Incidental finding of acquired cystic kidney disease associated renal cell carcinoma in an adolescent with kidney failure.

Acquired cystic kidney disease (ACKD) can occur in patients with chronic kidney disease and kidney failure, and its incidence increases with the duration of dialysis. In adults, ACKD is less common in the pre-dialysis group (~ 7%), but its incidence can be as high as 80% for those who are on dialysis for more than ten years. There is, however, very little information about the prevalence of ACKD in children. We report a case of malignant transformation of ACKD following a kidney transplant, highlighting the importance of surveillance of the native kidneys in paediatric patients who have been in long-term kidney replacement therapy.

A case report of multicentric carpotarsal osteolysis syndrome: Depiction of a debilitating disease course.

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder characterized by progressive osteolysis involving the carpal and tarsal bones, and often associated with nephropathy. It is caused by heterozygous mutation in the MAF bZIP transcription factor B (MAFB) gene. Heterogeneous clinical manifestation and wide spectrum of disease severity have been observed in patients with MCTO. Here, we report a case of a male patient who presented with kidney failure in childhood with progressive disabling skeletal deformity. He was diagnosed with MCTO at 31-years-old, where a de novo pathogenic heterozygous variant in NM_005461.5:c.212C>A: p.(Pro71His) of the MAFB gene was identified. While there has been little data on the long-term prognosis and life expectancy of this disease, this case report sheds light on the debilitating disease course with multiple significant morbidities of a patient with MCTO throughout his lifetime of 33 years.

Renal relapse in children and adolescents with childhood-onset lupus nephritis: a 20-year study.

OBJECTIVES: There is little data on renal relapse in childhood-onset LN (cLN). We investigate the incidence, predictive factors and outcomes related to renal relapse. METHODS: We conducted a retrospective cohort study of all cLN diagnosed at ≤18 years between 2001-2021 to investigate the incidence and outcomes related to renal relapse. RESULTS: Ninety-five Chinese cLN patients (91% proliferative LN) were included. Induction immunosuppression was prednisolone and CYC [n = 36 (38%)] or MMF [n = 33 (35%)]. Maintenance immunosuppression was prednisolone and MMF [n = 53 (54%)] or AZA [n = 29 (31%)]. The rates of complete remission/partial remission (CR/PR) at 12 months were 78.9%/7.4%. Seventy renal relapses occurred in 39 patients over a follow-up of 10.2 years (s.d. 5.9) (0.07 episode/patient-year). Relapse-free survival was 94.7, 86.0, 80.1, 71.2, 68.3, 50.3 and 44.5% at 1, 2, 3, 4, 5, 10 and 20 years, respectively. Multivariate analysis showed that LN diagnosis <13.1 years [adjusted hazard ratio (HRadj) 2.59 995% CI 1.27, 5.29), P = 0.01], AZA maintenance [HRadj 2.20 (95% CI 1.01, 4.79), P = 0.05], PR [HRadj 3.9 (95% CI 1.03, 9.19), P = 0.01] and non-remission [HRadj 3.08 (95% CI 1.35, 11.3), P = 0.04] at 12 months were predictive of renal relapse. Renal relapse was significantly associated with advanced chronic kidney disease (stages 3-5) and end-stage kidney disease (17.9% vs 1.8%, P < 0.01). Furthermore, patients with renal relapse showed an increased incidence of infections (30.8% vs 10.7%, P = 0.02), osteopenia (38.5% vs 17.9%, P = 0.04) and hypertension (30.8% vs 7.1%, P < 0.01). CONCLUSION: Renal relapse is common among cLN, especially among young patients, and is associated with an increased incidence of morbidity and mortality. Attaining CR and the use of MMF appear to decrease the incidence of renal relapse.

Managing Lupus Nephritis in Children and Adolescents.

