A 5-year survey of biopsy proven kidney diseases in Lebanon: significant variation in prevalence of primary glomerular diseases by age, population structure and consanguinity

Causes of nephrotic syndrome in Sweden: The relevance of clinical presentation and demographics

Background

Many pathological processes can disrupt the integrity of the glomerular capillary wall and cause a massive leakage of protein, resulting in nephrotic syndrome (NS). Clinical parameters such as age, sex, renal function, presence of diabetes, and how NS is defined influence the spectrum of underlying diseases. In this study, we examine how these parameters interact.

Methods

Age, sex, hematuria, proteinuria, plasma creatinine plasma albumin levels, and final diagnosis were retrieved for all adult patients with NS as an indication for biopsy and/or massive albuminuria in conjunction with low plasma albumin from the biopsy module of the Swedish Renal Registry (SRR) between 2014 and 2019. A basic calculator was developed to demonstrate the importance of clinical presentation in relation to the likelihood of having a specific diagnosis.

Results

A total of 913 unique patients were included in the study. Diabetic nephropathy (DN) and membranous nephropathy (MN) (both found in 17% of patients) were the most common diagnoses. With a stringent definition of NS, MN and minimal change nephropathy (MCN) increased in proportion. Among the cohort as a whole, MCN was the most frequent diagnosis in women and those < 50 years of age (found in 21% and 17%, respectively). In the case of patients aged between 50 and 70 years, those with chronic kidney disease stage 4, and those with negative dipstick tests for hematuria, the most common underlying disease was DN (in 23%, 30%, and 21% of cases, respectively). Among those with high-grade hematuria (dipstick grade 3 or 4), membranoproliferative glomerulonephritis was the most common diagnosis (14%), closely followed by IgA nephropathy (13%). Focal segmental glomerulosclerosis (9.7%) was less common than in many comparable studies.

Conclusion

Clinical parameters have a profound impact on the likelihood of different diagnoses in adult patients with NS. Differences in clinical practice and study inclusion criteria may be more important than genetic background and environmental factors when explaining differences between studies in different parts of the world.

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.

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.

Efficacy and safety of tacrolimus combined with glucocorticoid treatment for IgA nephropathy: a meta-analysis

Objective

As a classical immunosuppressant, tacrolimus (TAC) has been widely used in organ transplantation therapy, but the general benefits of TAC for the treatment of IgA nephropathy (IgAN) remain uncertain. We conducted a meta-analysis to examine the effects of TAC combined with glucocorticoid on IgAN.

Methods

We searched the information databases PubMed/Medline, Embase, Science Citation Index, Chinese Biomedical Literature and the Chinese databases VIP, CNKI and Wan Fang for randomized controlled trials of TAC combined with glucocorticoid as a therapy for IgAN.

Results

Ten relevant studies involving 472 patients were included in a meta-analysis. Overall, the TAC group showed a significant decrease in proteinuria compared with the control group (MD: −0.18 g/d, 95% CI: −0.32 to −0.04). No increased risk of adverse events was observed (OR: 0.93, 95% CI: 0.65 to 1.33). In general, the TAC group showed good tolerance.

Conclusion

Evidence to date clearly indicates that TAC combined with glucocorticoid is quite effective in reducing proteinuria and albuminuria in patients with IgAN. Moreover, we found that patients receiving TAC therapy did not show an increased risk of side effects compared with control group patients. TAC combined with glucocorticoid is a promising medication and merits further research.

Genetics of consanguinity and inbreeding in health and disease

CONTEXT

Inbreeding increases the level of homozygotes for autosomal recessive disorders and is the major objective in clinical studies. The prevalence of consanguinity and the degree of inbreeding vary from one population to another depending on ethnicity, religion, culture and geography. Global epidemiological studies have revealed that consanguineous unions have been significantly associated with increased susceptibility to various forms of inherited diseases.

OBJECTIVE

The study aimed to determine the role of consanguinity in human health and to highlight the associated risks for various diseases or disorders.

METHODS

PubMed and Google Scholar search engines were used to explore the published literature on consanguinity and its associated risks using the key words "consanguinity", "prevalence", "inbreeding depression", "coefficient of inbreeding", "child health", "mortality", "human health", "homozygosity" and "complex diseases" in different combinations. The studies were screened for eligibility on the basis of their epidemiological relevance.

RESULTS

This comprehensive assessment highlights the deleterious consequences in populations with a higher prevalence of consanguinity among different countries worldwide.

