Defining remission in childhood-onset lupus: PReS-endorsed consensus definitions by an international task force

OBJECTIVE

To derive childhood-onset SLE (cSLE) specific remission definitions for future treat-to-target (T2T) trials, observational studies, and clinical practice.

METHODS

The cSLE International T2T Task Force conducted Delphi surveys exploring paediatric perspectives on adult-onset SLE remission targets. A modified nominal group technique was used to discuss, refine, and agree on the cSLE remission target criteria.

RESULTS

The Task Force proposed two definitions of remission: 'cSLE clinical remission on steroids (cCR)' and 'cSLE clinical remission off steroids (cCR-0)'. The common criteria are: (1) Clinical-SLEDAI-2 K = 0; (2) PGA score < 0.5 (0-3 scale); (4) stable antimalarials, immunosuppressive, and biologic therapy (changes due to side-effects, adherence, weight, or when building up to target dose allowed). Criterion (3) in cCR is the prednisolone dose ≤0.1 mg/kg/day (maximum 5 mg/day), whereas in cCR-0 it is zero.

CONCLUSIONS

cSLE definitions of remission have been proposed, maintaining sufficient alignment with the adult-SLE definition to facilitate life-course research.

Cardiovascular outcomes improve in children with renovascular hypertension following endovascular and surgical interventions

BACKGROUND

Renovascular hypertension (RenoVH) is a cause of hypertension in children. A common cause of RenoVH is renal artery stenosis which acts by reducing blood supply to renal parenchyma and activating the renin-angiotensin-aldosterone axis, often leading to cardiac remodelling. This longitudinal observational study aims to describe occurrence of cardiovascular changes secondary to RenoVH and also any improvement in cardiac remodelling after successful endovascular and/or surgical intervention.

METHODS

All patients with RenoVH referred to our centre, who received ≥ 1 endovascular intervention (some had also undergone surgical interventions) were included. Data were collected by retrospective database review over a 22-year period. We assessed oscillometric blood pressure and eight echocardiographic parameters pre- and post-intervention.

RESULTS

One hundred fifty-two patients met inclusion criteria and had on average two endovascular interventions; of these children, six presented in heart failure. Blood pressure (BP) control was achieved by 54.4% of patients post-intervention. Average z-scores improved in interventricular septal thickness in diastole (IVSD), posterior Wall thickness in diastole (PWD) and fractional shortening (FS); left ventricular mass index (LVMI) and relative wall thickness (RWT) also improved. PWD saw the greatest reduction in mean difference in children with abnormal (z-score reduction 0.25, p < 0.001) and severely abnormal (z-score reduction 0.23, p < 0.001) z-scores between pre- and post-intervention echocardiograms. Almost half (45.9%) had reduction in prescribed antihypertensive medications, and 21.3% could discontinue all antihypertensive therapy.

CONCLUSIONS

Our study reports improvement in cardiac outcomes after endovascular + / - surgical interventions. This is evidenced by BP control, and echocardiogram changes in which almost half achieved normalisation in systolic BP readings and reduction in the number of children with abnormal echocardiographic parameters. A higher resolution version of the Graphical abstract is available as Supplementary information.

SUPPLEMENTARY INFORMATION

Outcome of immunosuppression in children with IgA vasculitis-related nephritis

BACKGROUND AND HYPOTHESIS

IgA vasculitis with nephritis (IgAVN) is the most common vasculitis in children. Treatment recommendations are, due to a lack of evidence, based on expert opinion resulting in variation. The aim of this study was to describe clinical presentation, treatment and outcome of an extremely large cohort of children with biopsy proven IgAVN to identify prognostic risk factors and signals of treatment efficacy.

METHODS

Retrospective data were collected on 1148 children with biopsy proven IgAVN between 2005 and 2019 from 41 international paediatric nephrology centres across 25 countries and analyzed using multivariate analysis. The primary outcome was estimated glomerular filtration rate (eGFR) and persistent proteinuria at last follow up.

RESULTS

The median follow up was 3.7 years (IQR 2-6.2). At last follow up, 29% of patients had an eGFR < 90 ml/min/1.73m2, 36% had proteinuria and 3% had chronic kidney disease stage 4-5. Older age, lower eGFR at onset, hypertension and histological features of tubular atrophy and segmental sclerosis were predictors of poor outcome. There was no evidence to support any specific second line immunosuppressive regimen to be superior to others, even when further analysing subgroups of children with reduced kidney function, nephrotic syndrome or hypoalbuminemia at onset. Delayed start of immunosuppressive treatment was associated with a lower eGFR at last follow up.

CONCLUSION

In this large retrospective cohort, key features associated with disease outcome are highlighted. Importantly there was no evidence to support that any specific immunosuppressive treatments were superior to others. Further discovery science and well-conducted clinical trials are needed to define accurate treatment and improve outcomes of IgAVN.

Therapeutic drug monitoring in childhood idiopathic nephrotic syndrome: a state of the art review

Immunosuppressants are commonly used as steroid-sparing agents in childhood idiopathic nephrotic syndrome (NS) to induce and sustain remissions. These drugs have narrow therapeutic indices with high inter- and intra-patient variability. Therapeutic drug monitoring (TDM) would therefore be essential to guide the prescription. Multiple factors in NS contribute to additional variability in drug concentrations, especially during relapses. In this article, we review the currently available evidence of TDM in NS and suggest a practical approach for clinicians' reference.

Is kidney biopsy necessary in children with idiopathic nephrotic syndrome?

AIM

To investigate the need, in the Northern European setting, to perform kidney biopsy in children with steroid-sensitive nephrotic syndrome.

METHODS

In this retrospective study 124 individuals aged 1-18 years with idiopathic nephrotic syndrome, followed in the paediatric hospitals in southern Sweden from 1999 to 2018, were included.

RESULTS

There was a median follow-up time of 6.5 (0.2-16.8) years. The majority (92%) of children were steroid-sensitive and of them, 60.5% were frequently relapsing or steroid-dependent. Microscopic haematuria was found at onset in 81.1% and hypertension in 8.7%. At least one kidney biopsy was performed in 93 (75%). The most common indication was a steroid-dependent or relapsing course (58.4%). One of 79 steroid-sensitive children had another histological diagnosis than minimal change nephropathy 1.3%, 95% confidence interval (0.002, 0.068). Bleeding occurred after eight biopsies (6.6%). Twenty individuals (30.7%) were transferred to adult units, 18 still on immunosuppression.

