Study of NLRP3 Single Nucleotide Polymorphisms in Juvenile Systemic Lupus Erythematosus (JSLE)

Juvenile systemic lupus erythematosus (JSLE) is a multifaceted multifactorial disorder with an unclear etiopathogenesis. Environmental factors, genetic factors, and dysregulated and defective immune system responses are known to have a role in JSLE etiopathogenesis. NLRP3 inflammasome, as an important contributor to immune-mediated inflammatory responses, is assumed to be involved in JSLE etiopathogenesis. To determine whether the NLRP3 genetic variants are altered in patients with JSLE. Fifty-three patients diagnosed with JSLE and 56 healthy sex-matched controls were studied. NLRP3 (C/G rs10754558, C/T rs3806265, C/T rs4612666, A/C rs35829419) gene polymorphisms were evaluated using a TaqMan single-nucleotide polymorphism assay. C allele at position rs3806265 was detected in higher frequencies in patients than in the control group (37.74% vs 23.21%, P-value = .028). At the genotype level at the same position, CT has a significantly higher frequency in patients than the healthy subjects (75.47% vs 46.43%, P-value = .003). The NLRP3 rs3806265 CT genotype was detected at a higher frequency in patients with JSLE than in the healthy control group.

Classification of systemic lupus erythematosus in children and adults

Systemic Lupus Erythematosus (SLE) is an autoimmune multisystem disease with a variable clinical phenotype and no single clinical, laboratory or pathological feature that can be used as a gold standard for disease classification or diagnosis. Classification criteria have been developed in an attempt to define homogenous groups of SLE patients for clinical research. They have been mainly validated in adult cohorts, given the much lower prevalence of SLE before puberty. The three commonly used sets of current classification criteria and their validation studies to date are described in this review. Challenges relating to classification of SLE patients, including important differences across age-groups and ethnicities, are explored along with future directions in the classification of SLE.

Global prevalence estimates of three chronic musculoskeletal conditions: club foot, juvenile idiopathic arthritis and juvenile systemic lupus erythematosus

BACKGROUND

Musculoskeletal (MSK) conditions are a major source of morbidity and disability. There is a lack of global comparable data on the burden of MSK conditions in children and young people. Our aim was to estimate the global prevalence of three MSK conditions - Talipes Equinovarus (Clubfoot), Juvenile Idiopathic Arthritis (JIA) and Juvenile Systemic Lupus Erythematosus (JSLE).

METHODS

Using reported prevalence rates, age-stratified population data within the World Bank Data Bank in 2017 and United Nations country classification, we estimated the prevalence of these MSK conditions in < 5 year olds (clubfoot) and < 16 year olds (JIA and JSLE) across the world.

RESULTS

We estimated that in 2017, there were ~ 675,061 < 5 year olds with clubfoot among 675,100,000 < 5 year olds, ~ 2,069,246 < 16 year olds with JIA and ~ 206,931 < 16 year olds with JSLE per 2,069,000,000 < 16 year olds, totalling ~ 2,951,238 with one of these conditions. Disease prevalence was greatest in Asia (South Asia), followed by Africa, Americas, Europe and Oceania.

CONCLUSIONS

An estimated 3 million children and young people globally are currently living with either clubfoot, JIA or JSLE; many in Asia and Africa. Further work is needed urgently to engage with global stakeholders to work together to improve access to effective care for the many who are affected and reduce the otherwise adverse lifelong impact on their health, quality of life and the impact on society.

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.

Vasculitis in Juvenile-Onset Systemic Lupus Erythematosus

Juvenile-onset systemic lupus erythematosus (JSLE) is a rare, heterogeneous multisystem autoimmune disease that can affect any organ, and present with diverse clinical and serological manifestations. Vasculitis can be a feature of JSLE. It more commonly presents as cutaneous vasculitis than visceral vasculitis, which can affect the central nervous system, peripheral nervous system, lungs, gut, kidneys, heart, and large vessels. The incidence and prevalence of vasculitis in JSLE has not been well described to date. Symptoms of vasculitis can be non-specific and overlap with other features of JSLE, requiring careful consideration for the diagnosis to be achieved and promptly treated. Biopsies are often required to make a definitive diagnosis and differentiate JSLE related vasculitis from other manifestations of JSLE, vasculopathies, and JSLE related antiphospholipid syndrome. Visceral vasculitis can be life threatening, and its presence at the time of JSLE diagnosis is associated with permanent organ damage, which further highlights the importance of prompt recognition and treatment. This review will focus on the presentation, diagnosis, management and outcomes of vasculitis in JSLE, highlighting gaps in the current evidence base.

The effectiveness and safety of biological therapeutics in juvenile-onset systemic lupus erythematosus (JSLE): a systematic review

OBJECTIVE

To systematically review and summarize the available literature regarding the effectiveness and safety of biologics in the treatment of juvenile-onset systemic lupus erythematosus.