CONCLUSIONS

To avoid the inbreeding load there is the need to improve socioeconomic and educational status and to increase public awareness of reproductive health and anticipated deleterious effects. Pre-marital and pre-conception counselling of consanguineous populations should be an integral part of health policy to train people and make people aware of its harmful consequences. Furthermore, runs of homozygosity (ROH) and whole-exome sequencing (WES) are useful tools in exploring new genomic signatures for the cause of inbreeding depression.

Tacrolimus combined with low-dose corticosteroids is an effective and safe therapeutic option for refractory IgA nephropathy

Tacrolimus (TAC) has been shown to improve remission from proteinuria in patients with refractory IgA nephropathy (IgAN); however, the efficacy and safety of TAC in such patients have not been fully explored. Therefore, the present study was conducted to evaluate the tolerance to and efficacy of TAC combined with low-dose corticosteroids in patients with refractory IgAN. This was a single-center retrospective study. A total of 28 patients with refractory IgAN were randomly included and received TAC plus corticosteroid; 26 patients received TAC and prednisone, and 2 patients received TAC and methylprednisolone. In addition, all patients were treated with an angiotensin inhibitor. Total urinary protein excretion, serum albumin, blood glucose, complete remission (CR), partial remission (PR), cholesterol, low-density lipoprotein (LDL), serum creatinine (Scr) and estimated GFR (eGFR) were tested at baseline and at 3, 6 and 12 months after the initiation of treatment in all patients. The primary endpoints were CR and PR. Secondary endpoints included changes of Scr, eGFR, clinical data and adverse events. After 12 months, CR was achieved in 40.1% of patients and PR in 43.4%, yielding a total response rate of 83.5%, and the total urinary protein excretion, serum albumin, cholesterol and LDL results were improved significantly compared with those at baseline. Proteinuria and serum albumin results were significantly improved by month 3 of treatment. Two patients relapsed during months 3-6 of follow-up. At the 12-month follow-up, renal function was improved compared with the baseline level as evidenced by eGFR and Scr, respectively. The blood glucose level was stable. One case of pneumococcal pneumonia developed in a patient treated with TAC plus low-dose methylprednisolone and one case of upper gastrointestinal hemorrhage was found in a patient treated with TAC plus low-dose prednisone; both cases completely recovered after treatment. In conclusion, TAC combined with low-dose corticosteroids may be an effective and safe therapeutic option for the treatment of refractory IgAN. However, given the small number of patients in this study, further prospective randomized controlled trials are required with a larger sample of participants and longer follow-up period.

Haematuria as a risk factor for chronic kidney disease progression in glomerular diseases: A review

Haematuria has long been considered to be a benign condition associated with glomerular diseases. However, new evidences suggest that haematuria has a pathogenic role in promoting kidney disease progression. An increased risk for end-stage renal disease has been reported in adolescents and young adults with persistent microscopic haematuria. A persistent impairment of renal function has been also reported following macroscopic haematuria-associated acute kidney injury in immunoglobulin A nephropathy. Haematuria-induced renal damage has been related to oxidant, cytotoxic and inflammatory effects induced by haemoglobin or haem released from red blood cells. The pathophysiological origin of haematuria may be due to a more fragile and easily ruptured glomerular filtration barrier, as reported in several glomerular diseases. In this review we describe a number of the key issues associated with the epidemiology and pathogenesis of haematuria-associated diseases, provide an update of recent knowledge on the role of haematuria on renal function outcome and discuss specific therapeutic approaches in this setting. KEY SUMMARY POINTS: 1. Glomerular haematuria is a common observation in a number of renal diseases that may lead to persistent renal injury. 2. Haematuria in children differs from that in adults in specific aspects, particularly in the frequency of glomerular diseases and renal disease outcome. 3. Regular follow-up of renal function in children with isolated microhaematuria may be recommended.

Pathological patterns of mesangioproliferative glomerulonephritis seen at a tertiary care center

Background: Mesangioproliferative glomerulonephritis (MesPGN) is a common morphological pattern that encompasses several groups of renal diseases including IgA nephropathy (IgAN), IgM nephropathy (IgMN), lupus nephritis (LN), C1q nephropathy (C1qN) and other entities. Objectives: The aim of this study was to analyze the pathological findings and the clinical features of cases of MesPGN seen at the king Abdulaziz University, in Saudi Arabia. Patients and Methods: A total of 750 percutaneous native renal biopsies were seen at our institution from January 2000 to December 2011. All the cases diagnosed as MesPGN on light microscopy (LM) were retrieved from the archives of pathology. The pathological features and the clinical data of these cases were reviewed. The clinical data was available for 80 cases only. Results: A total of 103 cases (14%) met the inclusion criteria for the diagnosis of MesPGN. The most common diagnostic entity was IgMN (46.6%) followed by IgAN (30%) along with few cases of class II LN, C1qN, minimal change disease (MCD), Alport's syndrome, focal segmental glomerulosclerosis (FSGS), thin basement membrane disease (TBMD), and fibrillary glomerulonephritis. The most common clinical presentation was nephrotic syndrome seen in 71% of 80 cases, followed by hematuria (14%). Histologically, focal mesangial proliferation was seen in 62% while diffuse proliferation was seen in 38% of the cases. Conclusion: Mesangioproliferative glomerulonephritis is an important cause of nephrotic syndrome in young adults in the western region of Saudi Arabia. Future studies from the region are needed to elucidate the clinical relevance of mesangial cell proliferation to the end stage kidney diseases.

