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Objective: Our objective was to evaluate the development of a systemic autoimmune rheumatic disease (SARD) in undifferentiated and asymptomatic individuals with antinuclear antibodies (ANAs). We comparatively evaluated those who did and did not develop a SARD and fulfillment of classification criteria. Methods: We conducted a cohort study of undifferentiated and asymptomatic patients with ANAs who were assessed for the development of a SARD. The primary outcome was a diagnosis of a SARD over a two‐year period. We assessed fulfillment of classification criteria. Risk ratios (RRs) were used to evaluate differences among those who did and did not progress to a SARD. Results: We evaluated 207 asymptomatic ANA‐positive or undifferentiated patients, of whom 23 (11%) progressed to a SARD, whereas 187 (89%) did not progress. Progressors developed systemic lupus erythematosus (SLE) (n = 11 [48%]), Sjögren disease (n = 5 [22%]), systemic sclerosis (n = 3 [13%]), rheumatoid arthritis (n = 1 [4%]), and from ANA‐positive to undifferentiated connective tissue disease (n = 3 [13%]). Fever (RR 0.89, 95% confidence interval [CI] 0.8–0.93) and antiphospholipid antibodies (RR 0.89, 95% CI 0.87–0.93) occurred less frequently, whereas arthritis (RR 1.74, 95% CI 1.20–2.55) occurred more frequently in progressors. Progressors to SLE had arthritis (91%), whereas none developed delirium, psychosis, or nephritis. Among patients with SLE, 100% fulfilled the EULAR/American College of Rheumatology (ACR) SLE criteria (sensitivity 91.7%, specificity 100%), whereas 73% fulfilled the 1997 ACR SLE criteria (sensitivity 81.8%, specificity 98.9%). Conclusion: Most undifferentiated/asymptomatic individuals with ANA do not progress to a SARD over a two‐year period. SLE progressors appear to have mild disease in the short term. The EULAR/ACR SLE criteria have improved ability to identify those who develop SLE. [ABSTRACT FROM AUTHOR]

Objectives Genome-wide association studies (GWAS) have identified loci associated with estimated glomerular filtration rate (eGFR). Few LN risk loci have been identified to date. We tested the association of SLE and eGFR polygenic risk scores (PRS) with repeated eGFR measures from children and adults with SLE. Methods Patients from two tertiary care lupus clinics that met ≥4 ACR and/or SLICC criteria for SLE were genotyped on the Illumina MEGA or Omni1-Quad arrays. PRSs were calculated for SLE and eGFR, using published weighted GWA-significant alleles. eGFR was calculated using the CKD-EPI and Schwartz equations. We tested the effect of eGFR- and SLE-PRSs on eGFR mean and variance, adjusting for age at diagnosis, sex, ancestry, follow-up time, and clinical event flags. Results We included 1158 SLE patients (37% biopsy-confirmed LN) with 36 733 eGFR measures over a median of 7.6 years (IQR: 3.9–15.3). LN was associated with lower within-person mean eGFR [LN: 93.8 (s. d. 26.4) vs non-LN: 101.6 (s. d. 17.7) mL/min per 1.73 m2 ; P  < 0.0001] and higher variance [LN median: 157.0 (IQR: 89.5, 268.9) vs non-LN median: 84.9 (IQR: 46.9, 138.2) (mL/min per 1.73 m2)2; P  < 0.0001]. Increasing SLE-PRSs were associated with lower mean eGFR and greater variance, while increasing eGFR-PRS was associated with increased eGFR mean and variance. Conclusion We observed significant associations between SLE and eGFR PRSs and repeated eGFR measurements, in a large cohort of children and adults with SLE. Longitudinal eGFR may serve as a powerful alternative outcome to LN categories for discovery of LN risk loci. [ABSTRACT FROM AUTHOR]

