Are children with IgA nephropathy different from adult patients?

BACKGROUND: Previously, several studies have indicated that pediatric IgA nephropathy (IgAN) might be different from adult IgAN, and treatment strategies might be also different between pediatric IgAN and adult IgAN. METHODS: We analyzed two prospective cohorts established by pediatric and adult nephrologists, respectively. A comprehensive analysis was performed investigating the difference in clinical and pathological characteristics, treatment, and prognosis between children and adults with IgAN. RESULTS: A total of 1015 children and 1911 adults with IgAN were eligible for analysis. More frequent gross hematuria (88% vs. 20%, p < 0.0001) and higher proteinuria (1.8 vs. 1.3 g/d, p < 0.0001) were seen in children compared to adults. In comparison, the estimated glomerular filtration rate (eGFR) was lower in adults (80.4 vs. 163 ml/min/1.73 m2, p < 0.0001). Hypertension was more prevalent in adult patients. Pathologically, a higher proportion of M1 was revealed (62% vs. 39%, p < 0.0001) in children than in adults. S1 (62% vs. 28%, p < 0.0001) and T1-2 (34% vs. 8%, p < 0.0001) were more frequent in adults. Adjusted by proteinuria, eGFR, and hypertension, children were more likely to be treated with glucocorticoids than adults (87% vs. 45%, p < 0.0001). After propensity score matching, in IgAN with proteinuria > 1 g/d, children treated with steroids were 1.87 (95% CI 1.16-3.02, p = 0.01) times more likely to reach complete remission of proteinuria compared with adults treated with steroids. CONCLUSIONS: Children present significantly differently from adults with IgAN in clinical and pathological manifestations and disease progression. Steroid response might be better in children.

Double filtration plasmapheresis for children with different types of critical kidney diseases: a single-center retrospective cohort study.

Background: Double filtration plasmapheresis (DFPP) was initially used to facilitate the conduction of ABO-incompatible renal transplantation. The applicability of DFPP has recently expanded to cover the removal of various antibodies in adults with immune-mediated diseases. However, DFPP is seldom used in children, with few reports addressing its efficacy and safety in this population. This study aimed to explore the efficacy and adverse effects of DFPP for pediatric patients with renal indications. Methods: Children who received DFPP between December 2017 and December 2020 at Tongji Hospital were retrospectively studied, and sub-grouped for analysis according to the types of disease. All children received 3 to 6 DFPP sessions within 2 to 3 weeks, and were assessed for clinical outcomes according to glomerular filtration rate, proteinuria and extra-renal symptoms. Pre- and post-DFPP plasma were collected to measure the levels of pathogenic autoantibodies, immunoglobulins, fibrinogen, albumin, calcium, etc. In-hospital complications were also recorded. Results: Totally there were 10 children receiving 44 sessions of DFPP, including 2 males and 8 females, with a median age of 11.2 years old (5-13 years) and a median weight of 42.1 kg (20-59 kg). Five patients were treated for systemic lupus erythematosus (SLE), three patients for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), one for C3 glomerulopathy and one for ABO-incompatible renal transplantation. Plasma autoantibodies decreased substantially by 93% and 89% in those with SLE and AAV after the last session, respectively. Complete or partial responses were achieved in 80%, 33.3%, 100% and 100% of patients with SLE, AAV, C3 glomerulopathy, and ABO-incompatible renal transplantation, respectively. The proportion of cumulative IgG, fibrinogen, and albumin removal at the end of the last sessions were 58.8%, 67.69%, and 14.05% respectively. The removal of calcium, potassium and creatinine were not statistically significant. A few episodes (4.55%) of hypotension were observed when fresh frozen plasma was used as the replacement fluid, and no bleeding nor severe anaphylaxis was noted. Conclusions: The efficacy and safety of DFPP treatment in children with SLE, AAV, C3 glomerulopathy and ABO-incompatible renal transplantation were described in the present study. DFPP is proven to be a safe apheresis method for children weighing more than 20 kg.

