Renal manifestations and complications of inflammatory bowel disease

Novel immune cross-talk between inflammatory bowel disease and IgA nephropathy

The mechanisms underlying the complex correlation between immunoglobulin A nephropathy (IgAN) and inflammatory bowel disease (IBD) remain unclear. This study aimed to identify the optimal cross-talk genes, potential pathways, and mutual immune-infiltrating microenvironments between IBD and IgAN to elucidate the linkage between patients with IBD and IgAN. The IgAN and IBD datasets were obtained from the Gene Expression Omnibus (GEO). Three algorithms, CIBERSORTx, ssGSEA, and xCell, were used to evaluate the similarities in the infiltrating microenvironment between the two diseases. Weighted gene co-expression network analysis (WGCNA) was implemented in the IBD dataset to identify the major immune infiltration modules, and the Boruta algorithm, RFE algorithm, and LASSO regression were applied to filter the cross-talk genes. Next, multiple machine learning models were applied to confirm the optimal cross-talk genes. Finally, the relevant findings were validated using histology and immunohistochemistry analysis of IBD mice. Immune infiltration analysis showed no significant differences between IBD and IgAN samples in most immune cells. The three algorithms identified 10 diagnostic genes, MAPK3, NFKB1, FDX1, EPHX2, SYNPO, KDF1, METTL7A, RIDA, HSDL2, and RIPK2; FDX1 and NFKB1 were enhanced in the kidney of IBD mice. Kyoto Encyclopedia of Genes and Genomes analysis showed 15 mutual pathways between the two diseases, with lipid metabolism playing a vital role in the cross-talk. Our findings offer insights into the shared immune mechanisms of IgAN and IBD. These common pathways, diagnostic cross-talk genes, and cell-mediated abnormal immunity may inform further experimental studies.

Assessment of the causal relationship between inflammatory bowel diseases and chronic kidney diseases: A two-sample bidirectional mendelian randomization study among European population

BACKGROUND

Kidney function can be impaired in patients with inflammatory bowel diseases (IBD), including Crohn's diseases (CD) and ulcerative colitis (UC). However, the causal relationship between IBD and chronic kidney diseases (CKD) remains unclear.

METHODS

We determined the causal association between IBD and CKD by performing two-sample bidirectional mendelian randomization (MR) analyses. Independent genetic variants were selected as instrumental variables (IVs) of the exposure from open-access genome-wide association studies (GWAS) among European ancestry. IVs-outcome estimates were extracted from three separate GWAS for IBD and two for CKD, respectively. Inverse-variance-weighted model was used as the primary MR method. The pleiotropic effect and heterogeneity were evaluated. For either direction, analyses were performed per outcome database and were subsequently meta-analysed.

RESULTS

Genetically predicted IBD was associated with higher risk of CKD (OR: 1.045, 95% CI: 1.016-1.073, P = 0.002) by including 42 344 IBD cases and 229 164 controls. Further analyses showed genetic liability to CD increased the risk of CKD (OR: 1.057, 95% CI: 1.027-1.087, p < 0.001) whereas UC did not (OR: 0.999, 95% CI:0.969-1.031, p = 0.970). In contrast, genetically predicted CKD was not associated with IBD (OR: 1.010, 95% CI: 0.965-1.056, p = 0.676), UC (OR: 1.011, 95% CI: 0.948-1.078, p = 0.746) and CD (OR: 1.024; 95% CI: 0.963-1.089, p = 0.447).

CONCLUSIONS

We concluded that CD, but not UC, can increase the risk of CKD causally. CD, but not UC, can increase the risk of chronic kidney disease causally. These findings enhance our understanding of the differential impact of IBD subtypes on CKD. It may be necessary to monitor kidney function regularly in patients with CD.

Concurrent chronic kidney disease in patients with inflammatory bowel disease, a systematic review and meta-analysis

Introduction

Inflammatory bowel disease (IBD) is a multi-organ autoimmune disease that commonly affects the gastrointestinal tract, but can also affect other organs throughout the body. Less is known, however, about kidney involvement in IBD. Although IBD has been associated with chronic kidney disease (CKD) and end-stage renal disease (ESRD), these results have been inconsistent. The present study analyzed the prevalence of concurrent CKD and ESRD in patients with IBD.

Methods

PubMed, Cochrane, Web of Science, and Embase were searched for studies published through October 2023 on IBD patients with concurrent CKD or ESRD. Outcomes included the incidence rates and odds ratios (OR) of concurrent CKD and ESRD in IBD patients. The quality of included studies was assessed using the Newcastle-Ottawa Scale, and sequential sensitivity was analyzed. Publication bias was evaluated using Egger's test.

Results

Nine studies were included in this meta-analysis. The combined results of eight studies, which included 239,042 IBD patients, showed that the prevalence of CKD in IBD patients was 5% (95% confidence interval [CI]: 1-9%). The combined results of two studies, which included 40,341 IBD patients, showed that the prevalence of ESRD in IBD patients was 0.2% (95% CI: -0.08-0.12%). The combined results of six case-control studies reported that the risk of CKD was significantly higher in patients with than without IBD (OR 1.36, 95% CI: 1.08-1.70, p = 0.008).

Conclusion

Although studies have shown an increased risk of CKD in IBD, due to the small number of included studies and high heterogeneity across studies, it is not enough to definitively conclude that CKD is more common in patients with IBD. But patients with IBD should be regularly monitored for CKD.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/.

Insights into renal and urological complications of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic condition characterized by immune-mediated inflammation in the gastrointestinal tract, which follows a relapsing and remitting course. Apart from affecting the gastrointestinal tract, IBD also has extra-intestinal manifestations (EIMs). While the etiology of extraintestinal manifestation remains unclear, it is theorized to be based on immunological responses influenced by genetic factors. Renal involvement is one of the EIMs observed in ulcerative colitis and Crohn's disease. The renal manifestations in IBD patients encompass a range of conditions including nephrolithiasis, amyloidosis, tubulointerstitial nephritis, glomerulonephritis (GN), obstructive pathologies, and chronic kidney disease (CKD). The incidence of CKD in IBD patients varies from 5%-15%. The decline in renal function can stem from various factors such as direct inflammatory damage to the kidneys leading to glomerular or tubular injury, or from complications like recurrent stones, amyloidosis, or GN. Additionally, nephrotoxic medications used in treating IBD, such as TNF-α inhibitors, calcineurin inhibitors, and aminosalicylates, can exacerbate the decline in renal function. Currently, there is a lack of consensus regarding these patients' screening and renal function monitoring. This review aims to assess the existing literature on the different renal complications among individuals with IBD, shedding light on their pathophysiology and management.

