Microproteinuria in patients with inflammatory bowel disease: Is it associated with the disease activity or the treatment with 5-aminosalicylic acid?

Inflammatory bowel disease increases the levels of albuminuria and the risk of urolithiasis: a two-sample Mendelian randomization study

BACKGROUND

Alterations in kidney function and increased risk of kidney diseases in patients with inflammatory bowel disease (IBD) have been reported, but the causal relationship remains unclear. Herein, Mendelian randomization was employed to identify the causal effect of inflammatory bowel disease on kidney function and the risk of chronic kidney disease (CKD), urolithiasis, and IgA nephropathy.

METHODS

The International Inflammatory Bowel Disease Genetics Consortium provided the summary-level genome-wide association study (GWAS) data that correlates with Crohn's disease (CD) and ulcerative colitis (UC). GWAS data for estimated glomerular filtration rate from serum creatinine (eGFRcrea), urine albumin-creatinine ratio (uACR), and CKD were obtained from the CKDGen Consortium, and GWAS data for urolithiasis were obtained from the FinnGen consortium. The summary-level GWAS data for IgA nephropathy were obtained from the meta-analysis of UK-biobank, FinnGen, and Biobank Japan. Inverse-variance weighted was used as the primary estimate. Furthermore, the Steiger test was used to validate the direction of causality.

RESULTS

The inverse-variance weighted data revealed that genetically predicted UC significantly increased uACR levels, while genetically predicted CD significantly increased the risk of urolithiasis.

CONCLUSIONS

UC increases the levels of uACR, and CD increases the risk of urolithiasis.

Glomerulonephritis and inflammatory bowel disease: A tale of gut-kidney axis dysfunction

The incidence and prevalence of Inflammatory Bowel Disease (IBD) has increased over the past decades, imposing a growing socioeconomic burden on healthcare systems globally. Most of the morbidity and mortality related to IBD is typically attributed to gut inflammation and its complications; yet the disease is characterized by various extraintestinal manifestations that can be severe. Glomerulonephritis (GN) is of particular interest since a significant proportion of patients evolve into end-stage kidney disease, requiring kidney replacement therapy and associated with high morbidity and mortality. Herein, we review the GN landscape in IBD and define the clinical and pathogenic associations reported to date in the literature. Underlying pathogenic mechanisms suggest either the initiation of antigen-specific immune responses in the inflamed gut that cross react with non-intestinal sites, such as the glomerulus, or that extraintestinal manifestations are gut-independent events that occur due to an interaction between common genetic and environmental risk factors. We present data associating GN with IBD either as a bona fide extraintestinal manifestation or reporting it as an extraneous co-existing entity, involving various histological subtypes, such as focal segmental glomerulosclerosis, proliferative GN, minimal change disease, crescentic GN, but most emphatically IgA nephropathy. Supporting the pathogenic interplay between gut inflammation and intrinsic glomerular processes, enteric targeting the intestinal mucosa with budesonide reduced IgA nephropathy-mediated proteinuria. Elucidating the mechanisms at play would provide insight not only into IBD pathogenesis but also into the gut's role in the development of extraintestinal diseases, such as glomerular diseases.

The pathological and outcome characteristics of renal lesions in Crohn's disease

Background

The inflammatory bowel disease, containing Crohn’s disease and ulcerative colitis, was rare in the population, especially in the complication of kidney disease. A few studies had found proteinuria played a potential indicator of inflammatory bowel disease occurrence and activity. This study aimed to better define the histopathologic spectrum and study the outcome of renal disease in Crohn’s disease.

Methods

A retrospective study of 3557 Crohn's disease from January 1^st, 2016 to July 1^st, 2021 in the Sixth Affiliated Hospital of Sun Yat-sen University identified 20 (0.56% [20/3557]) patients who underwent kidney biopsy. All biopsy specimens were examined by standard procedures containing light microscopy, immunofluorescence, and electron microscopy.