CONCLUSION

We have in our cohort of unselected children with idiopathic nephrotic syndrome confirmed that a kidney biopsy rarely gives important medical information in steroid-sensitive children without any other complicating factor and that the liberal policy of kidney biopsy in the Nordic countries safely can be changed.

International cohort of 382 children with lupus nephritis - presentation, treatment and outcome at 24 months

BACKGROUND

Children with lupus have a higher chance of nephritis and worse kidney outcome than adult patients.

METHODS

We retrospectively analyzed clinical presentation, treatment and 24-month kidney outcome in a cohort of 382 patients (≤ 18 years old) with lupus nephritis (LN) class ≥ III diagnosed and treated in the last 10 years in 23 international centers.

RESULTS

The mean age at onset was 11 years 9 months and 72.8% were females. Fifty-seven percent and 34% achieved complete and partial remission at 24-month follow-up, respectively. Patients with LN class III achieved complete remission more often than those with classes IV or V (mixed and pure). Only 89 of 351 patients maintained stable complete kidney remission from the 6th to 24th months of follow-up. eGFR ≥ 90 ml/min/1.73 m2 at diagnosis and biopsy class III were predictive of stable kidney remission. The youngest and the oldest age quartiles (2y-9y, 5m) (14y, 2m-18y,2m) showed lower rates of stable remission (17% and 20.7%, respectively) compared to the two other age groups (29.9% and 33.7%), while there was no difference in gender. No difference in achieving stable remission was found between children who received mycophenolate or cyclophosphamide as induction treatment.

CONCLUSION

Our data show that the rate of complete remission in patients with LN is still not high enough. Severe kidney involvement at diagnosis was the most important risk factor for not achieving stable remission while different induction treatments did not impact outcome. Randomized treatment trials involving children and adolescents with LN are needed to improve outcome for these children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Targetable NOTCH1 rearrangements in reninoma

Reninomas are exceedingly rare renin-secreting kidney tumours that derive from juxtaglomerular cells, specialised smooth muscle cells that reside at the vascular inlet of glomeruli. They are the central component of the juxtaglomerular apparatus which controls systemic blood pressure through the secretion of renin. We assess somatic changes in reninoma and find structural variants that generate canonical activating rearrangements of, NOTCH1 whilst removing its negative regulator, NRARP. Accordingly, in single reninoma nuclei we observe excessive renin and NOTCH1 signalling mRNAs, with a concomitant non-excess of NRARP expression. Re-analysis of previously published reninoma bulk transcriptomes further corroborates our observation of dysregulated Notch pathway signalling in reninoma. Our findings reveal NOTCH1 rearrangements in reninoma, therapeutically targetable through existing NOTCH1 inhibitors, and indicate that unscheduled Notch signalling may be a disease-defining feature of reninoma.

Towards development of treat to target (T2T) in childhood-onset systemic lupus erythematosus: PReS-endorsed overarching principles and points-to-consider from an international task force

OBJECTIVES

Application of 'treat-to-target' (T2T) in childhood-onset systemic lupus erythematosus (cSLE) may improve care and health outcomes. This initiative aimed to harmonise existing evidence and expert opinion regarding T2T for cSLE.

METHODS

An international T2T Task Force was formed of specialists in paediatric rheumatology, paediatric nephrology, adult rheumatology, patient and parent representatives. A steering committee formulated a set of draft overarching principles and points-to-consider, based on evidence from systematic literature review. Two on-line preconsensus meeting Delphi surveys explored healthcare professionals' views on these provisional overarching principles and points-to-consider. A virtual consensus meeting employed a modified nominal group technique to discuss, modify and vote on each overarching principle/point-to-consider. Agreement of >80% of Task Force members was considered consensus.

RESULTS

The Task Force agreed on four overarching principles and fourteen points-to-consider. It was agreed that both treatment targets and therapeutic strategies should be subject to shared decision making with the patient/caregivers, with full remission the preferred target, and low disease activity acceptable where remission cannot be achieved. Important elements of the points-to-consider included: aiming for prevention of flare and organ damage; glucocorticoid sparing; proactively addressing factors that impact health-related quality of life (fatigue, pain, mental health, educational challenges, medication side effects); and aiming for maintenance of the target over the long-term. An extensive research agenda was also formulated.

CONCLUSIONS

These international, consensus agreed overarching principles and points-to-consider for T2T in cSLE lay the foundation for future T2T approaches in cSLE, endorsed by the Paediatric Rheumatology European Society.

PReS-endorsed international childhood lupus T2T task force definition of childhood lupus low disease activity state (cLLDAS)

OBJECTIVE

To achieve a consensus-based definition of Low Disease Activity (LDA) for use in cSLE trials.

METHODS

The International cSLE T2T Task Force, comprising of paediatric rheumatologists/nephrologists, and adult rheumatologists undertook a series of Delphi surveys/consensus meetings to discuss, refine, and vote upon cSLE LDA criteria.

RESULTS

The Task Force agreed that LDA should be based upon the adult-SLE Lupus Low Disease Activity State definition (LLDAS), with modifications to make it applicable to cSLE (cLLDAS). They agreed upon five cLLDAS criteria: (1) SLE Disease Activity Index (SLEDAI)-2 K ≤4, with no activity in major organ systems; (2) no new features of lupus disease activity compared with the last assessment; (3) Physician Global Assessment score of ≤1 (0-3 scale); (4) prednisolone dose of ≤0.15 mg/kg/day, 7.5 mg/day/maximum; while on (5) stable antimalarials, immunosuppressives, and biologics.

CONCLUSIONS

A cSLE-appropriate definition of cLLDAS has been generated, maintaining alignment with the adult-SLE definition to promote life-course research.

