Early Outcomes in Children With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

Childhood Vasculitis

Of the primary vasculitis pediatricians are familiar with, Kawasaki disease and IgA vasculitis are the most common. The other large, medium and small vessel vasculitis are seldom seen in practice. Though rare, early diagnosis and appropriate management is critical for the best outcome. Primary vasculitis in the pediatric age group have several differential diagnoses which range from infections to monogenic causes such as deficiency of Adenosine Deaminase -2. Each child, therefore, needs a careful systematic approach.

Clinicopathological characteristics of pediatric ANCA-associated glomerulonephritis

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and glomerulonephritis is uncommon in children. We sought to characterize the histological and clinical features of the disease and report on risk factors for adverse outcomes in a pediatric cohort.

METHODS

Retrospective single-center cohort of all pediatric (< 20 years) patients diagnosed with ANCA-associated glomerulonephritis (AAGN) by kidney biopsy between 2002 and 2022 at Johns Hopkins University. Histological and clinical features were extracted from the medical record. Clinical, laboratory, and histological findings were analyzed to determine the association with kidney failure (KF) and/or death.

RESULTS

A total of 17 patients were identified (GPA n = 7, MPA = 10) with a median age of 15 years (IQR 12-17) at presentation, a slight female predominance (59%), with seven patients reaching the composite outcome of death (n = 1) or kidney failure (n = 6). There was no difference in presenting clinical symptoms or extra-renal manifestations between the two groups. Univariable Cox regression identified several factors associated with an increased hazard of endpoint including the degree of global or segmental sclerosis, interstitial fibrosis and tubular atrophy (IFTA), C3 and C1q staining, presence of subendothelial deposits, and proteinuria. Multivariable regression was not performed due to the small sample size. We saw a trend towards increased utilization of plasma exchange and a decrease in cyclophosphamide utilization in the more recent era. There was no association between treatment modality and outcome.

CONCLUSIONS

Pediatric AAGN is a rare disease associated with significant morbidity. We identified glomerulosclerosis and IFTA on histology, and proteinuria on initial presentation as risk factors for KF/death.

Update on antineutrophil cytoplasmic autoantibody vasculitis in children

PURPOSE OF REVIEW

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is often organ- or life-threatening in children and impacts them during important periods of psychosocial and physical development. This review covers recent advances in the pathophysiology, diagnosis, management, and outcomes of AAV in children and highlights the ongoing need for funding and increased research collaboration.

RECENT FINDINGS

Recent work has improved our understanding of AAV disease pathogenesis, potentially identifying new biomarkers and therapeutic targets. Collaborative clinical studies have also highlighted the variable manifestations in children and identified potential factors associated with poorer outcomes. Consensus-based treatment guidelines are also appearing, but clinical trials are still essential to better understanding treatment efficacy and safety in children affected by AAV. New, validated outcome measures, including those that are patient-reported, will facilitate these much-needed clinical trials in pediatric AAV.

SUMMARY

There is a continued need for more rigorous study in pediatric AAV, however, there is certainly excitement with the increase in recent research relevant to the pediatric population.

Predictive utility of ANCA positivity and antigen specificity in the assessment of kidney disease in paediatric-onset small vessel vasculitis

OBJECTIVES

The objective of this study is to evaluate whether anti-neutrophil cytoplasmic antibody (ANCA) seropositivity and antigen specificity at diagnosis have predictive utility in paediatric-onset small vessel vasculitis.

METHODS

Children and adolescents with small vessel vasculitis (n=406) stratified according to the absence (n=41) or presence of ANCA for myeloperoxidase (MPO) (n=129) and proteinase-3 (PR3) (n=236) were compared for overall and kidney-specific disease activity at diagnosis and outcomes between 1 and 2 years using retrospective clinical data from the ARChiVe/Paediatric Vasculitis Initiative registry to fit generalised linear models.

RESULTS

Overall disease activity at diagnosis was higher in PR3-ANCA and MPO-ANCA-seropositive individuals compared with ANCA-negative vasculitis. By 1 year, there were no significant differences, based on ANCA positivity or specificity, in the likelihood of achieving inactive disease (~68%), experiencing improvement (≥87%) or acquiring damage (~58%). Similarly, and in contrast to adult-onset ANCA-associated vasculitis, there were no significant differences in the likelihood of having a relapse (~11%) between 1 and 2 years after diagnosis. Relative to PR3-ANCA, MPO-ANCA seropositivity was associated with a higher likelihood of kidney involvement (OR 2.4, 95% CI 1.3 to 4.7, p=0.008) and severe kidney dysfunction (Kidney Disease Improving Global Outcomes (KDIGO) stages 4-5; OR 6.04, 95% CI 2.77 to 13.57, p<0.001) at onset. Nonetheless, MPO-ANCA seropositive individuals were more likely to demonstrate improvement in kidney function (improved KDIGO category) within 1 year of diagnosis than PR3-ANCA seropositive individuals with similarly severe kidney disease at onset (p<0.001).

CONCLUSIONS

The results of this study suggest important paediatric-specific differences in the predictive value of ANCA compared with adult patients that should be considered when making treatment decisions in this population.

Risk factors for renal outcomes in children with antineutrophil cytoplasmic antibody-associated vasculitis: a nationwide retrospective study in China

BACKGROUND

Pediatric antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a life-threatening systemic vasculitis featured by liability to renal involvement. However, there are few studies on the risk factors and predictive models for renal outcomes of AAV in children.

METHODS

Data from 179 AAV children in multiple centers between January 2012 and March 2020 were collected retrospectively. The risk factors and predictive model of end-stage renal disease (ESRD) in AAV were explored.

RESULTS

Renal involvement was the most typical manifestation (95.5%), and the crescent was the predominant pathological lesion (84.9%). The estimated glomerular filtration rate (eGFR) was evaluated in 114 patients, of whom 59.6% developed ESRD, and the median time to ESRD was 3.20 months. The eGFR [P = 0.006, odds ratio (OR) = 0.955, 95% confidence interval (CI) = 0.924-0.987] and the percentages of global glomerulosclerosis (pGGS; P = 0.018, OR = 1.060, 95% CI = 1.010-1.112) were independent risk factors for ESRD of renal biopsy. Based on the pGGS and eGFR at renal biopsy, we developed three risk grades of ESRD and one predictive model. The Kaplan‒Meier curve indicated that renal outcomes were significantly different in different risk grades (P < 0.001). Compared with serum creatinine at baseline, the predictive model had higher accuracy (0.86 versus 0.58, P < 0.001) and a lower coefficient of variation (0.07 versus 0.92) in external validation.

