Changes in spectrum of biopsy-proven kidney diseases within decade: an analysis based on 10 199 cases from South China

PURPOSE

To assess the regional epidemiological trends of kidney diseases over time in the South China using renal biopsy-proven cases.

METHODS

This retrospective observational cohort study was conducted at the Institute of Nephrology, Second Xiangya Hospital of Central South University, and encompasses all patients diagnosed with kidney disease via biopsy from 2012 to 2021.

RESULTS

The study sample consisted of 10 199 native kidneys, with a male-to-female ratio of 0.91:1 and an average age of 38.74 (±14.53) years. Primary glomerular nephropathy, systemic glomerular nephropathy (SGN), tubulointerstitial disease, and hereditary renal diseases accounted for 66.92 (6825)%, 24.49 (2498)%, 8.06 (822)%, and 0.53 (54)%, respectively. The leading pathologies of primary glomerular nephropathy remained the IgA nephropathy. The frequencies of IgA nephropathy and membranous nephropathy increased significantly, whereas the frequencies of minimal change disease and focal segmental glomerulosclerosis decreased (P < .001) between 2017 and 2021 than in the years 2012 and 2016. An earlier onset of membranous nephropathy was observed in the age group of 45-59 years compared to previous studies. The leading pathologies of SGN were found to be lupus nephritis (758 cases, 30.45%) and hypertension nephropathy (527 cases, 21.17%). The frequencies of hypertension nephropathy and diabetic nephropathy increased between 2017 and 2021 compared to 2012 and 2016 (P < .001), gradually becoming the leading pathological types of SGN. In elderly patients diagnosed with nephrotic syndrome, the frequencies of amyloidosis significantly increased (P < .01).

CONCLUSION

Our study may provide insights for kidney disease prevention and public health strategies. What is already known on this topic The pathological spectrum of kidney diseases has undergone significant transformations in the past decade, driven by the escalating incidence of chronic diseases. Although there are studies exploring the renal biopsy findings from various regions in China which present both similarities and differences in epidemiology, few large-scale reports from the South China in recent decades were published. What this study adds Our findings reveal the following key observations: (i) increased proportion of middle-aged patients leading to the increasing average age at the time of biopsy；(ii) the frequencies of IgA nephropathy and membranous nephropathy (MN) increased significantly, whereas the frequencies of minimal change disease and focal segmental glomerulosclerosis decreased (P < .001) between 2017 and 2021 than in the years 2012 and 2016; (iii) earlier onset of MN in the age group of 45-59 years old was found in our study; and (iv) a higher frequency of hypertension nephropathy and DN presented over time, and frequency of amyloidosis increased in elderly patients diagnosed with NS. How this study might affect research, practice, or policy This single-center yet a large-scale study of the kidney disease spectrum in South China may provide a reference point for the diagnosis, treatment, and prevention of chronic kidney disease.

Clinical Course of Adult FSGS and Minimal Change Disease in North American and Japanese Cohorts

Key Points

Data from different geographical regions highlighted the differences in clinical manifestations and treatment response of adult FSGS/minimal change disease. There were shared factors that were associated with treatment response across the cohorts: FSGS, higher BP, and lower eGFR. Recognizing geographical difference allows us better understanding of disease biology, risk prediction, and design of future clinical trials.

Background

Regional differences in presentation and clinical course of nephrotic syndrome (NS) have not been studied well because few studies directly compared the data from different intercontinental regions.

Methods

We included adult nephrotic patients with FSGS and minimal change disease (MCD) who received immunosuppressive therapy (IST) in a North American (Nephrotic Syndrome Study Network [NEPTUNE], N =89) or Japanese (Nagoya Kidney Disease Registry [N-KDR], N =288) cohort. Baseline characteristics and rates of complete remission (CR) were compared. Factors associated with time to CR were evaluated by Cox regression models.

Results

NEPTUNE participants had more FSGS (53.9 versus 17.0%) and family history of kidney disease (35.2 versus 3.2%). N-KDR participants were older (median 56 versus 43 years) and demonstrated greater levels of urine protein creatinine ratio (7.73 versus 6.65) and hypoalbuminemia (1.6 versus 2.2 mg/dl). N-KDR participants showed higher proportion of CR (overall: 89.2 versus 62.9%; FSGS: 67.3 versus 43.7%; MCD: 93.7 versus 85.4%). A multivariable model showed that FSGS (versus MCD: hazard ratio [HR], 0.28; 95% confidence interval [CI], 0.20 to 0.41), systolic BP (per 10 mm Hg: HR, 0.93; 95% CI, 0.86 to 0.99), and eGFR (per 10 ml/min per 1.73 m2: HR, 1.16; 95% CI, 1.09 to 1.24) were associated with time to CR. There were significant interactions in patient age (P = 0.004) and eGFR (P = 0.001) between the cohorts.

Conclusions

The North American cohort had more FSGS and more frequent family history. Japanese patients showed more severe NS with better response to IST. FSGS, hypertension, and lower eGFR were shared predictors of poor treatment response. Identifying shared and unique features across geographically diverse populations may help uncover biologically relevant subgroups, improve prediction of disease course, and better design future multinational clinical trials.

Nephrotic syndrome with Minimal Change Disease and Atopy in NorthAfrican adults

INTRODUCTION

In adults, minimal change disease (MCD) accounts for 15 to 25% of nephrotic syndrome (NS). Numerous reports have suggested a link between NS and atopy. However, data on treatment and prognosis of NS associated with allergy are limited.

AIM

To examine the presenting characteristics, treatments and outcomes of adults with allergic MCD in a North African center.

METHODS

This was an observational study using retrospectively collected data. Patients were recruited from the Nephrology department of Sahloul Hospital (Sousse, Tunisia) from January 2006 to December 2020. Adults with a biopsy proved MCD, which was associated with atopy, were included.

RESULTS

Fifteen patients (eight males, age mean±SD: 34±13 years) were included. High eosinophil and immunoglobulin E (IgE) levels were noted in three and twelve patients respectively. The IgE mean level at the initial presentation was 1431 IU/ml. Allergic skin tests were positive in nine patients. All patients were treated with corticosteroids, five had anti-histamine therapy and five had hyposensitization therapy, which was successful in two patients. Thirteen patients had relapsed during follow-up. Mean eosinophil level was significantly higher in patients with frequent relapses compared to those with infrequent relapses (5415/mm³ vs. 239.12/mm³, respectively, p=0.022). Two patients had progressed to chronic renal failure.

CONCLUSION

It is important to search for atopic disorders in patients with MCD to better control this disease and use specific treatments. However, the efficacy of anti-allergic therapies has to be proven.

Population-based identification and temporal trend of children with primary nephrotic syndrome: The Kaiser Permanente nephrotic syndrome study

INTRODUCTION

Limited population-based data exist about children with primary nephrotic syndrome (NS).

METHODS

We identified a cohort of children with primary NS receiving care in Kaiser Permanente Northern California, an integrated healthcare delivery system caring for >750,000 children. We identified all children <18 years between 1996 and 2012 who had nephrotic range proteinuria (urine ACR>3500 mg/g, urine PCR>3.5 mg/mg, 24-hour urine protein>3500 mg or urine dipstick>300 mg/dL) in laboratory databases or a diagnosis of NS in electronic health records. Nephrologists reviewed health records for clinical presentation and laboratory and biopsy results to confirm primary NS.

RESULTS

Among 365 cases of confirmed NS, 179 had confirmed primary NS attributed to presumed minimal change disease (MCD) (72%), focal segmental glomerulosclerosis (FSGS) (23%) or membranous nephropathy (MN) (5%). The overall incidence of primary NS was 1.47 (95% Confidence Interval:1.27-1.70) per 100,000 person-years. Biopsy data were available in 40% of cases. Median age for patients with primary NS was 6.9 (interquartile range:3.7 to 12.9) years, 43% were female and 26% were white, 13% black, 17% Asian/Pacific Islander, and 32% Hispanic.

CONCLUSION

This population-based identification of children with primary NS leveraging electronic health records can provide a unique approach and platform for describing the natural history of NS and identifying determinants of outcomes in children with primary NS.

Patterns of renal involvement in a cohort of patients with inflammatory bowel disease in Egypt

BACKGROUND AND STUDY AIM

Renal complications are frequent extraintestinal manifestations in inflammatory bowel disease (IBD). We aimed in our study to describe the spectrum of renal affection in our IBD patients.

PATIENTS AND METHODS

This study is a retrospective analysis of renal biopsies done for IBD patients who developed renal diseases, at Cairo University Hospital, from June 2005 to Jan. 2016. Results : Among 896 IBD patients, 218 patients (24.3%) developed renal affection. The onset of renal disease mandated renal biopsy at 5.6 ± 7.4 years after IBD diagnosis. Nephrotic range proteinuria was the most common indication for a renal biopsy [81 (37.15%) patients]. Amyloidosis was the most common renal pathological diagnosis [56 patients (25.7%)] followed by immunoglobulin A (IgA) nephropathy [35 patients (16.1%)], focal segmental glome- rulosclerosis (FSGS) [32patients (14.7%)], crescentic glomerulonephritis (CGN) [32 patients (14.7%)], membranous nephropathy (MN) [18 patients (8.25%)], minimal change disease [17 patients (7.7%)], chronic interstitial nephritis (CIN) [10 patients (4.6%)], acute tubular necrosis (ATN) [8 patients (3.7%)], thrombotic microangiopathy (TMA) [6 patients (2.75%)], and acute interstitial nephritis (AIN)[4 patients (1.8%)]. Variable renal histopathology diagnoses did not correlate with age, duration of IBD diagnosis, or drugs used for IBD treatment. Crescentic GN was significantly correlating with ASCA, ANCA-p, and ANCA-c in serum.