A multicenter retrospective study of calcineurin inhibitors in nephrotic syndrome secondary to podocyte gene variants

While 44-83% of children with steroid-resistant nephrotic syndrome (SRNS) without a proven genetic cause respond to treatment with a calcineurin inhibitor (CNI), current guidelines recommend against the use of immunosuppression in monogenic SRNS. This is despite existing evidence suggesting that remission with CNI treatment is possible and can improve prognosis in some cases of monogenic SRNS. Herein, our retrospective study assessed response frequency, predictors of response and kidney function outcomes among children with monogenic SRNS treated with a CNI for at least three months. Data from 203 cases (age 0-18 years) were collected from 37 pediatric nephrology centers. Variant pathogenicity was reviewed by a geneticist, and 122 patients with a pathogenic and 19 with a possible pathogenic genotype were included in the analysis. After six months of treatment and at last visit, 27.6% and 22.5% of all patients respectively, demonstrated partial or full response. Achievement of at least partial response at six months of treatment conferred a significant reduction in kidney failure risk at last follow-up compared to no response (hazard ratio [95% confidence interval] 0.25, [0.10-0.62]). Moreover, risk of kidney failure was significantly lower when only those with a follow-up longer than two years were considered (hazard ratio 0.35, [0.14-0.91]). Higher serum albumin level at CNI initiation was the only factor related to increased likelihood of significant remission at six months (odds ratio [95% confidence interval] 1.16, [1.08-1.24]). Thus, our findings justify a treatment trial with a CNI also in children with monogenic SRNS.

Mendelian steroid resistant nephrotic syndrome in childhood: is it as common as reported?

BACKGROUND

Primary steroid resistant nephrotic syndrome (SRNS) is thought to have either genetic or immune-mediated aetiology. Knowing which children to screen for genetic causes can be difficult. Several studies have described the prevalence of genetic causes of primary SRNS to be between 30 and 40%, but these may reflect a selection bias for genetic testing in children with congenital, infantile, syndromic or familial NS and thus may overestimate the true prevalence in a routine clinical setting.

METHODS

Retrospective electronic patient record analysis was undertaken of all children with non-syndromic SRNS and presentation beyond the first year of life, followed at our centre between 2005 and 2020.

RESULTS

Of the 49 children who met the inclusion criteria, 5 (10%) had causative variants identified, predominantly in NPHS2. None responded to immunosuppression. Of the 44 (90%) who had no genetic cause identified, 33 (75%) had complete or partial remission after commencing second-line immunosuppression and 67% of these had eGFR > 90 ml/min/1.73 m² at last clinical follow-up. Of the children who did not respond to immunosuppression, 64% progressed to kidney failure.

CONCLUSIONS

In our cohort of children with non-syndromic primary SRNS and presentation beyond the first year of life, we report a prevalence of detectable causative genetic variants of 10%. Those with identified genetic cause were significantly (p = 0.003) less likely to respond to immunosuppression and more likely (p = 0.026) to progress to chronic kidney disease. Understanding the genetics along with response to immunosuppression informs management in this cohort of patients and variant interpretation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Use of Rituximab in Childhood Idiopathic Nephrotic Syndrome

Rituximab is an established therapy in children with idiopathic nephrotic syndrome to sustain short- to medium-term disease remission and avoid steroid toxicities. Recent trials focus on its use as a first-line agent among those with milder disease severity. Rituximab is used in multidrug refractory nephrotic syndrome and post-transplant disease recurrence, although the evidence is much less substantial. Available data suggest that the treatment response to rituximab depends on various patient factors, dosing regimen, and the concomitant use of maintenance immunosuppression. After repeated treatments, patients are found to have an improving response overall with a longer relapse-free period. The drug effect, however, is not permanent, and 80% of patients eventually relapse and many will require an additional course of rituximab. This underpins the importance of understanding the long-term safety profile on repeated treatments. Although rituximab appears to be generally safe, there are concerns about long-term hypogammaglobulinemia, especially in young children. Reliable immunophenotyping and biomarkers are yet to be discovered to predict treatment success, risk of both rare and severe side effects, e.g. , persistent hypogammaglobulinemia, and guiding of redosing strategy. In this review, we highlight recent advances in the use of rituximab for childhood nephrotic syndrome and how the therapeutic landscape is evolving.

Long-term Efficacy and Safety of Repeated Rituximab to Maintain Remission in Idiopathic Childhood Nephrotic Syndrome: An International Study

Background: Long-term outcomes following multiple rituximab courses among children with frequently-relapsing, steroid-dependent nephrotic syndrome (FRSDNS) are unknown. Methods: A retrospective cohort study at 16 pediatric nephrology centers from 10 countries in Asia, Europe, and North America included children with FRSDNS who received ≥2 rituximab courses. Primary outcomes were relapse-free survival and adverse events. Results: 346 children (age 9.8 years, IQR 6.6-13.5; 73% boys) received 1149 rituximab courses. 145, 83, 50, 28, 22, and 18 children received 2, 3, 4, 5, 6 and ≥7 courses, respectively. Median follow-up was 5.9 years (IQR, 4.3-7.7). Relapse-free survival differed by treatment courses (clustered log-rank test p<0.001). Compared to the first course (10.0 months, 95% CI, 9.0-10.7), relapse-free period and relapse risk progressively improved following subsequent courses (12.0-16.0 months; HRadj, 0.03-0.13; 95% CI, 0.01-0.18; ps<0.001). B-cell depletion duration remained similar with repeated treatments (6.1 months, 95% CI, 6.0-6.3). Adverse events were mostly mild, most commonly hypogammaglobulinemia (50.9%), infection (4.5%), and neutropenia (3.7%). Side effects did not increase with more treatment courses nor higher cumulative dose. Only 78 of the 353 episodes of hypogammaglobulinemia were clinically significant. Younger age at presentation (2.8 vs 3.3 years; p=0.05) and at first rituximab (8.0 y vs 10.0 years; p=0.01) and history of steroid resistance (28% vs 18%; p=0.01) were associated with significant hypogammaglobulinemia. All 53 infective episodes resolved, except one patient with hepatitis B infection and another with EBV infection. There were 42 episodes of neutropenia, associated with history of steroid resistance (30% vs 20%, p=0.04). Upon last follow-up, 332 children (96%) had normal kidney function. Conclusion: Children receiving repeated rituximab for FRSDNS experience an improving clinical response. Side effects appear acceptable but significant complications can occur. These findings support repeated rituximab use in FRSDNS.

