Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Cross-Sectional Characteristics of Pediatric-Onset Discoid Lupus Erythematosus: Results of a Multicenter, Retrospective Cohort Study

• Discoid lupus may be associated with SLE. In this study, most children with discoid lupus did not have systemic disease. Concurrent SLE was highest in female adolescents (>10 years of age) with generalized discoid lupus, who had clinically aggressive disease. • Discoid lupus in adolescence should prompt thorough evaluation for SLE.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Identifying clinically meaningful severity categories for PROMIS pediatric measures of anxiety, mobility, fatigue, and depressive symptoms in juvenile idiopathic arthritis and childhood-onset systemic lupus erythematosus

PURPOSE

A key limitation to widespread adoption of patient-reported outcome (PRO) measures is the lack of interpretability of scores. We aim to identify clinical severity thresholds to distinguish categories of no problems, mild, moderate, and severe along the PROMIS® Pediatric T-score metric for measures of anxiety, mobility, fatigue, and depressive symptoms for use in populations with juvenile idiopathic arthritis (JIA) and childhood-onset systemic lupus erythematosus (cSLE).

METHODS

We used a modified standard setting methodology from educational testing to identify clinical severity thresholds (clinical cut scores). Using item response theory-based parameters from PROMIS item banks, we developed a series of clinical vignettes that represented different severity or ability levels along the PROMIS Pediatric T-score metric. In stakeholder workshops, participants worked individually and together to reach consensus on clinical cut scores. Median cut-score placements were taken when consensus was not reached. Focus groups were recorded and qualitative analysis was conducted to identify decision-making processes.

RESULTS

Nine adolescents (age 13-17 years) with JIA (33% female) and their caregivers, five adolescents (age 14-16 years) with cSLE (100% female) and their caregivers, and 12 pediatric rheumatologists (75% female) participated in bookmarking workshops. Placement of thresholds for bookmarks was highly similar across stakeholder groups (differences from 0 to 5 points on the PROMIS t-score metric) for all but one bookmark placement.

CONCLUSION

This study resulted in clinical thresholds for severity categories for PROMIS Pediatric measures of anxiety, mobility, fatigue, and depressive symptoms, providing greater interpretability of scores in JIA and cSLE populations.

Practice-based differences in paediatric discoid lupus erythematosus

BACKGROUND

Children with discoid lupus erythematosus (DLE) are at risk for disfigurement and progression to systemic lupus erythematosus (SLE). Consensus is lacking regarding optimal care for children with DLE.

OBJECTIVES

The aim of this study was to compare practice patterns among paediatric dermatologists/rheumatologists treating paediatric DLE.

METHODS

An online survey was sent to 292 paediatric rheumatologists in the Childhood Arthritis and Rheumatology Research Alliance and 200 paediatric dermatologists in the Pediatric Dermatology Research Alliance. Consensus was defined as ≥ 70% agreement.

RESULTS

Survey response rates were 38% (76 of 200) for dermatology and 21% (60 of 292) for rheumatology. Both specialties agreed that screening labs should include complete blood counts with differential, urinalysis, complement levels, erythrocyte sedimentation rate, antinuclear antibody and other autoantibodies, hepatic function and renal function/electrolytes. Both specialties agreed that arthritis or nephritis should prompt intensified evaluation for SLE. No other patient features achieved consensus as disease-modifying risk factors. Hydroxychloroquine was agreed upon as first-line systemic therapy, but consensus was lacking for second- or third-line treatment.

CONCLUSIONS

We found few areas of consensus and significant practice differences between paediatric dermatologists and rheumatologists treating DLE. Knowledge gaps include risk factors for SLE, optimal screening and treatment of refractory skin disease.