CONCLUSION

Amyloidosis is a common renal pathological diagnosis in our patients, and is followed by IgA nephropathy, and FSGS.

Urine volatile organic compounds as biomarkers for minimal change type nephrotic syndrome

Urinary volatile organic compounds (VOCs) profiling has recently received considerable attention because it can be obtained noninvasively and conveniently while it can be successfully used in a variety of diseases and can provide unique biomarkers. The aim of current study was to investigate potential biomarkers between minimal change type nephrotic syndrome (MCNS) and normal. Urinary samples were collected from 38 minimal change type nephrotic syndrome patients and 15 healthy controls. Solid phase microextraction (SPME) and chromatography- mass spectrometry (GC-MS) were used to analysis the urinary metabolites. To deal with the final data, the statistical methods principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLSDA) were performed. Six specific VOC biomarkers were present at abnormal levels in the urine of MCNS patients. These VOCs included trans-2,2-dimethyl-4-decene; pyrrole; carbamic acid, monoammonium salt; 1-butyne, 3,3-dimethyl-; diisopropylamine; and 4-heptanone. These biomarkers may be useful as a new diagnostic method and for monitoring the prognosis for MCNS patients.

Temporal and Demographic Trends in Glomerular Disease Epidemiology in the Southeastern United States, 1986-2015

BACKGROUND AND OBJECTIVES

Large-scale, contemporary studies exploring glomerular disease epidemiology in the United States are lacking. We aimed to determine 30-year temporal and demographic trends in renal biopsy glomerular disease diagnosis frequencies in the southeastern United States.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this cross-sectional, observational study, we identified all patients with a native kidney biopsy specimen showing one of 18 widely recognized glomerular disease diagnoses referred to the University of North Carolina Chapel Hill Division of Nephropathology between 1986 and 2015. Biopsy era (1986-1995, 1996-2005, and 2006-2015) and demographics (age, sex, and race) were our primary and secondary predictors, respectively, and the relative frequency of each glomerular disease diagnosis was our primary outcome.

RESULTS

Among 21,374 patients (mean age =48.3±18.3 years old; 50.8% men; 56.8% white; 38.3% black; 2.8% Latino; 1.4% Asian; 0.8% other), the frequency of diabetic glomerulosclerosis in renal biopsy specimens increased dramatically over the three decades (5.5%, 11.4%, and 19.1% of diagnoses, respectively; P for trend <0.001). The frequency of FSGS initially increased but then declined (22.6%, 27.2%, and 24.7%, respectively; P for trend =0.64). The frequencies of other common glomerular disease subtypes remained stable (IgA nephropathy and ANCA/pauci-immune GN) or declined (minimal change disease, membranous nephropathy, membranoproliferative GN, and lupus nephritis). These temporal trends were largely preserved within all demographic subgroups, although cross-sectional frequency distributions differed according to age, sex, and race.

CONCLUSIONS

We identified significant changes in relative renal biopsy frequencies of many glomerular disease subtypes over three decades. Temporal trends were consistently observed within all major demographic groups, although relative predominance of individual glomerular disease subtypes differed according to patient age, sex, and race. We propose that exploration of behavioral and environmental exposures that likely underlie these findings should be the focus of future hypothesis-driven research.

Minimal Change Disease

Minimal change disease (MCD) is a major cause of idiopathic nephrotic syndrome (NS), characterized by intense proteinuria leading to edema and intravascular volume depletion. In adults, it accounts for approximately 15% of patients with idiopathic NS, reaching a much higher percentage at younger ages, up to 70%-90% in children >1 year of age. In the pediatric setting, a renal biopsy is usually not performed if presentation is typical and the patient responds to therapy with oral prednisone at conventional doses. Therefore, in this setting steroid-sensitive NS can be considered synonymous with MCD. The pathologic hallmark of disease is absence of visible alterations by light microscopy and effacement of foot processes by electron microscopy. Although the cause is unknown and it is likely that different subgroups of disease recognize a different pathogenesis, immunologic dysregulation and modifications of the podocyte are thought to synergize in altering the integrity of the glomerular basement membrane and therefore determining proteinuria. The mainstay of therapy is prednisone, but steroid-sensitive forms frequently relapse and this leads to a percentage of patients requiring second-line steroid-sparing immunosuppression. The outcome is variable, but forms of MCD that respond to steroids usually do not lead to chronic renal damage, whereas forms that are unresponsive to steroids may subsequently reveal themselves as FSGS. However, in a substantial number of patients the disease is recurrent and requires long-term immunosuppression, with significant morbidity because of side effects. Recent therapeutic advances, such as the use of anti-CD20 antibodies, have provided long-term remission off-therapy and suggest new hypotheses for disease pathogenesis.

Epidemiology of Glomerular Disease in Southern Arizona: Review of 10-Year Renal Biopsy Data

Glomerulonephritis stands third in terms of the etiologies for end-stage kidney disease in the USA. The aim of this study was to look at the patterns of biopsy-proven glomerulonephritis based on data from a single center.Kidney biopsy specimens of all patients above the age of 18 years, over a 10-year period, who had diagnosis of nondiabetic glomerular disease, were selected for the study.The most common histopathological diagnosis was focal and segmental glomerulosclerosis (FSGS) (22.25%, 158/710) followed by membranous nephropathy (20.28%, 144/710) and immunoglobulin (Ig)A nephropathy (19.71%, 140/710). There was male preponderance in all histological variants except IgA nephropathy, lupus nephritis, and pauci-immune glomerulonephritis. The race distribution was uneven, and all histological variants, except minimal change disease and lupus nephritis, were more commonly seen in whites. In a separate analysis of the histological pattern in Hispanics, lupus nephritis was the most common pathology (28.70%, 62/216) followed by FSGS (18.05%, 39/216). In American Indian population, the most common pathology was IgA nephropathy (33.33%, 8/24) followed by FSGS (16.67%, 4/24).This study highlights the histopathological patterns of glomerular disease in southern Arizona. The data suggest regional and ethnic variations in glomerular disease that may point towards genetic or environmental influence in the pathogenesis of glomerular diseases.

[Idiopathic Nephrotic Syndrome: recommendations of the Nephrology Branch of the Chilean Society of Pediatrics. Part One]

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. 80 to 90% of cases respond to steroids (steroid-sensitive nephrotic syndrome) with good prognosis and long-term preservation of renal function over time. 70% of patients with SSNS have one or more relapses in their evolution, and of these, 50% behave as frequent relapsing or steroid-dependent, a group that concentrate the risk of steroid toxicity. Patients with steroid-resistant nephrotic syndrome have a poor prognosis and 50% of them evolve to end-stage renal disease. The goal of therapy is to induce and maintain remission of the disease, reducing the risk secondary to proteinuria while minimizing the adverse effects of treatments, especially with prolonged use of corticosteroids. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric SNI. In this first part, recommendations of steroid-sensitive nephrotic syndrome are discussed.

Spectrum of steroid-resistant and congenital nephrotic syndrome in children: the PodoNet registry cohort

BACKGROUND AND OBJECTIVES

Steroid-resistant nephrotic syndrome is a rare kidney disease involving either immune-mediated or genetic alterations of podocyte structure and function. The rare nature, heterogeneity, and slow evolution of the disorder are major obstacles to systematic genotype-phenotype, intervention, and outcome studies, hampering the development of evidence-based diagnostic and therapeutic concepts. To overcome these limitations, the PodoNet Consortium has created an international registry for congenital nephrotic syndrome and childhood-onset steroid-resistant nephrotic syndrome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Since August of 2009, clinical, biochemical, genetic, and histopathologic information was collected both retrospectively and prospectively from 1655 patients with childhood-onset steroid-resistant nephrotic syndrome, congenital nephrotic syndrome, or persistent subnephrotic proteinuria of likely genetic origin at 67 centers in 21 countries through an online portal.

RESULTS

Steroid-resistant nephrotic syndrome manifested in the first 5 years of life in 64% of the patients. Congenital nephrotic syndrome accounted for 6% of all patients. Extrarenal abnormalities were reported in 17% of patients. The most common histopathologic diagnoses were FSGS (56%), minimal change nephropathy (21%), and mesangioproliferative GN (12%). Mutation screening was performed in 1174 patients, and a genetic disease cause was identified in 23.6% of the screened patients. Among 14 genes with reported mutations, abnormalities in NPHS2 (n=138), WT1 (n=48), and NPHS1 (n=41) were most commonly identified. The proportion of patients with a genetic disease cause decreased with increasing manifestation age: from 66% in congenital nephrotic syndrome to 15%-16% in schoolchildren and adolescents. Among various intensified immunosuppressive therapy protocols, calcineurin inhibitors and rituximab yielded consistently high response rates, with 40%-45% of patients achieving complete remission. Confirmation of a genetic diagnosis but not the histopathologic disease type was strongly predictive of intensified immunosuppressive therapy responsiveness. Post-transplant disease recurrence was noted in 25.8% of patients without compared with 4.5% (n=4) of patients with a genetic diagnosis.