Objectives Cardiac involvement in neonatal lupus erythematosis (NLE) can present as myocarditis/endocardial fibroelastosis (EFE). It is unknown whether high-sensitivity cardiac troponin T (hs-cTnT) is useful in identifying subclinical myocardial inflammation in infants exposed prenatally to anti-Ro antibodies. This study reports hs-cTnT levels in infants exposed to anti-Ro antibodies with/without cardiac NLE and reports cardiac MRI (CMR) findings in a subset of these children. Methods The study included 45 consecutive infants exposed prenatally to anti-Ro antibodies with (n  = 7) or without (n  = 38) cardiac NLE, who were seen at the SickKids NLE Clinic between 2012 and 2014. Hs-cTnT levels were measured at least once, and those infants with values of ≥30 ng/l were offered the opportunity to undergo CMR. Descriptive statistics were performed. Results Of 38 infants without cardiac NLE, 25 had a hs-cTnT level of ≥30 ng/l (including 1 of >113 ng/l); of these, 8 underwent CMR (all without myocarditis/EFE). All 7 infants with cardiac NLE had at least one hs-cTnT level of ≥30 ng/l, but only 2/7 had a level of >113 ng/l; 4/7 infants with cardiac NLE had CMR (all without myocarditis/EFE); 6/7 infants with cardiac NLE had their steroid treatment adjusted based on the trend in their hs-cTnT levels. Conclusion Only 3/45 anti-Ro antibodies–exposed infants had hs-cTnT values outside the reference range reported in healthy infants. None of 12 infants who had CMR had subclinical myocarditis/EFE. Routine measurement of hs-cTnT in every anti-Ro antibody–exposed infant is not indicated. Further studies are needed to define the role of hs-cTnT as a biomarker for cardiac NLE. [ABSTRACT FROM AUTHOR]

Objective: Anti‐Ro antibody–positive mothers are frequently referred for serial echocardiography due to the fetal risk of developing heart block and endocardial fibroelastosis. Little is known why only some and not all offspring develop these cardiac manifestations of neonatal lupus (CNL). This prospective study examined associations between anti‐Ro antibody titers and fetal CNL. Methods: Antibody‐positive mothers referred since 2018 for fetal echocardiography at risk of CNL (group 1; n = 240) or with CNL (group 2; n = 18) were included. Maternal antibody titers were measured with a chemiluminescent immunoassay (CIA). Additional testing on diluted serum samples was used to quantify anti–Ro 60 antibody titers above the analytical measuring range (AMR) of the standard CIA (≥1,375 chemiluminescent units [CU]). Results: Among 27 total mothers with a fetal diagnosis of CNL, all displayed anti–Ro 60 antibody titers that exceeded the AMR of the CIA at least 10‐fold. Of 122 mothers in group 1 who underwent additional anti–Ro 60 antibody testing, event rates of CNL (n = 9) were 0% (0 of 45) among mothers with anti–Ro 60 antibody titers from 1,375–10,000 CU, 5% (3 of 56) among mothers with titers from 10,000–50,000 CU, but 29% (6 of 21) among mothers with titers >50,000 CU (odds ratio 13.1, P = 0.0008). Of mothers in group 2 with a primary diagnosis of CNL, 0% (0 of 18 mothers) had anti–Ro 60 antibody titers <10,000 CU, 44% (8 of 18 mothers) had titers from 10,000–50,000 CU, and 56% (10 of 18 mothers) had titers >50,000 CU. Conclusion: CNL is associated with substantially higher anti‐Ro antibody titers than are obtained using a standard CIA. Enhancing the assay measuring range allows an improved specificity of identifying pregnancies at risk of CNL. [ABSTRACT FROM AUTHOR]

Objectives Genetics plays an important role in SLE risk, as well as osteonecrosis (ON), a significant and often debilitating complication of SLE. We aimed to identify genetic risk loci for ON in people with childhood-onset (cSLE) and adult-onset (aSLE) SLE. Methods We enrolled participants from two tertiary care centres who met classification criteria for SLE. Participants had prospectively collected clinical data and were genotyped on a multiethnic array. Un-genotyped single nucleotide polymorphisms (SNPs) were imputed, and ancestry was inferred using principal components (PCs). Our outcome was symptomatic ON confirmed by imaging. We completed time-to-ON and logistic regression of ON genome-wide association studies (GWASs) with covariates for sex, age of SLE diagnosis, five PCs for ancestry, corticosteroid use and selected SLE manifestations. We conducted separate analyses for cSLE and aSLE and meta-analysed results using inverse-variance weighting. Genome-wide significance was P  < 5 × 10−8. Results The study included 940 participants with SLE, 87% female and 56% with cSLE. ON was present in 7.6% (n  = 71). Median age of SLE diagnosis was 16.9 years (interquartile range [IQR]: 13.5, 29.3), with median follow-up of 8.0 years (IQR: 4.2, 15.7). Meta-GWAS of cSLE and aSLE time-to-ON of 4 431 911 SNPs identified a significant Chr.2 SNP, rs34118383 (minor allele frequency = 0.18), intronic to WIPF1 (hazard ratio = 3.2 [95% CI: 2.2, 4.8]; P  = 1.0 × 10−8). Conclusion We identified an intronic WIPF1 variant associated with a 3.2 times increased hazard for ON (95% CI: 2.2, 4.8; P   =  1.0 × 10−8) during SLE follow-up, independent of corticosteroid exposure. The effect of the SNP on time-to-ON was similar in cSLE and aSLE. This novel discovery represents a potential ON risk locus. Our results warrant replication. [ABSTRACT FROM AUTHOR]