Lupus nephritis is an important manifestation of systemic lupus erythematosus, which leads to chronic kidney disease, kidney failure, and can result in mortality. About 35%-60% of children with systemic lupus erythematosus develop kidney involvement. Over the past few decades, the outcome of patients with lupus nephritis has improved significantly with advances in immunosuppressive therapies and clinical management. Nonetheless, there is a paucity of high-level evidence to guide the management of childhood-onset lupus nephritis, because of the relatively small number of patients at each centre and also because children and adolescents are often excluded from clinical trials. Children and adults differ in more ways than just size, and there are remarkable differences between childhood- and adult-onset lupus nephritis in terms of disease severity, treatment efficacy, tolerance to medications and most importantly, psychosocial perspective. In this article, we review the 'art and science' of managing childhood-onset lupus nephritis, which has evolved in recent years, and highlight special considerations in this specific patient population.

Humoral and Cellular Immunogenicity of 3 Doses of BNT162b2 in Children With Kidney Diseases.

Introduction: Patients with severe kidney diseases are at risk of complications from COVID-19; however, little is known about the effectiveness of COVID-19 vaccines in children and adolescents with kidney diseases. Methods: We investigated the immunogenicity and safety of an accelerated 3-dose primary series of COVID-19 vaccination among 59 pediatric patients with chronic kidney disease (CKD) (mean age 12.9 years; 30 male) with or without immunosuppression, dialysis, or kidney transplant. Dosage was 0.1 ml BNT162b2 to those aged 5 to 11 years, and 0.3 ml BNT162b2 to those aged 11 to 18 years. Results: Three doses of either vaccine type elicited significant antibody responses that included spike receptor-binding domain (S-RBD) IgG (90.5%-93.8% seropositive) and surrogate virus neutralization (geometric mean sVNT% level, 78.6%-79.3%). There were notable T cell responses. Weaker neutralization responses were observed among those on immunosuppression, especially those receiving higher number of immunosuppressants or on mycophenolate mofetil. Neutralization was reduced against Omicron BA.1 compared to wild type (WT, i.e., ancestral) (post-dose 3 sVNT% level; 82.7% vs. 27.4%; P < 0.0001). However, the T cell response against Omicron BA.1 was preserved, which likely confers protection against severe COVID-19. Infected patients exhibited hybrid immunity after vaccination, as evidenced by the higher Omicron BA.1 neutralization response among these infected patients who received 2 doses compared with those who were uninfected. Generally mild or moderate adverse reactions following vaccines were reported. Conclusion: An accelerated 3-dose primary series with BNT162b2 is immunogenic and safe in young children and adolescents with kidney diseases.

Long-term outcomes with rituximab as add-on therapy in severe childhood-onset lupus nephritis.

BACKGROUND: Long-term data pertaining to rituximab as add-on therapy in childhood-onset lupus nephritis (cLN) is scarce. METHODS: A retrospective cohort study was conducted on all patients with proliferative cLN, diagnosed ≤ 18 years and between 2005 and 2021, who received rituximab for LN episodes that were life/organ threatening and/or treatment resistant to standard immunosuppression. RESULTS: Fourteen patients with cLN (female, n = 10) were included, with median follow-up period of 6.9 years. LN episodes (class III, n = 1; class IV, n = 11; class IV + V, n = 2) requiring rituximab occurred at 15.6 years (IQR 12.8-17.3), urine protein:creatinine ratio was 8.2 mg/mg (IQR 3.4-10.1) and eGFR was 28 mL/min/1.73 m2 (IQR 24-69) prior to rituximab treatment. Ten and four patients received rituximab at 1500 mg/m2 and 750 mg/m2, which were given at 46.5 days (IQR 19-69) after commencement of standard therapies. Treatment with rituximab resulted in improvements in proteinuria (ps < 0.001), eGFR (ps < 0.01) and serological parameters, including haemoglobin levels, complement 3 levels and anti-dsDNA antibodies, compared with baseline. Rates of complete/partial remission at 6-, 12- and 24-month post-rituximab were 28.6/42.8%, 64.2/21.4% and 69.2/15.3%. All three patients who required acute kidney replacement therapy became dialysis-free after rituximab. Relapse rate following rituximab was 0.11 episodes/patient-year. There was no lethal complication or severe infusion reaction. Hypogammaglobulinaemia was the most frequent complication (45%) but was mostly asymptomatic. Neutropenia and infections were observed in 20% and 25% of treatments. Upon last follow-up, three (21%) and two (14%) patients developed chronic kidney disease (stage 2, n = 2; stage 4; n = 1) and kidney failure, respectively. CONCLUSION: Add-on rituximab is an effective and safe rescue therapy for cLN patients with life-/organ-threatening manifestations or treatment-resistance. A higher resolution version of the Graphical abstract is available as Supplementary information.