METHODS

PubMed was systematically searched for relevant literature (2012-2017 inclusive) using the following criteria: (1) patients diagnosed with juvenile-onset systemic lupus erythematosus (≤18 years at diagnosis); (2) treatment with any biological agent; and (3) outcome measures assessing effectiveness and safety. Systematic literature reviews, meta-analyses, randomized controlled trials, cohort studies, case control studies, cross sectional surveys and case-series with ≥3 patients were included. Independent extraction of articles by two authors using predefined criteria was performed. The quality of each study was assessed using CASP tools and Oxford CEBM Levels of Evidence.

RESULTS

Nine articles met inclusion criteria: six cohort studies, two case series and one pilot study, totalling 230 patients. All but one article reported the effects of rituximab, the other those of belimumab. Overall, patients had active disease refractory to standard of care regimens using corticosteroids and immunosuppressants. Available evidence for rituximab demonstrated improvements in disease activity, complement levels and anti-dsDNA titres accompanying a steroid-sparing effect.

CONCLUSION

Rituximab can be considered an effective treatment in juvenile-onset systemic lupus erythematosus patients with severe disease manifestations and/or refractory disease. Based on current evidence, use of belimumab in juvenile-onset systemic lupus erythematosus patients cannot be recommended. The long-term safety of these biological agents remains uncertain. Further prospective studies, ideally robust randomized controlled trials, are urgently needed to obtain more accurate data on the effectiveness and long-term safety of rituximab, belimumab and other biologics in juvenile-onset systemic lupus erythematosus.

Clinical predictors of proteinuric remission following an LN flare - evidence from the UK JSLE cohort study

BACKGROUND

Proteinuria is a well-known risk factor for progression of renal dysfunction in a variety of chronic kidney diseases. In adult-onset Systemic Lupus Erytematosus (SLE) patients with lupus nephritis (LN), proteinuria takes a significant period of time to normalise, with proteinuric remission being associated with improved renal survival and reductions in mortality. The length of time required to attain proteinuric remission has not previously been investigated in Juvenile-onset SLE (JSLE). The aim of this study was to elucidate when proteinuric remission occurs, and whether clinical/demographic factors at LN onset bear influence on the time to proteinuric remission.

METHODS

Participants of the UK JSLE Cohort Study and Repository were included if they had active LN (renal biopsy and/or renal British Isles Lupus Assessment Grade (BILAG) score defined active LN) and proteinuria. Univariate Cox proportional hazard regression modelling was used to explore factors associated with time to proteinuric recovery. Covariates with p-value < 0.2 were included in a multivariable Cox regression model, and backward stepwise variable selection applied.

RESULT

64/350 (18%) of UK JSLE Cohort Study patients fulfilled the study inclusion criteria. 25 (39%) achieved proteinuric remission within a median of 17 months (min 2.4, max 78). Within a multivariate Cox proportional hazard regression model, age at time of LN flare (p = 0.007, HR 1.384, CI 1.095-1.750), eGFR (p = 0.035, HR 1.016, CI 1.001-1.030) and haematological involvement (p = 0.016, HR 0.324, CI 0.129-0.812) at the time of LN onset were found to be significantly associated with time to proteinuric recovery.

CONCLUSIONS

A significant proportion of children with LN have on-going proteinuria approximately two years after their initial flare. Poor prognostic factors all at time of LN onset include younger age, low eGFR, and concomitant haematological involvement.

Urinary biomarkers in childhood lupus nephritis

Juvenile-onset systemic lupus erythematosus (JSLE) is a rare, severe multisystem autoimmune disease affecting the kidney (Lupus Nephritis, LN) in up to 80% of children. LN is more severe in children than adults, with potential for irreversible kidney damage requiring dialysis or transplant. Renal biopsy is currently the gold standard for diagnosing and monitoring LN, however, it is invasive and associated with complications. Urine biomarkers have been shown to be better than serum biomarkers in differentiating renal disease from other organ manifestations. Over the past decade, there have been an increasing number of studies investigating specific candidate biomarkers implicated in the pathogenesis of LN or screening for urinary biomarkers using hypothesis free methods. In this review, developments in urine biomarkers for LN will be reviewed, highlighting those that are of relevance to children and have gone through validation in independent international patient cohorts, bringing them close to clinical translation.