Genetic variants in interleukin genes and susceptibility to IgA nephropathy: a meta-analysis

Many existing studies have demonstrated that genetic variants in interleukin (IL) genes might have an impact on an individual's susceptibility to IgA nephropathy (IgAN); but individually published results are inconclusive. This meta-analysis aimed to derive a more precise estimation of the relationships between IL genetic variants and IgAN risk. We searched CISCOM, CINAHL, Web of Science, PubMed, Google Scholar, EBSCO, Cochrane Library, and China BioMedicine (CBM) and China National Knowledge Infrastructure (CNKI) databases from inception through August 1, 2013. Meta-analysis was performed using the STATA 12.0 software. Seven case-control studies were included with a total of 1135 IgAN patients and 1603 healthy controls. Our meta-analysis results revealed that genetic variants in IL-1 and IL-1RN genes were associated with an increased risk of IgAN. However, similar associations were not observed in IL-6, IL-10, and IL-22R genes. Subgroup analysis by ethnicity suggested that there were significant associations between IL genetic variants and an increased risk of IgAN among both Asian and Caucasian populations. Meta-regression analyses showed that gene types may be a major source of heterogeneity. No publication bias was detected in this meta-analysis. The present meta-analysis suggests that IL genetic variants may contribute to the risk of IgAN, especially in IL-1 and IL-1RN genes.

Epidemiologic data of adult native biopsy-proven renal diseases in Croatia

PURPOSE

There is a paucity of epidemiological data on biopsy-proven renal disease in Croatia. The purpose of this report is a review of clinical and histological data, over a period of 15 years, from the single biggest adult native renal biopsy center in Croatia.

METHODS

This report includes data from 922 adult native renal biopsies in patients referred from the whole country and performed in our center from 1996 till February 2012. Data on age, gender, serum creatinine, urine sediment, 24-h proteinuria, clinical syndrome and histological diagnosis were collected and analyzed retrospectively. In all patients, light, immunofluorescence and electron microscopic analysis was performed.

RESULTS

The median age of the patients was 48 years (interquartile range 36-59 years), and the majority of patients were men (57.8 %). The most common indication for renal biopsy was nephrotic syndrome (40.3 %) followed by asymptomatic urinary abnormalities (31.7 %). The most common biopsy-proven renal disease in total was IgA glomerulonephritis (19.3 %), followed by focal segmental glomerulosclerosis (FSGS) (15.8 %) and membranous glomerulonephritis (9.2 %). In men, similar results were found, while in women, the most common were hereditary nephritis (13.4 %), FSGS (12.9 %) and connective tissue disease-related glomerular disorders (11.6 %).

CONCLUSION

The presented data are an important contribution to the better understanding of the epidemiology of biopsy-proven renal disease in Croatia and Europe throughout comparison with other registry data. This data should be the basis for the formation of Croatian Registry of Renal Biopsies.

Non-IgA mesangioproliferative glomerulonephritis: a benign entity?

BACKGROUND

Non-IgA mesangioproliferative glomerulonephritis is a well recognized but less studied entity. The clinical manifestations, treatment response and long-term outcome have not been clearly defined.

METHODS

This single-centre study included patients with biopsy-proven non-IgA mesangioproliferative glomerulonephritis who had been on regular follow-up for >3 years. Their clinical features at presentation, response to therapy and long-term renal outcome are addressed in this study.

RESULTS

Nephrotic syndrome developed in 51 of 57 patients (89.4%). The majority of them--34 of 51(80%)--were steroid sensitive and had either infrequent or no relapse. However, steroid-dependent nephrotic syndrome occurred in eight patients (15.6%), while steroid resistance occurred in nine patients (17.6 %). Thirteen patients developed chronic kidney disease (CKD) with three progressing to end-stage renal disease, three to CKD Stage 4 and seven to CKD Stage 3.

CONCLUSIONS

Non-IgA mesangioproliferative glomerulonephritis is a disease, which is not benign, and is associated with significant treatment-related morbidity.