Presentation, treatment, and outcome of renovascular hypertension below 2 years of age

Renovascular hypertension in most cases requires endovascular treatment and/or surgery. This is technically much more difficult in small children and there is very limited published knowledge in this age group. We here present treatment and outcome of young children with renovascular hypertension at our institution. Children below 2 years of age, with renovascular hypertension between January 1998 and March 2020 were retrospectively reviewed. Demographics and treatment modalities were noted. Primary outcome was blood pressure within a week after the procedures and at last available visit. Sixty-six angiographies were performed in 34 patients. Median age at time of first angiography was 1.03 (interquartile range (IQR) 0.4-1.4) years and systolic blood pressure at presentation 130 (IQR 130-150) mm Hg. Thirty-eight percent (13/34) of children were incidentally diagnosed and 18% (6/34) presented with heart failure. Twenty-six (76%) children had main renal artery stenosis and 17 (50%) mid-aortic syndrome. Seventeen (50%) children showed intrarenal, six (18%) mesenteric, and three (9%) cerebrovascular involvement. Twenty patients underwent 45 percutaneous transluminal angioplasty procedures and seven children surgeries. In 44% of the 16 patients who underwent only percutaneous transluminal angioplasty blood pressure was normalized, 38% had improvement on same or decreased treatment and 19% showed no improvement. Complications were seen in 7.5% (5/66) of angiographies. In four of the seven (57%) children who underwent surgery blood pressure was normalized, two had improved (29%) and one unchanged (14%) blood pressure.

CONCLUSION

In small children with renovascular hypertension below the age of 2 years, percutaneous transluminal angioplasty caused significant improvement in blood pressure with low complication profile. Surgery can be recommended where percutaneous transluminal angioplasty and medical treatments failed.

WHAT IS KNOWN

• Renovascular hypertension is diagnosed in all age groups from a few weeks of life until adulthood. • Both angioplasty and surgery are significantly more difficult to perform in small children and the published information on short and long-term outcome in these children is very scarce.

WHAT IS NEW

• Children below the age of two years can safely and successfully undergo selective renal angiography and also safely be treated with angioplasty. • We here present a large group of babies and infants where angioplasty and in some cases surgery effectively and safely improved their blood pressure.

Defining renal remission in an international cohort of 248 children and adolescents with lupus nephritis

OBJECTIVE

We studied the rate of remission of lupus nephritis (LN) in an international cohort of 248 children and adolescents with biopsy proven LN. Five different definitions from scientific studies and the definitions recommended by the American College of Rheumatology and Kidney Disease Improving Global Outcomes (KDIGO) were used.

METHODS

Anonymized clinical data in patients with biopsy proven LN class ≥ III (International Society of nephrology/Royal Pathology Society-ISN/RPS) diagnosed and treated in the last 10 years in 23 international centers from 10 countries were collected. We compared the rate of patients in complete and partial remission applying the different definitions.

RESULTS

The mean age at diagnosis was 11 years and 4 month and 177 were females.The number of patients in complete and partial remission varied a lot between the different definitions. At 24 months, between 50% and 78.8% of the patients were in full remission as defined by the different criteria. The number of patients in partial remission was low, between 2.3% and 25%. No difference in achieved remission was found between boys and girls or between children and adolescents (P > 0.05). Patients with East Asian ethnicity reached remission more often than other ethnicities (P = 0.03-0.0008). Patients treated in high income countries showed a higher percentage of complete remission at 12 and 24 months (P = 0.002-0.000001).

CONCLUSION

The rate of children and adolescents with LN achieving remission varied hugely with the definition used. Our results give important information for long awaited treatment studies in children and young people.

Risk factors for kidney scarring and vesicoureteral reflux in 421 children after their first acute pyelonephritis, and appraisal of international guidelines

BACKGROUND

Acute pyelonephritis (AP) is a common bacterial infection in childhood. Follow-up guidelines on these children are controversial. This study aimed to identify risk factors for kidney scarring and vesicoureteral reflux (VUR). Furthermore, international follow-up guidelines were used for simulation to evaluate sensitivity and specificity.

METHODS

Urinary culture-confirmed first-time AP patients (aged 0-14 years) were enrolled (n = 421) from review of patient charts. All underwent kidney ultrasound (US) and a technetium-99m-dimercaptosuccinic acid (DMSA) scan or technetium-99m-mercaptoacetyltriglycine scinti-renography (MAG3) at 4-6 months of follow-up. The international guidelines used for simulation were from the National Institute of Health UK (NICE), the American Association of Paediatrics (AAP) and the Swedish Paediatric Society (SPS).

RESULTS

17.8% presented with an abnormal DMSA/MAG3 at follow-up, 7.1% were diagnosed with VUR grades III-V and 4.7% were admitted for surgery. Non-Escherichia coli infections, abnormal kidney US, elevated creatinine and delayed response to treatment (>48 h) were risk factors for abnormal DMSA findings and VUR grades III-V. NICE and SPS guidelines showed best sensitivity in diagnosing VUR grades III-V (75%) compared with AAP (56%).

CONCLUSIONS

Risk factors are helpful in identifying the children in need of further investigations and minimizing invasive work-up for the rest. International guidelines on follow-up detect a varying number of children with kidney damage and/or significant VUR. Future work must focus on identifying more specific risk factors, better imaging, or specific biomarkers, to enhance sensitivity and specificity in detecting the children at high risk for developing recurrent infections and/or nephropathy.

Calcineurin inhibitors in nephrotic syndrome secondary to podocyte gene mutations: a systematic review

BACKGROUND

Calcineurin inhibitor (CNI) use in genetic steroid-resistant nephrotic syndrome (SRNS) is controversial as response rate is reported to be lower than non-genetic disease and no plausible mechanism of action is known.

METHODS

We reviewed PubMed for publications on CNI use in hereditary SRNS to determine (1) CNI response rate; (2) impact of response on renal outcome; and (3) clinical and molecular predictors of response. Variant pathogenicity was assessed according to American College of Medical Genetics criteria and patients were assigned to 1 of 4 categories based on estimated genotype contribution to phenotype. Cases with non-existing phenotype-to-genotype contribution were excluded. Subgroup analysis was performed for the possible and confirmed genetic cases.

RESULTS

Data of 178 genetic SRNS cases from 22 studies were analyzed; 35% responded (fully or partially) to CNI with minimal change being the commonest biopsy pattern among responders. Full responders had superior kidney survival compared with partial and non-responders (log-rank test χ² = 10.7; P < 0.01). WT1 variant carriers were most likely to respond to CNI compared with any other mutation [OR 4.7 (2.0-11.3); P < 0.01].

