Ethan S Sen

Treatment of primary angiitis of the central nervous system in childhood with mycophenolate mofetil

OBJECTIVE To assess the use of mycophenolate mofetil (MMF) in the treatment of refractory primary angiitis of the CNS in childhood (cPACNS). METHODS A retrospective chart review was performed in patients with cPACNS who were treated with MMF following failure of a combination of corticosteroids and another immunosuppressant. RESULTS Three patients from two centres were included in this study. The age of onset of disease was 5, 6 and 9 years. All the patients improved when treated with MMF, such that the dose of corticosteroids could be weaned or stopped. CONCLUSIONS MMF should be considered for maintenance treatment in the management of patients with cPACNS refractory to the combination of corticosteroids and first-line immunosuppressive agents.

Genomic and clinical profiling of a national Nephrotic Syndrome cohort advocates a precision medicine approach to disease management

Steroid Resistant Nephrotic Syndrome (SRNS) in children and young adults has differing etiologies with monogenic disease accounting for 2.9-30% in selected series. Using whole exome sequencing we sought to stratify a national population of children with SRNS into monogenic and non-monogenic forms, and further define those groups by detailed phenotypic analysis. Pediatric patients with SRNS were identified via a national United Kingdom Renal Registry. Whole exome sequencing was performed on 187 patients, of which 12% have a positive family history with a focus on the 53 genes currently known to be associated with nephrotic syndrome. Genetic findings were correlated with individual case disease characteristics. Disease causing variants were detected in 26.2% of patients. Most often this occurred in the three most common SRNS-associated genes: NPHS1, NPHS2, and WT1 but also in 14 other genes. The genotype did not always correlate with expected phenotype since mutations in OCRL, COL4A3, and DGKE associated with specific syndromes were detected in patients with isolated renal disease. Analysis by primary/presumed compared with secondary steroid resistance found 30.8% monogenic disease in primary compared with none in secondary SRNS permitting further mechanistic stratification. Genetic SRNS progressed faster to end stage renal failure, with no documented disease recurrence post-transplantation within this cohort. Primary steroid resistance in which no gene mutation was identified had a 47.8% risk of recurrence. In this unbiased pediatric population, whole exome sequencing allowed screening of all current candidate genes. Thus, deep phenotyping combined with whole exome sequencing is an effective tool for early identification of SRNS etiology, yielding an evidence-based algorithm for clinical management.

Use of adalimumab in refractory non-infectious childhood chronic uveitis: efficacy in ocular disease—a case cohort interventional study

OBJECTIVE To assess the use of adalimumab in the treatment of refractory non-infectious childhood chronic uveitis. METHODS A case cohort interventional study was performed on patients with uveitis, who were treated with adalimumab after failure of treatment with a combination of corticosteroids and another immunosuppressant drug. Main outcome measures were (i) stability of vision, (ii) stability of inflammation and (iii) reduction of immunosuppressive load. Adverse events and reasons for stopping adalimumab were noted. RESULTS Seventeen patients from a single regional centre were included in the study. Nine patients had previously received an anti-TNF agent, and because of inefficacy, all were changed to adalimumab. At 12 months, fewer patients had visual acuity worse than LogMAR 0.4 (18% vs 32% at baseline). Using standardized uveitis nomenclature criteria, at 3 months, 50% of the patients eyes (n = 32) had improved, 16% had stable inflammation and 3% had worsened, whereas 31% were maintained with no anterior chamber cells. Six patients required courses of oral steroids for uveitis. Seven patients received intra- or periocular injections of steroids. Adalimumab treatment was interrupted in one patient because of varicella zoster infection. It was stopped in three patients. Seven (41%) patients reported injection site reactions. CONCLUSION In this group of children with refractory uveitis, use of adalimumab was associated with improvement in visual acuity and improving or stable ocular inflammation. However, it did not completely obviate the need for systemic or periocular steroid treatment. Prospective randomized controlled trials are required to help determine which subset of patients may benefit from adalimumab and the duration of treatment.