Ulcerative colitis and nephrotic syndrome: a two-sample Mendelian randomization study

To investigate the potential causal relationship between ulcerative colitis and nephrotic syndrome. We obtained the whole-genome association study data of ulcerative colitis in the European population from the GWAS database. Relevant single nucleotide polymorphisms (SNPs) were selected for analysis. We employed the inverse variance-weighted meta-analysis of multiplicative random effects models to obtain SNP-specific Wald ratio estimates, which assume horizontal pleiotropy. In addition, we performed sensitivity analyses using MR-Egger, weighted median, and IVW. Our findings suggest a strong association between ulcerative colitis and nephrotic syndrome (P < 0.05). After conducting sensitivity analyses, we found no evidence of horizontal pleiotropy or heterogeneity (P > 0.05). This study provides evidence for an association between ulcerative colitis and nephrotic syndrome, which may help us better understand the conditions of ulcerative colitis and nephropathy.

Renal manifestations in a cohort of pediatric patients with inflammatory bowel disease

BACKGROUND AND STUDY AIMS

Renal involvement in inflammatory bowel disease is rather uncommon. This study aims to describe the spectrum of renal involvement in pediatric patients with IBD and reduce delay in detection and management.

PATIENTS AND METHODS

This is a retrospective study of the renal function of all patients, aged <18 years, who have been followed for IBD in our pediatric gastroenterology department from January 2019 till January 2023.

RESULTS

From the 75 IBD patients included in this study 16 % had renal manifestations. The urinalysis revealed proteinuria in 7 patients, proteinuria and hematuria in 3 and proteinuria and glycosuria in 2 patients. All 12 patients with abnormal urinalysis underwent further investigation in order to determine the cause of renal damage and the results are as follows: 2 patients had glomerulonephritis and in other 2 patients renal damage was due to medication adverse effect, 1 had pyelonephritis in combination with chronic active tubulointerstitial nephritis and another 1 had thin basement membrane disease. Three patients had IBD-related dependent renal involvement and 1 resulted in chronic renal failure due to amyloidosis.

CONCLUSIONS

It is important for all clinicians to be aware of the possibility of renal manifestations in IBD patients for the early diagnosis and prevention of these manifestations and complications.

Safety of Biologics and Small Molecules for Inflammatory Bowel Diseases in Organ Transplant Recipients

PURPOSE

This study aimed to evaluate the safety of biologics and small molecules for the treatment of inflammatory bowel diseases (IBD) in patients receiving antirejection therapies after organ transplants.

MATERIALS AND METHODS

We reviewed the medical records of patients with IBD who received organ transplants at the Asan Medical Center between January 1989 and December 2021. We compared the parameters of patients receiving biologics or small molecules to those of patients without those therapies.

RESULTS

This study included a total of 53 patients (ulcerative colitis, 41; Crohn's disease, 6; and gastrointestinal Behçet's disease, 6). Among them, 15 patients were receiving biologics or small molecules and 38 were not. During a mean follow-up of 119 months, the proportion of patients experiencing severe infections was significantly higher in those treated with biologics or small molecules than in those not treated. However, other safety outcomes (e.g., malignancies, adverse events, including organizing pneumonia or hepatic failure, and death) were not different between the two groups. Kaplan-Meier curve analysis revealed no significant difference in the safety outcome rate related to the use of biologics or small molecules. During follow-up, eight patients underwent bowel resections for IBD. The rate of bowel resection was not different between the two groups.

CONCLUSION

The use of biologics or small molecules for patients with IBD who received organ transplants did not show a significant difference in safety outcomes. However, the possibility of severe infections must be considered.

Anti-Tumor Necrosis Factor Therapy and Risk of Kidney Function Decline and Mortality in Inflammatory Bowel Disease

Importance

Inflammatory bowel disease (IBD) is associated with adverse clinical outcomes, including chronic kidney disease and mortality, due in part to chronic inflammation. Little is known about the effects of anti-tumor necrosis factor (TNF) therapy on kidney disease progression and mortality among patients with new-onset IBD.

Objective

To examine the association of incident use of TNF inhibitors with subsequent decline in kidney function and risk of all-cause mortality.

Design, Setting, and Participants

This retrospective cohort study used data from the US Department of Veterans Affairs health care system. Participants were US veterans with new-onset IBD enrolled from October 1, 2004, through September 30, 2019. Data were analyzed from December 2022 to February 2024.

Exposures

Incident use of TNF inhibitors.

Main Outcomes and Measures

The main outcomes were at least 30% decline in estimated glomerular filtration rate (eGFR) and all-cause mortality.

Results

Among 10 689 patients (mean [SD] age, 67.4 [12.3] years; 9999 [93.5%] male) with incident IBD, 3353 (31.4%) had diabetes, the mean (SD) baseline eGFR was 77.2 (19.2) mL/min/1.73 m2, and 1515 (14.2%) were newly initiated on anti-TNF therapy. During a median (IQR) follow-up of 4.1 (1.9-7.0) years, 3367 patients experienced at least 30% decline in eGFR, and over a median (IQR) follow-up of 5.0 (2.5-8.0) years, 2502 patients died. After multivariable adjustments, incident use (vs nonuse) of TNF inhibitors was significantly associated with higher risk of decline in eGFR (adjusted hazard ratio [HR], 1.34 [95% CI, 1.18-1.52]) but was not associated with risk of all-cause mortality (adjusted HR, 1.02 [95% CI, 0.86-1.21]). Similar results were observed in sensitivity analyses.