Acute kidney injury in children with haematological malignancy: a territory-wide study.

BACKGROUND: In onco-nephrology, data on acute kidney injury (AKI) among children with haematological malignancies are scarce. METHODS: A retrospective cohort study of all patients in Hong Kong diagnosed with haematological malignancies from 2019 to 2021 before 18 years of age, was conducted to investigate the epidemiology, risk factors and clinical outcomes of AKI during the first year of treatment. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. RESULTS: We included 130 children with haematological malignancy at median age of 9.4 years (IQR, 3.9-14.1). Of these patients, 55.4% were acute lymphoblastic leukemia (ALL), 26.9% were lymphoma and 17.7% were acute myeloid leukemia (AML). Thirty-five patients (26.9%) developed 41 AKI episodes during the first year of diagnosis, corresponding to 32 episodes per 100-patient-year. A total of 56.1% and 29.2% of the AKI episodes occurred during induction and consolidation chemotherapy respectively. Septic shock (n = 12, 29.2%) was the leading cause of AKI; 21 episodes (51.2%) were stage 3 AKI; 12 episodes (29.3%) were stage 2 AKI; and 6 patients required continuous kidney replacement therapies. Tumor lysis syndrome and impaired baseline kidney function were significantly associated with AKI on multivariate analysis (P = 0.01). History of AKI was associated with chemotherapy postponement (37.1% vs. 16.8%, P = 0.01), worse 12-month patient survival (77.1% vs. 94.7%, log rank P = 0.002) and lower disease remission rate at 12-month (68.6% vs. 88.4%, P = 0.007), compared to patients without AKI. CONCLUSION: AKI is a common complication during treatment of haematological malignancies which is associated with worse treatment outcomes. A regular and dedicated surveillance program for at-risk patients should be studied in children with haematological malignancies for prevention and early detection of AKI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Long-Term Outcomes of Children and Adolescents With Biopsy-Proven Childhood-Onset Lupus Nephritis.

Introduction: Long-term data pertaining to childhood-onset lupus nephritis (cLN) remain extremely scarce. Methods: We conducted a retrospective cohort study of biopsy-proven cLN with onset age <18 years diagnosed from 2001 to 2020 to ascertain the long-term patient and kidney survival rates, and the incidence of advanced chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] <60 ml/min per 1.73 m2). Results: A total of 92 subjects (78 female; age 13.7 ± 3.3 years; all Chinese) were included, with follow-up duration of 10.3 years (interquartile range, 5.8-15.9). Of these, 83 children (90%) had proliferative lupus nephritis (LN) (Class III/IV ± V). Mycophenolate was used for induction in 36%, whereas 34% received cyclophosphamide (CYC); 55% received mycophenolate as maintenance immunosuppression. The rates of complete remission (CR) and partial remission (PR) at 6 months and 12 months, respectively, were 65% and 20% and 78% and 8%. Two patients died (mortality rate 2.1/1000 patient-years), with a standardized mortality ratio of 22.3. Three patients (3.2%) developed end-stage kidney disease (ESKD), and advanced CKD occurred in 5 patients (5.4%). Survival rates without advanced CKD, ESKD, or death were 96.7%, 94.2%, 92.7%, 83.2% and 83.2% at 1 year, 5 years, 10 years, 15 years, and 20 years, respectively. Multivariate analysis revealed that severe kidney failure necessitating dialysis at presentation (adjusted hazard ratio 37.7, 95% confidence interval [CI] 4.0-355.6, P = 0.002), nonresponse (NR) after 12 months of treatment (adjusted hazard ratio 11.2, 95% CI 2.3-54.9, P = 0.003), and multiple nephritis flares (adjusted hazard ratio 2.6, 95% CI 1.1-6.2, P = 0.03) were predictive of advanced CKD, ESKD, or death. Other adverse outcomes included infections (2.9 episodes/100 patient-years), osteopenia (32%), hypertension (17%), short stature (14%), and avascular necrosis (7%). Conclusion: The long-term outcomes of cLN appeared to have improved in the present era with effective immunosuppression, cautious drug tapering, and assurance of medication adherence. There is still an unacceptably high prevalence of adverse outcomes.