CONCLUSIONS

Renal involvement is the most common manifestation of pediatric AAV in China, of which more than half deteriorates into ESRD. The predictive model based on eGFR at renal biopsy and the pGGS may be stable and accurate in speculating the risk of ESRD in AAV children. Supplementary file 2 (MP4 18937 KB).

Headaches and Vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability making this a disorder of paramount importance to all clinicians. Headache may be an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. Primary neurologic vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible.

Anti-LAMP-2 Antibody Seropositivity in Children with Primary Systemic Vasculitis Affecting Medium- and Large-Sized Vessels

Chronic primary systemic vasculitis (PSV) comprises a group of heterogeneous diseases that are broadly classified by affected blood vessel size, clinical traits and the presence (or absence) of anti-neutrophil cytoplasmic antibodies (ANCA) against proteinase 3 (PR3) and myeloperoxidase (MPO). In small vessel vasculitis (SVV), ANCA are not present in all patients, and they are rarely detected in patients with vasculitis involving medium (MVV) and large (LVV) blood vessels. Some studies have demonstrated that lysosome-associated membrane protein-2 (LAMP-2/CD107b) is a target of ANCA in SVV, but its presence and prognostic value in childhood MVV and LVV is not known. This study utilized retrospective sera and clinical data obtained from 90 children and adolescents with chronic PSV affecting small (SVV, n = 53), medium (MVV, n = 16), and large (LVV, n = 21) blood vessels. LAMP-2-ANCA were measured in time-of-diagnosis sera using a custom electrochemiluminescence assay. The threshold for seropositivity was established in a comparator cohort of patients with systemic autoinflammatory disease. The proportion of LAMP-2-ANCA-seropositive individuals and sera concentrations of LAMP-2-ANCA were assessed for associations with overall and organ-specific disease activity at diagnosis and one-year follow up. This study demonstrated a greater time-of-diagnosis prevalence and sera concentration of LAMP-2-ANCA in MVV (52.9% seropositive) and LVV (76.2%) compared to SVV (45.3%). Further, LAMP-2-ANCA-seropositive individuals had significantly lower overall, but not organ-specific, disease activity at diagnosis. This did not, however, result in a greater reduction in disease activity or the likelihood of achieving inactive disease one-year after diagnosis. The results of this study demonstrate particularly high prevalence and concentration of LAMP-2-ANCA in chronic PSV that affects large blood vessels and is seronegative for traditional ANCA. Our findings invite reconsideration of roles for autoantigens other than MPO and PR3 in pediatric vasculitis, particularly in medium- and large-sized blood vessels.

Systemic vasculitis and headache

PURPOSE OF REVIEW

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system or so called neurovasculitides, lead to pervasive injury and disability making these disorder of paramount importance to clinicians.

RECENT FINDINGS

Headache is an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. A suspicion of vasculitis based on the history, clinical examination, or laboratory studies warrants prompt evaluation and treatment to forestall progression and avert cerebral ischemia or infarction. There has been remarkable progress in the pathogenesis, diagnosis, and treatment of primary adult and pediatric CNS vasculitides predicated on achievements in primary systemic forms.

SUMMARY

Vasculitis can be diagnosed with certainty after intensive evaluation that includes tissue confirmation whenever possible. Clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, tempered by the recognition of anticipated medication side effects.

Primary central nervous system vasculitis and headache: Ten themes

PURPOSE OF REVIEW

The primary central nervous system (CNS) vasculitides refers to clinicopathologic disorders that share the histopathology of inflammation of cerebral or spinal blood vessels. Unrecognized and therefore untreated, vasculitis of the CNS results in irreversible injury and disability making these disorders of paramount importance to clinicians.

RECENT FINDINGS

Headache is an important clue to vasculitic involvement of CNS vessels. CNS vasculitis can be primary, in which only intracranial or spinal vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. The suspicion of vasculitis based on the history, clinical examination, and laboratory studies warrants prompt evaluation and treatment to prevent cerebral ischemia or infarction.

SUMMARY

Primary CNS vasculitides can be diagnosed with certainty after intensive evaluation that includes tissue confirmation whenever possible. As in its systemic counterparts, clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, tempered by anticipated medication adverse effects.

Pediatric ANCA vasculitis: clinical presentation, treatment, and outcomes in a French retrospective study

BACKGROUND

Pediatric ANCA vasculitis is a rare group of diseases with a scarcity of data in children. Annual incidence appeared to increase in the last several years, placing higher interest in the clinical and therapeutical outcomes of the disorder. Also, the growing use of rituximab questions the latest outcomes in these diseases. We therefore conducted a retrospective study to better understand the current characteristics, management, and the latest outcomes of the disorder.

METHODS

We conducted a 9-year retrospective study of 46 children in 14 different centers across France to describe their clinical and laboratory presentations, therapeutic regimens, and kidney outcome.

RESULTS

P-ANCA appeared to be a potential marker for higher relapse risk. Compared to adults, we found that ear-nose-throat presentations were frequent (45.7%) and more severe. Despite an evolution in the treatment management, kidney outcome remained poor with a substantial proportion of chronic kidney disease (54.8% at 1 year). Mortality stays low with 3 patients (6.5%) deceased at the end of our study.

CONCLUSION

Clinical presentation was as previously described and time to diagnosis remains long. P-ANCA is a statistically significant marker for increased relapse risk. We observed a modification in the treatment regimens over the past several years with a growing use of rituximab and a decreasing use of cyclophosphamide. Despite these changes, kidney outcome remains poor and prospective studies should be conducted to assess the most appropriate therapeutic modality for each patient. A higher resolution version of the Graphical abstract is available as Supplementary information.

Childhood-Onset ANCA- Associated Vasculitis: single center experience from Central California

BACKGROUND

Childhood-onset ANCA-associated vasculitides (AAV) are characterized by necrotizing inflammation and include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Pediatric data is scare and there have been no prior studies examining the characteristics of pediatric AAV in Central California.

METHODS

This retrospective study comprised AAV patients ≤18 years of age, diagnosed between 2010 and 2021, in Central California. We analyzed initial presentation including demographics, clinical, laboratory characteristics, treatment, and initial outcomes.