Conclusions and Relevance

In this cohort study of US veterans with incident IBD, incident use (vs nonuse) of TNF inhibitors was independently associated with higher risk of progressive eGFR decline but was not associated with risk of all-cause mortality. Further studies are needed to elucidate potentially distinct pathophysiologic contributions of TNF inhibitor use to kidney and nonkidney outcomes in patients with IBD.

Exploring the autophagy-related pathogenesis of active ulcerative colitis

BACKGROUND

The pathogenesis of ulcerative colitis (UC) is complex, and recent therapeutic advances remain unable to fully alleviate the condition.

AIM

To inform the development of novel UC treatments, bioinformatics was used to explore the autophagy-related pathogenesis associated with the active phase of UC.

METHODS

The GEO database was searched for UC-related datasets that included healthy controls who met the screening criteria. Differential analysis was conducted to obtain differentially expressed genes (DEGs). Autophagy-related targets were collected and intersected with the DEGs to identiy differentially expressed autophagy-related genes (DEARGs) associated with active UC. DEARGs were then subjected to KEGG, GO, and DisGeNET disease enrichment analyses using R software. Differential analysis of immune infiltrating cells was performed using the CiberSort algorithm. The least absolute shrinkage and selection operator algorithm and protein-protein interaction network were used to narrow down the DEARGs, and the top five targets in the Dgree ranking were designated as core targets.

RESULTS

A total of 4822 DEGs were obtained, of which 58 were classified as DEARGs. SERPINA1, BAG3, HSPA5, CASP1, and CX3CL1 were identified as core targets. GO enrichment analysis revealed that DEARGs were primarily enriched in processes related to autophagy regulation and macroautophagy. KEGG enrichment analysis showed that DEARGs were predominantly associated with NOD-like receptor signaling and other signaling pathways. Disease enrichment analysis indicated that DEARGs were significantly linked to diseases such as malignant glioma and middle cerebral artery occlusion. Immune infiltration analysis demonstrated a higher presence of immune cells like activated memory CD4 T cells and follicular helper T cells in active UC patients than in healthy controls.

CONCLUSION

Autophagy is closely related to the active phase of UC and the potential targets obtained from the analysis in this study may provide new insight into the treatment of active UC patients.

The Natural History of Patients With Pre-Existing and De Novo Inflammatory Bowel Disease After Solid Organ Transplantation: EITOS Study of GETECCU

BACKGROUND

Limited data are available on the outcome of inflammatory bowel disease (IBD) in patients with solid organ transplantation (SOT). We describe the natural history of pre-existing IBD and de novo IBD after SOT.

METHODS

This was a retrospective, multicenter study that included patients with pre-existing IBD at the time of SOT and patients with de novo IBD after SOT. The primary outcome was IBD progression, defined by escalation of medical treatment, surgical therapy, or hospitalization due to refractory IBD. Risk factors were identified using multivariate Cox proportional hazard analysis.

RESULTS

A total of 177 patients (106 pre-existing IBD and 71 de novo IBD) were included. Most patients with pre-existing IBD (92.5%) were in remission before SOT. During follow-up, 32% of patients with pre-existing IBD had disease progression, with a median time between SOT and IBD progression of 2.2 (interquartile range, 1.3-4.6) years. In the de novo cohort, 55% of patients had disease progression with a median time to flare of 1.9 (interquartile range, 0.8-3.9) years after diagnosis. In the pre-existing IBD cohort, active IBD at the time of SOT (hazard ratio, 1.80; 95% confidence interval, 1.14-2.84; P = .012) and the presence of extraintestinal manifestations (hazard ratio, 3.10; 95% confidence interval, 1.47-6.54; P = .003) were predictive factors for IBD progression.

CONCLUSIONS

One-third of patients with pre-existing IBD and about half of patients with de novo IBD have disease progression after SOT. Active IBD at the time of SOT and the presence of extraintestinal manifestations were identified as risk factors for IBD progression.

Kidney Diseases Associated With Inflammatory Bowel Disease: Impact of Chronic Histologic Damage, Treatments, and Outcomes

INTRODUCTION

Kidney disease is a well-known extraintestinal manifestation (EIM) associated with inflammatory bowel disease (IBD), with a variety of underlying etiologies. However, little is known about the overall outcomes and predictors.

METHODS

This is a retrospective, observational cohort study. Patients with IBD in whom a native kidney biopsy was performed at Mayo Clinic (Rochester, MN) between 1994 and 2022, were included. Demographic, clinical, and histologic characteristics of prognostic interest were collected. The main outcomes were kidney failure, disease remission, kidney function changes at last follow-up, and death.

RESULTS

From a total cohort of 318 patients, we selected a study group of 111 patients followed-up with at our institution (45 ulcerative colitis [UC] and 66 Crohn's disease [CD]), with a mean age of 48 ± 17 years (40% females). IgA nephropathy (IgAN), chronic interstitial nephritis (CIN), and acute interstitial nephritis (AIN) were the most common diagnoses (22%, 19%, 13%, respectively). Median estimated glomerular filtration rate (eGFR) at presentation was 30 ml/min per 1.73 m2 (interquartile range [IQR]: 17-54) and urinary protein-to-creatinine ratio [UPCR] 0.8 g/g (0.3-3.4), without differences between IBD types. During a median follow-up of 59 months (12-109), 29 patients (26%) reached kidney failure. By multivariable analysis, the main predictors of kidney failure were age (hazard ratio [HR]: 1.04; P = 0.002), baseline eGFR (HR: 0.94; P = 0.003) and histologic chronicity score (HR: 4.01; P < 0.001). Therapeutic management varied according to underlying etiology. Global survival (kidney failure + death) was significantly better in patients who achieved complete or partial remission, or stabilization or improvement of kidney function.

CONCLUSION

One-fourth of patients with IBD with kidney disease may reach kidney failure, and the main determinants of this outcome is age, baseline eGFR, and degree of chronicity in kidney biopsy.