Uveitis associated with juvenile idiopathic arthritis

Uveitis is a potentially sight-threatening complication of juvenile idiopathic arthritis (JIA). JIA-associated uveitis is recognized to have an autoimmune aetiology characterized by activation of CD4+ T cells, but the underlying mechanisms might overlap with those of autoinflammatory conditions involving activation of innate immunity. As no animal model recapitulates all the features of JIA-associated uveitis, questions remain regarding its pathogenesis. The most common form of JIA-associated uveitis is chronic anterior uveitis, which is usually asymptomatic initially. Effective screening is, therefore, essential to detect early disease and commence treatment before the development of visually disabling complications, such as cataracts, glaucoma, band keratopathy and cystoid macular oedema. Complications can result from uncontrolled intraocular inflammation as well as from its treatment, particularly prolonged use of high-dose topical corticosteroids. Accumulating evidence supports the early introduction of systemic immunosuppressive drugs, such as methotrexate, as steroid-sparing agents. Prospective randomized controlled trials of TNF inhibitors and other biologic therapies are underway or planned. Future research should aim to identify biomarkers to predict which children are at high risk of developing JIA-associated uveitis or have a poor prognosis. Such biomarkers could help to ensure that patients receive earlier interventions and more-potent therapy, with the ultimate aim of reducing loss of vision and ocular morbidity.

New age of biological therapies in paediatric rheumatology

Many paediatric rheumatic diseases result from the abnormal activation or control of the immune system. Biologic drugs, which are synthesised within a biological system, have been designed to target specific molecules involved in cytokine signalling or cell–cell interactions. The past 15 years have seen a revolution in the range of effective treatments for rheumatic diseases, particularly juvenile idiopathic arthritis (JIA). As a result, the target of inactive disease and minimal long-term disease-associated damage is increasingly becoming achievable. In this article we review evidence from recent trials of the use of biologic drugs in the treatment of systemic JIA, juvenile dermatomyositis and juvenile systemic lupus erythematosus. We also highlight novel agents currently undergoing investigation which may broaden our therapeutic armamentarium over the coming decade. Key to these developments are well-designed multicentre controlled clinical trials and long-term safety monitoring as part of international drug registries.

Juvenile idiopathic arthritis-associated uveitis

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease of childhood, with JIA-associated uveitis its most common extra-articular manifestation. JIA-associated uveitis is a potentially sight-threatening condition and thus carries a considerable risk of morbidity. The aetiology of the condition is autoimmune in nature with the predominant involvement of CD4+ T cells. However, the underlying pathogenic mechanisms remain unclear, particularly regarding interplay between genetic and environmental factors. JIA-associated uveitis comes in several forms, but the most common presentation is of the chronic anterior uveitis type. This condition is usually asymptomatic and thus screening for JIA-associated uveitis in at-risk patients is paramount. Early detection and treatment aims to stop inflammation and prevent the development of complications leading to visual loss, which can occur due to both active disease and burden of disease treatment. Visually disabling complications of JIA-associated uveitis include cataracts, glaucoma, band keratopathy and macular oedema. There is a growing body of evidence for the early introduction of systemic immunosuppressive therapies in order to reduce topical and systemic glucocorticoid use. This includes more traditional treatments, such as methotrexate, as well as newer biological therapies. This review highlights the epidemiology of JIA-associated uveitis, the underlying pathogenesis and how affected patients may present. The current guidelines and criteria for screening, diagnosis and monitoring are discussed along with approaches to management.

Clinical genetic testing using a custom-designed steroid-resistant nephrotic syndrome gene panel: analysis and recommendations