Outcomes and perception of cloud-based remote patient monitoring in children receiving automated peritoneal dialysis: a prospective study.

BACKGROUND: Remote patient monitoring (RPM) for automated peritoneal dialysis (APD) may improve clinical outcomes. Paediatric data, however, remain extremely scarce. METHODS: We conducted a prospective observational study of children (0-18 years) receiving APD with cloud-based RPM over two 24-week periods (pre- and post-RPM). Primary outcomes were unplanned hospitalizations and fluid management. Children receiving APD without RPM (non-RPM) were included as control. RESULTS: Seven patients (6 females) receiving APD were enrolled in the RPM programme at 11.3 years (IQR 2.6-17.1). Main indications for RPM included history of fluid overload (n = 3) and non-adherence (n = 2). Ten children were included in the non-RPM group (6 females; 16.9 years, IQR 12.8-17.6). Four patients (57.1%, 95% CI 22.5-100%) experienced fewer unplanned hospitalizations and 5 patients (71.4%, 95% CI 34.1-100%) had shorter hospital stays during the post-RPM period. The hospitalization rates and length of stay were reduced by 45% and 42%, respectively. The higher hospitalization rates among the RPM group, compared to the non-RPM group, were no longer observed following implementation of RPM. There was a significant increase in ultrafiltration (565.6 ± 248.7 vs. 501.7 ± 286.6 ml/day, p = 0.03) and reduction in systolic blood pressure (114.1 ± 12.6 vs. 119.9 ± 11.19 mmHg, p = 0.02) during the post-RPM period. All patients demonstrated satisfactory adherence. Although quality of life (PedsQL 3.0 ESRD module) was not different pre- and post-RPM, all patients agreed in the questionnaires that the use of RPM improved their quality of life and sense of security. CONCLUSIONS: In conclusion, RPM in children receiving APD is associated with fewer and shorter unplanned hospitalizations, improved fluid management and favourable adherence to PD. 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.

Epidemiology and outcomes of pediatric transplant-associated thrombotic microangiopathy in Hong Kong.

BACKGROUND: Transplant-associated thrombotic microangiopathy (TA-TMA) is an under-recognized yet potentially devastating complication of hematopoietic stem cell transplantation (HSCT) which had increased awareness in recent years. This report summarizes the demographics and outcomes of pediatric TA-TMA in Hong Kong. METHODS: All patients aged below 18 years who underwent HSCT in the Hong Kong Children's Hospital and were diagnosed to have TA-TMA during the 2-year period from April 1, 2019 to March 31, 2021 were included. RESULTS: A total of 73 transplants (51 allogeneic and 22 autologous) in 63 patients had been performed. Six patients (four males and two females) developed TA-TMA at a median duration of 2.5 months post-HSCT. The incidence rate was 9.52%. Of the six TA-TMA patients, five underwent allogenic one underwent autologous HSCT, respectively. Three of them were histologically proven. All four patients with cyclosporine had stopped the drug once TA-TMA was suspected. Median six doses of eculizumab were administered to five out of six patients. Three patients died (two due to fungal infection and one due to acute-on-chronic renal failure) within 3 months upon diagnosis of TA-TMA. Among three survivors, two stabilized with mild stage 2 chronic kidney disease (CKD) while the other suffered from stage 5 end-stage CKD requiring lifelong dialysis. CONCLUSION: In conclusion, recognition and diagnosis of TA-TMA are challenging. Early recognition and prompt administration of complement blockage with eculizumab may be beneficial in selected cases. Further prospective research studies are recommended to improve the management and outcomes of TA-TMA.