Absolute and Relative Risks of Kidney and Urological Complications in Patients With Inflammatory Bowel Disease

INTRODUCTION

The burden of kidney and urological complications in patients with inflammatory bowel disease (IBD) remains poorly characterized.

METHODS

We analyzed association between developing IBD (as a time-varying exposure) and relative risks of receiving diagnoses of chronic kidney disease (CKD), acute kidney injury (AKI), or kidney stones, and experiencing a clinically-relevant decline in estimated glomerular filtration rate (eGFR) (CKD progression; composite of kidney failure or an eGFR decline ≥30%) in 1,682,795 individuals seeking healthcare in Stockholm, Sweden, during 2006-2018. We quantified 5- and 10-year absolute risks of these complications in a parallel matched cohort of IBD cases and random controls matched (1:5) on sex, age, and eGFR.

RESULTS

During median 9 years, 10,117 participants developed IBD. Incident IBD was associated with higher risks of kidney-related complications compared with non-IBD periods: hazard ratio (HR) (95% confidence interval) was 1.24 (1.10-1.40) for receiving a CKD diagnosis and 1.11 (1.00-1.24) for CKD progression. For absolute risks, 11.8% IBD cases had a CKD event within 10-year. Of these, 6.4% received a CKD diagnosis, and 7.9% reached CKD progression. The risks of AKI (HR 1.97 [1.70-2.29]; 10-year absolute risk 3.6%) and kidney stones (HR 1.69 [1.48-1.93]; 10-year absolute risk 5.6%) were also elevated. Risks were similar in Crohn's disease and ulcerative colitis.

DISCUSSION

More than 10% of patients with IBD developed CKD within 10-year from diagnosis, with many not being identified through diagnostic codes. This, together with their elevated AKI and kidney stone risks, highlights the need of established protocols for kidney function monitoring and referral to nephrological/urological care for patients with IBD.

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.

Identification of shared gene signatures and molecular mechanisms between chronic kidney disease and ulcerative colitis

Background

There is a complex interaction between chronic kidney disease (CKD) and ulcerative colitis (UC), but the pathophysiological mechanisms underlying the coexistence of CKD and UC are unclear. This study aimed to investigate the key molecules and pathways that may mediate the co-occurrence of CKD and UC through quantitative bioinformatics analysis based on a public RNA-sequencing database.

Methods

The discovery datasets of CKD (GSE66494) and UC (GSE4183), as well as validation datasets of CKD (GSE115857) and UC (GSE10616), were downloaded from the Gene Expression Omnibus (GEO) database. After identifying differentially expressed genes (DEGs) with GEO2R online tool, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for the DEGs were performed. Next, protein-protein interaction network was constructed with Search Tool for the Retrieval of Interacting Genes (STRING) and visualized by Cytoscape. Gene modules were identified by the plug-in MCODE and hub genes were screened using the plug-in CytoHubba. Then, correlation between immune cell infiltration and hub genes was analyzed, and the receiver operating characteristic curves were used to assess the predictive value of hub genes. Finally, immunostaining of human specimens was used to validate the relevant findings.

Results

A total of 462 common DEGs were identified and selected for further analyses. GO and KEGG enrichment analyses indicated that these DEGs were primarily enriched in immune- and inflammation-related pathways. Among them, the PI3K-Akt signaling pathway ranked top in both discovery and validation cohorts, and the key signal molecule phosphorylated Akt (p-Akt) was shown to be significantly overexpressed in human CKD kidneys and UC colons, and further elevated in CKD-UC comorbidity specimens. Moreover, nine candidate hub genes, including CXCL8, CCL2, CD44, ICAM1, IL1A, CXCR2, PTPRC, ITGAX, and CSF3, were identified, of which ICAM1 was validated as a common hub gene. Besides, immune infiltration analysis revealed that neutrophils, macrophages, and CD4⁺ T memory cells significantly accumulated in both diseases, and ICAM1 was remarkably associated with neutrophil infiltration. Furthermore, intercellular adhesion molecule1 (ICAM1)-mediated neutrophil infiltration was validated to be upregulated in kidney and colon biopsies of CKD and UC patients, and further increased in patients diagnosed with both CKD and UC. Finally, ICAM1 had shown critical value as a diagnostic marker for the co-occurrence of CKD and UC.

Conclusions

Our study elucidated that immune response, PI3K-Akt signaling pathway, and ICAM1-mediated neutrophil infiltration might be the common pathogenesis of CKD and UC, and identified ICAM1 as a key potential biomarker and therapeutic target for the comorbidity of these two diseases.

A tetrapeptide from maize combined with probiotics exerted strong anti-inflammatory effects and modulated gut microbiota in DSS-induced colitis mice

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by recurrent gastrointestinal inflammation caused by abnormal immune response, and patients usually have intestinal flora imbalance. At present, the pathogenesis of UC is not well understood, and it appears that there is chronic activation of the immune and inflammatory cascade in genetically susceptible individuals. Some food supplements such as specific peptides and probiotics have been investigated and shown the potential for the treatment of UC. The purpose of this study is to investigate the therapeutic effect and potential mechanism of tetrapeptide from maize (TPM) and probiotic treatment on dextran sulfate sodium (DSS)-induced UC in C57BL/6J mice. Our results indicated that the therapeutic effects of TPM and probiotics are positively associated with a reduction in pro-inflammatory cytokine levels and restoration of the gut microbiota. Treatment with TPM or probiotics effectively alleviated the adverse effects of UC, including weight loss, shortened colon length, and colon and kidney tissue damage in mice. Additionally, both TPM and probiotics significantly reduced pro-inflammatory cytokine levels and oxidative stress in UC mice, and the effect was more pronounced when both were used together. Moreover, co-treatment with TPM and probiotics increased the diversity of gut microbes in UC mice, reduced the ratio of Firmicutes to Bacteroidetes (F/B) and increased the abundance of bacterial species, including Muribaculaceae, Alistipes, Ligilactobacillus and Lactobacillus, and has been shown to be beneficial for a variety of pathological conditions.

