p = 0.008); and white matter atrophy (p = 0.03) than patients who were negative for AQP4-Abs. Furthermore, AQP4-Ab-positive patients were more likely to have received cyclophosphamide (p = 0.028), antiepileptic drugs (p = 0.032) and plasma exchange therapy (p = 0.049).

CONCLUSION

jSLE patients with higher severity scores, neurological disorders, or white matter lesions could develop antibodies against AQP4. We recommend more studies for systematic screening of AQP4-Ab positivity in jSLE patients to confirm its relationship with neurological disorders.

Clinical Determinants of Childhood Onset Systemic Lupus Erythematosus among Early and Peri-Adolescent Age Groups

Introduction: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that is associated with significant morbidity and mortality. SLE disproportionately affects women and minorities. Childhood-onset SLE (cSLE) in particular tends to be more aggressive than adult-onset SLE. Despite substantial improvements in the treatment of cSLE, there is significant variability in treatment responses and long-term outcomes. Furthermore, there is a paucity of studies involving cSLE, and in particular, cSLE among different age groups. The aim of this study was to test the hypothesis that an early-onset cSLE cohort would demonstrate unique characteristics with distinctive clinical and laboratory features at disease onset. We specifically investigated whether clinical, epidemiological, or serological factors are differentially associated with early- and late-onset cSLE. This could have direct impact on clinical management with the goal of improving outcomes and quality of life for children with SLE. Methods: Our study was conducted at a large tertiary center. We included 213 subjects seen at our pediatric rheumatology clinic aged 4−17 years. Epidemiologic, clinical phenotype, disease severity, serology, treatment, and outcome data were compared between subjects with cSLE onset prior to 10 years of age (early-onset disease, n = 43) and those with cSLE onset greater than 10 years of age (peri-adolescent disease, n = 170). We compared clinical features between early- and peri-adolescent onset cSLE in order to investigate the association between age at disease onset of cSLE and clinical disease expression and outcomes. Results: Of the 213 subjects with cSLE in our study, 43 subjects had early-onset disease (age 2 to ≤9 years) and 170 patients had peri-adolescent onset disease. We found that early-onset cSLE was associated with a higher prevalence of positive anti-dsDNA antibody at cSLE diagnosis, higher anti-dsDNA antibody titer at cSLE diagnosis, rash, and azathioprine use (p < 0.001, p = 0.004, p = 0.011, and p = 0.008, respectively). In contrast, we found that peri-adolescent onset cSLE (≥10 years of age) was associated with worse disease activity (SLEDAI range 0−24) (p < 0.001), higher SLICC at diagnosis (p < 0.001), as well as a higher rate of mycophenolate mofetil and hydroxychloroquine use (p = 0.003 and p < 0.001, respectively). There were no significant differences in the prevalence of neuropsychiatric symptoms or the development of Class IV/Class V lupus nephritis between the early-onset and peri-adolescent groups.

A systematic review exploring the bidirectional relationship between puberty and autoimmune rheumatic diseases

BACKGROUND

Autoimmune rheumatic diseases (ARDs) are associated with a significant sex-bias, which becomes more evident post-puberty. This systematic review aims to elucidate the bidirectional relationship between puberty and ARD-related outcomes.

METHODS

Studies published in English until October 2019 were identified using a systematic search of endocrinology and rheumatology literature. Information was extracted on study design, sample size, demographics, puberty outcome measures, disease outcome measures, and main findings. The methodological quality of the studies included was analysed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Sixteen non-randomised studies reporting on the impact of puberty on ARD outcomes (n = 7), ARD impact on puberty-related outcomes (n = 8), or both (n = 1) have been identified. The impact of puberty on ARD outcomes were investigated in patients with juvenile idiopathic arthritis (JIA)-associated uveitis (n = 1), juvenile systemic lupus erythematosus (JSLE) (n = 5) or in healthy controls who developed adult-onset SLE (n = 1) or had non-specific symptoms (n = 1). The impact of ARD on puberty outcomes was explored in JIA (n = 4) and JSLE (n = 3). Quality assessment of studies showed a small to moderate risk of bias overall (NOS 4-9/9). Due to large heterogeneity of the studies it was not possible to perform a meta-analysis. Multiple studies reported on delayed puberty in patients with JIA/JSLE, menstrual and hormonal abnormalities, and lower height and weight than controls. Earlier (pre-pubertal) onset of JSLE was correlated with more severe disease and more need for systemic treatment.

CONCLUSION

A bidirectional relationship exists between puberty and ARDs; however, more and better research is required to elucidate the complexity of this relationship. We propose puberty-related clinical assessments in patients with ARDs, which can improve patient outcomes and facilitate future research.

Improving musculoskeletal health for children and young people - A 'call to action'

This chapter describes the musculoskeletal (MSK) context in children and young people as an important contributor to the global non-communicable disease burden. Through selected MSK conditions, we describe the impact on patients, families and communities and highlight the challenges that need to be addressed. We focus on opportunities for better working together and describe exemplar initiatives to raise awareness, workforce capacity building, models of care and research agendas to have a greater global context.

Juvenile-onset systemic lupus erythematosus: Update on clinical presentation, pathophysiology and treatment options

Juvenile-onset systemic lupus erythematosus (jSLE) accounts for up to 20% of all SLE patients. Key differences between juvenile- and adult-onset (aSLE) disease include higher disease activity, earlier development of damage, and increased use of immunosuppressive treatment in jSLE suggesting (at least partial) infectivity secondary to variable pathomechanisms. While the exact pathophysiology of jSLE remains unclear, genetic factors, immune complex deposition, complement activation, hormonal factors and immune cell dysregulation are involved to variable extents, promising future patient stratification based on immune phenotypes. Though less effective and potentially toxic, jSLE patients are treated based upon evidence from studies in aSLE cohorts. Here, age-specific clinical features of jSLE, underlying pathomechanisms, treatment options and disease outcomes will be addressed. Future directions to improve the care of jSLE patients, including implementation of the Single Hub and Access point for pediatric Rheumatology in Europe (SHARE) recommendations, biomarkers, treat to target and personalized medicine approaches are discussed.