CONCLUSIONS

These findings support the current recommendation for using CNI as first-line treatment for children with SRNS whilst genetic analyses are pending. This would allow assessment of treatment response even in cases later established as genetic ensuring that benefits on kidney function are balanced with treatment toxicity.

Rituximab in children with steroid sensitive nephrotic syndrome: in quest of the optimal regimen

Rituximab has emerged as an effective and important therapy in children with complicated frequently relapsing and steroid-dependent nephrotic syndrome to induce long-term disease remission and avoid steroid toxicities. The optimal rituximab regimen is not totally well defined, and there are many varying practices worldwide. We will in this review describe how patient factors, rituximab dose, and use of maintenance immunosuppression affect treatment outcomes. Specifically, low-dose rituximab without concomitant immunosuppression is associated with shorter relapse-free duration while other regimens have comparable outcomes. Patients with more severe disease generally have worse response to rituximab. Although rituximab appears to be generally safe, there are growing concerns of chronic hypogammaglobulinemia and impaired immunity especially in young children. Reliable prognostications and biomarkers for guiding subsequent treatments to avoid excessive treatments are yet to be identified. In this review, we will outline the, as we see it, best approach of rituximab in childhood steroid sensitive nephrotic syndrome at the present state of knowledge.

MO1006COMPARISON OF DIFFERENT DEFINITION OF PARTIAL AND COMPLETE REMISSION IN A COHORT OF CHILDREN WITH LUPUS NEPHRITIS*

Background and Aims

Lupus Nephritis (LN) occurs in up to 80% of children with SLE and it affects the long term outcome and the overall survival. Achieving and maintaining renal remission is crucial. However definition of remission in children is not clearly defined. We compared the outcomes using different published definitions of complete and partial remission.

Method

248 children with biopsy proven LN class III or higher (ISN/RPS) diagnosed and treated in 23 international centers in the last 10 years were included. Data regarding their renal outcome were collected for twenty-four months after the start of induction therapy. We applied seven definitions of remission to compare the number of children achieving partial and complete remission. Definitions applied have been adapted from the Bristol-Myers Squibb (BMS) trial, the American College of Rheumatology (ACR) recommendations, the Lupus Nephritis Assesment with Rituximab (LUNAR) trial, the Aspreva Lupus Management Study (ALMS) trial, the Abatacept and Cyclophosphamide Combination: Efficacy and Safety Study (ACCESS) trial, the Kidney Disease Improving Global outcomes (KDIGO) guidelines and the Two-Year, Randomized, Controlled Trial of Belimumab in Lupus Nephritis (BLISS-LN).

We also focused on the BMS trial, the ACCESS trial and the KDIGO guidelines definitions to analyse the importance of gender, age, ethnicity and the economic income of the country (as defined by the World Bank) where patients had been treated.

Results

The mean age at diagnosis was 11 years and 4 month. 71.4% were females. They were mainly East-Asian (34.3%), South-Asian (24.6%) and Caucasian (18.6%). 42.7 % were from middle income countries and 57.3% high income countries. The kidney biopsies showed LN class III in 35.5%; class IV in 45.6% and class V in 18.9%.

The different definitions varied significantly in terms of outcomes, with that of the ACCESS trial having the highest percentages of complete remission and the BMS trial the lowest (Figure 1). A relatively small percentage of children achieved partial remission during the follow-up for all the definitions (Figure 2).

Focusing on the BMS, ACCESS and KDIGO definitions, we found no statistically significant differences of gender and age in the rate of children entering complete remission at 6, 12 and 24 months. East Asian children did however achieve remission more often than other ethnic groups (p &lt; 0.05) (Figure 3).

Children treated in high income countries showed a statistically significant higher percentage of complete remission at 12 and 24 months (p &lt; 0.05) (Figure 4).

Conclusion

Rate of complete and partial remission varied considerably when using the different definitions. Ethnicity and income of the country where the patients were treated did influence outcome. The findings of our study can help in deciding how to define remission in urgently needed future treatment studies in children.

Biopsy-proven Henoch-Schönlein purpura nephritis: a single center experience

BACKGROUND

Knowledge on normal progress and treatment of Henoch-Schönlein purpura nephritis (HSPN) is limited. This study reviews outcome, clinical, pathological, and therapeutic factors affecting the prognosis of HSPN patients.

METHODS

Forty-nine children with biopsy-confirmed HSPN diagnosed between September 2008 and 2018 were included. Demographics, clinical and laboratory data, treatment, and outcome were recorded at the time of biopsy, 3, 6, 12, and 24 months and at last visit. Clinical outcome was graded according to Meadow's criteria.

RESULTS

The median age at time of biopsy was 10.1 years (IQR:5.7) and female/male ratio 24/25. At presentation, 40.8% of patients had nonnephrotic proteinuria, 18.4% nephrotic syndrome (NS), 4.1% nephritic syndrome (NephrS), and 36.7% NephrS+NS. There were 11 patients with an estimated glomerular filtration rate below 90 ml/min/1.73 m². Biopsy specimens were classified according to International Study of Kidney Diseases in Children (ISKDC) and Oxford Classification MEST-C scoring systems. Forty-one patients received angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, 37 patients steroids, and 35 patients other immunosuppressive medications. At last visit, 24 patients had stage 1 chronic kidney disease (CKD), three stage 2 CKD, and two had stage 5 CKD. Neither clinical parameters nor ISKDC biopsy grade or treatment modalities effected the final outcome. The Oxford classification showed significantly increased segmental glomerulosclerosis in patients with unfavorable outcome. Favorable outcome was associated with shorter time from kidney involvement to biopsy and start of treatment.

CONCLUSION

A large proportion of patients continued to show signs of CKD at last follow-up while only a small proportion developed stage 5 CKD.

The effect of levamisole on kidney function in children with steroid-sensitive nephrotic syndrome

BACKGROUND

Levamisole is frequently used as a steroid-sparing agent in children with steroid-sensitive nephrotic syndrome. Side effects, such as neutropenia, gastro-intestinal upset and skin rash, have been reported. We noted an increase in creatinine in some of our patients, but literature on the effect of levamisole on kidney function is lacking.

