Renal biopsy findings in Iran: case series report from a referral kidney center

Spectrum and Distribution of Biopsy-proven Kidney Diseases: A 12-year Survey of a Single Center in Iran

Data about the prevalence of biopsy-proven kidney diseases in Iran are rare, and none of the previous studies used electron microscopy for diagnosis. This study aimed to analyze the prevalence of biopsy-proven kidney diseases in Iran's primary referral center. To the best of our knowledge, this is the most extensive study carried out in Iran. Reports of kidney biopsy samples from patients referred to our center in 2007-2018 were reviewed for demographic data, clinical presentation, and final diagnosis. Statistical analyses were performed. Among the 3455 samples received, 2975 were analyzed. Nephrotic syndrome (39%) was the most common cause of biopsy, followed by subnephrotic proteinuria (18%), hematuria in association with proteinuria (15%), renal failure (9%), isolated hematuria (6%), and lupus nephritis (LN) (4%). The most common diagnoses were membranous glomerulonephritis (17.9%), focal segmental glomerulosclerosis (FSGS) (15.9%), LN (13.7%), minimal histopathological findings (unsampled FSGS vs. minimal change disease, 12.1%), Immunoglobin A nephropathy (IgAN) (6.5%) and Alport syndrome (6.1%). NS and proteinuria were the most common indications for a kidney biopsy. IgAN and LN were the most common causes of primary and secondary glomerulonephritis, presenting with hematuria and proteinuria, respectively. Although membranous glomerulonephritis was the most common disease, it has been replaced by FSGS in recent years.

Clinicopathological spectrum of biopsy-proven renal diseases of patients at a single center in Sri Lanka: a cross sectional retrospective review

BACKGROUND

The clinical presentation of renal diseases can vary widely. The lack of a comprehensive national registry for Sri Lanka makes it difficult to provide a detailed record of the various clinical presentations and histopathology of renal disorders in the nation. Therefore, this study aims to provide a record of the spectrum of renal diseases in Sri Lanka.

METHODS

Renal biopsies performed at the nephrology unit in Colombo South Teaching Hospital (CSTH), Sri Lanka from March 2018 to October 2019 was retrospectively studied. Indications for renal biopsy were nephrotic range proteinuria, sub nephrotic range proteinuria, acute kidney injury without obvious etiology, chronic renal disease without obvious etiology and haematuria.

RESULTS

A total of 140 native kidney biopsies were analyzed in which majority were females (55.7%). The mean age of the population was 46 ± 15.3 years. The most common indications for renal biopsy were nephrotic range proteinuria (54.3%), followed by sub-nephrotic range proteinuria (14.3%), nephrotic range proteinuria with haematuria (14.3%), sub-nephrotic range proteinuria with haematuria (9.3%), AKI without known cause (4.3%), and CKD without known cause (3.6%). The leading histopathological diagnoses were FSGS (22.1%), lupus nephritis (20%), PSGN (17.1%), DN (12.1%), HTN (9.3%), MCD (6.4%), IgA nephropathy (5.7%), IN (4.3%), vasculitis (2.1%), and MGN (0.7%).

CONCLUSIONS

The most common indication for renal biopsy was nephrotic range proteinuria in our population. FSGS was the most prevalent histopathological diagnosis and the least frequent diagnosis reported was MGN. The spectrum of renal diseases could differ according to the study location and it changes over time. Therefore, a renal biopsy registry is needed for documenting the changing disease pattern in Sri Lanka.

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.