RESULTS

Of 21 patients with AAV, 12 were categorized as MPA and 9 with GPA. Median age at diagnosis was 13.7 years in MPA cohort and 14 years in GPA. MPA cohort were majority females (92% versus 44%). 57% of the cohort were racial/ethnic minority including Hispanics (n = 9), Asians (n = 2), multiracial (n = 1) and 43% were white (n = 9). MPA patients were more frequently Hispanic (67%), meanwhile GPA patients were frequently white (78%). Median duration of symptoms prior to diagnosis was 14 days in MPA cohort and 21 days in GPA cohort. Renal involvement was frequent (100% in MPA and 78% in GPA). GPA cohort had frequent ear, nose and throat (ENT) involvement (89%). All patients were ANCA positive. All Hispanic patients were MPO positive, meanwhile 89% of white patients were PR3 positive. MPA cohort tended towards more severe disease with 67% requiring ICU admission and 50% requiring dialysis. Two deaths were reported in MPA cohort, related to Aspergillus pneumonia and pulmonary hemorrhage. In MPA cohort, 42% received cyclophosphamide in combination with steroids and 42% received rituximab in combination with steroids. GPA patients received cyclophosphamide, either with steroids alone (78%) or in combination with steroids and rituximab (22%).

CONCLUSIONS

Microscopic polyangiitis was the most frequent AAV subtype with female preponderance, shorter duration of symptoms at onset and higher proportion of racial/ ethnic minority patients. Hispanic children demonstrated frequent MPO positivity. Trends towards higher rates of ICU requirement and need for dialysis upon initial presentation was noted in MPA. Patients with MPA received rituximab more frequently. Future prospective studies are needed to understand differences in presentation and outcomes in childhood onset AAV between diverse racial-ethnic groups.

Association of Pediatric Vasculitis Activity Score with immunoglobulin A vasculitis with nephritis

BACKGROUND

Immunoglobulin A vasculitis with nephritis (IgAVN) is the most serious complication affecting long-term prognosis. Understanding the risk factors and markers for the development of IgAVN is essential. The aim of this study is to identify IgAVN-associated factors and to evaluate the usability of Pediatric Vasculitis Activity Score (PVAS) at diagnosis as an early marker for the development of IgAVN.

METHODS

We conducted a retrospective case-control study of 314 patients divided into two groups: those with nephritis (IgAVN) and without nephritis (non-IgAVN). The groups were compared in terms of clinical symptoms, laboratory values, and PVAS values.

RESULTS

In total, 18.5% of the patients had IgAVN; they were older than the non-IgAVN patients (median age was 8.8, p < 0.05). Arthritis/arthralgia, abdominal pain, and intestinal bleeding were more common, systolic and diastolic BP were higher in IgAVN (p < 0.05). CRP, serum creatinine, and urine protein/Cr, PVAS were higher, while serum albumin was lower in IgAVN (p < 0.05). The receiver operator characteristic curve (ROC) analysis showed that IgAV patients with a determined cut-off PVAS value greater than 3 had 70.7% sensitivity in predicting whether or not they would develop IgAVN. Logistic regression analysis found that PVAS > 3 and low serum albumin at the time of diagnosis were independent risk factors for IgAVN.

CONCLUSION

Our study revealed that PVAS > 3 at diagnosis is an independent predictor of IgAVN. Patients with PVAS > 3 should be followed more closely to ensure early diagnosis and management of IgAVN. A higher resolution version of the Graphical abstract is available as Supplementary information.

Adult and childhood vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability, making this a disorder of paramount importance to all clinicians. There has been remarkable progress in the pathogenesis, diagnosis, and treatment of primary CNS and PNS vasculitides, predicated on achievement in primary systemic forms. Primary neurological vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible. Clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, unfortunately without the benefit of RCTs, and tempered by the recognition of anticipated medication side effects. It may be said that efforts to define a disease are attempts to understand the very concept of the disease. This has been especially evident in systemic and neurological disorders associated with vasculitis. For the past 100 years, since the first description of granulomatous angiitis of the brain, the CNS vasculitides have captured the attention of generations of clinical investigators around the globe to reach a better understanding of vasculitides involving the central and peripheral nervous system. Since that time it has become increasingly evident that this will necessitate an international collaborative effort.

Motor sequela of adult and pediatric stroke: Imminent losses and ultimate gains

Stroke is the leading cause of neurological disability in the United States and worldwide. Remarkable advances have been made over the past 20 years in acute vascular treatments to reduce infarct size and improve neurological outcome. Substantially less progress has been made in the understanding and clinical approaches to neurological recovery after stroke. This chapter reviews the epidemiology, bedside examination, localization approaches, and classification of stroke, with an emphasis on motor stroke presentations and management, and promising research approaches to enhancing motor aspects of stroke recovery.

Clinical and Renal Histology Findings and Different Responses to Induction Treatment Affecting the Long-Term Renal Outcomes of Children With ANCA-Associated Vasculitis: a Single-Center Cohort Analysis

Introduction

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is relatively rare in children. This article aimed to analyze clinical and renal histology findings and different responses to induction treatment associated with the long-term renal outcomes in children with AAV in a single center.

Methods

All pediatric patients with AAV admitted to Tongji Hospital from January 2002 to January 2021 were included in the study. The demographic, clinical, pathological, laboratory, and treatment data and outcomes were collected and analyzed to identify predictors associated with response to induction treatment and progression to end-stage renal disease (ESRD).

Results

In total, 48 children with AAV were included in this cohort; 81.25% of them were women, and 91.7% were microscopic polyangiitis (MPA). Kidney involvement was found in 45 patients (93.75%). The most common histopathological subtype was crescentic form in this cohort according to Berden's classification. In total, 34 patients (70.8%) showed eGFR <60 ml/min/1.73 m2 at the time of diagnosis. Complete and partial remission was achieved in 8 patients (16.7%) and 19 patients (39.6%), respectively, following 6-month induction treatment. Half of the patients eventually progressed to ESRD at a mean time of (13.04 ± 15.83) months after diagnosis. The independent predictors of nonremission following induction treatment and progression to ESRD were baseline eGFR <60 ml/min/1.73 m2 and hypertension at diagnosis. Renal survival significantly decreased over time in patients with renal sclerotic subtypes or those with nonremission following induction treatment by Kaplan-Meier curve estimation.