METHODS

A retrospective cohort study was conducted, including patients 1-18 years of age, treated for steroid-sensitive nephrotic syndrome with levamisole at Great Ormond Street Hospital for Children between January 2010 and January 2020. Data was collected on clinical observations and serum creatinine values before, during and after treatment. eGFR was calculated using the Schwartz equation.

RESULTS

In total, 75 children were included in the analysis. The median duration of treatment was 19 (IQR 12-27) months. The median estimated GFR was 134 (IQR 119-160), 101 (IQR 91-113) and 116 (IQR 106-153) ml/min/1.73 m², respectively, before, during and after treatment with levamisole. The difference between eGFR before and after treatment compared with during treatment was statically significant (P < 0.0001). During the treatment period, the eGFR decrease was not progressive. The median levamisole dose was 2.5 (IQR 2.3-2.6) mg/kg on alternate days, and the dose was not correlated with the decrease in eGFR (r = 0.07, 95% CI - 0.22 to 0.35).

CONCLUSION

Levamisole significantly decreases eGFR. However, this decrease is not progressive or irreversible and would not be an indication to discontinue the treatment.

COVID-19 in children treated with immunosuppressive medication for kidney diseases

BACKGROUND

Children are recognised as at lower risk of severe COVID-19 compared with adults, but the impact of immunosuppression is yet to be determined. This study aims to describe the clinical course of COVID-19 in children with kidney disease taking immunosuppressive medication and to assess disease severity.

METHODS

Cross-sectional study hosted by the European Rare Kidney Disease Reference Network and supported by the European, Asian and International paediatric nephrology societies. Anonymised data were submitted online for any child (age <20 years) with COVID-19 taking immunosuppressive medication for a kidney condition. Study recruited for 16 weeks from 15 March 2020 to 05 July 2020. The primary outcome was severity of COVID-19.

RESULTS

113 children were reported in this study from 30 different countries. Median age: 13 years (49% male). Main underlying reasons for immunosuppressive therapy: kidney transplant (47%), nephrotic syndrome (27%), systemic lupus erythematosus (10%). Immunosuppressive medications used include: glucocorticoids (76%), mycophenolate mofetil (MMF) (54%), tacrolimus/ciclosporine A (58%), rituximab/ofatumumab (11%). 78% required no respiratory support during COVID-19 illness, 5% required bi-level positive airway pressure or ventilation. Four children died; all deaths reported were from low-income countries with associated comorbidities. There was no significant difference in severity of COVID-19 based on gender, dialysis status, underlying kidney condition, and type or number of immunosuppressive medications.

CONCLUSIONS

This global study shows most children with a kidney disease taking immunosuppressive medication have mild disease with SARS-CoV-2 infection. We therefore suggest that children on immunosuppressive therapy should not be more strictly isolated than children who are not on immunosuppressive therapy.

Rituximab in childhood steroid-sensitive nephrotic syndrome: are multiple subsequent courses safe and effective?

INTRODUCTION

Idiopathic nephrotic syndrome is the most common glomerular disease in children. The majority of patients respond well to steroids. However, the relapse rate is high and many develop steroid dependency. Although other immunosuppressive medicines are successfully used as steroid-sparing agents, some children still have frequent relapsing episodes. Rituximab (RTX), a chimeric anti-CD20 monoclonal antibody, has shown to be effective in treating difficult frequently relapsing/steroid-dependent nephrotic syndrome (FR/SDNS). Data on the effectiveness and long-term treatment outcomes of repeated courses of RTX are, however, scarce.

MATERIAL AND METHODS

Children and young people with FR/SDNS, aged 1-18 years, who received RTX at Great Ormond Street Hospital (GOSH) from 2006 to 2018 were reviewed.

RESULTS

During these 12 years, 103 children with FR/SDNS received RTX infusions at GOSH. Among these, 58 cases needed repeated courses of RTX: 2, 3, 4, 5, 6 and 7 repeated courses were given to 21, 21, 7, 5, 1 and 3 patients, respectively. The overall median time to relapse post-RTX was 11 months (range 1-53 months). There was no change in relapse-free interval with subsequent courses of RTX. No difference was found between age groups, genders and ethnicities. No severe side effects were noted.

CONCLUSIONS

RTX seems to be safe even after several repeated courses. However, long-term follow-up and further studies are needed, with a focus on side-effects in particular.

Genetics of renovascular hypertension in children

OBJECTIVE

In most cases of renovascular hypertension in children, the cause is unclear. The aim of this study was to investigate genetic variation as a factor in the development of renovascular hypertension in children.

METHODS

In a cohort of 37 unrelated children from a single tertiary referral center, exome sequencing was performed. We assessed variants in recognized and suspected disease genes and searched for novel ones with a gene-based variant-burden analysis.

RESULTS

In the majority of patients, exome sequencing could not identify causative variants. We found a pathogenic variant in a recognized associated disease gene in five patients (three pathogenic variants in NF1, one in ELN and a deletion of chromosome 7q11.23, consistent with Williams syndrome). In two other patients, (likely) pathogenic variants were found in putative renovascular hypertension genes (SMAD6 and GLA), with clinical implications for both. Ten additional patients carried variants of uncertain significance (VUS) in known (n = 4) or putative (n = 6) renovascular hypertension disease genes. Rare variant burden analysis yielded no further candidate genes.

CONCLUSION

Genetic contributors, such as germline mutations in NF1, ELN, 7q11.23del were present in only 5 out of 37 (14%) children with renovascular hypertension. Twelve other children (32%) had potentially causal variants identified, including a pathogenic variant in SMAD6; a vasculopathy gene hitherto unknown to link with renovascular hypertension. Most importantly, our data show that exome sequencing can rarely identify the cause of renovascular hypertension in nonsyndromic children. We suggest that nongenetic factors or somatic genetic variation will play a more important role.