CONCLUSIONS

The PodoNet cohort may serve as a source of reference for future clinical and genetic research in this rare but significant kidney disease.

Comparison of characteristics of chronic kidney diseases between Tibet plateau and plain areas

BACKGROUND

The purpose of the current study was to investigate the pathological characteristics of chronic kidney diseases in the Tibet plateau and the plain.

METHODS

77 cases from the Tibet plateau and 154 cases from the plain of renal biopsied patients with chronic kidney diseases were compared in a randomized, and parallel controlled manner. Pathological characteristics were defined according to the standards of WHO and associated classifications.

RESULTS

The ration of sex was shown that most of patients in the plateau region were female, whereas those in the plain were male. The characteristics of pathological types were shown that the patients in the plateau region were primarily minimal change disease, but IgA nephropathy was rare; meanwhile, the proportional lupus nephritis (LN) ratio of the secondary glomerulonephritis in the plateau region was significantly lower than those in the plain region.

CONCLUSIONS

The current data demonstrated that the most common kidney disease in the Tibet Plateau region is still the primary glomerulonephritis as the same as those in the plain region. However, the primary glomerular disease in the plateau region is minimal change disease, and the most common clinical manifestations are the nephrotic syndrome. The IgA nephropathy in the plain is the most frequent disease. In terms of the secondary renal diseases, Henoch-Schnolein purpura nephritis are dominated in the plateau region, whereas LN-based diseases are frequently found in the plain. There is a statistical significance existed between those two groups.

Kidney Biopsy: An Experience from Tertiary Hospital

INTRODUCTION

Kidney Biopsy is an important diagnostic tool in Nephrology. It is useful in Nephrology in terms of diagnosis, prognosis and management. There is little information on renal biopsy data from central Nepal. We describe our center`s experience in kidney biopsy in term of histological patterns, complications and outcomes.

METHODS

We prospectively analyzed the biopsies data of patients over a period of one and half year. All kinds of kidney disease patients were included for kidney biopsy, irrespective of their clinical syndromes and underlying diagnosis.

RESULTS

A total of 75 biopsies were analyzed. Majority of them were females; 42 (56%). Most of the biopsies; 63 (84%) were from younger subjects ≤ 45 years and majority of them fell in the age group 11-20 years. Most common clinical renal syndrome to undergo biopsy was Sub Nephrotic range Proteinuria in 40 (53.3%). Among comorbid conditions, 40 (53.3%) had Hypertension. The most common histological pattern seen was Mesangial proliferative Glomerulonephritis seen in 18 (24%). Among complications associated with the procedure, macroscopic hematuria was seen in 5 (6.7%) cases and clinically significant perinephric hematoma causing pain was seen in 4 (5.3%). There was no mortality associated with biopsy procedure.

CONCLUSIONS

Sub Nephrotic range Proteinuria was the commonest clinical renal Syndrome observed. In terms of renal histology, Mesangial Proliferative Glomerulonephritis (MesPGN) was the commonest histological pattern observed. Kidney biopsy is a safe procedure without any significant adverse events.

Mutational analysis of ACTN4, encoding α-actinin 4, in patients with focal segmental glomerulosclerosis using HRM method

α-Actinin 4, encoded by ACTN4, is an F-actin crosslinking protein which belongs to the spectrin gene superfamily. It has a head-to-tail homodimer structure with three main domains. Mutations in ACTN4 are associated with idiopathic nephrotic syndrome (NS). However, until today only a few mutations have been described in this gene. We used genomic DNA of 48 patients with focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) to screen for ACTN4 mutations by high-resolution melting analysis (HRM). Suspect samples were sequenced and compared with healthy controls. To investigate the prevalence and possible effect of some substitutions found in FSGS/MCD patients we also looked for these changes in patients with IgA nephropathy (IgAN) and membranous glomerulonephritis (MGN). We found 20 exonic and intronic substitutions in the group of 48 Czech patients. The substitution 2242A>G (p.Asn748Asp) is a candidate mutation which was identified in one patient but not in any of the 200 healthy controls. Exon 19 seems to be a variable region due to the amount of revealed polymorphisms. In this region we also found three unreported substitutions in IgAN patients, c.2351C>T (p.Ala784Val), c.2378G>A (p.Cys793Tyr) and c.2393G>A (p.Gly798Asp). These substitutions were not found in any tested healthy controls. To conclude, the ACTN4 mutations are not a frequent cause of FSGS/MCD in Czech adult patients. One new ACTN4 mutation has been identified.

Coexistent findings of renal glomerular disease with Hashimoto's thyroiditis

AIM AND BACKGROUND

Hashimoto's thyroiditis (HT) is a common autoimmune thyroid disease with a female preponderance. Renal involvement in HT is not uncommon. In the present study, we aimed to define the frequency and characteristics of the glomerular diseases associated with HT and further the understanding of any common pathogenesis between HT and glomerular disease.

MATERIALS AND METHODS

We reviewed retrospectively 28 patients with HT who were referred to our Department because of unexplained haematuria, proteinuria or renal impairment from 2007 to 2011. Routine laboratory investigations including blood count, serum biochemistry, urinalysis and 24-h urinary protein excretion were performed on all patients. Renal biopsy was performed in 20 patients with HT, and the specimens were examined by light microscopy and immunofluorescence staining.

RESULTS

We detected four cases of focal segmental glomerulosclerosis (FSGS), four membranous glomerulonephritis (MGN), two minimal-change disease (MCD), three immunoglobulin A nephritis (IgAN), three chronic glomerulonephritis (CGN) and one amyloidosis. In three patients, the renal biopsy findings were nonspecific. Daily urinary protein excretion and glomerular filtration rates were found to be independent of the level of thyroid hormone and thyroid-specific autoantibodies.

CONCLUSION

Glomerular pathologies associated with HT are similar to those in the general population, the most common lesions being MGN, FSGS and IgA nephritis.

Minimal change disease, the leading cause of glomerulopathies in paediatric population at Peshawar

BACKGROUND

Glomerulonephritis (GN) is a relatively rare disease with numerous subtypes. Most regional nephrology centres see only a limited number of patients with each type of GN every year. The objective of this study was to find out the pattern of glomerulopathies in paediatric population, undergoing renal biopsy in Peshawar.

METHODS

This was a prospective study carried out at the Department of Nephrology, Khyber Teaching Hospital, Peshawar from May 2002 to May 2004. Ultrasound guided percutanous renal biopsies were carried out in patients with the findings of: 1) Nephrotic range proteinuria in children, 2) Non-nephrotic range proteinuria with evidence of hypertension/haematuria/deranged renal function or active sediments on urine microscopy, 3) Steroid resistant nephrotic syndrome in children, and 4) Children with nephrotic syndrome who were not tolerant of steroid therapy or were considered for immunosuppressive drugs.

RESULTS

A total of 155 renal biopsies were taken. Out of these 90 were male patients and 65 were female. The most common histopathological lesion among children population was Minimal Change Disease (42.66%) followed by Focal Segmental Glomerulosclerosis (25.33%) and Membranous Glomerulonephritis (16.0%). Nephrotic range proteinuria was most prevalent in Minimal Change Disease and Membranous Glomerulonephritis followed by Focal Segmental Glomerulosclerosis. Non-nephrotic range proteinuria was mostly seen in patients with Membranoprolifirative Glomerulonephritis.

CONCLUSION

In paediatric population, Minimal Change Disease is the most commonly encountered glomerulopathy, followed by Focal Segmental Glomerulosclerosis and Membranous Glomerulonephritis.

Pathology of nondiabetic glomerular disease among adult Iraqi patients from a single center

Almost all forms of glomerular diseases have been reported in diabetics. In a recent series, 12% of those with type I and 27% of those with type II diabetes were found to have non diabetic renal disease. We studied 80 adult diabetic Iraqi patients who were diagnosed with glomerular disease on native kidney biopsies from January 2000 to April 2008. Membranoproliferative GN was seen in 32 patients (40%), focal and segmental glomerulosclerosis in 16 patients (20%), membranous nephropathy in 20 patients (25%), minimal change disease in 8 patients (10%), renal amyloidosis in 4 patients (5%). In conclusion Membranoproliferative GN was the most common histological diagnosis in our diabetic patients undergoing renal biopsy.

Childhood primary glomerular diseases in the western region of Saudi Arabia

We report our institute experience on primary glomerular disease in children in the western region of Saudi Arabia over the last 18 years (1988 to 2006). A total of 169 cases were identified as primary glomerular diseases in children and adolescent with age range from first year of life till 18 years. Minimal change disease and focal segmental glomerulosclerosis were the commonly encountered primary glomerular diseases (20.1%and 19.5% respectively), mesangioproliferative glomerulonephritis IgM nephropathy (14.8%), IgA nephropathy (10.7%), postinfectious glomerulonephritis (9.5%), membranous glomerulonephritis (7.1%), membranoproliferative glomerulonephritis (5.9%) and mesangioproliferative glomerulonephritis with negative immunofluorescence (5.9%). The less frequently encountered primary glomerular diseases were congenital nephritic syndrome Finnish type (2.4%), Alport syndrome (2.4%), dense deposit disease (1.2%), and mesangio-proliferative glomerulonephritis with IgG positive (0.6%). We concluded that minimal change disease and focal segmental glomerulosclerosis are the most common primary glomerular disorder en-countered in children in our series and with similar age distribution.