Glomerular Diseases in the Colombian Caribbean: Data from the Colombian Nephropathy Registry (NEFRORED®)

Our study aimed to describe the glomerular diseases, both primary glomerular disease (PGD) and secondary glomerular disease (SGD) in the Colombian Caribbean based on the first regional Colombian Nephropathy Registry (NEFRORED®). A descriptive and retrospective study of adult patients with glomerular diseases from the Colombian Caribbean region was made. All diagnoses by renal biopsy with light microscopy and immunofluorescence obtained between January 2008 and June 2018 were recorded. Eight hundred and seventy-one renal biopsies were obtained. The main clinical indication for biopsy was nephritic syndrome (36%). SGD was more frequent than PGD (55% vs. 45%). Within SGD group, lupus nephritis (LN) was the most frequent etiology (83%). Within PGD group, membranous nephropathy (33%) and focal segmental glomerulosclerosis (FSGS) (19%) were the most common glomerular diseases. At a 24-month follow-up, the patients with FSGS and paraproteinemia-mediated glomerular disease had the worst renal survival prognosis. This is the first Colombian Nephropathy Registry in a Caribbean population, demonstrating a high predominance of SGD due to LN.

Pattern of kidney diseases in Northern India: an overview through histopathological findings in biopsy-proven cases

Background

A kidney biopsy is being increasingly performed for the diagnosis of renal diseases. It is a reasonably safe procedure that helps not only to reach the correct diagnosis based on histopathological findings but also helps in predicting the clinical course and outcome. The pattern of kidney diseases varies not only in far apart geographical regions but also in the same country. This study was done to evaluate the demographic pattern and spectrum of kidney diseases in renal biopsy-proven cases in an admitted patient of a tertiary care hospital of northern India.

Results

The mean age of patients was 41.3 years ± 18.39 years, and the male-to-female ratio was 1.7:1. The most common indication for biopsy in this study was nephrotic syndrome (40.5%). The primary glomerular disease was most common, accounting for 57.5% of cases. Membranous nephropathy (MN) was the most frequently observed histopathological diagnosis not only in the primary glomerular disease category (22.9%) but of all cases (13.2%) as well. Among secondary cases, diabetic nephropathy was most frequent, constituting 43.4% cases. Interstitial and vascular diseases accounted for 18.8% and 1.8% of total cases, respectively. While minimal change disease (MCD) was the most common diagnosis in < 18-year age group, membranous nephropathy was most common above this age. Regarding the gender factor, membranoproliferative glomerulonephritis had an equal distribution among both genders, while MCD had a female preponderance.

Conclusions

Primary glomerular disease is the predominant kidney disease in northern India with MN being the most common histopathological diagnosis. The spectrum of kidney diseases varied with patient’s age and gender.

Epidemiology of IgA Nephropathy: A Global Perspective

IgA nephropathy (IgAN), or Berger's disease, is the most common primary glomerular disease worldwide, but varies largely in its geographic distribution. A systematic review of 1,619 publications from the five continental regions of the world was performed to assess the prevalence of IgAN in different worldwide regions and analyze factors responsible for geographic differences. All observational studies that described the prevalence and incidence data on glomerulonephritis were considered. IgAN is more frequent in Asian populations (45 cases per million population/y in Japan) than in Caucasians (31 cases per million population/y in France). These differences are owing to some relevant aspects: (1) systematic mass screening of urine in populations, as occurring in some Asian countries (Hong Kong, Japan, Korea, and Singapore), is not common in Western countries; (2) general practitioners and health care professionals in Western countries underestimate persistent microscopic hematuria and/or mild proteinuria in apparently healthy individuals causing late referral to a nephrologist; and (3) nephrologists adopt different indications for kidney biopsy in individuals with persistent urinary abnormalities. In addition, differences also are owing to the source of data, because the frequency of IgAN observed in a nephrology center with a high incidence of kidney biopsies is higher than in a regional renal biopsy registry that receives data from many centers. In conclusion, greater efforts should be made to diagnose IgAN earlier in individuals who manifest persistent microhematuria and/or mild proteinuria and to introduce less stringent indications for kidney biopsies. This preventive approach, followed by early therapy, may reduce the global burden of end-stage kidney disease caused by IgAN.

Incidence of glomerulonephritis and non-diabetic end-stage renal disease in a developing middle-east region near armed conflict

BACKGROUND

Estimates of the incidence of glomerulonephritis (GN) and end-stage renal disease (ESRD) in an Iraqi population are compared with the United States (US) and Jordan.