Objective: To report the 2‐year efficacy and safety of tocilizumab (TCZ) in patients with polyarticular‐course juvenile idiopathic arthritis (JIA). Methods: Patients ages 2–17 years with active polyarticular‐course JIA, in whom treatment with methotrexate was unsuccessful, received 16 weeks of open‐label intravenous TCZ in part 1 (once every 4 weeks: 8 mg/kg or 10 mg/kg for body weight [BW] <30 kg; 8 mg/kg for BW ≥30 kg). Assessments were based on the JIA–American College of Rheumatology (ACR) response (defined as percentage of improvement in ≥3 of the 6 JIA core response variables [CRVs]). Patients with at least a JIA‐ACR30 response (defined as ≥30% improvement in ≥3 of the 6 JIA CRVs without worsening in >1 of the remaining JIA CRVs by >30%) at week 16 were randomly assigned (1:1) to receive TCZ or placebo in part 2. Patients remained in part 2 until either week 40 or the occurrence of JIA flare. Upon starting part 3, all patients received open‐label TCZ. At week 104 of the study, efficacy was assessed using JIA‐ACR50/70/90 response rates (defined as 50%, 70%, or 90% improvement, respectively), achievement of inactive disease, and the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS‐71). Safety was assessed in the all‐exposure population per 100 patient‐years of exposure. Results: Overall, 188 patients entered part 1, 166 patients entered part 2, and 160 patients entered part 3. By week 104, among the 188 patients in the modified intent‐to‐treat group who received TCZ, JIA‐ACR50/70/90 response rates were 80.3%/77.1%/59.6%, respectively, the median JADAS‐71 score decreased from 3.6 at week 40 to 0.7 at week 104, 51.1% of patients had achieved inactive disease, and 31 of 66 patients who had been receiving glucocorticoids discontinued them. Adverse event (AE) and serious AE rates were 406.5 per 100 patient‐years and 11.1 per 100 patient‐years, respectively. The infection rate was 151.4 per 100 patient‐years, and the serious infection rate was 5.2 per 100 patient‐years. Conclusion: Patients treated with TCZ for polyarticular‐course JIA showed high‐level disease control for up to 2 years. The TCZ safety profile was consistent with that previously reported. [ABSTRACT FROM AUTHOR]

Objective. Recent studies have suggested that prenatal exposure to HCQ reduces the risk of cardiac neonatal lupus. The aim of this study is to assess if maternal intake of antimalarials (AMs) throughout pregnancy lowered the risk of cardiac and non-cardiac neonatal lupus. Methods. Consecutive children seen between 1 January 1984 to 1 October 2013 born to women with a CTD and positive anti-Ro and/or anti-La antibodies were eligible for this single-centre retrospective cohort study. A total of 315 individuals were screened and 268 participants were included. Exposure to AMs was defined as HCQ or chloroquine throughout pregnancy. Outcomes were cardiac and non-cardiac neonatal lupus. Frequentist and Bayesian analyses were performed. We hypothesized that prenatal AM exposure would decrease the risk of cardiac but not non-cardiac neonatal lupus. Results. A total of 268 pregnancies were included; 73 were exposed to AMs throughout pregnancy. Ninety-nine children developed neonatal lupus, 117 remained unaffected and 52 children did not develop cardiac neonatal lupus but could not be categorized as unaffected since their full non-cardiac neonatal lupus status was unknown. Logistic regression suggested a protective effect of AM on cardiac neonatal lupus, but results were not statistically significant [odds ratio (OR) 0.21; P = 0.07]. Bayesian analysis showed that the probability of obtaining a protective effect (OR<1.0) for cardiac neonatal lupus was significant (98.7%). The effect of AMs on non-cardiac neonatal lupus was not significant (OR 0.78; P = 0.21). Conclusion. In this large single-centre cohort study, exposure to AMs throughout pregnancy was asso- ciated with a decreased probability of developing cardiac but not non-cardiac neonatal lupus. [ABSTRACT FROM AUTHOR]