Renal manifestations in inflammatory bowel disease: a systematic review

As extra-intestinal manifestations (EIMs) are frequent in inflammatory bowel disease (IBD) and affect morbidity and sometimes even mortality, vigilance in the surveillance of EIMs and installing the appropriate treatment are essential. Data on renal manifestations in patients with IBD are however rare. Nevertheless, up to 5-15% of adult patients with IBD will develop chronic kidney disease over time. The pathophysiology of renal involvement in patients with IBD is complex and poorly understood, with a wide range of renal disorders affecting the glomeruli and/or the tubular structure. Furthermore, medication used to treat IBD can be potentially nephrotoxic and metabolic complication due to the disease itself can furthermore cause renal damage. The aim of this systematic review is to provide an overview of the existing data in literature on these renal manifestations and complications in patients with IBD.

Chemically Induced Colitis-Associated Cancer Models in Rodents for Pharmacological Modulation: A Systematic Review

Animal models for colitis-associated colorectal cancer (CACC) represent an important tool to explore the mechanistic basis of cancer-related inflammation, providing important evidence that several inflammatory mediators play specific roles in the initiation and perpetuation of colitis and CACC. Although several original articles have been published describing the CACC model in rodents, there is no consensus about the induction method. This review aims to identify, summarize, compare, and discuss the chemical methods for the induction of CACC through the PRISMA methodology.

METHODS

We searched MEDLINE via the Pubmed platform for studies published through March 2021, using a highly sensitive search expression. The inclusion criteria were only original articles, articles where a chemically-induced animal model of CACC is described, preclinical studies in vivo with rodents, and articles published in English.

RESULTS

Chemically inducible models typically begin with the administration of a carcinogenic compound (as azoxymethane (AOM) or 1,2-dimethylhydrazine (DMH)), and inflammation is caused by repeated cycles of colitis-inducing agents (such as 2,4,6-trinitrobenzenesulfonic acid (TNBS) or dextran sulfate sodium (DSS)). The strains mostly used are C57BL/6 and Balb/c with 5-6 weeks. To characterize the preclinical model, the parameters more used include body weight, stool consistency and morbidity, inflammatory biomarkers such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, angiogenesis markers such as proliferating cell nuclear antigen (PCNA), marker of proliferation Ki-67, and caspase 3, the presence of ulcers, thickness or hyperemia in the colon, and histological evaluation of inflammation.

CONCLUSION

The AOM administration seems to be important to the CACC induction method, since the carcinogenic effect is achieved with just one administration. DSS has been the more used inflammatory agent; however, the TNBS contribution should be more studied, since it allows a reliable, robust, and a highly reproducible animal model of intestinal inflammation.

Therapy patterns and surveillance measures of Inflammatory Bowel Disease patients beyond disease-related hospitalization: a claims-based cohort study

Introduction

Medical care and surveillance of inflammatory bowel disease (IBD) patients have been shown to be far from satisfactory. Data on therapy patterns and surveillance measures in IBD patients are scarce. We, therefore, aimed to compare the therapy patterns and surveillance management of IBD patients in the year before and after IBD-related hospitalization.

Methods

We examined medical therapy, surveillance management (influenza vaccination, dermatologist visits, Pap smear screening, creatinine measurements, iron measurements, and ophthalmologist visits) and healthcare utilization in 214 ulcerative colitis (UC) and 259 Crohn's disease (CD) patients who underwent IBD-related hospitalization from 2012 to 2014.

Results

IBD-related drug classes changed in 64.5% of IBD patients following hospitalization. During the 1-year follow-up period, biological treatment increased in UC and CD patients, while steroid use decreased. Following hospitalization, 63.1% of UC and 27.0% of CD patients received 5-ASA. Only 21.6% of all IBD patients had a flu shot, and 19.6% of immunosuppressed IBD patients were seen by a dermatologist in the follow-up; other surveillance measures were more frequent. Surveillance before hospital admission and consultations by gastroenterologists were strongly correlated with surveillance during the postoperative follow-up, while gender and diagnosis (UC vs. CD) were not. During the 1-year follow-up, 20.5% of all IBD patients had no diagnostic or disease-monitoring procedure.

Discussion/Conclusion

Surveillance measures for IBD patients are underused in Switzerland. Further research is needed to examine the impact of annual screenings and surveillance on patient outcomes.

Kidney function monitoring in inflammatory bowel disease: The MONITORED consensus

BACKGROUND AND AIMS

Patients with inflammatory bowel diseases (IBD) are exposed to drug-related nephrotoxicity and kidney-related extra-intestinal manifestations (EIMs). Patients should be monitored but guidance is lacking in current international recommendations. The objective of the Kidney Function Monitoring in Inflammatory Bowel Disease (MONITORED) initiative was to achieve an expert consensus about monitoring kidney function in IBD.

METHODS

A literature review was first conducted. Then, an expert consensus meeting, involving 28 attendees representing French-speaking gastroenterologists and nephrologists, was held as part of an academic initiative on May 28, 2021. An anonymous Delphi process was used to discuss and vote on statements. Agreement was defined as at least 75% of participants voting for any one statement.

RESULTS

Experts reached consensus on 11 criteria for referral to the nephrologist. Concerning kidney function monitoring, participants unanimously validated the use of serum creatinine with estimation of the glomerular filtration rate via the MDRD or CKD-EPI equations. A blood ionogram and a urine sample with measurement of a protein-to-creatinine ratio were also broadly agreed validated. Experts recommended performing this monitoring at IBD diagnosis, prior introducing a new treatment, and annually for EIMs screening and evaluation of treatment tolerance. An evaluation 3 months after starting mesalamine and then every 6 months was felt necessary, while for biologics an annually monitoring was deemed sufficient.

CONCLUSION

The MONITORED consensus proposed guidelines on how to monitor kidney function in IBD. These recommendations should be considered in clinical practice to preserve kidney function and ensure the best approach to our patients.

Knowledge of 5-aminosalicylic acid nephrotoxicity and adherence to kidney function monitoring of patients with inflammatory bowel disease

BACKGROUND AND AIM

5-Aminosalicylic acid (5-ASA) nephrotoxicity is a rare and idiosyncratic condition in patients with inflammatory bowel disease (IBD), which may lead to end-stage kidney failure. Kidney function monitoring is recommended in clinical practice to prevent this complication. However, no data is available regarding the knowledge and adherence of patients with IBD to this monitoring.