Renal histological findings in adults in Jamaica

BACKGROUND

In 2006, it was reported that Focal and Segmental Glomerulosclerosis (FSGS), Minimal Change Disease (MCD) and Membranous Glomerulonephritis (MGN) were the commonest primary glomerular diseases identified from percutaneous kidney biopsies done in Jamaica for that year (n = 76). The sample size was thought to be small and might have affected the reported findings. So a three-year review of percutaneous kidney biopsies in Jamaica was carried out.

METHODS

Histology reports and clinical data were reviewed for percutaneous kidney biopsies performed from January 2005 to December 2007. Demographic data (age, gender), laboratory investigations such as serum urea, serum creatinine, proteinuria, haematuria, 24-hour urinary protein, and creatinine clearance, and clinical diagnosis were collected from the histology requisition form.

RESULTS

There was a total of 224 native kidney biopsies performed. There were 91 males (40.6%) and 133females (59.4%). Age distribution showed a total number of 25 paediatric cases (11.2%) and 199 adult cases (88.8%). Proteinuria was present in 171 cases (76.3%) and haematuria in 86 cases (38.4%). Of the total biopsies done, 78 cases (39.2%) had primary glomerular diseases, 110 cases (55.3%) had secondary glomerular diseases and 11 (5.5%) biopsies were reported as either normal or inadequate for histological diagnosis. The most common reasons indicated for percutaneous kidney biopsy were proteinuria, haematuria and staging of lupus nephritis. Most common histological findings for primary glomerular disease after percutaneous kidney biopsy were FSGS (n = 34), MGN (n = 15) and MCD (n = 12). In secondary glomerular diseases (n = 110), there were more females (70.8%) than males. Systemic lupus erythematosus was present in 63.3%. Histology of lupus nephritis according to the International Society of Nephrologists classification shows Membranous Lupus Nephritis [MLN] (40.20%), Diffuse Lupus Nephritis [DLN] (19.5%) and Minimal Mesangial Lupus Nephritis [MMLN] (14.3%) as the common histological types.

CONCLUSIONS

The most common histological finding for primary glomerular disease following percutaneous kidney biopsy was FSGS, MCD and MGN. Membranous Lupus Nephritis was the commonest histological type for lupus nephritis in this series.

[Primary glomerulopathies in Lithuania: a retrospective analysis of renal biopsy cases (2000-2006)]

A retrospective study of 1363 native kidney biopsies, performed at Lithuanian nephrology units and investigated at the National Center of Pathology during the period of 2000-2006, was carried out. Inflammatory glomerulopathies constituted 63.6% of all primary glomerulopathies (834 cases); IgA nephropathy was the most frequent disease (35.0%). The incidence of membranoproliferative glomerulonephritis decreased from 22.6% reported in Lithuania previously (1995-1999) to 16.7% in this study; however, it was still higher compared to most European countries. Extracapillary proliferative glomerulonephritis and diffuse endocapillary proliferative glomerulonephritis accounted for 9.1% and 4.4%, respectively. Noninflammatory glomerulopathies were relatively rare: focal and segmental glomerulosclerosis made up 14.8%; minimal change disease, 9.7%; membranous nephropathy, 7.4%. However, their incidence increased compared to the previously reported in 1995-1999 (9.5%, 5.8%, and 4.3%, respectively). It can be concluded that inflammatory glomerulopathies were predominant in Lithuania in 2000-2006; however, these glomerulopathies were less prominent as compared to the previously reported data in 1995-1999.

Minimal change nephrotic syndrome and classical Hodgkin's lymphoma: Report of 21 cases and review of the literature

Minimal change nephrotic syndrome (MCNS) is described as a paraneoplastic manifestation of classical Hodgkin's lymphoma (cHL). We reassessed the pathophysiological and clinical significance of this association. A retrospective study was performed to evaluate a cohort of adult patients who developed MCNS and cHL. Twenty-one patients recruited in 15 French centers were analyzed. cHL was associated with inflammatory and general symptoms in most cases. The morphological subtype was predominantly nodular sclerosis (71.4%). MCNS appeared before the diagnosis of lymphoma in eight patients (38.1%) and in this case, it was characterized by a nephrotic syndrome (NS) frequently resistant (50%) or dependent (12.5%) to steroid treatment. Interestingly, diagnosis (3-120 months after MCNS) and effective treatment of the hemopathy were associated with the disappearance of the MCNS. cHL was diagnosed before MCNS in nine patients (42.9%), and in this case, glomerulopathy was associated with cHL relapse in 55.5% of cases. In four patients (19%), the two diseases occurred simultaneously. Extensive immunohistochemical study of lymph nodes was performed in eight patients and did not reveal particular features. In conclusion, MCNS associated with cHL is frequently dependent or resistant to steroid regimen, but remission of NS is obtained with the cure of lymphoma.

Thin glomerular basement membrane nephropathy: incidence in 3471 consecutive renal biopsies examined by electron microscopy

CONTEXT

Thin glomerular basement membrane (GBM) nephropathy is often equated with benign familial hematuria, although it may occur sporadically and may not always be benign. Thin GBM nephropathy is reported to occur in at least 1% of the population, although its reported incidence varies considerably in different studies because there are presently no uniform criteria for its diagnosis by electron microscopy (EM).

OBJECTIVE

To determine the incidence of thin GBM nephropathy in a large sample of renal biopsies using a basic methodology that can easily be applied in any diagnostic EM laboratory.

DESIGN

Direct measurements of GBM thickness were made from electron micrographs at 3 specified points along each of 10 randomly selected glomerular capillaries to determine an average GBM thickness for each of 50 males and 50 females, ages 9 to 80 years, with minimal-change nephropathy or acute interstitial nephritis, without hematuria. The means of the average GBM thickness values were 330 +/- 50 (SD) nm in the males and 305 +/- 45 nm in the females; normal ranges for each sex were defined as being within 2 SD of these means. The average GBM thickness was then similarly determined for renal biopsies with suspected thin GBMs examined from January 2000 to December 2004; a total of 3471 renal biopsies were examined by EM during this period.

SETTING

Academic medical center renal pathology/EM laboratory.

RESULTS

Excluding biopsies with immunoglobulin A nephropathy, which is known to be frequently associated with thin GBMs, and biopsies with Alport syndrome, 67 biopsies (1.9% of total) had an average GBM thickness below the sex-specific normal range. Of these, 37 biopsies were performed specifically because of hematuria and had an average GBM thickness of 121 to 215 nm (mean, 185 +/- 20 nm). The remaining 30 (0.9%) biopsies, with average GBM thicknesses of 143 to 227 nm (mean, 190 +/- 20 nm), represent cases of incidentally discovered thin GBM nephropathy.

CONCLUSIONS

Based on the frequency of incidentally discovered cases and taking into account excluded cases and biopsies (eg, with diabetic nephropathy) in which diagnosis of incidental thin GBM nephropathy by EM is not possible, the incidence of thin GBM nephropathy in our population is estimated to be between 1% and 2%. Diseases most often associated with incidental thin GBM nephropathy were focal segmental glomerulosclerosis (10 cases) and minimal-change nephropathy (5 cases).

Reduced bone mineral density in adults treated with high-dose corticosteroids for childhood nephrotic syndrome

BACKGROUND

Children with minimal change nephrotic syndrome (MCNS) receive repeated courses of high dose oral prednisolone. No previous study has investigated the impact of this on final bone mineral density (BMD). Young adults previously reported in a large follow-up study of children with MCNS were invited to participate in a cross-sectional study. Areal BMD (aBMD) of the spine (L1-4), left femoral neck, and total left hip was measured using dual x-ray absorptiometry (DXA), and volumetric BMD (vBMD) of the distal radius was measured by pQCT. BMD results were compared with reference data provided by the manufacturers of the densitometers.

METHODS

Thirty-four (24 male) of the original cohort of 62 participated in the study. The mean (SD) final height Z score of the cohort was -0.45 (0.92) (P = 0.007) and mean BMI Z score 1.62 (1.53) (P < 0.0001).

RESULTS

There was a highly significant reduction in distal radial trabecular vBMD; the mean Z score was -0.95 (0.99) and T score -1.04 (1.01) (both P < 0.0001); however, there was no reduction in distal radial total vBMD, the mean Z score being 0.00 (0.95) and T score -0.08 (0.99), (P = 0.99 and 0.66, respectively). The aBMD of the lumbar spine and femoral neck also showed a reduction in T scores [-0.45 (1.27), P = 0.045 and -0.49 (0.86), P = 0.002, respectively], but not Z scores [-0.37 (1.28) and -0.15 (0.87), respectively, both P = NS]. Total hip aBMD was not different from the control population.

CONCLUSION

Adult survivors of childhood MCNS have a significant reduction in forearm trabecular vBMD, placing them at increased fracture risk at this site.