Objective To determine whether longer disease duration negatively impacts carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), and pulse wave velocity (PWV) in a cohort of patients with childhood-onset systemic lupus erythematosus (SLE), and to compare CIMT, FMD, and PWV in patients with childhood-onset SLE with those in healthy children and explore determinants of vascular test results in childhood-onset SLE. Methods Cross-sectional analysis was performed in a prospective longitudinal cohort of patients with childhood-onset SLE at the latest followup visit. Clinical and laboratory data were collected for patients with childhood-onset SLE. CIMT, FMD, and PWV were measured using standardized protocols in patients with childhood-onset SLE and healthy children. Correlations between disease duration and results of the 3 vascular tests were performed. Vascular data in patients with childhood-onset SLE were compared with those in healthy children. Multivariable linear regression was used to identify determinants of CIMT, FMD, and PWV in childhood-onset SLE. Results Patients with childhood-onset SLE (n = 149) and healthy controls (n = 178) were enrolled. The median age of the patients was 17.2 years (interquartile range [IQR] 15.7-17.9 years), and their median disease duration was 3.2 years (IQR 1.8-4.9 years). The median age of the healthy children was 14.7 years (IQR 13.1-15.9 years). Longer disease duration correlated with worse FMD (r = −0.2, P = 0.031) in patients with childhood-onset SLE. Patients with childhood-onset SLE had smaller (better) CIMT, higher (better) FMD, and similar PWV compared with healthy controls. Linear regression analysis explained <24% of the variation in vascular test results in patients with childhood-onset SLE, suggesting that other variables should be explored as important determinants of CIMT, FMD, and PWV. Conclusion In this cohort of 149 patients with childhood-onset SLE, patients did not have worse CIMT, FMD, or PWV than did healthy controls. Longer disease duration was associated with worse FMD, suggesting progressive endothelial dysfunction over time. [ABSTRACT FROM AUTHOR]

Objective Systemic lupus erythematosus (SLE) is characterized by increased cardiovascular risk in adult-onset and childhood-onset SLE. Type I interferons (IFNs) appear to play a prominent role in premature vascular damage in adult-onset SLE, at least in part, by inducing impairments in the phenotype and function of endothelial progenitor cells (EPCs), thereby hampering vascular repair. It is not clear whether EPC dysfunction is present in childhood-onset SLE in association with a type I IFN signature. Methods The phenotype and numbers of EPCs were quantified in patients with childhood-onset SLE, patients with juvenile idiopathic arthritis (JIA), and matched healthy control subjects. In a separate cohort of patients with childhood-onset SLE, markers of subclinical atherosclerosis and endothelial dysfunction were quantified using standardized protocols and analyzed for associations with serum type I IFN activity. Results EPC numbers and function were significantly decreased in patients with childhood-onset SLE compared with patients with JIA and healthy control subjects. Serum from patients with childhood-onset SLE impaired differentiation of EPCs into mature endothelial cells in healthy controls, and this effect was blocked by inhibition of the type I IFN pathway. Type I IFN activity in serum was not significantly associated with subclinical atherosclerosis and endothelial function in patients with childhood-onset SLE. Conclusion As in adult-onset SLE, childhood-onset SLE is characterized by phenotypic and functional EPC abnormalities, which are likely triggered by type I IFNs. Although cross-sectional analysis revealed no global association between type I IFN signatures and vascular measures of subclinical atherosclerosis, longitudinal assessments are needed to evaluate whether progression of vascular damage in patients with childhood-onset SLE is associated with type I IFNs, as observed in patients with adult-onset SLE. [ABSTRACT FROM AUTHOR]