METHODS

As a part of routine practice, patients with IBD under treatment or previously treated with 5-ASA were systematically interviewed about knowledge of 5-ASA nephrotoxicity and adherence to kidney function monitoring. We reported here the experience among the first 103 consecutive patients seen in a French referral center.

RESULTS

A total of 103 patients (93.2% ulcerative colitis, 5.8% Crohn's disease, and 1% unclassified colitis) were analyzed. Among them, 70% were informed about the need for kidney function monitoring, and in most cases, information was provided by their gastroenterologist (94.4%). The adherence rate to monitoring was very high (84.7%). Monitoring consisted of serum creatinine and estimated glomerular filtration rate in most cases (97.2%), while 24-h proteinuria was less frequently used (69.4%). These tests were performed twice or ≥3 times per year by 44.4 and 41.7% of patients, respectively. One case of isolated elevation of proteinuria related to 5-ASA treatment was observed.

CONCLUSION

We reported for the first time that patients with IBD are well informed and adherent to kidney function monitoring of treatment with 5-ASA. The monitoring performed by their treating physician was generally in accordance with current recommendations.

Recurrent urinary tract infection with antibiotic-resistant Klebsiella pneumoniae in a patient with Crohn's disease: A case report

Recurrent urinary tract infections with resistant strains of Klebsiella pneumoniae are a potential complication of the long-term use of immunosuppressive therapy in patients with Crohn's disease.

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.

Different renal manifestations associated with very early onset pediatric inflammatory bowel disease: case report and review of literature

Background

Inflammatory bowel diseases are characterized by chronic inflammation of the gastrointestinal tract. In particular, Crohn disease and ulcerative colitis represent the two most common types of clinical manifestations. Extraintestinal manifestations of inflammatory bowel diseases represent a common complications, probably reflecting the systemic inflammation. Renal involvement is reported in 4–23% of cases. However, available data are limited to few case series and retrospective analysis, therefore the real impact of renal involvement is not well defined.

Case presentation

We report the case of a 10-years old male affected by very early onset unclassified-Inflammatory bowel diseases since he was 1-year old, presenting with a flare of inflammatory bowel diseases associated with acute kidney injury due to granulomatous interstitial nephritis. Of interest, at 7-year-old, he was treated for IgA nephropathy.

To our knowledge, no previous reports have described a relapse of renal manifestation in inflammatory bowel diseases, characterized by two different clinical and histological phenotypes.

Conclusions

The link between the onset of kidney injuries with flares of intestinal inflammation suggest that nephritis maybe considered an extra-intestinal manifestation correlated with active inflammatory bowel disease. However, if granulomatous interstitial nephritis represents a cell-mediated hypersensitivity reaction than a true extraintestinal manifestation of inflammatory bowel diseases is still not clarified. We suggest as these renal manifestations here described may be interpreted as extraintestinal disorder and also considered as systemic signal of under treatment of the intestinal disease.

Inflammatory Bowel Disease Is More Common in Patients with IgA Nephropathy and Predicts Progression of ESKD: A Swedish Population-Based Cohort Study

BACKGROUND

Case reports suggest an association between inflammatory bowel disease, a chronic autoimmune condition linked to increased circulating IgA levels, and IgA nephropathy, the most common form of primary GN and a leading cause of ESKD.

METHODS

In a Swedish population-based cohort study, we compared 3963 biopsy-verified IgA nephropathy patients with 19,978 matched controls between 1974 and 2011, following up participants until 2015. Inflammatory bowel disease data and ESKD status were obtained through national medical registers. We applied Cox regression to estimate hazard ratios (HRs) for future inflammatory bowel disease in IgA nephropathy and conditional logistic regression to assess risk of earlier inflammatory bowel disease in IgA nephropathy. We also explored whether inflammatory bowel disease affects development of ESKD in IgA nephropathy.

RESULTS

During a median follow-up of 12.6 years, 196 (4.95%) patients with IgA nephropathy and 330 (1.65%) matched controls developed inflammatory bowel disease (adjusted HR, 3.29; 95% confidence interval [95% CI], 2.73 to 3.96). Inflammatory bowel disease also was more common before a confirmed IgA nephropathy diagnosis. Some 103 (2.53%) IgA nephropathy patients had an earlier inflammatory bowel disease diagnosis compared with 220 (1.09%) controls (odds ratio [OR], 2.37; 95% CI, 1.87 to 3.01). Both logistic regression (OR, 2.60; 95% CI, 2.02 to 3.35) and time-varying Cox regression (HR, 1.84; 95% CI, 1.33 to 2.55) demonstrated that inflammatory bowel disease was associated with increased ESKD risk in patients with IgA nephropathy.

CONCLUSIONS

Patients with IgA nephropathy have an increased risk of inflammatory bowel disease both before and after their nephropathy diagnosis. In addition, among patients with IgA nephropathy, comorbid inflammatory bowel disease elevates the risk of progression to ESKD.

Renal involvement in paediatric inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease, ulcerative colitis and inflammatory bowel disease unclassified, is a chronic inflammatory disorder that predominantly affects the gastrointestinal (GI) tract and has a rising incidence in both children and adults. Symptoms are caused by inappropriate inflammatory response triggered by interaction between the environment, gut microbiome and host immune system in a genetically susceptible individual. Extranintestinal manifestations of IBD are common and can affect any body system outside the gut; they can precede or run parallel to GI inflammation. Renal involvement in IBD is uncommon and can be part of extraintestinal manifestation or metabolic complications of IBD. Many medications used to treat IBD can cause renal damage. Renal manifestation in children with IBD can range from asymptomatic biochemical abnormalities to variable stages of renal impairment with significant morbidity and even mortality burden.