Conclusions

Our study demonstrates that women, MPA, and crescentic subtypes are predominant in pediatric AAV in China. Initial renal failure (eGFR <60 ml/min/1.73 m2), hypertension, sclerotic pathological subtype, and nonremission following induction treatment are predictive of long-term renal outcomes.

[Primary vasculitides in childhood and adulthood]

Primary systemic vasculitides can be observed at any age. Some vasculitides occur preferentially in childhood, such as Kawasaki syndrome or immunoglobulin A (IgA) vasculitis, whereas others, such as giant cell arteritis, occur beyond the age of 50 years. Vasculitides occurring in childhood or adolescence and adulthood may have different phenotypes, different disease courses and outcomes depending on the age of manifestation. For example, those with Takayasu arteritis beginning in adolescence have different vascular involvement, a higher degree of systemic inflammation and a more aggressive course of disease than those with adult-onset disease. In contrast, IgA vasculitis is more severe in adults than in children. The causes for the age predilections and different age-dependent disease manifestations have not yet been clarified. The therapeutic principles are similar for vasculitides occurring in children or adolescents and adults. The first international evidence-based treatment recommendations are now available for juvenile vasculitides, although the evidence for certain forms of treatment is still very limited. The treatment of adult vasculitides can be guided by numerous national and international guidelines and recommendations. Many vasculitides carry a high risk of morbidity and mortality and the timely detection and treatment are therefore necessary. In this article, similarities and differences in the clinical presentations, treatment, courses and prognosis of vasculitides in children or adolescents and adults are discussed.

Renal Involvement and Its Treatment in Pediatric Patients With Proteinase-3 Anti-Neutrophil Cytoplasmic Antibody Positive Granulomatosis With Polyangiitis: A Case Series

We describe three pediatric patients between the ages of 10 and 14 years old who were diagnosed with granulomatosis with polyangiitis (GPA) between 2014 and 2019. Each case involves variations in presentation, symptomatology, diagnostics, and induction and maintenance therapy regimens. Patient 1 presented with significant renal involvement, hypertensive emergency, and focal alveolar hemorrhage, a rare presentation of GPA that causes up to 60% mortality.Patient 2 presented with minimal renal involvement and a diffuse petechial rash, which is the most common cutaneous presentation of GPA. Finally, patient 3 presented with significant renal involvement and later on with symptoms of idiopathic intracranial hypertension (IIH), a unique and rare presentation associated with GPA. Despite the heterogeneity of these cases, the similar therapy regimens used in each case successfully achieved induction and maintenance of disease remission, providing an evidentiary basis for these treatment regimens even in severe and unusual pediatric GPA cases.

Recent Advances in Pediatric Vasculitis

This article provides an overview of the clinical presentation and diagnosis of select pediatric primary systemic vasculitides. Important advances in understanding the pathogenesis of these rare diseases also are discussed and efforts to harmonize treatment through consensus-based guidelines and multicenter and international collaborations highlighted.

Pulmonary manifestations and outcomes in paediatric ANCA-associated vasculitis: a single-centre experience

OBJECTIVES

ANCA-associated vasculitis (AAV) usually involves the renal and respiratory systems, but the paediatric literature on pulmonary manifestations and outcomes is limited. We aimed to describe pulmonary manifestations and outcomes after therapy in a cohort of paediatric AAV (pAAV) patients.

METHODS

A retrospective chart review of all patients <19 years presenting to our institution with AAV between 1/2008 and 2/2018 was conducted. Patient demographics, clinical presentation, diagnostic testing, therapy and pulmonary outcomes over the first 3 years after presentation were evaluated.

RESULTS

A total of 38 patients were included; all had ANCA positivity by immunofluorescence. A total of 23 had microscopic polyangiitis (MPA), 13 had granulomatosis with polyangiitis and 2 had eosinophilic granulomatosis with polyangiitis. A total of 30 (79%) had pulmonary manifestations, with cough (73%) and pulmonary haemorrhage (67%) being the most common. Abnormalities were noted in 82% of chest CT scans reviewed, with nodules and ground-glass opacities being the most common. At 6, 12 and 36 months follow-up, respectively, 61.8%, 39.4% and 29% of patients continued to show pulmonary manifestations. Five MPA patients with re-haemorrhage are described in detail.

CONCLUSION

MPA was more common than granulomatosis with polyangiitis, with pulmonary involvement being common in both. MPA patients had more severe pulmonary manifestations. Chest CT revealed abnormal findings in a majority of cases. A subgroup of young MPA patients experienced repeat pulmonary haemorrhage. Treatment modality and response were comparable in different subtypes of AAV, except for this young MPA group. Additional prospective studies are needed to better understand the different phenotypes of pAAV.

Prognostic Factors and Long-Term Outcome with ANCA-Associated Kidney Vasculitis in Childhood

BACKGROUND AND OBJECTIVES

ANCA-associated vasculitis is extremely rare in children. We report the clinicopathologic features, long-term outcomes, and prognostic factors of a large pediatric cohort of patients with ANCA-associated kidney vasculitis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective study included 85 consecutive patients with kidney biopsy specimen-proven ANCA-associated vasculitis from tertiary referral centers in Italy and Canada. Kidney biopsy specimens were categorized as focal, crescentic, sclerotic, or mixed, according to the Berden classification. The prognostic significance of baseline clinical, laboratory, and histologic findings was analyzed with respect to kidney failure or CKD stage 3-5/kidney failure.

RESULTS

A total of 53 patients had microscopic polyangiitis (62%), and 32 had granulomatosis with polyangiitis (38%). Rapidly progressive GN was the most frequent presentation (39%); a third of the patients also had nephrotic-range proteinuria. Kidney biopsy specimens were classified as focal in 21% of the patients, crescentic in 51%, sclerotic in 15%, and mixed in 13%. Remission-induction therapies included cyclophosphamide in 78% of patients. A total of 25 patients (29%) reached kidney failure. The median (interquartile range) time to kidney failure or last follow-up was 35 (6-89) months in the whole cohort, and 73 (24-109) months among the patients who did not reach this outcome. Patients whose biopsy specimens showed sclerotic histology had significantly shorter kidney survival (hazard ratio, 11.80; 95% confidence interval, 2.49 to 55.99) and survival free of CKD stage 3-5 (hazard ratio, 8.88; 95% confidence interval, 2.43 to 32.48), as compared with those with focal/mixed histology. Baseline eGFR, low serum albumin, hypertension, central nervous system complications, and sclerotic histology, which reflected severe kidney involvement, were associated with both kidney failure and CKD stage 3-5/kidney failure at unadjusted analysis; no independent prognostic factors emerged at multivariable analysis.