Background: Studies of paediatric patients with membranous lupus nephritis (MLN) have yielded variable results, mostly due to the inclusion of mixed, i.e. proliferative nephritis. The aim of this study was to describe clinical and laboratory findings at the diagnosis of paediatric non-proliferative MLN, report the outcome and identify predictors of remission. Methods: A single-center cohort study of consecutive children diagnosed with non-proliferative MLN was performed. Clinical and laboratory measures and treatment regimens were obtained in prospective standardized assessments. Renal outcome was measured by renal parameters and steroid requirement. Predictors for remission and time to remission were determined. Results: A total of 30 children were identified with a median follow-up time 4.1 years. Of 21 patients followed for more than 2 years, 19 (90 %) achieved clinical remission, and 16 (76 %) achieved a state of maintained clinical remission on low-dose prednisone. Three patients developed proliferative nephritis on subsequent renal biopsy. Lower albumin at the time of biopsy was correlated with a lower rate of remission and longer time to remission. Conclusions: Among our paediatric patient cohort the outcome of non-proliferative MLN in systemic lupus erythematosus was good. The majority of patients did not require aggressive immunosuppressive treatment to reach a stable disease state on low-dose steroid treatment. [ABSTRACT FROM AUTHOR]

Background/Purpose: Biologic therapies have revolutionized the management of rheumatic diseases of childhood. However, these medications are associated with adverse effects including the possible development of neoplasms. The aim of our study was to determine the rate as well as risk factors for the development of neoplasms in patients with JIA treated with biologics. Methods: We performed a retrospective review of the rheumatology biologic registry (RBR) at The Hospital for Sick Children (SickKids), Toronto, Canada, one of the largest quarternary pediatric referral centres in North America. Demographic and neoplastic data, clinical course and medication history were extracted from the RBR and clinical charts. Unless specified, data was expressed as median (IQR). The study was approved by the SickKids Ethics Review Board. Results: The cohort consisted of 357 patients with rheumatic diseases who were on one or more biologics between January 1997 and August 2013. Juvenile Idiopathic Arthritis (JIA) was the most common diagnosis [302/357 (84.5%)]. A total of 6/357 (1.68%) patients developed a neoplasm: 4 with JIA, 1 each with idiopathic uveitis and polyarteritis nodosa. (Refer to t87) [ABSTRACT FROM AUTHOR]

Background/Purpose: Cytopenias including thrombocytopenia and autoimmune hemolytic anemia(AIHA) are common in childhood-onset SLE (cSLE) and may be refractory to conventional therapy with corticosteroids, IVIG and/or other immunosuppressives. Rituximab appears to be an effective therapy for cytopenias, although no long term studies have been completed, and few cSLE patients have been reported. Our objectives were to examine our experience, determine the rate and durability of response to rituximab, and evaluate its safety in our cSLE population with refractory cytopenias. Methods: A single center retrospective cohort study of patients diagnosed with cSLE between Jan 1, 2003 and Dec 31, 2012. Inclusion criteria were SLE diagnosed <18th birthday, refractory cytopenia (thrombocytopenia and/or AIHA) with inadequate response to conventional therapy, and treatment with rituximab during the study period. Demographic, clinical, laboratory, and treatment data were examined. Complete response for thrombocytopenia was defined as platelets >100 × 109/L, and for AIHA hemoglobin >120 g/L. B-cell phenotyping was determined at regular intervals. Outcomes examined included the time to clinical response, time to B-cell depletion, and the duration of response. Adverse events studied included the incidence of persistent (>12 months) hypogammaglobulinemia, infusion reactions and infections requiring hospitalization. Results: 398 patients were diagnosed with cSLE during the study period; 24 (6%) received rituximab for refractory cytopenia. Rituximab was given either as 4 weekly doses of 375 mg/m2 or 2 doses of 500 mg/m2 separated by 14 days, depending on the year. There was a female predominance (18/24, 75%), the median age was 13.2 y (range 4-18). Fifteen (63%) had thrombocytopenia, 5 (21%) had AIHA, and 4 (17%) had both. The median (IQR) time from cytopenia onset to rituximab therapy was 517 (237, 892) days. Complete response to 1st course of rituximab occurred by 30 days in 15 (63%), by 90 days in an additional 3 (13%) patients, by 180 days in 3 (13%) patients, and by 1 year in 2 (8%) patients; 1 patient failed to respond. For thrombocytopenia, the time to complete response was 17(13, 62) days and for AIHA 54 (24, 98) days. Five (21%) patients had one or more flare episodes at 21 (14.6, 27.3) months. No patient with thrombocytopenia in the absence of AIHA flared following 1st dose of rituximab. All patients who had B cell phenotyping had complete depletion of CD20 B cells at 16 (14, 30) days. The time to B cell reconstitution was 331 (175, 468) days. Transient infusion reactions included fever, erythematous pruritic rash, and hypotension in 2 patients. Four patients had transient hypogammaglobulinemia. Three patients had persistent undetectable IgG and received monthly IVIG replacement; 2 had recurrent infections. One patient (who was not hypogammaglobulinemic) had varicella zoster 10 weeks following rituximab. No other hospitalizations for infection were observed within 1 year of rituximab administration. Conclusion: Rituximab appears to be a well tolerated, safe, and long-lasting therapy for cSLE patients with refractory cytopenias. Longer term data is required to assess the incidence and clinical significance of hypogammaglobulinemia. [ABSTRACT FROM AUTHOR]