Clinical characteristics of children with membranous lupus nephritis: the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry

Objective The objective of this article is to describe and compare clinical features, treatment, and renal outcomes of children with membranous lupus nephritis (MLN), through analysis of a national multicenter registry. Methods Patients with pediatric systemic lupus erythematosus (SLE) and MLN from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry were included. Demographic, disease and medication-related data were collected between 2010 and 2014 from 59 CARRA Legacy Registry sites. Results A total of 132 individuals had MLN, either in isolation or in combination with proliferative LN. Seventy-four patients had pure MLN. The proportion of patients with daily corticosteroid treatment was similar among groups (96%, 91%, and 96%, for class III+V, IV+V, and V, respectively, p = 0.67). Proportion of individuals exposed to any disease-modifying antirheumatic drug (DMARD) or biologic was similar among the three groups (83%, 91%, 95% for class III+V, IV+V, and V, respectively, p = 0.189). Proportion of patients with decreased glomerular filtration rate (less than 90 ml/min/1.73 m²) was significantly different among groups (4%, 38%, and 4%, for class III+V, IV+V, and V, respectively, p < 0.0001). Conclusion This is the largest reported cohort of children with MLN. More research is needed to understand treatment practices for pediatric MLN, particularly decisions related to pharmacologic treatment of pure MLN. More work is also needed to identify prognostic factors and predictors of outcome for pediatric MLN. Future observational studies will be a first step toward understanding and formulating a standardized approach to treatment of pediatric membranous LN and allowing for the initiation of prospective comparative effectiveness studies and interventional trials.

Use of atorvastatin in systemic lupus erythematosus in children and adolescents

OBJECTIVE

Statins reduce atherosclerosis and cardiovascular morbidity in the general population, but their efficacy and safety in children and adolescents with systemic lupus erythematosus (SLE) are unknown. This study was undertaken to determine the 3-year efficacy and safety of atorvastatin in preventing subclinical atherosclerosis progression in pediatric-onset SLE.

METHODS

A total of 221 participants with pediatric SLE (ages 10-21 years) from 21 North American sites were enrolled in the Atherosclerosis Prevention in Pediatric Lupus Erythematosus study, a randomized double-blind, placebo-controlled clinical trial, between August 2003 and November 2006 with 36-month followup. Participants were randomized to receive atorvastatin (n=113) or placebo (n=108) at 10 or 20 mg/day depending on weight, in addition to usual care. The primary end point was progression of mean-mean common carotid intima-media thickening (CIMT) measured by ultrasound. Secondary end points included other segment/wall-specific CIMT measures, lipid profile, high-sensitivity C-reactive protein (hsCRP) level, and SLE disease activity and damage outcomes.

RESULTS

Progression of mean-mean common CIMT did not differ significantly between treatment groups (0.0010 mm/year for atorvastatin versus 0.0024 mm/year for placebo; P=0.24). The atorvastatin group achieved lower hsCRP (P=0.04), total cholesterol (P<0.001), and low-density lipoprotein (P<0.001) levels compared with placebo. In the placebo group, CIMT progressed significantly across all CIMT outcomes (0.0023-0.0144 mm/year; P<0.05). Serious adverse events and critical safety measures did not differ between groups.

CONCLUSION

Our results indicate that routine statin use over 3 years has no significant effect on subclinical atherosclerosis progression in young SLE patients; however, further analyses may suggest subgroups that would benefit from targeted statin therapy. Atorvastatin was well tolerated without safety concerns.

Laboratory markers of cardiovascular risk in pediatric SLE: the APPLE baseline cohort