CONCLUSIONS

Children with ANCA-associated kidney vasculitis often have aggressive presentation; a third of such children progress to kidney failure and this usually occurs early during follow-up. A severe clinical presentation is associated with the development of CKD or kidney failure.

Consensus Treatment Plans for Severe Pediatric Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

There is no standardized approach to the treatment of pediatric antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (ped-AAV). Because of the rarity of ped-AAV, randomized trials have not been feasible. The Childhood Arthritis and Rheumatology Research Alliance (CARRA) developed consensus treatment plans (CTPs) for severe ped-AAV to enable the future study of comparative effectiveness and safety.

METHODS

A workgroup of CARRA members (rheumatologists and nephrologists) formed the AAV working group. This group performed a literature review on existing evidence-based treatments and guidelines for the management of AAV. They determined that the target population for CTP development was patients <18 years with new-onset granulomatosis with polyangiitis (GPA), microscopic polyangiitis, or renal-limited AAV (eosinophilic-GPA was excluded) with presentation confined to those with severe disease i.e. organ- or life-threatening. Face-to-face consensus conferences employed nominal group techniques to identify treatment strategies for remission-induction and remission-maintenance, data elements to be systematically collected, and outcomes to be measured over time.

RESULTS

The ped-AAV workgroup developed two CTPs for each of the remission-induction and remission-maintenance of severe AAV. A corticosteroid-weaning regimen for induction and maintenance, a core dataset, and outcome measures were also defined. A random sample of CARRA membership voted acceptance of the CTPs for remission-induction and remission-maintenance with a 94% (75/80) and 98% (78/80) approval rate respectively.

CONCLUSION

Consensus methodology established standardized CTPs for treating severe ped-AAV. These CTPs were in principle accepted by CARRA-wide membership for pragmatic comparative effectiveness evaluation in a long-term registry.

Autoantibodies Against Lysosome Associated Membrane Protein-2 (LAMP-2) in Pediatric Chronic Primary Systemic Vasculitis

Background

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small vessel vasculitis in adults and children that commonly affects the kidneys. Although the frequent antigenic, and presumed pathogenic, targets of ANCA in AAV are proteinase-3 (PR3) and myeloperoxidase (MPO), ANCA against lysosome associated membrane protein-2 (LAMP-2), a lesser known ANCA antigen that is expressed on the glomerular endothelium, are present in some adults with AAV-associated renal disease. LAMP-2-ANCA has not been assessed in children with chronic systemic vasculitis, and, if present, would be a potentially valuable biomarker given that treatment decisions for these pediatric patients at diagnosis are largely informed by kidney function.

Methods

A custom ELISA, using commercially available reagents, was designed to detect autoantibodies to human LAMP-2 in serum. Sera obtained from 51 pediatric patients at the time of diagnosis of chronic primary systemic vasculitis (predominantly AAV) were screened. LAMP-2-ANCA titers were evaluated for correlation with clinical metrics of disease activity (pediatric vasculitis activity score [pVAS], C-reactive protein [CRP] concentration, and erythrocyte sedimentation rate [ESR]), MPO- and PR3-ANCA titers, and renal function (glomerular filtration rate [GFR], renal-specific pVAS, and serum creatinine concentration).

Results

LAMP-2-ANCA (>1,000 ng/ml) were detected in 35% (n = 18) of pediatric systemic vasculitis patients, of which, 10 (20% of all patients) were found to have high positive titers (>1,500 ng/ml). Undetectable or negative titres (<500 ng/ml) were identified in 12% (n = 6) of patients, those with titers between 500 and 1,000 ng/ml were considered low with unknown clinical relevance (53%, n = 27). Although LAMP-2-ANCA titers did not significantly differ between patients with AAV versus ANCA-negative vasculitis, only AAV patients had high concentrations (>1,500 ng/ml) of LAMP-2-ANCA. LAMP-2-ANCA titers did not correlate with measures of disease activity (pVAS, CRP, or ESR) at the time of diagnosis. In contrast, for patients with 12-month post diagnosis follow-up, a negative correlation was observed between the change in GFR (from diagnosis to 12-month follow-up) and LAMP-2-ANCA titer at diagnosis.

Conclusions

Moderate to high LAMP-2-ANCA titers were detected in 35% (18/51) of children with chronic systemic vasculitis affecting small-to-medium vessels. Although the highest concentrations of LAMP-2-ANCA in this population were observed in individuals positive for classic ANCA (MPO- or PR3-ANCA), similar to previous reports on adult patients, LAMP-2-ANCA titers do not correlate with classic ANCA titers or with overall disease activity at diagnosis. Renal disease is a common manifestation in systemic small-medium vessel vasculitis (both in adults and children, though more severe in children) and our preliminary data suggest LAMP-2-ANCA at diagnosis may be a risk factor for more severe renal disease.

Case Report: Systemic Small-Vessel Vasculitis in an Adolescent With Active Ulcerative Colitis

Introduction: Small-vessel vasculitis (SVV) is a rare immunological disease that affects arterioles, capillaries and venules. It causes purpura, but can also manifest in other organs, including the gastrointestinal tract. SVV and inflammatory bowel disease (IBD) co-occur more frequently than would be expected by chance. Case description: A 16-year-old girl, who had been diagnosed with ulcerative colitis (UC) 2 years earlier at a general hospital, developed purpura, progressive abdominal pain with frequent bloody diarrhea and frontotemporal headache and swelling while on azathioprine and mesalamine maintenance therapy. Serology was positive for perinuclear antineutrophil cytoplasmic antibodies (p-ANCA) without antiprotease- or myeloperoixidase antibodies. Endoscopy revealed active left-sided UC and atypical ulcerations in the ascending colon. Biopsies of these ulcerations and of affected skin revealed leukocytoclastic vasculitis. Initially this was interpreted as an extraintestinal manifestation of UC that would subside when remission was induced, consequently infliximab was started. Over the next 3 weeks she developed severe burning pain in her right lower leg that progressed to a foot drop with numbness and the purpura progressed to bullous lesions. The diagnosis was adjusted to ANCA-associated vasculitis with involvement of skin, bowel and peripheral nerves. Infliximab was discontinued and induction treatment with high-dose prednisolone and cyclophosphamide was given until remission of SVV and UC was achieved. Subsequently, infliximab induction and maintenance was re-introduced in combination with methotrexate. Remission has been maintained successfully for over 2 years now. The foot drop only partly resolved and necessitated the use of an orthosis. Conclusion: Pediatric patients with IBD who present with purpuric skin lesions and abdominal pain should be evaluated for systemic involvement of SVV, which includes endoscopic evaluation of the gastrointestinal tract. We discuss a practical approach to the diagnosis, evaluation and management of systemic SVV with a focus on prompt recognition and early aggressive therapy to improve outcome.

