Spectrum of biopsy proven renal disease in South Asian children: Two decades at a tropical tertiary care centre

Percutaneous kidney biopsies in children: a 24-year review in a tertiary center in northern Portugal

INTRODUCTION

Percutaneous kidney biopsy (KB) is crucial to the diagnosis and management of several renal pathologies. National data on native KB in pediatric patients are scarce. We aimed to review the demographic and clinical characteristics and histopathological patterns in children who underwent native percutaneous KB over 24 years.

METHODS

Retrospective observational study of patients undergoing native percutaneous KB in a pediatric nephrology unit between 1998 and 2021, comparing 3 periods: period 1 (1998-2005), period 2 (2006-2013), and period 3 (2014-2021).

RESULTS

We found that 228 KB were performed, 78 (34.2%) in period 1, 91 (39.9%) in period 2, and 59 (25.9%) in period 3. The median age at KB was 11 (7-14) years. The main indications for KB were nephrotic syndrome (NS) (42.9%), hematuria and/or non-nephrotic proteinuria (35.5%), and acute kidney injury (13.2%). Primary glomerulopathies were more frequent (67.1%), particularly minimal change disease (MCD) (25.4%), IgA nephropathy (12.7%), and mesangioproliferative glomerulonephritis (GN) (8.8%). Of the secondary glomerulopathies, lupus nephritis (LN) was the most prevalent (11.8%). In group 1, hematuria and/or non-nephrotic proteinuria were the main reasons for KB, as opposed to NS in groups 2 and 3 (p < 0.01). LN showed an increasing trend (period 1-3: 2.6%-5.3%) and focal segmental glomerular sclerosis (FSGS) showed a slight decreasing trend (period 1-3: 3.1%-1.8%), without statistical significance.

CONCLUSIONS

The main indication for KB was NS, which increased over time, justifying the finding of MCD as main histological diagnosis. LN showed an increase in incidence over time, while FSGS cases did not increase.

Renal pathology in adult and paediatric population of Japan: review of the Japan renal biopsy registry database from 2007 to 2017

BACKGROUND

The Japan Renal Biopsy Registry (J-RBR), a nationwide, web-based, registry system, started in 2007. This study aimed to summarise the epidemiology of biopsy-diagnosed kidney disease in Japan over 10 years.

METHODS

We analysed the J-RBR database, from 2007 to 2017. Patients' clinical data collected at the time of biopsy and histopathological diagnoses were used for epidemiological and clinicopathologic analyses.

RESULTS

The predominant renal biopsy diagnoses were immunoglobulin A nephropathy (39.2%), lupus nephritis (6.5%) and minimal change disease (6.0%) in younger adults (19-64 years), and membranous nephropathy (17.4%), antineutrophil cytoplasmic antibody-associated vasculitis or anti-glomerular basement membrane glomerulonephritis (13.0%), and immunoglobulin A nephropathy (12.5%) in older adults (≥ 65 years). The percentages of patients diagnosed with membranoproliferative glomerulonephritis and immunoglobulin A nephropathy decreased, whereas those with immunoglobulin A vasculitis and diabetic nephropathy increased over the decade. In paediatric patients (< 19 years), immunoglobulin A nephropathy (36.1%), minimal change disease (17.6%), and immunoglobulin A vasculitis (8.6%) were the predominant diagnoses. The percentage of patients diagnosed with immunoglobulin A vasculitis increased over the decade. Based on the sex distribution, minimal change disease and membranous nephropathy were predominant in men aged < 20 and > 40 years, respectively, whereas immunoglobulin A vasculitis and antineutrophil cytoplasmic antibody-associated vasculitis or anti-glomerular basement membrane glomerulonephritis were predominant in women in their 20s and 30s and aged < 50 years, respectively. Immunoglobulin A nephropathy was predominant in men at most ages and in women in their 20s to 40s.

CONCLUSIONS

This study describes the distribution and changes in kidney biopsy diagnoses over 10 years in Japan and paves the way for future research on kidney diseases in adults and children.

Epidemiology and Outcomes of Glomerular Diseases in Low- and Middle-Income Countries

Glomerular diseases account for a significant proportion of chronic kidney disease in low-income and middle-income countries (LMICs). The epidemiology of glomerulonephritis is characterized inadequately in LMICs, largely owing to unavailable nephropathology services or uncertainty of the safety of the kidney biopsy procedure. In contrast to high-income countries where IgA nephropathy is the dominant primary glomerular disease, focal segmental glomerulosclerosis is common in large populations across Latin America, Africa, Middle East, and South East Asia, while IgA nephropathy is common in Chinese populations. Despite having a high prevalence of known genetic and viral risk factors that trigger focal segmental glomerulosclerosis, membranoproliferative glomerulonephritis also is common in adults and children in some African countries. Treatment of glomerular diseases in adults and children in LMICs largely is dependent on corticosteroids in combination with other immunosuppressive therapy, which often is cyclophosphamide because of its ready availability and low cost of treatment, despite significant adverse effects. Partial and/or complete remission status reported from studies of glomerular disease subtypes vary across LMIC regions, with high rates of kidney failure, mortality, and disease, and treatment complications often reported. Improving the availability of nephropathology services and ensuring availability of specific therapies are key measures to improving glomerular disease outcomes in LMICs.