Embolisation of an aneurysmal high-flow renal arteriovenous fistula in a paediatric patient: simultaneous arterial and venous approach.

BACKGROUND: A large aneurysmal renal arteriovenous fistula (AVF) can cause hypokalaemic hypertension due to activation of renin-aldosterone system due to steal effect from renal parenchyma. In comparison to nephrectomy, endovascular embolisation of renal AVF is minimally invasive and can be nephron sparing, thus preserving renal function. However, such embolisation is technically challenging and can be associated with high risk of embolic migration. CASE PRESENTATION: We present a case of successful embolisation of a large aneurysmal renal AVF in a 11-year-old girl. The AVF was initially treated with coil embolization via transarterial route, resulting in partial migration of coil into inferior vena cava. After removal of the migrated coil via transvenous snaring, coils were deployed simultaneously via transarterial and transvenous routes to prevent migration. AVF flow dampened but residual flow persisted at 1 month follow up. A second embolization session with additional coil deployment and N-butyl cyanoacrylate (NBCA) injection resulted in successful occlusion of the AVF. At 3 months follow up, the girl's blood pressure and serum potassium level have normalized without need of antihypertensive agent or potassium supplements. CONCLUSION: Endovascular embolisation can be an effective nephron sparing treatment for large aneurysmal renal AVF. This is particularly important in paediatric patients as most renal function can be preserved with their expected longer life span. Risk of coil migration can be controlled by simultaneous transarterial and transvenous deployment. Complete occlusion of AVF can be aided by additional use of NBCA.

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

BACKGROUND: Long-term outcomes after multiple courses of rituximab among children with frequently relapsing, steroid-dependent nephrotic syndrome (FRSDNS) are unknown. METHODS: A retrospective cohort study at 16 pediatric nephrology centers from ten countries in Asia, Europe, and North America included children with FRSDNS who received two or more courses of rituximab. Primary outcomes were relapse-free survival and adverse events. RESULTS: A total of 346 children (age, 9.8 years; IQR, 6.6-13.5 years; 73% boys) received 1149 courses of rituximab. A total of 145, 83, 50, 28, 22, and 18 children received two, three, four, five, six, and seven or more courses, respectively. Median (IQR) follow-up was 5.9 (4.3-7.7) years. Relapse-free survival differed by treatment courses (clustered log-rank test P<0.001). Compared with the first course (10.0 months; 95% CI, 9.0 to 10.7 months), relapse-free period and relapse risk progressively improved after subsequent courses (12.0-16.0 months; HRadj, 0.03-0.13; 95% CI, 0.01 to 0.18; P<0.001). The duration of B-cell depletion remained similar with repeated treatments (6.1 months; 95% CI, 6.0 to 6.3 months). Adverse events were mostly mild; the most common adverse events were hypogammaglobulinemia (50.9%), infection (4.5%), and neutropenia (3.7%). Side effects did not increase with more treatment courses nor a higher cumulative dose. Only 78 of the 353 episodes of hypogammaglobulinemia were clinically significant. Younger age at presentation (2.8 versus 3.3 years; P=0.05), age at first rituximab treatment (8.0 versus 10.0 years; P=0.01), and history of steroid resistance (28% versus 18%; P=0.01) were associated with significant hypogammaglobulinemia. All 53 infective episodes resolved, except for one patient with hepatitis B infection and another with EBV infection. There were 42 episodes of neutropenia, associated with history of steroid resistance (30% versus 20%; P=0.04). Upon last follow-up, 332 children (96%) had normal kidney function. CONCLUSIONS: Children receiving repeated courses of 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.