Lung biopsy in the diagnosis of pediatric ANCA-associated vasculitis

OBJECTIVE

To investigate pulmonary histopathologic features in a cohort of pediatric patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) who underwent a lung biopsy as part of their evaluation. We report the safety and the findings of lung biopsies in this population.

METHODS

After IRB approval, we performed a retrospective chart review of all patients <18 years of age presenting to our institution with a diagnosis of pediatric AAV (pAAV) who underwent lung biopsy. We reviewed histopathologic features, serologies, the timing of biopsy, and complications.

RESULTS

Fourteen patients met inclusion criteria, nine patients with microscopic polyangiitis (MPA), and five patients with granulomatosis with polyangiitis (GPA). All patients had positive ANCA serology. 13/14 patients required admission on initial presentation for respiratory symptoms; 11/13 required respiratory support. The indication for biopsy was confirmation of diagnosis before initiating therapy in 11 patients (78%), part of the infectious evaluation in two (14%), and part of interstitial lung disease evaluation in one (7%). 11/14 (78%) biopsies had findings consistent with AAV diagnosis: 6/9 (67%) of the MPA patients compared with 5/5 (100%) of the GPA patients. The most common findings on histopathology were vascular inflammation and signs of alveolar hemorrhage. The only reported complication after lung biopsy was pneumothorax in four patients (28%).

CONCLUSION

Lung biopsy had a higher diagnostic yield in GPA compared with MPA patients. In our cohort, a diagnosis of AAV could be made with clinical features and positive serology but was confirmed by lung histopathology in the majority of cases. Obtaining a lung biopsy for diagnostic purposes in pAAV should be reserved for uncertain cases where the diagnosis cannot be confirmed clinically and with serology.

CanVasc Consensus Recommendations for the Management of Antineutrophil Cytoplasm Antibody-associated Vasculitis: 2020 Update

OBJECTIVE

In 2015, the Canadian Vasculitis Research Network (CanVasc) created recommendations for the management of antineutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV) in Canada. The current update aims to revise existing recommendations and create additional recommendations, as needed, based on a review of new available evidence.

METHODS

A needs assessment survey of CanVasc members informed questions for an updated systematic literature review (publications spanning May 2014 to September 2019) using Medline, Embase, and Cochrane. New and revised recommendations were developed and categorized according to the level of evidence and strength of each recommendation. The CanVasc working group used a 2-step modified Delphi procedure to reach > 80% consensus on the inclusion, wording, and grading of each new and revised recommendation.

RESULTS

Eleven new and 16 revised recommendations were created and 12 original (2015) recommendations were retained. New and revised recommendations are discussed in detail within this document. Five original recommendations were removed, of which 4 were incorporated into the explanatory text. The supplementary material for practical use was revised to reflect the updated recommendations.

CONCLUSION

The 2020 updated recommendations provide rheumatologists, nephrologists, and other specialists caring for patients with AAV in Canada with new management guidance, based on current evidence and consensus from Canadian experts.

Coughing up clues: 16-year-old girl with acute haemoptysis

A 16-year-old previously well girl presented with bilateral painful lower leg swelling and non-pruritic blanching rash across her torso and upper and lower limbs. These symptoms started after commencing amoxicillin for presumed tonsillitis. She was diagnosed with serum sickness-like illness and started on non-steroidal agents. The rash and painful leg swelling improved over the next 48 hours. However, she subsequently developed fevers, cough and new-onset haemoptysis.She continued to deteriorate with increasing amounts of haemoptysis, work of breathing and escalating respiratory support requirements. Serial chest radiographs showed worsening lung consolidation and enlarging pleural effusion. A CT chest revealed extensive bilateral lung consolidation, most likely pulmonary haemorrhage. Subsequent investigations showed positive classic antineutrophil cytoplasmic antibody, confirming the diagnosis of granulomatosis with polyangiitis.

Measuring Vasculitis with Numbers: Outcome Scores

Primary Systemic Vasculitides (PSV) are a heterogeneous group of diseases. Outcome scores are important to evaluate vasculitis patients in a more structured and standard way and these help physicians to predict patients with poor prognosis or high risk of relapse. Furthermore, we need reliable outcome measures for clinical trials. There are a number of vasculitis outcome scores available in the clinical practice with different strengths and limitations. These are mainly measures of disease activity, disease damage, response to treatment and quality of life. Birmingham Vasculitis Activity Score (BVAS) and its pediatric version aim to evaluate a wide scope of PSV. On the other hand, some outcome studies have focused on a single vasculitis type since the whole group includes different diseases with heterogeneous clinical features. The aim of this review is to provide an overview on outcome measures currently being used in the evaluation of patients with PSV. We mainly focus on immunoglobulin A vasculitis/Henochschönlein purpura, Kawasaki disease, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, polyarteritis nodosa, Takayasu arteritis and Behçet's disease.

Childhood- Versus Adult-Onset Primary Vasculitides: Are They Part of the Same Clinical Spectrum?

PURPOSE OF THE REVIEW

Most of the primary vasculitis in children and adults has different clinical manifestations for the same disease, which suggests that they might not be part of the same clinical spectrum and requires a different approach in order to reduce the morbidity and mortality of these patients. In this work, we review the most recent literature and the most important studies that describe and compare adult and children primary vasculitides pathogenesis, clinical presentation, and treatment approach. Accordingly, we discuss recent research involving clinical trials, comparison studies, and pathogeny for these vasculitides.

RECENT FINDINGS

Clinical manifestations in the different primary vasculitis change in predominance from adults to children. There is a female sex predominance for the ANCA vasculitides in children compared with adults, but the same treatment works in most cases for both groups. Identifying the diverse clinical spectrum in both adults and children primary vasculitides will reduce the need to extrapolate the diagnostic criteria from one group to another and individualize it, which will allow the clinician to establish a better approach.