Increased endothelin 1 expression in adult-onset minimal change nephropathy with acute renal failure

BACKGROUND

Acute renal failure (ARF) occurs in some adult patients with minimal change nephropathy (MCN). To investigate clinical and pathological factors associated with developing ARF, we compared clinical features and kidney pathological characteristics of endothelin 1 (ET-1) expression in patients with adult-onset MCN with and without ARF.

METHODS

The patient population consisted of 53 patients consecutively diagnosed with adult-onset MCN during a 10-year period. Based on creatinine clearance, 25 patients were assigned to the ARF group and 28 patients were assigned to the non-ARF group.

RESULTS

Clinical data show that the ARF group had a higher blood pressure, higher serum cholesterol level, and lower serum albumin level than the non-ARF group. Pathological data showed more severe foot-process effacement, interstitial edema, and flattened tubular epithelium in the same group. Greater ET-1 expression was detected in vessels, tubules, and glomeruli of the ARF compared with non-ARF group. The ARF group experienced a lower steroid response rate. However, there was no significant difference in stability of remission to steroid treatment in patients who achieved a remission.

CONCLUSION

ARF associated with enhanced kidney ET-1 expression is a reversible complication of MCN that occurs frequently in patients with apparently expanded extracellular fluid. Presumptively, ARF may develop as an amplification of the underlying pathogenesis of MCN involved in enhanced ET-1 expression, which may be superimposed by a transient episode of circulatory insufficiency during diuretic treatment.

Primary glomerular diseases in Brazil (1979-1999): is the frequency of focal and segmental glomerulosclerosis increasing?

AIMS

Different patterns of glomerulonephritis (GN) are reported from all over the world and the occurrence of primary GN is changing in the course of time. We report the frequencies of primary GN in a major teaching hospital in Brazil, from 1979-1999.

METHODS

The case files of renal biopsies of primary GN were reviewed. The included patients were > 14 years of age, with native kidneys, and the specimens were examined with at least light and immunofluorescence microscopy. We excluded biopsy results of patients with any kind of known secondary glomerular involvement. Differences in proportions of diagnoses between the periods over time were evaluated using Chi-square test for trend.

RESULTS

We considered 943 patients for the analysis. Focal and segmental glomerulosclerosis (FSGS) was the most common lesion (n = 279), followed by membranous GN (n = 140), membranoproliferative type I GN (n = 109) and IgA nephropathy (n = 109). FSGS (32.1%) was the most frequent diagnosis among nephrotic patients whereas IgAN (29.4%) predominated in non-nephrotic ones. The occurrence of FSGS increased from the earlier to the later periods: 22.3% (1979-1983), 23.7% (1984-1988), 35.7% (1989-1993), 33.9% (1994-1999), p < 0.05. The increase in frequency of FSGS was proportionally higher in non-nephrotic patients and FSGS became as common as IgA nephropathy in this group (31.6% and 28.0%, respectively) from 1994-1999.

CONCLUSIONS

FSGS was the most common pattern of primary glomerulonephritis and its relative frequency seems to be increasing in biopsied patients over time. The reasons for this behavior are unclear and warrant further investigations.

Renal and thymic pathology in thymoma-associated nephropathy: report of 21 cases and review of the literature

BACKGROUND

Acquired thymic disease (malignant thymoma or thymic hyperplasia) is associated with various autoimmune diseases, such as myasthenia gravis (MG), pure red-cell aplasia (PRCA), pemphigus vulgaris or systemic lupus erythematosus (SLE). Renal disease has rarely been observed in association with thymoma.

METHODS

This retrospective, multicentric study collected data on patients with thymic disease and biopsy-proven renal involvement.

RESULTS

Twenty-one patients were studied (age: 49+/-14 years; male/female ratio: 8/13). Thymic pathology revealed mostly high-grade malignant thymoma (B2 and AB type); two cases were associated with non-malignant thymic hyperplasia. MG was found in nine out of 21 cases, SLE in three, PRCA in three and pemphigus in two. In 47% of these cases, nephropathy occurred after curative treatment of thymoma (108+/-83 months; range: 8-180 months), mainly based on surgical thymectomy associated with radiotherapy. Clinical and laboratory findings included nephrotic syndrome (75%), renal failure (50%), frequent presence of antinuclear antibodies and hypogammaglobulinaemia. Renal pathology showed minimal change disease in 14 patients and focal segmental glomerulosclerosis (FSGS) in one. Membranous nephropathy was observed in four cases, ANCA-associated glomerulonephritis in two and thrombotic microangiopathy in one. Most patients with minimal change disease or FSGS (11/13) were steroid-sensitive. Despite good response to steroids, 38% of patients died from thymoma and 17% developed end-stage renal failure.

CONCLUSIONS

Glomerulopathy can be associated with thymoma or thymic hyperplasia. The present series shows that minimal change disease is the most frequent thymoma-associated glomerular lesion and that it may occur several years after thymectomy.

Rectal cancer with paraneoplastic nephropathy: association of vascular endothelial growth factor

A patient with advanced rectal cancer was complicated by progressing proteinuria and hypoproteinemia. Low anterior resection was a procedure of choice. A surgical specimen obtained by intraoperative renal biopsy showed the findings of minimal change nephrotic syndrome. After surgery, nephropathy remitted promptly and completely. Her pre/postoperative serum level of vascular endothelial growth factor was 1,880/52.3 pg/ml, suggesting its elevation was associated with the nephropathy. Immunohistochemistry revealed strongly expressed tumor vascular endothelial cell growth factor. Minimal change nephrotic syndrome is a rare type of paraneoplastic nephropathy, and successful remission may require therapeutic resection of the underlying tumor, or administration of a vascular endothelial growth factor antagonist if the tumor is unresectable.

Increasing incidence of focal segmental glomerulosclerosis and an examination of demographic patterns

BACKGROUND

Idiopathic focal segmental glomerulosclerosis (FSGS) is one of the leading causes of the nephrotic syndrome in adults and an important cause of end-stage renal disease. Its incidence has dramatically increased in the last two decades and it is especially prevalent among black patients. The trend of FSGS incidence has not been reported beyond 1997.

METHODS

We retrospectively reviewed all renal biopsies performed at our institution between 1986 and 2002 and identified patients with diagnoses consistent with primary glomerulopathy (PG), which included: minimal-change disease (MCD), idiopathic focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MGN), IgA nephropathy (IgA), membrano-proliferative glomerulonephritis (MPGN) and mesangioproliferative glomerulonephritis. Patients with possible secondary causes for their renal disease were excluded. Clinical data at the time of biopsy and follow-up data were collected and analyzed.

RESULTS

During the period from January 1986-December 2002, 299 renal biopsies were performed and 132 patients were diagnosed with PG. FSGS was the most common form of PG representing 37.8% of all PG followed by IgA 27.3%, MGN 16.6% and MCD 9.1%. Among FSGS patients 59% were females, 64% had nephrotic range proteinuria and 54% had the nephrotic syndrome. Mean serum creatinine was 2.0 +/- 0.2 mg/dl and mean protein excretion was 6.1 +/- 1.0 g/day. The incidence of FSGS increased from 19.3% (1986-1991) and 16.6% (1992-1997) to 58.5% in the period from 2002. The increase occurred among black and Hispanic patients (33.3-79.2%) as well as white patients (12.5-51.5%). Black and Hispanic patients with PG presented for renal biopsy at a significantly younger age than white patients (p = 0.003), with mean age 37.5 +/- 2.0 years vs. 50.3 +/- 1.8 years. White FSGS patients were significantly older than white non-FSGS patients (mean age 56.4 +/- 3.2 years vs. 48.0 +/- 2.0 years, p = 0.03). Black and Hispanic FSGS patients were also older when compared to their non-FSGS counter-parts (mean age 40.6 +/- 2.8 years vs. 32.1 +/- 2.0 years, p = 0.04). When patients were stratified by age (< 45 years and > or = 45 years), FSGS was the most common diagnosis in both age groups among black and Hispanic patients (55.1% and 88.8%) but only among older white patients (36.2%).

CONCLUSIONS

The incidence of FSGS as a proportion of PG in our population has increased markedly in the most recent time period analyzed (1998-2002). The increase has occurred among both white and black and Hispanic patients. We also found that FSGS was most prevalent in patients > or = 45 years.

[The incidence of renal diseases as diagnosed by biopsy in Hungary]

AIM AND METHODS

The authors analysed the incidence of renal diseases as diagnosed by biopsy in the population living on the southern Great Hungarian Plain. 798 biopsy specimens were examined between 1990 and 2002.