Urinary tract infections in children

Urinary tract infections (UTIs) in children are among the most common bacterial infections in childhood. They are equally common in boys and girls during the first year of life and become more common in girls after the first year of life. Dividing UTIs into three categories; febrile upper UTI (acute pyelonephritis), lower UTI (cystitis), and asymptomatic bacteriuria, is useful for numerous reasons, mainly because it helps to understand the pathophysiology of the infection. A single episode of febrile UTI is often caused by a virulent Escherichia coli strain, whereas recurrent infections and asymptomatic bacteriuria commonly result from urinary tract malformations or bladder disturbances. Treatment of an upper UTI needs to be broad and last for 10 days, a lower UTI only needs to be treated for 3 days, often with a narrow-spectrum antibiotic, and asymptomatic bacteriuria is best left untreated. Investigations of atypical and recurrent episodes of febrile UTI should focus on urinary tract abnormalities, whereas in cases of cystitis and asymptomatic bacteriuria the focus should be on bladder function.

Both the rituximab dose and maintenance immunosuppression in steroid-dependent/frequently-relapsing nephrotic syndrome have important effects on outcomes

Rituximab is an effective treatment for steroid-dependent/ frequently-relapsing nephrotic syndrome (SDFRNS) in children. However, the optimal rituximab regimen remains unknown. To help determine this we conducted an international, multicenter retrospective study at 11 tertiary pediatric nephrology centers in Asia, Europe and North America of children 1-18 years of age with complicated SDFRNS receiving rituximab between 2005-2016 for 18 or more months follow-up. The effect of rituximab prescribed at three dosing levels: low (375mg/m²), medium (750mg/m²) and high (1125-1500mg/m²), with or without maintenance immunosuppression (defined as concurrent use of corticosteroids, mycophenolate motile or calcineurin inhibition at first relapse or for at least six months following the rituximab treatment) was examined. Among the 511 children (median age 11.5 year, 67% boys), 191, 208 and 112 received low, medium and high dose rituximab, respectively. Within this total cohort of 511 children, 283 (55%) received maintenance immunosuppression. Renal biopsies were performed in 317 children indicating the predominant histology was minimal change disease (74%). Without maintenance immunosuppression, low-dose rituximab had a shorter relapse-free period and a higher relapse risk (8.5 months) than medium (12.7 months; adjusted hazard ratio, 0.62) and high dose (14.3 months; adjusted hazard ratio, 0.50; all significant). With maintenance immunosuppression, the relapse-free survival in low-dose rituximab (14 months) was similar to medium (10.9 months; adjusted hazard ratio, 1.23) and high dose (12.0 months; adjusted hazard ratio, 0.92; all non-significant). Most adverse events were mild. Thus, children receiving low-dose rituximab without maintenance immunosuppression had the shortest relapse-free survival. Hence, both rituximab dose and maintenance immunosuppression have important effects on the treatment outcomes.

Fifteen-minute consultation: Why and how do children get urinary tract infections?

This paper describes urinary tract infections (UTI) from the perspective of a disturbed balance between bacterial virulence and host defence. In some children, a UTI is caused by a virulent Escherichia coli, while in other cases children with abnormal renal tracts can get infected by almost any bacteria. Such knowledge can help in guiding treatment, investigations and follow-up of a child with a UTI.

Genetic Identification of Two Novel Loci Associated with Steroid-Sensitive Nephrotic Syndrome

BACKGROUND

Steroid-sensitive nephrotic syndrome (SSNS), the most common form of nephrotic syndrome in childhood, is considered an autoimmune disease with an established classic HLA association. However, the precise etiology of the disease is unclear. In other autoimmune diseases, the identification of loci outside the classic HLA region by genome-wide association studies (GWAS) has provided critical insights into disease pathogenesis. Previously conducted GWAS of SSNS have not identified non-HLA loci achieving genome-wide significance.

METHODS

In an attempt to identify additional loci associated with SSNS, we conducted a GWAS of a large cohort of European ancestry comprising 422 ethnically homogeneous pediatric patients and 5642 ethnically matched controls.

RESULTS

The GWAS found three loci that achieved genome-wide significance, which explain approximately 14% of the genetic risk for SSNS. It confirmed the previously reported association with the HLA-DR/DQ region (lead single-nucleotide polymorphism [SNP] rs9273542, P=1.59×10^-43; odds ratio [OR], 3.39; 95% confidence interval [95% CI], 2.86 to 4.03) and identified two additional loci outside the HLA region on chromosomes 4q13.3 and 6q22.1. The latter contains the calcium homeostasis modulator family member 6 gene CALHM6 (previously called FAM26F). CALHM6 is implicated in immune response modulation; the lead SNP (rs2637678, P=1.27×10^-17; OR, 0.51; 95% CI, 0.44 to 0.60) exhibits strong expression quantitative trait loci effects, the risk allele being associated with lower lymphocytic expression of CALHM6.

CONCLUSIONS

Because CALHM6 is implicated in regulating the immune response to infection, this may provide an explanation for the typical triggering of SSNS onset by infections. Our results suggest that a genetically conferred risk of immune dysregulation may be a key component in the pathogenesis of SSNS.

A Markov Multi-State model of lupus nephritis urine biomarker panel dynamics in children: Predicting changes in disease activity

BACKGROUND

A urine 'biomarker panel' comprising alpha-1-acid-glycoprotein, ceruloplasmin, transferrin and lipocalin-like-prostaglandin-D synthase performs to an 'excellent' level for lupus nephritis identification in children cross-sectionally. The aim of this study was to assess if this biomarker panel predicts lupus nephritis flare/remission longitudinally.

METHODS

The novel urinary biomarker panel was quantified by enzyme linked immunoabsorbant assay in participants of the United Kingdom Juvenile Systemic Lupus Erythematosus (UK JSLE) Cohort Study, the Einstein Lupus Cohort, and the South African Paediatric Lupus Cohort. Monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1 were also quantified in view of evidence from other longitudinal studies. Serial urine samples were collected during routine care with detailed clinical and demographic data. A Markov Multi-State model of state transitions was fitted, with predictive clinical/biomarker factors assessed by a corrected Akaike Information Criterion (AICc) score (the better the model, the lower the AICc score).

RESULTS

The study included 184 longitudinal observations from 80 patients. The homogeneous multi-state Markov model of lupus nephritis activity AICc score was 147.85. Alpha-1-acid-glycoprotein and ceruloplasmin were identified to be the best predictive factors, reducing the AICc score to 139.81 and 141.40 respectively. Ceruloplasmin was associated with the active-to-inactive transition (hazard ratio 0.60 (95% confidence interval [0.39, 0.93])), and alpha-1-acid-glycoprotein with the inactive-to-active transition (hazard ratio 1.49 (95% confidence interval [1.10, 2.02])). Inputting individual alpha-1-acid-glycoprotein/ceruloplasmin values provides 3, 6 and 12 months probabilities of state transition.