CUBN gene mutations may cause focal segmental glomerulosclerosis (FSGS) in children.

BACKGROUND: Imerslund-Gräsbeck Syndrome (IGS) is mainly caused by CUBN gene biallelic mutations. Proteinuria accompanies IGS specific symptoms in about half of the patients, isolated proteinuria is rarely reported. Here we present 3 patients with isolated proteinuria and focal segmental glomerulosclerosis (FSGS) caused by CUBN gene biallelic pathogenic variants. METHOD: Whole exome sequencing was performed on three children with isolated proteinuria. CUBN gene biallelic pathogenic variants were found and then verified by sanger sequencing. Their clinical, pathological and molecular genetic characteristics were analyzed and correlated accordingly. RESULTS: All three children presented with isolated proteinuria, no megaloblastic anemia. Their urine levels of ß2 microglobulin were normal or slightly higher. Renal biopsies showed focal segmental glomerulosclerosis with mild glomerular mesangial hypercellularity, partial effacement of foot processes and podocyte microvillation. Two of them were found to carry compound heterozygous mutations and one homozygous mutation of CUBN gene. Totally four CUBN gene biallelic pathogenic variants were identified, including c.9287 T > C (p.L3096P), c.122 + 1G > A, c.7906C > T (p.R2636*), c.10233G > A (p.W3411*). Except for intron splice-site mutation, all other variants are located in highly conserved sites of CUB domain for binding to albumin. CONCLUSION: The results demonstrate that CUBN gene mutations may cause isolated proteinuria pathologically presented as FSGS. Our cases extend the spectrum of renal manifestation and genotype of CUBN gene mutations.

The top 100 most-cited articles on adult spinal deformity: The most popular topics are still sagittal plane parameters and complications.

Purpose: This study aimed to summarize the characteristics of the 100 most-cited articles on adult spinal deformity (ASD) and to analyze past and current research hotspots and trends. Methods: Literature searches (from inception to 28 April 2022) using Web of Science databases were conducted to identify ASD-related articles. The top 100 most-cited articles were collected for further analysis. Meanwhile, author keywords from articles published in the last 5 years were selected for further analysis. Results: The top 100 most-cited articles on ASD were selected from 3,354 papers. The publication year ranged from 1979 to 2017, and all papers were written in English. The citation count among them ranged from 100 to 1,145, and the mean citation number was 215.2. The foremost productive first author was Schwab F. University of Washington had the largest number of publications. The United States of America had the largest number of published articles (n = 84) in this field. Spine was the most popular journal. Complications were the most studied themes. The visualization analysis of author keywords from the literature in the recent 5 years showed that complications, sagittal plane parameters, and surgical techniques are still the research hotspots, and minimally invasive surgery will continue to develop rapidly. Conclusion: Based on a comparative analysis of the results of bibliometric and visualization, complications and sagittal plane parameters are still the major topics of research at present and even later, and minimally invasive surgery has a growth trend in this field of ASD.

Case Report: Successful Treatment of Refractory Interstitial Lung Disease With Cyclosporine A and Pirfenidone in a Child With SLE.

Interstitial lung disease (ILD) as an initial manifestation of lupus is rare, especially in young children. Here, we report a case of a 3-year-old boy who presented with fever, shortness of breath, and facial erythema. Clinical examination suggested a diagnosis of active systemic lupus erythematosus (SLE) with butterfly rash, anemia, positive antinuclear antibody, positive anti-double-stranded DNA, and hypocomplementemia. On retrospective review of the patient's records, multiple chest computed tomography (CT) images showed non-specific interstitial pneumonia + organizing pneumonia pattern, with no further autoimmune work-up during the visit to a respiratory department. In our opinion, persistent interstitial pneumonia may be a clue to connective tissue disease. The patient received steroid treatment for 1 year, and the radiological and immunological resolution was noted. However, he still suffered from cough and dyspnea. After a 1-year follow-up, he was hospitalized again for SLE relapse. While continuing corticosteroid therapy, the patient was given combination therapy consisting of cyclosporine A (CsA) and monthly-pulse cyclophosphamide for 6 months, and decreased proteinuria was noted. However, the patient's respiratory symptoms and pulmonary radiologic findings did not improve significantly. With continued steroid therapy, the patient was started on a daily regimen of CsA and pirfenidone. Both drugs were sufficiently effective to allow gradual reduction of steroid dosage. After 2 years of treatment, marked improvements in symptoms, pulmonary function and chest CT images were observed. Our experience with this case emphasizes that prompt work-up for connective tissue disease (CTD) should be considered in young children with ILD, and pirfenidone might be a useful add-on therapy with immunosuppressive agents for refractory CTD-ILD in pediatric patients. Nevertheless, further clinical trials including larger numbers of patients need to assess the efficiency and safety of this combination therapy for refractory CTD-ILD.