Results

Twenty cases were shown in this review study. Subnephrotic proteinuria (30% [6 of 20]), persistent hematuria and proteinuria (25% [5 of 20]), and isolated hematuria with acanthocytes (25% [5 of 20]) were the main indications for kidney biopsy. The most common diagnosis was IgA nephropathy (70% [14/20]), followed by minimal change disease (10% [2/20]), acute interstitial nephritis (5% [1/20]), granulomatous interstitial nephritis (5% [1/20]), non-IgA mesangial proliferative nephritis (5% [1/20]) and thin basement membrane nephropathy (5% [1/20]). The Lee classification of IgA nephropathy was mostly II or III level. Glomerular mesangial hyperplasia was the most common pathologic manifestation according to the MEST-C Sore. After twelve-month treatment, the majority of patients turned to complete remission of renal disease by measuring proteinuria, while 3 patients still stayed in the relapse stage and 6 patients turned to partial remission by measuring hematuria.

Conclusions

IgA nephropathy is the most common kidney biopsy diagnosis in Crohn's disease. Renal damage in Crohn's disease mainly involves the glomerulus, especially the mesangial matrix. After the treatment, proteinuria might be in remission, but hematuria remains.

Efficacy of a functional food ingredient from Ensete superbum Roxb Cheesman peel in reducing the severity of ulcerative colitis in murine model

Ulcerative colitis is a recurrent inflammatory illness of the colon with an elevated risk of developing colon cancer. The drugs presently used to treat UC cause adverse effects and are...

Prevalence of Renal Stones Among Patients With Inflammatory Bowel Disease in Saudi Arabia

INTRODUCTION

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases (IBD) that affect the gastrointestinal tract with no identified etiology. IBD has been associated with several extraintestinal manifestations (EIMs), including renal involvement such as renal stones (nephrolithiasis), resulting in significant morbidity. This study aims to estimate the prevalence of renal stones among IBD patients in Saudi Arabia.

METHODS

This is a retrospective study conducted at King Abdulaziz University Hospital between January 2019 and December 2020. All IBD patients with abdominal imaging studies were included in the study regardless of their age. Data were collected from the electronic hospital information system and analyzed.

RESULTS

A total of 363 IBD patients fulfilled the study inclusion criteria. Nephrolithiasis was detected radiologically in 3.6% of the cohort (5.1% of UC and 2.7% of CD patients). Patients with renal stones are older (P=0.002) and more likely to be diabetic (P=0.047), have microscopic hematuria (P<0.001), and proteinuria (P=0.002). Binary logistic regression analysis showed that older age at diagnosis (P=0.003) and microscopic hematuria (P=0.02) are independent predictors for renal stones.

CONCLUSION

 The study reported that 3.6% of Saudi IBD patients had renal stones, with a higher prevalence of renal stones formation among UC patients than Crohn's. Older age at diagnosis and the presence of microscopic hematuria may predict the development of renal stones. Future studies should be conducted in a prospective manner at multiple centers across Saudi Arabia for further investigation.

Kidney function monitoring to prevent 5-aminosalicylic acid nephrotoxicity: What the gastroenterologist should know

BACKGROUND

The kidney function monitoring is recommended in routine practice to detect 5-aminosalicylic acid (5-ASA) related nephrotoxicity, although is not standardized. The optimal monitoring is unknown, especially the best timing and which tests to perform. We summarized why, how, and when to perform the monitoring for patients treated with 5-ASA and provided an overview of the current guidelines on this topic.

METHOD

Relevant studies on this topic were searched in PubMed, Embase, and Web of Science databases from July to August 2020.

RESULTS

Serum creatinine, the estimated glomerular filtration rate, and 24-h proteinuria are the 3 main tests used for the monitoring in daily practice. Regarding the timing, several monitoring strategies have been proposed and guidelines are available too, but they provide conflicting information. To date, there is no medical evidence-based that one strategy is better than another. Comorbidities, chronic renal disease, use of nephrotoxic drugs or concomitant steroid therapy also impact the nephrotoxicity risk. Based on the literature review we proposed a kidney function monitoring strategy to guide physicians in clinical practice.