Background There are many single-gene causes of steroid-resistant nephrotic syndrome (SRNS) and the list continues to grow rapidly. Prompt comprehensive diagnostic testing is key to realising the clinical benefits of a genetic diagnosis. This report describes a bespoke-designed, targeted next-generation sequencing (NGS) diagnostic gene panel assay to detect variants in 37 genes including the ability to identify copy number variants (CNVs). Methods This study reports results of 302 patients referred for SRNS diagnostic gene panel analysis. Phenotype and clinical impact data were collected using a standard proforma. Candidate variants detected by NGS were confirmed by Sanger sequencing/Multiplex Ligation-dependent Probe Amplification with subsequent family segregation analysis where possible. Results Clinical presentation was nephrotic syndrome in 267 patients and suspected Alport syndrome (AS) in 35. NGS panel testing determined a likely genetic cause of disease in 44/220 (20.0%) paediatric and 10/47 (21.3%) adult nephrotic cases, and 17/35 (48.6%) of haematuria/AS patients. Of 71 patients with genetic disease, 32 had novel pathogenic variants without a previous disease association including two with deletions of one or more exons of NPHS1 or NPHS2. Conclusion Gene panel testing provides a genetic diagnosis in a significant number of patients presenting with SRNS or suspected AS. It should be undertaken at an early stage of the care pathway and include the ability to detect CNVs as an emerging mechanism for genes associated with this condition. Use of clinical genetic testing after diagnosis of SRNS has the potential to stratify patients and assist decision-making regarding management.

Diagnosing haemophagocytic syndrome

Haemophagocytic syndrome, or haemophagocytic lymphohistiocytosis (HLH), is a hyperinflammatory disorder characterised by uncontrolled activation of the immune system. It can result from mutations in multiple genes involved in cytotoxicity or occur secondary to a range of infections, malignancies or autoimmune rheumatic diseases. In the latter case, it is also known as macrophage activation syndrome (MAS). Characteristic features are persistent fever, hepatosplenomegaly, petechial/purpuric rash, progressive cytopenias, coagulopathy, transaminitis, raised C reactive protein, falling erythrocyte sedimentation rate, hypertriglyceridaemia, hypofibrinogenaemia and extreme hyperferritinaemia often associated with multi-organ impairment. Distinguishing HLH from systemic sepsis can present a major challenge. Criteria for diagnosis and classification of HLH and MAS are available and a serum ferritin >10 000 µg/L is strongly supportive of HLH. Without early recognition and appropriate treatment, HLH is almost universally fatal. However, with prompt referral and advancements in treatment over the past two decades, outcomes have greatly improved.

The Safety and Efficacy of Noncorticosteroid Triple Immunosuppressive Therapy in the Treatment of Refractory Chronic Noninfectious Uveitis in Childhood

Objective. To assess the safety and efficacy of noncorticosteroid triple immunosuppressive therapy in the treatment of refractory chronic noninfectious childhood uveitis. Methods. Subjects were retrospectively selected from a database. Patients were included if they were diagnosed with chronic, noninfectious uveitis at 16 years of age or under and treated with triple immunosuppressive therapy for at least 6 months (following failure of a combination of 2 immunosuppressants). Patient demographics, diagnoses, duration of uveitis, drug dosages, active joint inflammation, and ophthalmologic data were recorded. Efficacy outcomes for triple therapy were recorded at 6 months. Results. Thirteen patients with bilateral uveitis were included. Using Standardized Uveitis Nomenclature (SUN) criteria, at 6 months only 11 eyes (42%) had a 2-step improvement in anterior chamber cell inflammation (n = 26). In addition, 2 patients required additional oral corticosteroid treatment. There were 4 significant infectious adverse events during a total of 21.9 patient-years (PY) on triple therapy (0.18 events per PY). Conclusion. In this group of children with refractory uveitis, addition of a third immunosuppressive agent did not confer substantial benefit in redressing ocular inflammation and was associated with significant infections in a minority of patients.

How to use antistreptolysin O titre

Group A streptococcus (GAS) is the cause of a wide range of acute suppurative and, following a latent period, non-suppurative diseases such as rheumatic fever and poststreptococcal glomerulonephritis. Diagnosis of the latter group requires evidence of preceding GAS infection. The bacteria produce a range of extracellular antigens, including streptolysin O, which induce an antibody response in the host. A rise in antistreptolysin O titre (ASOT) is indicative of preceding GAS infection. In clinical practice, often only a single ASOT measurement is available and its timing in relation to a possible GAS infection is unknown. Interpretation of the result in this context is liable to misdiagnosis. In order to optimise diagnosis of preceding GAS infection, at least two sequential ASOT measurements, together with simultaneous assay for anti-DNase B, a second antistreptococcal antibody, is recommended.