A Presumed Synonymous Mutation of PKD2 Caused Autosomal Dominant Polycystic Kidney Disease in a Chinese Family.

OBJECTIVE: Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by the pathogenic mutation of PKD1 or PKD2 gene and usually affects bilateral kidneys. Synonymous mutations are generally assumed to be neutral as they do not alter amino acids. Herein, we described an extremely rare ADPKD child caused by a heterozygous synonymous mutation of PKD2 gene accompanied by massive proteinuria and congenital solitary kidney. METHODS: Clinical characteristics of the patients were summarized. Whole-exome sequencing was performed to screen the disease-causing gene mutation, and reverse transcription polymerase chain reaction (RT-PCR) and Sanger sequencing were applied to analyze the impact of the identified mutation on gene transcription and splicing. RESULTS: Polycystic changes were found in the solitary kidney of a girl initially presented with nephrotic-range proteinuria. Thereafter her mother and 2 other family members were diagnosed to be ADPKD. Whole-exome sequencing of the proband identified a heterozygous synonymous mutation (c.1716G>A, p.Lys572=) located in the splicing site of exon 7 in PKD2 gene, which was co-segregated with the PKD phenotype in the family. RT-PCR and direct sequencing of amplified products revealed that this heterozygous synonymous mutation led to exon7 skipping in PKD2 gene. CONCLUSION: We reported an extremely rare child case of ADPKD2 in combination with solitary kidney and nephrotic-range proteinuria, and firstly confirmed the pathogenicity of a heterozygous synonymous mutation (c.1716G>A) in PKD2 gene. The results indicate that synonymous mutations should not be excluded from disease-causing if they are located in splicing site of an exon.

Novel pathogenic OCRL mutations and genotype-phenotype analysis of Chinese children affected by oculocerebrorenal syndrome: two cases and a literature review.

BACKGROUND: Oculocerebrorenal syndrome of Lowe is a rare X-linked disorder characterized by congenital cataracts, mental retardation, and proximal tubulopathy. This condition is caused by a mutation of OCRL gene (located at chromosome Xq26.1), which encodes an inositol polyphosphate 5-phosphatase. CASE PRESENTATION: We identified two novel OCRL mutations in two unrelated Chinese boys, each with a severe phenotype of Lowe syndrome. A novel de novo deletion (hemizygous c.659_662delAGGG, p.E220Vfs*29) was present in patient 1 and a novel splicing mutation (hemizygous c.2257-2A > T) that was maternally inherited was present in patient 2. A renal biopsy in patient 2 indicated mild mesangial proliferative glomerulonephritis, mild focal mononuclear cells infiltration, and interstitial focal fibrosis. Moreover, renal expression of OCRL-1 protein in patient 2 was significantly reduced compared to a control patient with thin basement membrane disease. CONCLUSIONS: This study reports two novel OCRL variants associated with severe ocular and neurologic deficiency, despite only mild renal dysfunction. Based on our two patients and a literature review, the genotype-phenotype correlation of OCRL mutations with this severe phenotype of Lowe syndrome suggest a possible clustering of missense, deletion, and nonsense mutations in the 5-phosphatase domain and Rho-GAP domain in the Chinese population.