CONCLUSION

A baseline assessment should be performed in all patients treated with 5-ASA. The monitoring should be carried out according to the other nephrotoxic factors. A tight monitoring may reduce morbidity and mortality of drug nephrotoxicity.

Inflammatory bowel disease: Looking beyond the tract

Inflammatory bowel disease is a chronic inflammatory condition that encompasses Crohn's disease and ulcerative colitis. Inflammatory bowel disease is not exclusive to the gastrointestinal system, as it has been identified to be associated with extraintestinal manifestations that encompass every other organ system in the human body. This review article will comprehensively review the current knowledge on extraintestinal manifestations of inflammatory bowel disease. In addition, it will discuss the recommendations for screening and surveillance for extraintestinal manifestations in these patients since early appropriate diagnosis is imperative in preventing morbidity and cancer development.

[Tubulointerstitiel nephritis and Crohn's disease, nephrotoxicity or extraintestinal manifestation of Crohn's disease? About a case]

Extraintestinal manifestations in inflammatory bowel disease involve most frequently the joints, the skin, the eyes, the liver and the biliary tract. Renal involvement is rare, and manifested as nephrolithiasis, tubulointerstitial nephritis, glomerulonephritis and amyloidosis. In patients with inflammatory bowel disease, renal disease is most frequently due to treatment nephrotoxicity and rarely as a guenine extraintestinal manifestation of inflammatory bowel disease. We are reporting a case of tubulointerstitial nephritis as an extraintestinal manifestation of Crohn's disease and we are explaining the diagnostic difficulty to distinguish this from drug-induced nephrotoxicity.

Tubulointerstitial nephritis: diagnosis, treatment, and monitoring

Tubulointerstitial nephritis (TIN) is a frequent cause of acute kidney injury (AKI) that can lead to chronic kidney disease (CKD). TIN is associated with an immune-mediated infiltration of the kidney interstitium by inflammatory cells, which may progress to fibrosis. Patients often present with nonspecific symptoms, which can lead to delayed diagnosis and treatment of the disease. Etiology can be drug-induced, infectious, idiopathic, genetic, or related to a systemic inflammatory condition such as tubulointerstitial nephritis and uveitis (TINU) syndrome, inflammatory bowel disease, or immunoglobulin G4 (IgG4)-associated immune complex multiorgan autoimmune disease (MAD). It is imperative to have a high clinical suspicion for TIN in order to remove potential offending agents and treat any associated systemic diseases. Treatment is ultimately dependent on underlying etiology. While there are no randomized controlled clinical trials to assess treatment choice and efficacy in TIN, corticosteroids have been a mainstay of therapy, and recent studies have suggested a possible role for mycophenolate mofetil. Urinary biomarkers such as alpha1- and beta2-microglobulin may help diagnose and monitor disease activity in TIN. Screening for TIN should be implemented in children with inflammatory bowel disease, uveitis, or IgG4-associated MAD.

Renal Involvement in Inflammatory Bowel Diseases

The prevalence of extraintestinal manifestations in inflammatory bowel diseases varies from 6% to 46%. The aetiology of extraintestinal manifestations remains unclear. There are theories based on an immunological response influenced by genetic factors. Extraintestinal manifestations can involve almost every organ system. They may originate from the same pathophysiological mechanism of intestinal disease, or as secondary complications of inflammatory bowel diseases, or autoimmune diseases susceptibility. The most frequently involved organs are the joints, skin, eyes, liver and biliary tract. Renal involvement has been considered as an extraintestinal manifestation and has been described in both Crohn's disease and ulcerative colitis. The most frequent renal involvements in patients with inflammatory bowel disease are nephrolithiasis, tubulointerstitial nephritis, glomerulonephritis and amyloidosis. The aim of this review is to evaluate and report the most important data in the literature on renal involvement in patients with inflammatory bowel disease. Bibliographical searches were performed of the MEDLINE electronic database from January 1998 to January 2015 with the following key words (all fields): (inflammatory bowel disease OR Crohn's disease OR ulcerative colitis) AND (kidney OR renal OR nephrotoxicity OR renal function OR kidney disease OR renal disease OR glomerulonephritis OR interstitial nephritis OR amyloidosis OR kidney failure OR renal failure) AND (5-aminosalicylic acid OR aminosalicylate OR mesalazine OR TNF-α inhibitors OR cyclosporine OR azathioprine OR drugs OR pediatric).