Overview of the Vasculitides

The systemic vasculitides are heterogeneous clinicopathologic disorders that share the common feature of vascular inflammation. The resulting disorder can vary depending on involvement of specific organs, caliber of blood vessels, the underlying inflammatory process, and individual host factors. The cumulative result is diminished blood flow, vascular alterations, and eventual occlusion with variable ischemia, necrosis, and tissue damage. An international revised nomenclature system provides the necessary nosology and findings relevant to classify each of the vasculitides. This article is an introduction and overview of the clinical presentation, differential diagnosis, laboratory evaluation, and treatment of systemic and nervous system vasculitides.

Childhood-Onset Eosinophilic Granulomatosis with Polyangiitis with a Vulvar Granuloma: A Case Report and Review of the Literature

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare multisystem necrotizing vasculitis associated with eosinophilia and extravascular granuloma and classically involving the upper and lower airways. There have only been a few reported cases of gynecologic involvement in EGPA.

CASE

We present an 8-year-old girl diagnosed with EGPA with a vulvar granuloma in what is, to our knowledge, the first reported pediatric gynecologic manifestation of EGPA. Interestingly, the vulvar granuloma did not respond to initial immunosuppressant treatment with prednisone and methotrexate and required treatment regimen modification with mycophenolate mofetil resulting in granuloma resolution.

SUMMARY AND CONCLUSION

EGPA in the pediatric population has a relatively high mortality rate compared with in the adult population thus it is important that vulvar granulomas associated with EGPA should be included in the differential diagnosis of a vulvar mass allowing for the prompt diagnosis and treatment of this potentially fatal disease in children.

Epidemiology and clinical features of childhood-onset anti-neutrophil cytoplasmic antibody-associated vasculitis: a clinicopathological analysis

BACKGROUND

This study was performed to determine the clinical features and outcomes of childhood-onset anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), particularly microscopic polyangiitis (MPA).

METHODS

A retrospective Japanese multicenter study was performed in patients diagnosed with AAV before 16 years of age.

RESULTS

Of 49 patients with AAV, 36 were female. The diagnoses were as follows: MPA (n = 38, 78%), granulomatosis with polyangiitis (GPA; n = 9, 18%), eosinophilic granulomatosis with polyangiitis (EGPA; n = 1, 2%), and other (n = 1, 2%). The median age at onset was 10.7 years, and median time to diagnosis was 2.0 months. Twenty-seven (55%) patients were identified through a school urinary screening program. Initial symptoms included fever and fatigue (45%), and renal (71%), pulmonary (29%), ocular (20%), and mucocutaneous involvement (22%). Although 27 (55%) patients achieved remission and none had died at the last follow-up, at least one recurrence occurred in 13 (48%) patients after a median of 48 months and was more common in patients with GPA (P < 0.01). After a median follow-up of 43 months, seven (14%) patients (all with MPA) progressed to end-stage renal disease (ESRD).

CONCLUSIONS

Childhood-onset AAV has an estimated prevalence of 3.41-4.28 per million children and is characterized by female predominance and high frequency of detection in school urinary screening programs. More than 10% of patients with childhood-onset AAV still progress to ESRD without achieving remission. Histological chronicity is a factor associated with ESRD.

Hallmark trials in ANCA-associated vasculitis (AAV) for the pediatric rheumatologist

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a complex group of systemic vasculitides that are characterized by primary small-to-medium sized blood vessel inflammation with the presence of autoantibodies known as ANCA. AAV diseases include Granulomatosis with Polyangiitis (GPA), Eosinophilic Granulomatosis with Polyangiitis (EGPA), and Microscopic Polyangiitis (MPA). AAVs are challenging conditions associated with high cumulative disease and treatment related morbidity and mortality. Given its rarity and the resulting paucity of pediatric-specific clinical trial evidence, pediatric rheumatologists have had to often extrapolate from adult literature for management and therapeutic decisions. The aim of this review is to provide a comprehensive overview of the important findings and overall conclusions of critical landmark clinical trials in the induction and maintenance treatments in adult AAV for the pediatric rheumatologist. This review also highlights the outcomes of recent pediatric AAV observational studies and discusses the future research priorities in pediatric AAV management.

Stroke due to Vasculitis in Children and Adults

The vasculitides are diseases characterized by inflammation of blood vessels and inflammatory leukocytes in vessel walls. There is an increased propensity for ischemic stroke, resulting from compromise of vessel lumina with distal tissue ischemia; and hemorrhagic or nonhemorrhagic stroke, and aneurysmal formation and bleeding, due to loss of vessel integrity.

Granulomatous Angiitis: Twenty Years Later

Granulomatous inflammation, the prototypical histopathology of adult and childhood vasculitis, is characterized by inflammation of blood vessels accompanied by giant cells and epithelioid cells in the walls of cerebral vessels ranging from small leptomeningeal veins to large named cerebral arteries. Headache, hemiparesis, mental changes, abnormal cerebrospinal fluid protein content, and pleocytosis are suggestive features that warrant brain and leptomeningeal biopsy to make the diagnosis certain and begin cytotoxic therapy to improve outcome.

Treatment of Vasculitis of the Nervous System

The diagnosis of primary central and peripheral nerve vasculitides should be established with certainty if suspected before commencing potent immunosuppressive therapy. The aim of induction therapy is to rapidly control the underlying inflammatory response and stabilize the blood-brain and blood-nerve barriers, followed by maintenance immunosuppression tailored to the likeliest humoral and cell-mediated autoimmune inflammatory vasculitic processes.

Epidemiology and Outcomes of Granulomatosis With Polyangiitis in Pediatric and Working-Age Adult Populations In the United States: Analysis of a Large National Claims Database

OBJECTIVE

The incidence and prevalence of granulomatosis with polyangiitis (GPA) in the US is not well characterized. Owing to its rarity, outcomes data in pediatric-onset GPA are also lacking. The aims of this study were to describe the epidemiology of GPA and outcomes in GPA patients in the US, and to compare outcomes between pediatric and working-age adult patients.

METHODS

A retrospective cohort study using the 2006-2014 Truven Health Analytics MarketScan Commercial Claims and Encounters Database was conducted. The incidence and prevalence rates of pediatric and adult GPA (age <65 years) were calculated. Outcomes among the 2 age groups were analyzed.