Increased expression of low density granulocytes in juvenile-onset systemic lupus erythematosus patients correlates with disease activity

Neutrophils are implicated in a wide range of non-infectious inflammatory conditions. A subset of neutrophils in the peripheral circulation of systemic lupus erythematosus (SLE) patients has been described and termed low density granulocytes (LDGs). This study investigates the expression of LDG in juvenile-onset SLE (JSLE) patients compared to controls, and any correlations with disease activity.Neutrophils and LDGs were isolated from JSLE (n = 13) and paediatric non-inflammatory control patients (n = 12). Cell populations were assessed and compared using flow cytometry and morphological analysis. Standard clinical data, which included disease activity markers/scores, were collected for each patient.Significantly increased LDG expression (%mean ± SEM, range) was observed in JSLE patients (10.4 ± 3.26, 3.41-36.3) compared to controls (2.4 ± 0.44, 0.36-5.27; p = 0.005). A statistically significant positive correlation was observed between LDG expression and the British Isles Lupus Activity Group (correlation coefficient 0.685; p = 0.010) and SLE Disease Activity Index (correlation coefficient 0.567; p = 0.043) and the biomarker of dsDNA-antibodies (correlation coefficient 0.590; p = 0.043).Here we observe increased expression in LDGs in JSLE patients, which correlate with dsDNA antibody concentration and scores of disease activity. These correlations indicate that the increased LDG expression observed in this study may have a potential role in the pathogenesis of JSLE, and may be a useful biomarker.

Comparison of bone mass and quality determinants in adolescents and young adults with juvenile systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA)

BACKGROUND

Few prospective data have been published on the comparison of bone density and quality in homogeneous groups of patients with juvenile systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA).

OBJECTIVE AND HYPOTHESIS

The objective of this study is to perform a longitudinal evaluation of the prevalence and the characteristics of bone mass and quality and to evaluate the differences on the bone parameters, using DXA, pQCT and QUS.

POPULATION AND/OR METHODS

Forty-three JSLE patients (35 females, 8 males, median age 18.8, range 14.0-34.1 years) have been studied with DXA, pQCT and QUS scans and compared with 138 JIA patients (112 females, 26 males, median age 18.9, range 13.4-33.2 years), and 79 controls (59 females, 20 males; median age 19.3, range 13.5-36.5 years). Of these, 39 patients (32 females and 7 males, median age 20.3, range 16.6-36.8 years) with JSLE were followed longitudinally and compared with 131 patients (108 females, 23 males median age 20.7, range 15.8-37.1 years) with JIA and 63 controls (48 females, 15 males; median age 21.9, range 15.5-38.3 years).

RESULTS

JSLE patients have a higher bone cortical density (CrtBMD) than controls and JIA patients (p < 0.005). However, JSLE and JIA patients have a significantly reduced bone trabecular density (TrbBMD) compared to controls (p < 0.0001), with no differences between JSLE and JIA. In addition, JIA patients show a significantly reduced muscle area (MuscleCSA) compared to JSLE and controls (p < 0.001). Conversely, fat area (FatCSA) is significantly increased both in JIA and JSLE patients when compared to controls (p < 0.001), with no differences between the JSLE and JIA groups. Analogous results are observed in the polar resistance to stress (SSIp). On longitudinal evaluation, contrary to CrtBMD, the difference between BMAD SDS, TrbBMD, MuscleCSA and FatCSA remains unchanged; in JSLE patients, SSIp is stable in comparison to JIA and controls without any difference between the two groups.

CONCLUSIONS

The evaluation of bone density and structure parameters in JSLE patients highlights significant differences compared with JIA patients and controls. These data might indicate a different pathogenesis of bone damage in the two entities, and suggest a different diagnostic and therapeutic approach to improve the peak bone mass.

Predictors of access to care in juvenile systemic lupus erythematosus: evidence from the UK JSLE Cohort Study

OBJECTIVE

The objective of this study was to investigate factors that may influence the interval between symptom onset and JSLE diagnosis.

METHODS

Data from all patients recruited to the UK JSLE Cohort Study between 2006 and 2011 and meeting ACR criteria for lupus were analysed. Variables associated with time between symptom onset and diagnosis were identified using correlation tests. Linear regression was used to identify independent predictors of access to care.

RESULTS

Two hundred and fifty-seven children with JSLE were included in the analysis (216 females, 41 males, ratio 5.3:1). The median time from symptom onset to diagnosis was 0.4 years (range 0.0-14.1 years, interquartile range 0.2-1.4). A linear regression model identified being of African or Caribbean origin (P = 0.006), Asian (P = 0.045), referred by a paediatrician (P = 0.047) or having nephritis (P = 0.045) at presentation as independent predictors of shorter time to diagnosis. Being of Caribbean or Asian origin, compared with white, was associated with a 56% and 37% reduction in geometric mean time to diagnosis, respectively. Similarly, being referred to paediatric rheumatology by a paediatrician or having nephritis at presentation was also associated with a 32% and 36% reduction in geometric mean time to diagnosis, respectively.

CONCLUSION

Within this national UK cohort, ethnic origin, initial source of referral and having lupus nephritis at presentation were strong predictors of the interval to establishing a diagnosis of JSLE.