RESULTS

The most common diseases in decreasing order of frequency were IgA nephropathy (15%), membranous nephropathy (12%), thin-basement-membrane nephropathy (8%), minimal change nephropathy (7%), lupus glomerulonephritis (7%), focal sclerosis (6%), hypertensive kidney disease and arteriolosclerosis (5%), diabetic nephropathy (5%), and crescentic glomerulonephritis (4%). The most frequent diseases in decreasing order of frequency in children were minimal change nephropathy, thin-basement-membrane nephropathy, Henoch-Schönlein nephropathy and IgA nephropathy; in adults were IgA nephropathy, membranous nephropathy, lupus glomerulonephritis and thin-basement-membrane nephropathy; and in the elderly were membranous nephropathy, amyloidosis, crescentic glomerulonephritis and diabetic nephropathy. The incidence of the diseases differed significantly between the genders in IgA nephropathy, thin-basement-membrane nephropathy, lupus glomerulonephritis, chronic sclerosing nephropathy and Alport nephropathy. At the time of the biopsy, 69 patients were suffering from diabetes mellitus. 37 patients were diagnosed as having diabetic nephropathy, and 32 as having non-diabetic nephropathy. In 6 cases, the diabetic nephropathy was accompanied by other glomerular disorders. In more than half of the diabetic patients with non-diabetic nephropathy, membranous nephropathy or focal sclerosis was diagnosed. Crescentic glomerulonephritis was diagnosed on 30 occasions, which was due to vasculitis in 20 cases, proliferative glomerulonephritis in 7 cases and anti-glomerular-basement-membrane nephritis in 3 cases. In the middle-aged and the elderly, the renal disease was relatively often a consequence of systemic disease.

CONCLUSION

The incidence and the gender distribution of renal diseases diagnosed by biopsy were similar to those reported by other European kidney biopsy centres. IgA nephropathy was the most frequent disease in the biopsy registry of the authors. The high incidence of thin-basement-membrane nephropathy seems to be related to consequent biopsy examinations of glomerular haematuria. In diabetics and the elderly, the diagnosis of the renal disease may be challenging.

[Renal function in subjects with minimal change steroid-responsive nephrotic syndrome in childhood]

Steroid-responsive idiopathic nephrotic syndrome (SRlNS) with minimal change disease (MCD) is the most common cause of nephrosis in childhood. MCD is no longer considered to be easily curable and the finding of minimal changes is no guarantee that the disease will not progress to renal failure or to another form of glomerulonephritis. In the present work, renal function was studied in subjects presenting with SRINS and MCD in childhood. Attention focused on glomerular filtration, integrity of the filtration membrane, reabsorption in the proximal tubule, and renal vessels. The influence of age, age at onset, recurrences, duration of the active phase, duration of remission, 24-hour protein loss and Up/UCr ratio on renal function was analyzed. An attempt was made to establish if patients with lasting remission require periodic follow-up by a nephrologist. The study group consisted of 31 subjects with SRINS in childhood. Remission of at least one year was ascertained at the time of study. A hyperfiltration subgroup (n=11) with creatinine clearance (Ccr) of > 150 mL/min/1.73 m2 was formed. The control group included twelve healthy volunteers matched for age and gender. Creatinine and lithium clearance, fractional lithium secretion, and the Up/UCr ratio were calculated according to standard formulas. Albumin and immunoglobulin G secretion was measured using cross-star immunofixation. Protein content in urine was determined with the method of Exton and renal vessels were imaged using Doppler USG. Significant reduction in creatinine and lithium clearance was disclosed in SRlNS patients. The reduction was proportional to the time since the last episode of the disease. Glomerular hyperfiltration was found in 35.5% of subjects. Fractional lithium secretion was higher in the study than control group. This discrepancy was particularly evident in subjects with Ccr below 120 mL/min/1.73 m2. In 40% of subjects, mild selective proteinuria was confirmed which did not correlate with renal function. Renal vessels were free of thrombo-embolic lesions.

CONCLUSIONS

1. Deterioration of renal filtration proportional to the time since the last episode of nephrosis was diagnosed in subjects treated for SRINS in childhood. Hyperfiltration revealed in 1/3 of subjects may be associated with a poorer prognosis. 2. Abnormal tubular reabsorption was observed solely in subjects with Ccr below 120 mL/ min/1.73 m2. 3. Mild selective proteinuria was without any effect on renal function. 4. MCD had no long-term effect on renal vessels. 5. In spite of long lasting remission of SRINS with MCD in childhood, the risk of disease progression remains and follow-up is necessary.

Is there really an increase in non-minimal change nephrotic syndrome in children?

BACKGROUND

Reports on the worldwide increase in focal segmental glomerulosclerosis (FSGS) in childhood may have been hampered by referral bias. A true increase in FSGS possibly could alter the current practice of withholding renal biopsy in childhood nephrotic syndrome (NS) unless the patient fails to respond to a 28-day course of corticosteroid therapy.

METHODS

With these questions in mind, we analyzed a 17-year database covering a 275,000-child population with mandatory referral. The incidence of NS per 100,000 childhood population per year was calculated, charts of 159 patients with NS seen between 1985 and 2002 were reviewed, and a receiver operating characteristic (ROC) plot analysis was performed to analyze the diagnostic performance of remission time.

RESULTS

Results show that 115 of 159 patients had minimal change NS, diagnosed either on the basis of corticosteroid response (n = 89), verified by renal biopsy (n = 14), or with minimal change plus mesangial immunoglobulin M on histological examination (n = 12). The remaining 44 patients underwent a renal biopsy showing FSGS (n = 29; 18.2%), diffuse mesangial hypercellularity (n = 8; 5%), membranoproliferative glomerulonephritis (n = 1; 0.6%), membranous nephropathy (n = 3; 1.9%), or other diagnoses (n = 3). The incidence of FSGS increased significantly (P = 0.0253) from 0.37 to 0.94/100,000-child population/y in the two 8(1/2)-year intervals of our study. ROC plot analysis confirmed diagnostic sensitivity and specificity greater than 80% for remission time between 21 and 28 days of therapy.

CONCLUSION

We confirm the increasing incidence of FSGS in children with idiopathic NS in a well-defined catchment area and, at the same time, find no reason to change the initial therapy and current indications to perform renal biopsy in childhood NS.

[Epidemiology of chronic glomerular diseases]

Chronic glomerular diseases are the cause of 35 to 55% of end-stage renal failure, according to countries or regions. In France, the estimated annual incidence of nondiabetic glomerular nephropathies is 82 per million population. IgA deposits, membranous and minimal change glomerulopathies, and focal and segmental glomerulosclerosis are the most common; crescent proliferative glomerulonephritis has the worse prognosis. Combined patient and kidney survival varies from 24 to 62% according to histologic types. Their incidence remains relatively stable in contrast with the constant rise of type 2 diabetic nephropathy. Over the 90s, the annual incidence rate of renal replacement therapy for end-stage renal failure due to diabetes doubled in Europe, reaching 10 to 50 per million population according to the country in Europe, and 144 per million population in the United States.

Hypothesis: dysregulation of immunologic balance resulting from hygiene and socioeconomic factors may influence the epidemiology and cause of glomerulonephritis worldwide

Glomerular diseases show diverse epidemiological characteristics throughout the world, which has been suggested to be caused by differences in genetics of the underlying populations or environmental exposure to the putative antigens or agents that either trigger or induce the disease. Recently, an alteration in immune balance of the T helper 1 (T(H)1) and T helper 2 (T(H)2) subsets has been implicated as a mechanism to explain the relative increase in allergic diseases in industrialized nations. According to the Hygiene Hypothesis, overcrowding and poor hygiene early in life may protect from atopic diseases because exposure to microbes predisposes in favor of a T(H)1-dominant response. Conversely, dominance of the T(H)2 subset would be responsible for the increasing incidence of allergies. We present the hypothesis that this imbalance may help explain the predilection for membranoproliferative glomerulonephritis (GN) and mesangial proliferative GN to be associated with developing and/or poor nations, whereas immunoglobulin A nephropathy and minimal change disease are observed more commonly in industrialized nations. The implication of the Hygiene Hypothesis is that clinical expression of immune-mediated renal disease would depend on the prevailing T(H)1/T(H)2 balance, rather than the etiologic agent, and it may help explain the epidemiological pattern of glomerular diseases worldwide.

Recurrent disease in renal transplants

Histology compatible with minimal change glomerulonephritis and associated with nephrotic syndrome has been reported as an occasional curiosity post-renal transplantation. Focal segmental glomerulosclerosis (FSGS) has a recurrence rate of approximately 20%. Age <15 years, an aggressive clinical course of the original disease and diffuse mesangial proliferation on native biopsy, are considered predictive of relapse. At present there are no tests that can accurately predict the likelihood of recurrence. Data from paediatric patients whose primary disease was FSGS were, on average, 90% more likely to lose a graft from a live donor and 50% more likely to lose a graft from a cadaveric donor compared with recipients with structural disorders. Recurrence in a subsequent graft is expected if the first graft was affected, but not if the first graft did not demonstrate recurrence. The best-established and most effective treatment of recurrent disease requires both plasma exchange and cyclophosphamide. Familial focal and segmental glomerulosclerosis, although rare, is important to recognize, as it is a different syndrome to idiopathic FSGS of childhood and overall transplant survival is good. Adults with 'secondary' FSGS would not be expected to be at risk of recurrent disease in a renal transplant.

The expanding spectrum of renal diseases associated with antiphospholipid syndrome

BACKGROUND

The association of thrombotic events and/or pregnancy complications with circulating antiphospholipid antibodies defines antiphospholipid syndrome (APS). In previous reports, renal involvement in APS consisted mainly of thrombotic vascular complications involving large vessels or intrarenal small-sized vessels (APS nephropathy). We report 9 cases of glomerulonephritis associated with APS. These cases are characterized by predominant pathological features distinct from vascular APS nephropathy.