Background/Purpose: Macrophage activation syndrome (MAS), a life-threatening inflammatory emergency of children with rheumatic diseases, is increasingly recognized in pediatric systemic lupus erythematosus (pSLE). The challenge is to differentiate active pSLE from MAS in order to make correct treatment decisions. The purpose of this study is to generate a decision tree for the recognition of MAS in newly diagnosed pSLE and test the performance of these proposed criteria in an independent pSLE cohort. Methods: A retrospective cohort study of consecutive patients requiring admission to SickKids Hospital with newly diagnosed, active pSLE between January 2002 and July 2007 (training cohort) was performed. All patients met ≥4/11 ACR criteria. Data collection on: 1) Clinical features including fever, CNS dysfunction, splenomegaly, hepatomegaly and hemorrhage; 2) laboratory parameters; CBC, ESR, CRP, C3, C4, ferritin, AST, ALT, LDH, albumin, bilirubin, triglycerides, LDL, HDL, urea, creatinine, sodium, coagulation parameters including INR, PTT, fibrinogen and D-Dimer, and soluble IL-2 receptor (sIL-2R) and CD163. Patients were assigned to one of 2 cohorts exclusively (MAS/non-MAS). Putative predictor variables were compared between cohorts. A decision tree analysis for diagnosis of MAS in pSLE was constructed using recursive partitioning, and decision rules were subsequently applied to an independent cohort of newly diagnosed, active pSLE diagnosed and admitted to SickKids between July 2007 and July 2013 (testing cohort) to determine the sensitivity and specificity of the proposed criteria. Results: The training cohort consisted of 56 pSLE patients: 9 (16%) diagnosed with MAS and 47 non-MAS patients. Splenomegaly was more common in the non-MAS cohort, with no other differences in clinical characteristics between cohorts. Of all the available laboratory data, ALT ≥ 45 units/L, neutrophils < 1.65 × 103/mm3 and ferritin < 836 µg/L identified 56% of the patients with MAS (R2 = 0.75) with 100% specificity. The testing cohort consisted of 9 (20%) MAS and 37 non-MAS pSLE patients. The proposed thresholds for ALT, neutrophil count and ferritin demonstrated a sensitivity of 11% and specificity of 97%. Conclusion: MAS is a life threatening complication of pSLE. Early recognition is challenging yet critical for appropriate therapy. PSLE patient with and without MAS have many similar clinical and laboratory features. Using statistical modeling, the initial criteria developed maintained excellent specificity but poor sensitivity for distinguishing MAS from active SLE at diagnosis in the testing cohort. Hence, new validated models are required for the early recognition of MAS among pSLE patients. Future analyses are planned to address these issues. [ABSTRACT FROM AUTHOR]