As part of the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) Trial, a prospective multicenter cohort of 221 children and adolescents with systemic lupus erythematosus (SLE) (mean age 15.7 years, 83% female) underwent baseline measurement of markers of cardiovascular risk, including fasting levels of high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), lipoprotein A (Lpa), homocysteine and high-sensitivity C-reactive protein (hs-CRP). A cross-sectional analysis of the baseline laboratory values and clinical characteristics of this cohort was performed. Univariable relationships between the cardiovascular markers of interest and clinical variables were assessed, followed by multivariable linear regression modeling. Mean levels of LDL, HDL, Lpa, TG, hs-CRP and homocysteine were in the normal or borderline ranges. In multivariable analysis, increased Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), prednisone dose, and hypertension (HTN) were independently associated with higher LDL levels. Higher hs-CRP and creatinine clearance were independently related to lower HDL levels. Higher body mass index (BMI), prednisone dose, and homocysteine levels were independently associated with higher TG levels. Only Hispanic or non-White status predicted higher Lpa levels. Proteinuria, higher TG and lower creatinine clearance were independently associated with higher homocysteine levels, while use of multivitamin with folate predicted lower homocysteine levels. Higher BMI, lower HDL, and longer SLE disease duration, but not SLEDAI, were independently associated with higher hs-CRP levels. The R(2) for these models ranged from 7% to 23%. SLE disease activity as measured by the SLEDAI was associated only with higher LDL levels and not with hs-CRP. Markers of renal injury (HTN, proteinuria, and creatinine clearance) were independently associated with levels of LDL, HDL, and homocysteine, highlighting the importance of renal status in the cardiovascular health of children and adolescents with SLE. Future longitudinal analysis of the APPLE cohort is needed to further examine these relationships.

Association between beta2-glycoprotein I gene polymorphisms and pediatric SLE and antiphospholipid antibodies

Antibodies against phospholipids (PL) and PL-binding proteins have been causally implicated in antiphospholipid syndrome (APS). Mutations in the fifth domain of the beta2-glycoprotein I (beta2GPI) protein, a putative PL-binding site, may play a critical role in APS pathogenesis. The purpose of this study was to identify associations between beta2GPI mutations and both antiphospholipid antibodies (aPL) and their associated clinical manifestations in a pediatric and adolescent cohort and to search for novel mutations. Genetic analysis of beta2GPI was performed in 58 youths with systemic lupus erythematosus (SLE) and/or aPL, to identify known polymorphisms at amino acids 247 and 306 as well as novel mutations in exon 7 of the beta2GPI gene, and their association with aPL-associated clinical manifestations. Our results demonstrate an association between substitution of Val for Leu at AA247 (L247V) of beta2GPI and both the development of aPL (P = 0.05) and aPL-associated clinical manifestations (P = 0.03) among pediatric patients. The odds ratio associated with risk of aPL-associated clinical manifestations for the homozygous VV polymorphism was 5.5 (CI 1.3-23, P = 0.03) for the overall cohort, and 4.75 (CI 0.66-55.49, P = 0.06) after adjusting for ethnicity. The association was not significant after stratifying for SLE versus non-SLE. Association between the VV genotype at amino acid 247 of beta2GPI and clinical disease supports a genetic cause for APS among children and adolescents. Neither novel exon 7 beta2GPI mutations or the previously described C306G polymorphism was identified in this pediatric cohort.

Systemic lupus erythematosus and antiphospholipid syndrome in children and adolescents

Systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) can be associated with significant morbidity in children and adolescents. Renal involvement in SLE appears to be more severe and more frequent in the pediatric age group, with the major predictors for poor outcome being the severity of histopathologic lesions, severity of renal impairment at diagnosis, and hypertension. In addition to currently recognized cardiovascular and pulmonary involvement, accelerated atherosclerosis is of increasing concern in young individuals with SLE, because of both disease effects and medication usage. Neuropsychiatric SLE seen in childhood ranges from subtle cognitive dysfunction to severe central nervous system involvement; however, there is controversy over the value of different diagnostic studies. APS in children may be associated with SLE, idiopathic, or associated with viral infections. Systemic anticoagulation is recommended for patients with thrombotic events, but long-term management has not been well studied in children.