METHODS

We reviewed consecutive renal biopsies examined in 2 French university hospitals between 1980 and 2002 and identified renal biopsies performed in patients with primary APS.

RESULTS

We identified 29 biopsies performed in patients with APS. Twenty biopsies showed characteristic features of APS nephropathy. In 9 cases, predominant pathological features distinct from vascular APS nephropathy were noted: membranous nephropathy (3 cases), minimal change disease/focal segmental glomerulosclerosis (3 cases), mesangial C3 nephropathy (2 cases), and pauci-immune crescentic glomerulonephritis (1 case). In 7 cases, the presentation of renal symptoms was subacute or chronic. Two patients experienced episodes of acute renal failure. At referral, median creatinine clearance was 50 mL/min (0.83 mL/s) (range, 18 to 117 mL/min [0.30 to 1.95 mL/s]). Proteinuria was noted in all cases (range, 1.5 to 15 g/d), with nephrotic syndrome in 4 cases. Lupus anticoagulant was present in all cases, and anticardiolipin antibodies, in 8 cases. Anti-DNA antibodies repeatedly were negative in all cases. Treatment consisted of antihypertensive therapy (6 cases), anticoagulant drugs (5 cases), steroids (4 cases), and antiplatelet drugs (3 cases). At last follow-up, renal function remained stable in 7 patients. Of 2 patients presenting with acute renal failure, 1 patient recovered normal renal function, whereas the other patient progressed to end-stage renal failure.

CONCLUSION

The cases reported here represent a new aspect of the expanding spectrum of renal diseases encountered in association with APS.

Risk factors for cyclosporine-induced tubulointerstitial lesions in children with minimal change nephrotic syndrome

BACKGROUND

Cyclosporine (CsA) is effective for the treatment of children with steroid-dependent and -resistant nephrotic syndrome (NS), but it can result in chronic CsA nephrotoxicity including CsA-induced tubulointerstitial lesions. The factors responsible for the development of CsA-induced tubulointerstitial lesions are unknown.

METHODS

To identify the risk factors for the development of CsA-induced tubulointerstitial lesions in children with minimal change NS who had been treated with long-term moderate-dose CsA, we compared several clinical and laboratory factors of 37 patients with and without CsA-induced tubulointerstitial lesions by the Mann-Whitney U test, Fisher's exact test, and stepwise logistic-regression analysis.

RESULTS

Thirteen patients had CsA-induced tubulointerstitial lesions and 24 patients had none. Among clinical and laboratory factors, the duration of CsA treatment (P = 0.003) and the duration of heavy proteinuria during CsA treatment (P = 0.024) were related to the development of CsA-induced tubulointerstitial lesions as determined by the univariate analyses. Indeed, CsA-induced tubulointerstitial lesions were found in 2 of 18 (11%) patients who had been treated with CsA for less than 24 months, but in 11 of 19 patients (58%) who had been treated for more than 24 months (P = 0.005). They were also found in 4 of 23 patients (17%) who had heavy proteinuria for less than 30 days during CsA treatment, but in 9 of 14 patients (64%) who had heavy proteinuria for more than 30 days (P = 0.006). Stepwise logistic-regression analysis revealed that the duration of CsA treatment for more than 24 months (chi2 = 6.203, P = 0.013) and the duration of heavy proteinuria during CsA treatment for more than 30 days (chi2 = 5.871, P = 0.015) were independent risk factors for the development of CsA-induced tubulointerstitial lesions.

CONCLUSIONS

Duration of the CsA treatment and the duration of heavy proteinuria during CsA treatment were independent significant risk factors for the development of CsA-induced tubulointerstitial lesions in children with MCNS who had been treated with long-term moderate-dose CsA.

Pretransplant serum C-reactive protein and the risk of chronic allograft nephropathy in renal transplant recipients: a pilot case-control study

Multiple factors contribute to the development of chronic allograft nephropathy (CAN) in renal transplant recipients, and atherogenesis is considered to be an important pathologic process contributing to the development of this disease. There is growing acknowledgment of the role of inflammation in the pathogenesis of atherosclerosis, and markers of inflammation, such as C-reactive protein (CRP), have been shown to predict atherosclerotic vascular disease in the general and end-stage renal disease populations. In this pilot study, we hypothesized that elevations in pretransplant concentrations of CRP predict an increased incidence of CAN after renal transplantation. This case-control study compared pretransplant CRP levels in patients with allograft dysfunction and biopsy-proven CAN (n = 15) with a control group of transplant recipients with normal allograft function (n = 43). The median concentration of serum CRP was significantly higher in the CAN versus the control patients (13.1 +/- 3.9 mg/L versus 3.5 +/- 2.5 mg/L; P = 0.01). This difference was sustained when restricting to patients who did not experience acute rejection. When dividing the patients into tertiles based on CRP concentration, the adjusted risk of CAN increased more than threefold with each increment in CRP by tertile (adjusted odds ratio, 3.16; P = 0.03). The findings of our pilot study show an association between pretransplant elevations of CRP and CAN in end-stage renal disease patients who go on to receive a renal transplant. Cohort studies in larger groups of transplant patients are needed to confirm a causal pathway between pretransplant inflammation, atherogenesis, and CAN.

Changing trends of histopathology in childhood nephrotic syndrome in western Saudi Arabia

OBJECTIVE

It is widely accepted that minimal change nephrotic syndrome is the most common cause of nephrosis in children. Recent studies have demonstrated an increasing incidence of focal segmental glomerulosclerosis in adults and children. This study was conducted to analyze the trend of histopathologic subtypes in idiopathic nephrotic syndrome in the western area of the Kingdom of Saudi Arabia.

METHODS

To determine the possible changes in the etiology of childhood nephrosis, the clinical charts of 46 pediatric patients diagnosed with idiopathic nephrotic syndrome between 1997 and 2001, group A, were reviewed. Results were compared with our initial published data of 132 patients with idiopathic nephrotic syndrome diagnosed between 1983 and 1992, group B.

RESULTS

There was no difference in the percentage of biopsies between group A (43%) and group B (31.8%), P= 0.9. There was a decline in the incidence of minimal change nephrotic syndrome in recent years. Even if we assume that all patients without a histological diagnosis had minimal change nephrotic syndrome, presumptive minimal change nephrotic syndrome, the total incidence of minimal change nephrotic syndrome (biopsy proven + presumptive) in group A, was only 65% compared to 79.5% in group B, P=0.02. The incidence of focal segmental glomerulosclerosis was significantly greater in biopsies performed in the recent period, group A, 35% versus group B, 16.7%, P=0.05, and in the total number when we included the presumptive minimal change nephrotic syndrome, group A, 15.2% and group B, 5.3%, P<0.0001. Similarly we found an increased incidence of membranoprolifrative glomerulonephritis in total patients when we included the presumptive minimal change nephrotic syndrome, group A, 13.0% and group B, 5.3%, P=0.02.

CONCLUSION

There is a shift toward an increasing prevalence of focal segmental glomerulosclerosis and membranoprolifrative glomerulonephritis over the years in the western area of the Kingdom of Saudi Arabia. These findings may have significant implications in the management of childhood nephrotic syndrome.

Spectrum of adolescent-onset nephrotic syndrome in Indian children

There are few data regarding adolescent-onset nephrotic syndrome (NS) and no guidelines for biopsy criteria and treatment protocol. This study was conducted to analyze the clinical spectrum of adolescent-onset NS and evaluate possible biopsy criteria in these children. A prospective analysis was carried out on all patients with idiopathic NS (fulfilling the ISKDC criteria) with onset between 1 and 18 years of age. They were evaluated clinically, followed by biochemical investigations and kidney biopsy. These characteristics of patients with onset between 1 and 12 years (group A) were compared with the same parameters in patients with onset between 12 and 18 years of age (group B) referred to our hospital over the same period. Among all clinical parameters, microhematuria was significantly more prevalent in adolescents (P<0.001). Kidney biopsy was performed in 88% of adolescent patients. Focal segmental glomerulosclerosis (FSGS) was the most-common histopathology in group B (46.3%) compared with minimal change disease (MCD) in group A (42.9%). Group B had a significantly higher frequency of membranoproliferative glomerulonephritis (MPGN) (P<0.005) and a significantly lower frequency of MCD (P<0.001). The biochemical parameters at the onset were similar. On comparing microhematuria, hypertension, and renal insufficiency at presentation, we observed that two or more of these features were present in all patients with MPGN and only in 19.6% of adolescents with MCD, mesangioproliferative glomerulonephritis, and FSGS. The frequency of steroid resistance was significantly higher in group B (P<0.001). In conclusion, adolescent-onset NS differs from the childhood variety in having a significantly higher frequency of hematuria, steroid resistance, and evidence of non-MCD, especially MPGN, on histopathology. Kidney biopsy can be restricted to those adolescents who have at least two abnormal clinical/biochemical features or are steroid non-responders.