Renal insufficiency in IBD--prevalence and possible pathogenetic aspects

BACKGROUND AND AIMS

Extraintestinal manifestations of parenchymatous organs like kidney are rarely noticed in Inflammatory Bowel Disease (IBD). The aim of this study was to investigate the prevalence of renal insufficiency (RI) in IBD and look for potential causative factors and pathogenetic aspects.

METHODS

The study consists of two parts; the first determined the prevalence of RI in IBD and the second possible causative factors. For the first part all patients with IBD who had been investigated at our institution in the period from March 2006 to December 2007 were included. For the second part 25 IBD patients with RI were matched with 50 IBD patients without RI. To determine causative factors several gastroenterologic and renal parameters were compared between these two groups.

RESULTS

Eleven out of 775 patients with IBD had RI, all of them suffering from Crohn's disease (CD). This led to a prevalence of 1.99% for patients with CD and of 0% for patients with ulcerative colitis (UC). Concerning IBD risk factors only duration of disease (p=0.002) and length of resected small bowel (p=0.004) had a significant impact. Two nephrologic parameters, recurrent urolithiasis and the number of interventions due to kidney stones, were risk factors for the development of RI (p=0.03).

CONCLUSIONS

RI is a rare (2%) but relevant complication in CD, not found in UC. Extensive small bowel resection and recurrent urolithiasis seem to be the major causative factors.

Extraintestinal manifestations and complications in IBD

More than one-third of patients with IBD are affected by extraintestinal manifestations or extraintestinal complications beyond the intestinal manifestation of the disease. The most common manifestations include arthropathies, mucocutaneous and ophthalmological manifestations, as well as conditions affecting the hepatobiliary system, both in Crohn's disease and ulcerative colitis. However, less frequent manifestations, such as pulmonary or neurological manifestations, should also be considered in patients with IBD. Several extraintestinal manifestations follow the course of the underlying intestinal activity, whereas others are independent from the intestinal inflammation. Extraintestinal complications such as iron-deficiency anaemia and osteoporosis are consequences of the intestinal disease or of disease-specific treatment. As extraintestinal manifestations and complications strongly influence quality of life, and to avoid severe complications, adequate treatment is mandatory in affected patients. We provide a comprehensive overview of different extraintestinal manifestations and complications, including their management, in patients with IBD.

Drug-induced nephrotoxicity in inflammatory bowel disease

Conservative management of inflammatory bowel disease (IBD) is based on a combination of drugs, including aminosalicylates (ASAs), steroids, antibiotics, immunosuppressives and biologic agents. Although various side effects have been related to treatment regimens, drug-induced nephrotoxicity is rather uncommon. Furthermore, it is often underestimated since renal function deterioration may be attributed to the underlying disease. The nephrotoxicity of ASAs and cyclosporine A seems well established, but recent data have suggested a possible role of biologic agents such as infliximab and adalimubab in renal impairment. The aim of this review is to summarize the nephrotoxic effects of medical treatment as well as to express possible caveats in the administration of novel agents in IBD.

Effect of 5-aminosalicylates on renal function in patients with inflammatory bowel disease: 4-year follow-up study

OBJECTIVE

Nephrotoxicity has been described in some patients with inflammatory bowel disease (IBD) treated with 5-aminosalicylates (5-ASA). Our aim was to conduct a retrospective study of IBD patients, both with and without 5-ASA treatment, who underwent regular evaluation of renal function over a 4-year period.

METHODS

Serum creatinine was measured before the start of 5-ASA therapy, and thereafter yearly up to 4 years. Creatinine clearance (Cl(Cr)) was estimated from serum creatinine (Cockroft and Gault formula). The influence of 5-ASA treatment on renal function was assessed by univariate and multivariate analysis.