CONCLUSIONS

Alpha-1-acid-glycoprotein was predictive of active lupus nephritis flare, whereas ceruloplasmin was predictive of remission. The Markov state-space model warrants testing in a prospective clinical trial of lupus nephritis biomarker led monitoring.

Management of steroid-resistant nephrotic syndrome in children and adolescents

More than 85% of children and adolescents (majority between 1-12 years old) with idiopathic nephrotic syndrome show complete remission of proteinuria following daily treatment with corticosteroids. Patients who do not show remission after 4 weeks' treatment with daily prednisolone are considered to have steroid-resistant nephrotic syndrome (SRNS). Renal histology in most patients shows presence of focal segmental glomerulosclerosis, minimal change disease, and (rarely) mesangioproliferative glomerulonephritis. A third of patients with SRNS show mutations in one of the key podocyte genes. The remaining cases of SRNS are probably caused by an undefined circulating factor. Treatment with calcineurin inhibitors (ciclosporin and tacrolimus) is the standard of care for patients with non-genetic SRNS, and approximately 70% of patients achieve a complete or partial remission and show satisfactory long-term outcome. Additional treatment with drugs that inhibit the renin-angiotensin axis is recommended for hypertension and for reducing remaining proteinuria. Patients with SRNS who do not respond to treatment with calcineurin inhibitors or other immunosuppressive drugs can show declining kidney function and are at risk for end-stage renal failure. Approximately a third of those who undergo renal transplantation show recurrent focal segmental glomerulosclerosis in the allograft and often respond to combined treatment with plasma exchange, rituximab, and intensified immunosuppression.

A comprehensive characterization of myocardial and vascular phenotype in pediatric chronic kidney disease using cardiovascular magnetic resonance imaging

BACKGROUND

Children with chronic kidney disease (CKD) have increased cardiovascular mortality. Identifying high-risk children who may benefit from further therapeutic intervention is difficult as cardiovascular abnormalities are subtle. Although transthoracic echocardiography may be used to detect sub-clinical abnormalities, it has well-known problems with reproducibility that limit its ability to accurately detect these changes. Cardiovascular magnetic resonance (CMR) is the reference standard method for assessing blood flow, cardiac structure and function. Furthermore, recent innovations enable the assessment of radial and longitudinal myocardial velocity, such that detection of sub-clinical changes is now possible. Thus, CMR may be ideal for cardiovascular assessment in pediatric CKD. This study aims to comprehensively assess cardiovascular function in pediatric CKD using CMR and determine its relationship with CKD severity.

METHODS

A total of 120 children (40 mild, 40 moderate, 20 severe pre-dialysis CKD subjects and 20 healthy controls) underwent CMR with non-invasive blood pressure (BP) measurements. Cardiovascular parameters measured included systemic vascular resistance (SVR), total arterial compliance (TAC), left ventricular (LV) structure, ejection fraction (EF), cardiac timings, radial and longitudinal systolic and diastolic myocardial velocities. Between group comparisons and regression modelling were used to identify abnormalities in CKD and determine the effects of renal severity on myocardial function.

RESULTS

The elevation in mean BP in CKD was accompanied by significantly increased afterload (SVR), without evidence of arterial stiffness (TAC) or increased fluid overload. Left ventricular volumes and global function were not abnormal in CKD. However, there was evidence of LV remodelling, prolongation of isovolumic relaxation time and reduced systolic and diastolic myocardial velocities.

CONCLUSION

Abnormal cardiovascular function is evident in pre-dialysis pediatric CKD. Novel CMR biomarkers may be useful for the detection of subtle abnormalities in this population. Further studies are needed to determine to prognostic value of these biomarkers.

Paediatric anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis: an update on renal management

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a group of disorders characterized by necrotizing inflammation of the small to medium vessels in association with autoantibodies against the cytoplasmic region of the neutrophil. Included in this definition are granulomatosis with polyangiitis (GPA, formerly known as Wegener's granulomatosis), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (formerly known as Churg-Strauss syndrome). AAV are chronic, often relapsing diseases that can be organ or life threatening. Despite immunosuppression, the morbidity and mortality remain high. Renal involvement contributes significantly to the morbidity with high numbers of patients progressing to end-stage kidney disease. Current therapies have enabled improvements in renal function in the short term, but evidence for long-term protection is lacking. In MPA, renal involvement is common at presentation (90%) and often follows a more severe course than that seen in paediatric GPA. Renal biopsy remains the 'gold standard' in diagnosing ANCA-associated glomerulonephritis. While GPA and MPA are considered separate entities, the two are managed identically. Current treatment regimens are extrapolated from adult studies, although it is encouraging to see recruitment of paediatric patients to recent vasculitis trials. Traditionally more severe disease has been managed with the 'gold standard' treatment of glucocorticoids and cyclophosphamide, with remission rates achieved of between 70 and 100%. Other agents employed in remission induction include anti-tumor necrosis factor-alpha therapy and mycophenolate mofetil. Recently, however, increasing consideration is being given to rituximab as a therapy for children in severe or relapsing disease, particularly for those at risk for glucocorticoid or cyclophosphamide toxicity. Removal of circulating ANCA through plasma exchange is a short-term measure reserved for severe or refractory disease. Maintenance therapy usually involves azathioprine. The aim of this article is to provide a comprehensive review of paediatric AAV, with a focus on renal manifestations, and to highlight the recent advances made in therapeutic management.

What's new in paediatric hypertension?

Paediatric hypertension predisposes to hypertension and cardiovascular disease in adult life. Despite clear guidelines, there remains a lack of screening. Diagnosis remains challenging given the high rate of false-positive high blood pressure (BP) readings at a single visit; thus, multiple visits are required to confirm the diagnosis. Depending on the normative data sets used, hypertension in overweight and obese children can be underestimated by up to 20%. Specific BP targets are required for subgroups such as adolescents, children with chronic kidney disease (CKD) and type 1 diabetes. High dietary salt intake is a risk factor for cardiovascular disease. Given the rise in processed food consumption, children in developed nations are likely to benefit from salt restriction at a population-based level.