Background/Purpose: 1) To determine the longitudinal disease activity trajectory of an inception cohort of Juvenile Dermatomyositis (JDM) patients, 2) To identify predictor(s) for longitudinal disease activity trajectory of JDM. Methods: A single-center, inception cohort of juvenile dermatomyositis (JDM) patients (age of diagnosis <18 years old), recruited within 1 year of their initial presentation was studied. The patients were accrued from January 1991 to December 2010, in a JDM subspecialty clinic. Patients were evaluated at every clinic visit for disease activity with the modified Disease Activity Score (mDAS). Baseline disease features-DASm, swallowing difficulty, skin ulcer, calcinosis, duration of symptoms before evaluation, age and gender-were evaluated as predictors of the longitudinal trajectory of JDM. Time-varying treatment effects were also tested. Longitudinal trajectory modeling was performed with mixed random effects modeling (random slopes). Results: Ninety-five JDM patients (33 males, 35%) were studied. The median age of onset was 7.8 (25th-75th percentile (P): 4.9-12.1) years. The median mDAS score at presentation was 7 (25th-75th P: 6-9), the median skin subscale score was 3 (25th-75th P: 2-4), the median musculoskeletal subscale was 4 (25th-75th P: 3-6). The median duration of follow-up was 4.6 (25th-75th P: 2.4-6.9) years. All patients in the cohort were treated with a standardized protocol comprising prednisone alone (before 2000) or methotrexate (MTX) and prednisone (after 2000). The disease trajectory of mDAS in this inception cohort followed a rapid reduction of activity within the first 2 years with a minor flare in disease activity beyond 2 years. Baseline nailfold abnormality predicted a slower improvement in mDAS trajectory. Higher baseline mDAS predicted faster improvement in mDAS trajectory. Treatment with MTX and prednisone predicted reductions in disease activity 3 and 6 months later respectively. Conclusion: Disease activity trajectory of JDM showed a general rapid reduction of mDAS followed by a small flare of disease activity beyond 2 years. Baseline nailfold abnormality and mDAS predicted future evolution of disease trajectory. The effects of treatment were observed only 3-6 months after. [ABSTRACT FROM AUTHOR]

Background/Purpose: Childhood-onset systemic lupus erythematous (cSLE) has a more severe clinical course with higher disease activity and involvement of major organs compared to adult-onset SLE. Avascular necrosis (AVN) is a significant morbidity causing pain and disability, sometimes requiring joint replacement surgery. Our objective was to examine the frequency and risk factors for symptomatic AVN in cSLE. Methods: A single center matched case-control design was used. 617 patients with cSLE followed at SickKids Lupus Clinic between July 1982 and June 2013 were included in the study. The AVN cohort consisted of 37 patients identified with clinical findings of symptomatic AVN and diagnosis confirmed by one or more imaging modalities. Three controls were matched to each AVN patient by date and age at diagnosis (± 1 year). Baseline clinical, laboratory and treatment characteristics were compared between the patients with AVN and the controls by univariate analyses and if statistically significant, were included in a multivariable logistic regression model. Results: A total of 37/617 (6%) patients developed symptomatic AVN during follow-up at SickKids. The majority was female (30/37, 81%) and of Asian descent (20/37, 54%). The mean age at diagnosis was 16.1 years (±2.1), with median time to AVN of 1.52 years. Only 2/37 (5%) of patients developed AVN prior to the onset of puberty. The hip was the most commonly involved joint (26/37, 70%) with bilateral involvement in 49% (18/37) of patients. Compared to the matched non-AVN cohort, patients with AVN had higher incidence of CNS disease (p = 0.003), nephritis (p < 0.001), acute or chronic renal failure (p = 0.029), but less frequent photosensitivity (p = 0.006). Patients with AVN also required greater cumulative prednisone from cSLE diagnosis to AVN (364 ± 53 vs. 232 ± 36 mg/kg, p < 0.001), higher prednisone dose at time of AVN diagnosis (±3 months, 0.30 ± 0.25 vs. 0.19 ± 0.24 mg/kg, p = 0.012), maximal daily prednisone dose (1.25 ± 0.36 vs. 0.71 ± 0.53 mg/kg, p < 0.001) and more frequent use of pulse methylprednisolone therapy (39% vs. 10%, p < 0.001). The median prednisone dose at time of AVN was 0.27 vs. 0.09 mg/kg. Multivariable regression analysis confirmed nephritis, CNS disease, maximal daily prednisone dose and use of pulse methylprednisolone as significant predictors of symptomatic AVN development. Overall disease activity from SLE diagnosis to AVN diagnosis as measured by adjusted mean SLEDAI was not significantly different (6310 ± 976 vs. 4994 ± 440, p = 0.165). Conclusion: cSLE patients with severe organ involvement including nephritis and CNS disease, higher maximal daily dose of prednisone, and more frequent use of pulse methylprednisolone are more likely to develop symptomatic AVN. [ABSTRACT FROM AUTHOR]