RESULTS

A total of 5,562 cases of GPA were identified, of which 214 (3.8%) were pediatric onset and 5,348 (96.2%) were adult onset. The incidence rate of pediatric-onset GPA was 1.8 cases per 1 million person-years, compared to 12.8 cases per 1 million person-years in working-age adults. There was a slight female preponderance in both groups (63% and 53% among pediatric and adult GPA patients, respectively). Rates of hospitalization and severe infections were high in both children and working-age adults, but children had more frequent hospitalizations (rate ratio [RR] 1.3 [95% confidence interval (95% CI) 1.1-1.4]) and 2-3-times higher rates of leukopenia (RR 2.6 [95% CI 1.5-4.3]), neutropenia (RR 2.2 [95% CI 1.2-4.0]), and hypogammaglobulinemia (RR 3.7 [95% CI 2.0-6.4]). Time-to-event analyses showed no differences in the time to hospitalization, severe infection, major relapse, or end-stage renal disease.

CONCLUSION

This study represents the largest cohort of GPA reported to date. Pediatric GPA patients experienced more frequent hospitalizations and were more vulnerable to hematologic complications than non-elderly adult patients.

Treatment Options for Resistant Kawasaki Disease

"Resistant" Kawasaki disease is defined by the American Heart Association as failure to respond within 36 h following the first dose of intravenous immunoglobulin. The optimal management of resistant Kawasaki disease remains uncertain, the outcomes are potentially serious, and the cost of some treatments is considerable. We review the current evidence to guide treatment of resistant Kawasaki disease. Given the relative rarity, there are few trial data, and studies tend to be small and methodologically heterogeneous, making interpretation difficult and limiting generalisability. The literature on resistant Kawasaki disease should be interpreted with reference to current expert consensus guidelines.

Primary Vasculitis in Childhood: GPA and MPA in Childhood

Childhood onset anti-neutrophilic cytoplasmic antibody (ANCA) associated vasculitis (AAV) is a rare group of primary systemic vasculitides affecting medium and small blood vessels. AAV includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), and renal limited ANCA vasculitis. These disorders are associated with severe clinical manifestations, frequent relapses and a high cumulative morbidity, and often present with multisystem involvement. Renal involvement is common in the pediatric age group, characterized by pauci-immune necrotizing and crescentic glomerulonephritis which frequently progresses to chronic kidney disease in adulthood. ANCAs against proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO) (MPO-ANCA) remain the hallmark of AAV and are integral to the disease pathogenesis. Newer understanding of neutrophil extracellular traps and complement activation have provided better insights into disease pathogenesis. A pediatric vasculitis working group has developed and validated childhood vasculitis classification criteria and disease activity and damage scores. No specific pediatric treatment recommendations exist due to rare nature of the illness in pediatric population. Smaller case series have been published on the efficacy of adult treatment regimens in pediatric patients. The prognosis often remains guarded with frequent relapses and a high cumulative morbidity. The aim of this article is to provide a comprehensive review on pediatric AAV with a focus on recent observations regarding epidemiology, disease pathogenesis, treatment, and prognosis.

Childhood systemic vasculitis

Vasculitides are characterized by inflammation of the vessel wall. Most of the vasculitides tend to occur in vessels of a specific size and certain target organs. In this review, we discuss each specific childhood vasculitis according to the latest Chapel Hill Consensus Conference 2012 nomenclature system and the Ankara 2008 classification criteria. We have also reviewed the clinical and laboratory characteristics and the recent treatment recommendations for the vasculitides we encounter in children.

Childhood- versus adult-onset ANCA-associated vasculitides: A nested, matched case-control study from the French Vasculitis Study Group Registry

OBJECTIVE

To investigate differences between childhood-onset ANCA-associated vasculitides (cAAVs) and matched adult-onset controls (aAAVs).

METHODS

cAAV clinical pictures at onset and outcomes were compared to a randomly selected sample of aAAV patients from the French Vasculitis Study Group Registry. Cases and controls were matched for AAV (granulomatosis with polyangiitis [GPA], microscopic polyangiitis [MPA] or eosinophilic granulomatosis with polyangiitis [EGPA]), sex and year of enrollment. Medications, disease activity and damage were prospectively recorded. Kaplan-Meier curves and the log-rank test were used to analyze case-vs.-control differences for predefined outcomes.

RESULTS

Comparing 35 cAAVs (25 GPA, 4 MPA, 6 EGPA) to 151 aAAVs (106 GPA, 17 MPA, 28 EGPA), their respective median follow-up durations were 71 and 64months (P=0.49), and, at baseline, children had less frequent myalgias (P=0.005) and peripheral neuropathy (P<0.001) but were more frequently febrile (P<0.05). Rates of renal involvement were comparable (13 [37%] cAAVs vs. 73 [48%] aAAVs; P=0.31). Initial GPA-associated ischemic abdominal pain and nasal cartilage damage were more common in cAAVs than aAAVs (P<0.05). During follow-up, the cAAV relapse rate was higher (24.5 vs. 18.7 flares per 100 patient-years; P<0.05) and, at last visit, cases had accumulated more damage, mostly ear, nose & throat sequelae (P=0.001), associated with longer maintenance therapy (P=0.03), than aAAV controls. Four (11.4%) cAAV and 13 (8.6%) aAAV patients died (P=0.53).

CONCLUSION

cAAVs are severe diseases, characterized by a higher relapse rate, more accrued damage and longer maintenance therapy than for aAAVs.

Glomerular Diseases in Children

Unique challenges exist in the diagnosis and treatment of glomerular diseases with their onset during childhood. Mounting evidence supports the notion that earlier onset cases occur due to larger numbers of genetic risk alleles. Nearly all causes of adult-onset glomerulonephritis, nephrotic syndrome, and thrombotic microangiopathy have also been described in children, although the prevalence of specific causes differs. Postinfectious glomerulonephritis, Henoch-Schönlein purpura nephritis, and minimal change disease remain the most common causes of glomerular disease in younger children in the United States and can be diagnosed clinically without need for biopsy. IgA nephropathy is the most common pediatric glomerular disease diagnosed by kidney biopsy and is considered the most common chronic glomerulopathy worldwide. In both developing and developed countries, there is a strong relationship between infectious diseases and nephritis onset or relapse. Although research has led to a better understanding of how to classify and manage glomerular diseases in children, the need for disease-specific biomarkers of activity and chronicity remains a hurdle. The strength of the immune system and the growth and maturation that occurs during adolescence are unique and require age-specific approaches to disease management.