Renal biopsy reports in nephritic syndrome: Update

BACKGROUND

Nephritic syndrome (NiS) is a major indicator of serious renal diseases necessitating kidney biopsies for histopathological evaluations, but due to the lack of comprehensive reviews in the literature, the current understanding of the syndrome and its significance is limited.

AIM

To collect all the evidence retrievable from the literature on the diagnoses made on the renal biopsies performed for NiS as the indication to the procedure.

METHODS

A literature search was conducted to find studies reporting final diagnoses on renal biopsies in NiS patients. Data were pooled and analyzed with stratifications on age and regions. Meta-analyzes were performed using Stata v.9.

RESULTS

Overall, 26414 NiS patients from the total number of 96738 kidney biopsy diagnoses reported by 47 studies from 23 countries from all continents (except sub-Saharan Africa) were found and analyzed. NiS was the indication for renal biopsy in 21% of the patient populations across the reviewed studies. Immunoglobulin A (IgA) nephropathy was the single most frequent diagnosis in these patients (approximately 38%) followed by lupus nephritis (approximately 8%) and Henoch Schönlein purpura (approximately 7%). IgA nephropathy was the most frequent diagnosis reported for the NiS patients from the East Asia, comprising half of all the cases, and least prevalent in South Asia. Considering the age subgroups, adult (vs pediatric or elderly) patients were by far the most likely age group to be diagnosed with the IgA nephropathy. A myriad of such regional and age disparities have been found and reported.

CONCLUSION

As the indication for renal biopsy, NiS represents a very distinctive epidemiology of final renal disease diagnoses compared to the other major syndromes.

Clinical and histological features in pediatric and adolescent/young adult patients with renal disease: a cross-sectional analysis of the Japan Renal Biopsy Registry (J-RBR)

BACKGROUND

Only a few studies have investigated epidemiological and clinicopathological information regarding pediatric and adolescent and young adult (AYA) patients with renal disease. The purpose of this study was to clarify the differences and relationship of clinicopathological findings between pediatric and AYA patients using the Japan Renal Biopsy Registry (J-RBR).

METHODS

This cross-sectional study analyzed data from patients registered in the J-RBR between 2007 and 2017. Clinicopathological findings at diagnosis were analyzed for 3,463 pediatric (age < 15 years) and 6,532 AYA (age 15-30 years) patients.

RESULTS

Although chronic nephritic syndrome was the most common clinical diagnosis at age > 5 years, nephrotic syndrome was the most frequent diagnosis at age < 4 years. The most common pathological diagnosis as classified by pathogenesis in pediatric patients was primary glomerular disease (except IgA nephropathy), whereas IgA nephropathy was increased in AYA patients. Mesangial proliferative glomerulonephritis was the most common pathological diagnosis as classified by histopathology in both pediatric and AYA patients. Minor glomerular abnormalities were the most frequent histopathologic diagnoses of nephrotic syndrome in childhood, but their frequency decreased with age.

CONCLUSION

To the best of our knowledge, this is the first report of clinicopathological features of pediatric and AYA patients in a large nationwide registry of renal biopsy. There were differences of clinical, pathological and histopathologic findings between pediatric and AYA patients.

Epidemiology of 10-year paediatric renal biopsies in the region of southern Croatia

Background

Information about renal diseases in children is available from national registries of renal biopsies. Aim of the study was to compare the clinical presentation of glomerular diseases and tubulointerstitial space diseases with pathohistological diagnosis of indicated renal biopsies from pediatric population in the Croatian region of Dalmatia.

Methods

Out of 231 pediatric patients with suspected glomerular and tubulointerstitial diseases, 54 underwent ultrasound-guided renal biopsy at University Hospital of Split. Kidney allograft biopsy, and re-biopsy were excluded. The biopsy sections were examined under light microscopy, immunofluorescence and electron microscopy. The data was reviewed to determine the pathohistological spectrum and clinicopathologic correlations. We retrospectively analyzed kidney biopsy data from 2008 to 2017 and compared them to that between 1995 and 2005.

Results

The mean age of patients was 9.84 ± 5.4 years. Male:female ratio was 1.2:1. The main indications for biopsy were pure nephrotic syndrome without hematuria (25.9%), non-nephrotic proteinuria with haematuria (22.2%), nephritic syndrome with nephrotic proteinuria (18.5%), and isolated hematuria (16.7%). The most common pathohistological findings were IgA nephropathy (IgAN, 24.1%), minimal change disease (MCD, 16.7%), Henoch-Schönlein purpura glomerulonephritis (HSPN, 14.8%), Alport syndrome and focal segmental glomerulosclerosis (AS and FSGS, 11.1% each), tubulointerstitial nephritis and membranous glomerulopathy (TIN and MGN, 3.7% each), while other cases were diagnosed rarely.

Conclusions

Changes in epidemiology of renal diseases in children between the analyzed periods showed an increasing trend of IgAN, MCD, HSPN, AS and FSGS, while mesangioproliferative glomerulonephritis (MesPGN) and endoproliferative glomerulonephritis (EDGN) showed a decreasing trend that can be explained with the new pathohistological classification.