RESULTS

A total of 150 IBD patients (ulcerative colitis in 45%, Crohn's disease in 55%) were included. Sixty-two patients were receiving 5-ASAs (95% coated mesalazine, mean dose 1.9 +/- 0.8 g/day). Both serum creatinine levels and ClCr were similar in patients with and without 5-ASA treatment, and remained stable throughout the 4-year follow-up in patients taking 5-ASAs. In the multivariate analysis, 5-ASA treatment (or its dose) was not correlated with serum creatinine levels or Cl(Cr). No interstitial nephritis was reported during follow-up.

CONCLUSION

5-ASA-related renal disease was not found in our series, suggesting that the occurrence of renal impairment in IBD patients receiving these drugs is exceptional. Our results do not support the recommendation of serum creatinine monitoring in patients receiving 5-ASA treatment.

Evaluation of disease activity markers in dogs with idiopathic inflammatory bowel disease

OBJECTIVES

To evaluate the clinical utility of serum tumour necrosis factor-alpha, C-reactive protein and microalbuminuria as disease activity markers in canine idiopathic inflammatory bowel disease.

METHODS

Dogs with chronic gastrointestinal disease for which no underlying cause could be identified were considered to have idiopathic inflammatory bowel disease and were included in the study. Serum tumour necrosis factor-alpha was assessed using a canine-specific ELISA, C-reactive protein by immunoturbidometric assay and quantitative microalbuminuria was analysed using a monoclonal antibody directed against canine albumin. The canine inflammatory bowel disease activity index and histopathologic grade were used to assess disease severity; biologic markers were then compared with the canine inflammatory bowel disease activity index and histopathologic grade.

RESULTS

Sixteen dogs were included in the study. C-reactive protein level was mildly elevated in 15 dogs. Microalbuminuria was elevated in two of 15 dogs, and tumour necrosis factor-alpha was not detected in any dog tested. No correlation was found between the canine inflammatory bowel disease activity index and C-reactive protein or microalbuminuria or between histopathologic grade and C-reactive protein or microalbuminuria. There was no correlation between histopathologic grade and the canine inflammatory bowel disease activity index.

CLINICAL SIGNIFICANCE

Although only a small number of dogs were evaluated, this study does not support the use of serum tumour necrosis factor-alpha measured by canine-specific ELISA or microalbuminuria in the evaluation of disease activity in dogs with idiopathic inflammatory bowel disease. Although mildly elevated in most dogs, C-reactive protein did not reflect disease severity as assessed by the canine inflammatory bowel disease activity index or histopathologic grade.

5-Aminosalicylates and renal function in inflammatory bowel disease: a systematic review

Nephrotoxicity has been described in some patients with inflammatory bowel disease (IBD) treated with 5-aminosalicylic acid (5-ASA). Studies with 5-ASA treatment in which serum creatinine or creatinine clearance was measured regularly show that nephrotoxicity is exceptional (mean rate of only 0.26% per patient-year). There have been several case reports, including 46 patients, of renal disease associated with 5-ASA treatment in patients with IBD. 5-ASA treatment-related nephrotoxicity is reported most often within the first 12 months, but also delayed presentation after several years has been shown. The absence of a clear relationship between 5-ASA dose and the risk of nephrotoxicity suggests that this complication is idiosyncratic rather than dose-related. Most of the patients with renal disease associated with 5-ASA treatment suffered interstitial nephritis, with symptoms and signs being nonspecific, which may delay detection for many months. The nephrotoxicity potential of mesalazine and sulfasalazine seems to be similar. The risk with different oral preparations of 5-ASA is probably too small to influence the choice of agent. Mesalazine should be withdrawn when renal impairment manifests in a patient with IBD; if this does not result in a fall in serum creatinine, then renal biopsy should be considered. A trial of high-dose steroid may be recommended in patients whose renal function does not respond to drug withdrawal. The optimal monitoring schedule of serum creatinine in patients receiving 5-ASA treatment remains to be established, as there is no evidence to date that either the test, or the frequency of testing, improves patient outcomes.