Pediatric Wegener's granulomatosis complicated by central nervous system vasculitis

An unusual case of central nervous system vasculitis in pediatric Wegener's granulomatosis, a rare disorder that infrequently presents during childhood, is reported. A 13-year-old girl with Wegener's granulomatosis, whose initial presentation resembled Henoch-Schonlein purpura, developed recurring seizures. MRI of the brain demonstrated multiple areas of increased signal in the occipital, parietal, and frontal lobes, consistent with central nervous system vasculitis. Although both peripheral and cranial neuropathies have been reported in patients with Wegener's granulomatosis, cerebral vasculitis is unusual, particularly in childhood. This case emphasizes the need to consider Wegener's granulomatosis in the differential diagnosis of both unexplained seizures and central nervous system vasculitis in children with systemic illness.

Aberrant intermolecular disulfide bonding in a mutant HLA-DM molecule: implications for assembly, maturation, and function

HLA-DM (abbreviated DM) is an MHC-encoded glycoprotein that catalyzes the selective release of peptides, including class II-associated invariant chain peptides, from MHC class II molecules. To perform its function, DM must assemble in the endoplasmic reticulum (ER), travel to endosomes, and interact productively with class II molecules. We have described previously an EBV-transformed B cell line, 7.12.6, which displays a partial Ag presentation defect and expresses a mutated DM beta-chain with Cys79 replaced by Tyr. In this study, we show that HLA-DR molecules in 7.12.6 have a defect in peptide loading and accumulate class II-associated invariant chain peptides (CLIP). Peptide loading is restored by transfection of wild-type DMB. The mutant DM molecules exit the ER slowly and are degraded rapidly, resulting in greatly reduced levels of mutant DM in post-Golgi compartments. Whereas wild-type DM forms noncovalent alphabeta dimers, such dimers form inefficiently in 7.12.6; many mutant DM beta-chains instead form a disulfide-bonded dimer with DM alpha. Homodimers of DM beta are also detected in 7.12.6 and in the alpha-chain defective mutant, 2.2.93. We conclude that during folding of wild-type DM, the native conformation is stabilized by a conserved disulfide bond involving Cys79beta and by noncovalent contacts with DM alpha. Without these interactions, DM beta can form malfolded structures containing interchain disulfide bonds; malfolding is correlated with ER retention and accelerated degradation.

Clinical characteristics of antiphospholipid antibody syndrome in children

OBJECTIVE

To evaluate the clinical features and outcome of antiphospholipid syndrome (APS) in children.

STUDY DESIGN

Retrospective chart review of patients seen at the Children's Hospital of Philadelphia and Children's Seashore House Pediatric Rheumatology Center between 1988 and 1993.

RESULTS

Nine patients with ages ranging from 8 months to 17 years are presented. Clinical features of five patients with primary APS, described in detail, were digital ischemia, stroke, chorea, Addison disease, and pulmonary vaso-occlusive disease. The four children with secondary APS had systemic lupus erythematosus. Clinical features of these patients include livedo reticularis, deep venous thrombosis, and pulmonary hypertension. Antiphospholipid titers, results of coagulation studies, and serologic findings did not predict outcome.

CONCLUSION

APS in children has diverse clinical features similar to those in adults and should be considered in cases of unexplained vaso-occlusive disease.

Analysis of HLA-DMB mutants and -DMB genomic structure

The HLA-DM locus encodes class II-like A and B chains and apparently regulates the antigen presentation function of conventional major histocompatibility complex (MHC) class II molecules. Here we describe the HLA-DMB mutations in three presentation defective B lymphoblastoid cells lines (B-LCL), 7.19.6, 10.6.6, and 10.78.6, which express DMB transcripts of abnormal length. Mutant 7.19.6 has a C-->T point mutation that introduces a 5' splice site into exon 3 of DMB. The independently derived mutants, 10.6.6 and 10.78.6, each harbor a G-->A mutation in exon 3 and also lack an identical downstream segment of RNA. Mapping of DMB intron/exon borders, using a genomic clone, revealed that the segment missing in mutants 10.6.6 and 10.78.6 represents the fourth exon of DMB; no mutations were found within exon 4 in either 10.6.6 or 10.78.6, however. In addition, the DMB gene was found to have a six exon genomic structure, typical of MHC class II B genes.