METHODS

The study set consist of renal biopsies performed in 2012 and 2013 in the Kurdish provinces of Northern Iraq. The age specific and age standardized incidence of GN was calculated from the 2011 population. ESRD incidence was estimated from Sulaimaniyah dialysis center records of patient's inititating hemodialysis in 2017.

RESULTS

At an annual biopsy rate of 7.8 per 100,000 persons in the Kurdish region, the number of diagnoses (2 years), the average age of diagnosis, and annual age standardized incidence (ASI)/100,000 for focal segmental glomerulosclerosis (FSGS) was n = 135, 27.3 ± 17.6 years, ASI = 1.6; and for all glomerulonephritis (GN) was n = 384, 30.4 ± 17.0 years, ASI = 5.1. FSGS represented 35% of GN biopsies, membranous glomerulonephritis 18%, systemic lupus erythematosus 13%, and immunoglobulin A nephropathy 7%. For FSGS and all GN, the peak age of diagnoses was 35-44 years of age with age specific rates declining after age 45. The unadjusted annual ESRD rate was 60 per million with an age specific peak at 55-64 years and a decline after age 65. The assigned cause of ESRD was 23% diabetes, 18% hypertension, and 12% GN with FSGS comprising 41% of biopsy-diagnosed, non-diabetic ESRD.

CONCLUSIONS

The regional incidence of ESRD in Northern Iraq is much lower than the crude incidences of 100 and 390 per million for Jordan and the US respectively. This is associated with low renal disease rates in the Iraqi elderly and an apparent major contribution of FSGS to ESRD.

Acute interstitial nephritis in the south of Iran; an observational study

Background

Acute interstitial nephritis (AIN) is an emerging cause of acute kidney injury (AKI) during the recent years.

Objectives:

There is no data about prevalence, causes, clinical manifestation and outcomes of AIN in our region. Hence, in this study we aimed to find the prevalence of AIN and describe the causes, clinical presentation, and the outcome of AIN in the native kidney biopsies.

Patients and Methods:

We reviewed 934 native kidney biopsies from 2006 to 2014 and collected the data of patients with the diagnosis of AIN including medical history, clinical findings, para-clinical data, pathologic findings, treatment and outcomes.

Results:

Prevalence of AIN in our center during 2006 to 2014 was 2.5% of all renal biopsies. The common cause of AIN in our study was drugs. Of those patients admitted to hospital due to AIN, 17 patients (70.8%) received corticosteroid, five of them (29.4%) received pulse of corticosteroid, and 12 patients (70.6%) received oral drug. Around, 54.2% of the patients had hemodialysis during admission. Eight patients had received both dialysis and corticosteroid. Two of them (8.3%) remained on dialysis and 8 (33.3%) developed chronic kidney disease, but 14 (58.3%) patients recovered.

Conclusions:

The prevalence of AIN in our study is comparable to other studies and we found the great impact of medications on development of AIN.

Acute interstitial nephritis - a reappraisal and update

Acute interstitial nephritis (AIN) is an under recognized and under diagnosed cause of acute kidney injury (AKI). It is estimated to account for 15 - 20% of cases of AKI; it is the reported diagnosis in 2.8% of all kidney biopsies, and 13.5% of biopsies done specifically for acute renal failure. Considerable evidence implicates antigen initiated cell-mediated injury in the pathogenesis of AIN. Drugs account for 70% of all cases, with over 150 different agents incriminated. The remaining cases are due to infections, autoimmune diseases, and rarely idiopathic. The central component of renal injury in AIN is altered tubular function, which usually precedes decrements in filtration rate. The key to early diagnosis is vigilance for the presence of tubular dysfunction in non-oliguric individuals, especially in patients with modest but gradual increments in creatinine level. The utility of urinary biomarkers to diagnose AIN in its early nascent and potentially reversible stage remains to be determined. Prompt recognition, elimination of the offending source of antigen, and use of a limited course of steroid therapy where indicated, will result in complete resolution in ~ 65% of cases, partial resolution in up to 20%, and irreversible damage in the rest.