Long-term outcome of biopsy-proven idiopathic tubulointersitial nephritis with or without uveitis in children-a nationwide follow-up study

BACKGROUND

Only a few studies reporting the long-term outcome of children with idiopathic tubulointerstitial nephritis (TIN) and uveitis syndrome (TINU) are available. We studied the long-term kidney and ocular outcome in a nationwide cohort of children with TIN or TINU.

METHODS

All patients followed up for a minimum of 1 year by a paediatrician and an ophthalmologist were enrolled. The data on plasma creatinine (P-Cr), estimated glomerular filtration rate (eGFR), proteinuria, hypertension and uveitis were collected retrospectively.

RESULTS

Fifty-two patients were studied. Median age at time of diagnosis was 13.1 (1.8-16.9) years and median follow-up time was 5.7 (1.1-21.2) years. Forty-five (87%) patients were initially treated with glucocorticoids. The median of the maximum P-Cr was 162 μmol/l (47-1,016) and that of eGFR 47 ml/min/1.73m² (8-124). Uveitis was diagnosed in 33 patients (63%) and 21 (40%) patients developed chronic uveitis. P-Cr normalised in a median of 2 months. Eleven (21%) patients had nephritis recurrence during or after discontinuation of glucocorticoids. At the latest follow-up, 13 (25%) patients had eGFR < 90 ml/min/1.73m² (median 83; 61-89 ml/min/1.73m²). Six patients had tubular proteinuria; all presented with TIN without uveitis. Seven (13%) patients were hypertensive. Eleven (21%) patients had uveitis. One patient developed uraemia and was later transplanted.

CONCLUSIONS

Our study questions the previously reported good long-term kidney and ocular outcome of patients with TIN/TINU. Decreased kidney function and/or ocular co-morbidities may persist for several years; thus, both kidney and ocular follow-up for at least 1 year is warranted. A higher resolution version of the Graphical abstract is available as Supplementary information.

Inflammatory bowel disease: Therapeutic limitations and prospective of the stem cell therapy

Inflammatory bowel disease (IBD), consisting primarily of ulcerative colitis and Crohn’s disease, is a group of debilitating auto-immune disorders, which also increases the risk of colitis-associated cancer. However, due to the chronic nature of the disease and inconsistent treatment outcomes of current anti-IBD drugs (e.g., approximately 30% non-responders to anti-TNFα agents), and related serious side effects, about half of all IBD patients (in millions) turn to alternative treatment options. In this regard, mucosal healing is gaining acceptance as a measure of disease activity in IBD patients as recent studies have correlated the success of mucosal healing with improved prognosis. However, despite the increasing clinical realization of the significance of the concept of mucosal healing, its regulation and means of therapeutic targeting remain largely unclear. Here, stem-cell therapy, which uses hematopoietic stem cells or mesenchymal stem cells, remains a promising option. Stem cells are the pluripotent cells with ability to differentiate into the epithelial and/or immune-modulatory cells. The over-reaching concept is that the stem cells can migrate to the damaged areas of the intestine to provide curative help in the mucosal healing process. Moreover, by differentiating into the mature intestinal epithelial cells, the stem cells also help in restoring the barrier integrity of the intestinal lining and hence prevent the immunomodulatory induction, the root cause of the IBD. In this article, we elaborate upon the current status of the clinical management of IBD and potential role of the stem cell therapy in improving IBD therapy and patient’s quality of life.

Gastrointestinal complications after kidney transplantation

Gastrointestinal complications are common after renal transplantation, and they have a wide clinical spectrum, varying from diarrhoea to post-transplant inflammatory bowel disease (IBD). Chronic immunosuppression may increase the risk of post-transplant infection and medication-related injury and may also be responsible for IBD in kidney transplant re-cipients despite immunosuppression. Differentiating the various forms of post-transplant colitis is challenging, since most have similar clinical and histological features. Drug-related colitis are the most frequently encountered colitis after kidney transplantation, particularly those related to the chronic use of mycophenolate mofetil, while de novo IBDs are quite rare. This review will explore colitis after kidney transplantation, with a particular focus on different clinical and histological features, attempting to clearly identify the right treatment, thereby improving the final outcome of patients.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

The Influence of a Nanopatterned Scaffold that Mimics Abnormal Renal Mesangial Matrix on Mesangial Cell Behavior

The alteration of mesangial matrix (MM) components in mesangium, such as type IV collagen (COL4) and type I collagen (COL1), is commonly found in progressive glomerular disease. Mesangial cells (MCs) responding to altered MM, show critical changes in cell function. This suggests that the diseased MM structure could play an important role in MC behavior. To investigate how MC behavior is influenced by the diseased MM 3D nanostructure, we fabricated the titanium dioxide (TiO2)-based nanopatterns that mimic diseased MM nanostructures. Immortalized mouse MCs were used to assess the influence of disease-mimic nanopatterns on cell functions, and were compared with a normal-mimic nanopattern. The results showed that the disease-mimic nanopattern induced disease-like behavior, including increased proliferation, excessive production of abnormal MM components (COL1 and fibronectin) and decreased normal MM components (COL4 and laminin α1). In contrast, the normal-mimic nanopattern actually resulted in cells displaying normal proliferation and the production of normal MM components. In addition, increased expressions of α-smooth muscle actin (α-SMA), transforming growth factor β1 (TGF-β1) and integrin α5β1 were detected in cells grown on the disease-mimic nanopattern. These results indicated that the disease-mimic nanopattern induced disease-like cell behavior. These findings will help further establish a disease model that mimics abnormal MM nanostructures and also to elucidate the molecular mechanisms underlying glomerular disease.

Inflammatory bowel disease in patients undergoing renal biopsies

BACKGROUND

There are no good data in the literature on the prevalence of inflammatory bowel disease (IBD) in patients with kidney disease and we do not know whether IBD affects the course of kidney disease or if the type of IBD is an influential factor. The aim of this study was to evaluate the prevalence of IBD among patients who have undergone renal biopsies due to clinical indications and to elucidate whether the presence of IBD influences renal and patient outcomes.