Demographics and long-term outcomes of children with end-stage kidney disease: A 20-year territory-wide study.

AIM: To evaluate the demographics and long-term patient outcomes of children with end-stage kidney disease in Hong Kong. METHODS: We conducted a cohort study at the Paediatric Nephrology Centre, the designated site providing kidney replacement therapy (KRT) for children in Hong Kong. The clinical characteristics and outcomes of all children who initiated chronic KRT before 19 years, between 2001 and 2020, were analysed. RESULTS: One hundred forty-seven children (50% male) received KRT at a mean age of 11.4 ± 5.7 years. The incidence of ESKD was 6.28 per million age-related population (pmarp). The leading cause of ESKD was congenital anomalies (33%). Ten children (7%) had pre-emptive kidney transplants, 104 (71%) and 33 (22%) patients received automated peritoneal dialysis and haemodialysis as initial KRT. The incidence of ESKD increased over time, and were 4.38, 5.07, 6.15 and 9.17 pmarp during 2001-2005, 2006-2010, 2011-2015 and 2016-2020, respectively (p = .005). Ninty-seven patients (66%) received kidney transplants and the median time to receive a kidney graft was 3.7 years (95% CI 3.1-4.3). Only 10 patients had pre-emptive kidney transplants. The mortality rate was 9.1 deaths per 1000-patient-years (95%CI 4.6-16.2). The survival probabilities at 1-, 5-, 10- and 15-year were 100%, 94.8% (95%CI 90.7-98.9%), 89.7% (95% CI 83.4%-95.9%), 87.1% (95% CI 79.3%-94.9%), respectively. Standardised mortality ratio was 54.5. 72% of deaths were due to infections. Young infants and those without kidney transplants were associated with worse survival (p < .01). Multivariate analysis demonstrated that dialysis was the only factor associated with significantly increased risk of death (HRadj 12.9, 95% CI 2.7-63.2, p = .002). CONCLUSION: We observed an increasing incidence of paediatric ESKD in Hong Kong with considerable waiting time to kidney transplant. Mortality risk is comparable to other developed countries and is highest among dialysis population. Efforts should be made to facilitate early access to paediatric kidney transplantation in Hong Kong.

When should we start and stop ACEi/ARB in paediatric chronic kidney disease?

Renin-angiotensin-aldosterone inhibitors (RAASi) are the mainstay therapy in both adult and paediatric chronic kidney disease (CKD). RAASi slow down the progression of kidney failure by optimization of blood pressure and reduction of proteinuria. Despite recommendations from published guidelines in adults, the evidence related to the use of RAASi is surprisingly scarce in children. Moreover, their role in advanced CKD remains controversial. Without much guidance from the literature, paediatric nephrologists may discontinue RAASi in patients with advanced CKD due to apparent worsening of kidney function, hyperkalaemia and hypotension. Current data suggest that this strategy may in fact lead to a more rapid decline in kidney function. The optimal approach in this clinical scenario is still not well defined and there are varying practices worldwide. We will in this review describe the existing evidence on the use of RAASi in CKD with particular focus on paediatric data. We will also address the use of RAASi in advanced CKD and discuss the potential benefits and harms. At the end, we will suggest a practical approach for the use of RAASi in children with CKD based on current state of knowledge.

Vertical gaze palsy and intraoral numbness in a patient with neuro-psychiatric systemic lupus erythematosus: A case report and literature review.

We report, to the best of our knowledge, the first case of neuropsychiatric systemic lupus erythematosus with clinical presentation of bilateral upward gaze palsy and intraoral numbness. Magnetic resonance imaging of the brain was able to identify the pathogenic lesion at the left side of midbrain, involving the vertical gaze center and sensory pathways for innervating the buccal and hard palate mucosa. A course of aggressive immunosuppressive treatment resulted in prompt resolution of gaze palsy and the midbrain lesion.