The spectrum of glomerular diseases on renal biopsy: data from a single tertiary center in oman

OBJECTIVE

To study the pattern of glomerular disease (GD) from the result of renal biopsies at our center.

METHODS

We conducted a retrospective review of 190 adult native renal biopsy reports from the pathology registry of renal biopsy performed at our hospital between 1992 and 2010.

RESULTS

Lupus nephritis was the most common pathology 48/133 (36.1%) with a female preponderance. The most common primary glomerular disease was focal segmental glomerulosclerosis (FSGS) 26/133(19.5%), followed by membranous glemerulopathy (MGN) 13/133 (9.8%), and mesangial proliferative glomerulonephritis 6/133 (4.5%). IgA nephropathy and acute proliferative glomerulonephritis each accounted for 4/133 (3.0%). Membranoproliferative glomerulonephritis accounted for 3/133 (2.3%). Focal proliferative and cresentic glomerulonephritis each accounted for 2/133 (1.5%). Vasculitis was not common and there was no report of anti-GBM disease.

CONCLUSION

Among the secondary glomerular diseases, lupus nephritis was the commonest condition with a female preponderance. Among the primary glomerular diseases, FSGS was the commonest. These results are consistent with global trend. IgA nephropathy is not common as the case in the Caucasian population. Vasculitis was not common and there was no report of anti-GBM disease.

Analysis of clinicopathologic correlations in Iranian patients with lupus nephritis

OBJECTIVE

To determine clinical features of different histopathological presentations in patients with lupus nephritis (LN).

METHODS

Clinical and pathological features of 71 biopsy-proven LN patients were analyzed in a cross-sectional study during 2005-2011.

RESULTS

Sixty-five women (91.5%) and six men (8.5%) were studied. The mean Activity Index (AI) and Chronicity Index (CI) were 6.2 ± 3.1 and 1.7 ± 1.5, respectively. The most common histopathologic presentation of kidneys was class IV (52.1%). Patients with more advanced International Society of Nephrology and the Renal Pathology Society (ISN/RPS) classes, had longer disease duration (P = 0.007), higher levels of blood urea nitrogen (P = 0.004) and serum creatinine (P = 0.035). The most frequent active lesion seen in renal biopsies was endocapillary hypercellularity (83.1%) while glomerular sclerosis was the most common chronic lesion (52.1%). Patients with chronic lesions, including glomerular sclerosis (P = 0.032), fibrous crescent (P = 0.001), interstitial fibrosis (P = 0.025) and tubular atrophy (P = 0.049) had higher serum creatinine levels. Hypertension was mainly seen in patients who had interstitial fibrosis and tubular atrophy (P = 0.026, 0.002 respectively). Moreover, subjects with renal failure had been more frequently involved with fibrinoid necrosis/karyorrhexis (P = 0.003), interstitial inflammation (P = 0.009), fibrous crescents (P = 0.041), tubular atrophy (P = 0.008) and interstitial fibrosis (P < 0.001).

CONCLUSION

We found that both histopathologic classification (ISN/RPS criteria) and histopathologic grading (US National Institutes of Health activity and chronicity indices) correlate to some clinical manifestations of LN. Considering these correlations may help to determine the patients' clinicopathologic status, prognosis and the need to immediate treatment. Nevertheless, it is necessary to clarify the accuracy of these findings in larger-scale prospective studies.

An unusual case of anti-glomerular basement membrane disease presenting with nephrotic syndrome

Anti-glomerular basement membrane (anti-GBM) disease is a vasculitic disease characterized by acute kidney injury, oliguria, hematuria and proteinuria. Proteinuria is rarely in the nephrotic range. A case of anti-GBM disease with proteinuria of 22.5 g/day is discussed. Immunofluorescence showed strong linear IgG deposits while electron microscopy showed widespread visceral epithelial cell foot cell process effacement. No electron dense immune complex-type deposits were identified. Pathology findings were not suggestive of simultaneous presentation of anti-GBM disease and other diseases associated with nephrotic range proteinuria. Anti-GBM disease should be considered in a comprehensive differential diagnosis of severe proteinuria.