The changing pattern of glomerulonephritis in Singapore over the past two decades

This study reviews the pattern of glomerulonephritis (GN) in Singapore over the past 2 decades. In the earlier decade the pattern was typical of most Asian countries with mesangial proliferative GN (Mes GN) (56%) as the most common form of primary GN including the nephrotic syndrome (40%). In the 2nd decade the pattern undergoes a change. Though Mes GN is the commonest primary GN (42%), the commonest form of nephrotic syndrome is now minimal change disease (30%) with Mes GN decreasing to 25% among all primary nephrotic syndromes. Both minimal change and focal global sclerosis account for 50% of steroid/cyclophosphamide responsive GN today. Membranous GN though still uncommon, has increased from 3% (1st decade) to 6% (2nd decade) (p < 0.01). IgA nephritis is still the commonest primary GN occurring in Singapore (42% of all primary GN in the 1st decade and 45% in the 2nd decade). The present pattern of GN in Singapore, though, still predominantly Asian with the preponderance of mesangial proliferative GN with a relatively low incidence of membranous GN contrasts with the pattern in the West where membranous GN is the commonest form of primary GN. Even the incidence of FSGS has not increased as in the West where there is a rising incidence. The underlying basis for most GN in Singapore as in other Asian countries and elsewhere is antigen-driven: infective antigen as well as food or other allergens.

The paucity of minimal change disease in adolescents with primary nephrotic syndrome

Data are sparse regarding the histological lesions associated with the primary nephrotic syndrome in adolescents. To our knowledge there are only two published articles that have specifically addressed the histopathological lesions that typify idiopathic nephrotic syndrome in the adolescent population. We reviewed our experience from the last 14 years of children between the ages of 12 and 18 years who were referred to our center for the evaluation of the nephrotic syndrome. A total of 29 adolescents met the inclusion criteria for this review. All patients were biopsied prior to the initiation of treatment. The sex ratio consisted of 52% males and 48% females and the racial breakdown was largely African-American, with 83% black adolescents, 7% Hispanic, and 10% Caucasian patients. Minimal change nephrotic syndrome (MCNS), the predominant lesion of children at an early age, was noted in only 20% of patients. The majority of patients (55.2%) had focal segmental glomerulosclerosis (FSGS); 7% had IgM nephropathy and 3.5% had diffuse mesangial hypercellularity. Only 7% of biopsied adolescents had membranoproliferative glomerulonephritis. Our results indicate that the most common lesion in this predominantly African-American patient population is FSGS, with only a small number showing MCNS. Thus, in our experience derived from a racially mixed population, adolescents with the nephrotic syndrome are less likely to have MCNS than younger children.

Changing etiologies of unexplained adult nephrotic syndrome: a comparison of renal biopsy findings from 1976-1979 and 1995-1997

Data compiled during the 1970s and early 1980s indicated that during these periods, membranous nephropathy was the most common cause of unexplained nephrotic syndrome in adults, followed in order of frequency by minimal-change nephropathy and focal segmental glomerulosclerosis (FSGS). However, we and others recently reported an increase in the incidence of FSGS over the past two decades, and the number of cases of FSGS diagnosed by renal biopsies in these centers now exceeds the number of cases of membranous nephropathy. Nonetheless, as a substantial fraction of patients with FSGS do not have the nephrotic syndrome, it remained unclear as to what extent the relative frequencies of FSGS and other glomerulopathies as causes of the nephrotic syndrome have changed over this time. To address this concern, we reviewed data from 1,000 adult native kidney biopsies performed between January 1976 and April 1979 and from 1,000 biopsies performed between January 1995 and January 1997, identified all cases with a full-blown nephrotic syndrome of unknown etiology at the time of biopsy, and compared the relative frequencies with which specific diseases were diagnosed in these latter cases between the two time intervals. The main findings of this study were that, first, during the 1976 to 1979 period, the relative frequencies of membranous (36%) and minimal-change (23%) nephropathies and of FSGS (15%) as causes of unexplained nephrotic syndrome were similar to those observed in previous studies during the 1970s and early 1980s. In contrast, from 1995 to 1997, FSGS was the most common cause of this syndrome, accounting for 35% of cases compared with 33% for membranous nephropathy. Second, during the 1995 to 1997 period, FSGS accounted for more than 50% of cases of unexplained nephrotic syndrome in black adults and for 67% of such cases in black adults younger than 45 years. Third, although the relative frequency of nephrotic syndrome due to FSGS was two to three times higher in black than in white patients during both study periods, the frequency of FSGS increased similarly among both racial groups from the earlier to the later period. Fourth, the frequency of minimal-change nephrotic syndrome decreased from the earlier to the later study period in both black and white adults. Fifth, the relative frequency of membranoproliferative glomerulonephritis as a cause of the nephrotic syndrome declined from the 1976 to 1979 period to the 1995 to 1997 period, whereas that of immunoglobulin A nephropathy appeared to increase; the latter accounted for 14% of cases of unexplained nephrotic syndrome in white adults during the latter study period. Finally, 10% of nephrotic adults older than 44 years had AL amyloid nephropathy; none of these patients had multiple myeloma or a known paraprotein at the time of renal biopsy.

The racial prevalence of glomerular lesions in nephrotic adults

We retrospectively evaluated the prevalence of primary glomerular lesions in adults who had a renal biopsy for nephrotic proteinuria. From July 1975 to May 1994, 340 patients undergoing renal biopsies evaluated at Rush-Presbyterian-St Lukes Medical Center had the primary glomerular lesions of minimal-change disease, focal segmental glomerular sclerosis (FSGS), membranous glomerulonephritis (MGN), membranoproliferative glomerulonephropathy, immunoglobulin A nephropathy, and immunotactoid glomerulopathy. The patients had a mean age of 43 +/- 17 years, 57% were male, and 50% were white, 36% were black, 7% were of other race, and 7% were of unknown race. The distribution of lesions for black patients was minimal-change disease 14%, FSGS 57%, MGN 24%, membranoproliferative glomerulonephritis 2%, immunoglobulin A 2%, and immunotactoid glomerulopathy 1%; for white patients, the distribution of lesions was minimal-change disease 20%, FSGS 23%, MGN 36%, membranoproliferative glomerulonephropathy 6%, immunoglobulin A 8%, and immunotactoid glomerulopathy 6%. The prevalence of FSGS was significantly greater (P < 0.0001) and that for MGN, immunoglobulin A, and immunotactoid glomerulopathy was significantly less (P < 0.05) for black patients compared with white patients. In a logistic regression analysis, race remained the only significant predictor of FSGS (P = 0.0001), with black patients four times as likely to have FSGS as white patients. The distribution of lesions among white patients was similar based on gender, age, and biopsy period. For black patients the distribution was also similar based on gender and age, but over 20 years the incidence of FSGS increased from 39% (1975 to 1984) to 64% (1985 to 1994) (P < 0.01). Thus, significant racial differences in the distribution of primary glomerular lesions exists. This has important prognostic and therapeutic implications for nephrotic adults.

Increasing incidence of focal-segmental glomerulosclerosis among adult nephropathies: a 20-year renal biopsy study

Studies and textbooks from the 1970s and early 1980s list focal-segmental glomerulosclerosis (FSGS) as accounting for 10% to 15% of cases of idiopathic nephrotic syndrome in adults, although a recent review by D'Agati (Kidney Int 46:1223-1241, 1994) reported an approximately sevenfold increase in the incidence of FSGS from 1974 to 1993 in an active renal biopsy practice. To investigate possible changes in the incidence of FSGS in our renal biopsy practice, we reviewed reports from all nontransplant, adult (> or = 18 years) renal biopsies received in our laboratory from 1974 to 1993, which comprised 7,420 cases. All diagnoses of membranous nephropathy (MN), minimal change nephropathy (MCN), and FSGS made in each year were compiled; cases clearly or suspicious of being secondary to an underlying systemic disease, glomerulonephritis, or drug reaction were excluded. Relative frequencies of MN, MCN, and FSGS among these three diseases and among all biopsies were calculated for each year of the study. Regression analysis showed a significant (P < 0.001) increase in the odds of a diagnosis of FSGS over the study period: 7.6% per year among all biopsies and 6.8% per year among cases of MN, MCN, and FSGS only. Among all biopsies, the yearly incidence of FSGS increased from 4.0% +/- 0.6% (mean +/- SD) during the period between 1974 and 1979 to 12.2% +/- 2.0% during the period from 1987 to 1993. The odds of a diagnosis of MN (mean yearly incidence, 9.5% +/- 1.9%) did not vary significantly over the study period while the odds of a diagnosis of MCN (mean yearly incidence, 4.0% +/- 1.2%) declined at a rate of 2.2% per year (P < 0.03). Frequencies of diagnosis of MN, MCN, and FSGS by two pathologists were almost identical. Review of available slides from cases of FSGS revealed 21 (none before 1980) with characteristic histologic features of the collapsing glomerulopathy (CG) variant of FSGS. No more than four cases of CG were observed in any year of the study, and CG accounted for 4.7% of total FSGS cases for which diagnostic slides were available. Compared with 42 patients with non-CG FSGS, the CG cohort showed a greater percentage of black patients (86% v 38%), significantly higher mean levels of serum creatinine (3.8 +/- 2.7 mg/dL v 1.9 +/- 1.5 mg/dL) and urinary protein (14.3 +/- 9.6 g/24 hr v 7.7 +/- 5.8 g/24 hr) at the time of renal biopsy, and a greater likelihood of and more rapid progression to end-stage renal failure.(ABSTRACT TRUNCATED AT 400 WORDS)