METHODS

We collected retrospective data on concomitant diseases, especially IBD, from adult patients undergoing renal biopsy for any clinical indication between 2000 and 2012 at Tampere University Hospital, Tampere, Finland. Information was systematically collected on the activity of IBD, medication for IBD, surgery performed for IBD and markers of kidney function.

RESULTS

Of the 819 patients biopsied, 35 (4.3%) had IBD. The prevalence of IBD was 13.3 and 4.6% in patients with tubulointerstitial nephritis (TIN) and immunoglobulin A nephropathy (IgAN), respectively. In comparison, the prevalence of IBD in the Finnish population is 0.6%. Ulcerative colitis and Crohn's disease were equally represented. The presence of IBD showed no impact on renal and patient outcomes.

CONCLUSIONS

IBD should not be overlooked in patients undergoing renal biopsies, especially those diagnosed with TIN or IgAN. The renal findings did not associate with the activity of intestinal inflammation. Whether a concomitant IBD truly affects the course of chronic kidney disease should be examined in further studies.

Preclinical Study in Vivo for New Pharmacological Approaches in Inflammatory Bowel Disease: A Systematic Review of Chronic Model of TNBS-Induced Colitis

The preclinical studies in vivo provide means of characterizing physiologic interactions when our understanding of such processes is insufficient to allow replacement with in vitro systems and play a pivotal role in the development of a novel therapeutic drug cure. Chemically induced colitis models are relatively easy and rapid to develop. The 2,4,6-trinitrobenzenesulfonic acid (TNBS) colitis model is one of the main models in the experimental studies of inflammatory bowel disease (IBD) since inflammation induced by TNBS mimics several features of Crohn’s disease. This review aims to summarize the existing literature and discuss different protocols for the induction of chronic model of TNBS-induced colitis. We searched MEDLINE via Pubmed platform for studies published through December 2018, using MeSH terms (Crohn Disease.kw) OR (Inflammatory Bowel Diseases.kw) OR (Colitis, Ulcerative.kw) AND (trinitrobenzenesulfonic acid.kw) AND (disease models, animal.kw) AND (mice.all). The inclusion criteria were original articles, preclinical studies in vivo using mice, chronic model of colitis, and TNBS as the inducer of colitis and articles published in English. Chronic TNBS-induced colitis is made with multiple TNBS intrarectal administrations in an average dose of 1.2 mg using a volume lower than 150 μL in 50% ethanol. The strains mostly used are Balb/c and C57BL/6 with 5–6 weeks. To characterize the preclinical model the parameters more used include body weight, stool consistency and morbidity, inflammatory biomarkers like interferon (IFN)-γ, myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10, presence of ulcers, thickness or hyperemia in the colon, and histological evaluation of the inflammation. Experimental chronic colitis is induced by multiple rectal instillations of TNBS increasing doses in ethanol using Balb/c and C57BL/6 mice.

Predicting the Need for a Tier II Ototoxicity Study From Early Renal Function Data

History has established that many drugs, such as the antibiotics, chemotherapies, and loop diuretics, are capable of inducing both nephrotoxicity and ototoxicity. The exact mechanisms by which cellular damage occurs remain to be fully elucidated. Monitoring the indices of renal function conducted in the Food and Drug Administration's prescribed set of early investigational new drug (IND)-enabling studies may be the first signs of ototoxicity properties of the new drug candidate. In developing improved and efficacious new molecular entities, it is critically necessary to understand the cellular and molecular mechanisms underlying the potential ototoxic effects as early in the drug development program as possible. Elucidation of these mechanisms will facilitate the development of safe and effective clinical approaches for the prevention and amelioration of drug-induced ototoxicity prior to the first dose in man. Biomarkers for nephrotoxicity in early tier I or tier II nonclinical IND-enabling studies should raise an inquiry as to the need to conduct a full auditory function assay early in the game to clear the pipeline with a safer candidate that has a higher probability of continued therapeutic compliance once approved for distribution.

[Renal and Urinary Manifestations of Inflammatory Bowel Disease]

The incidence of inflammatory bowel disease (IBD) is increasing rapidly and extra-intestinal manifestations in IBD are also increasing. The prevalence of renal and urinary involvement in IBD ranges from 4-23%. Nephrolithiasis is the most common urinary complication in IBD patients. Parenchymal renal disease is rare but has been well documented and presents most commonly as glomerulonephritis or tubulointerstitial nephritis. The overall morbidity of IBD-related renal manifestations is significant. Therefore, a high index of clinical suspicion and optimal monitoring of the renal function are needed for the early diagnosis and prevention of IBD-related renal manifestations and complications.

Extraintestinal Manifestations of Inflammatory Bowel Disease: Epidemiology, Etiopathogenesis, and Management

PURPOSE OF REVIEW

Extraintestinal manifestations (EIMs) of inflammatory bowel disease (IBD) represent a complex array of disease processes with variable epidemiologic penetrance, genetic antecedents, and phenotypic presentations. The purpose of this review is to provide an overview of primary and secondary EIMs as well as salient treatment strategies utilized.

RECENT FINDINGS

While the genetic antecedents remain incompletely understood, the treatment armamentarium for EIMs has expanded with new pharmaceutical drug classes that effectively treat IBD. EIMs are an increasingly recognized complication of IBD that require prompt recognition, multidisciplinary management, and a multifaceted therapeutic approach. This review highlights the complexities and ramifications of EIM management and offers therapeutic guidance.

A Review of Extraintestinal Manifestations and Complications of Inflammatory Bowel Disease

Extraintestinal manifestations (EIMs) are common in inflammatory bowel disease (IBD), in both Crohn's disease and ulcerative colitis. Almost any organ system can be affected, including the musculoskeletal, dermatologic, renal, hepatopancreatobiliary, pulmonary and ocular systems. However, the musculoskeletal and dermatologic systems are the most commonly involved sites of manifestations. While some manifestations such as peripheral arthritis and erythema nodosum have an association with IBD activity, others such as axial arthropathy, pyoderma gangrenosum and primary sclerosing cholangitis have an independent disease course. This review provides a summary of the most common EIMs in IBD and their prevalence and management.

Kidney transplantation in patients with inflammatory bowel diseases (IBD): analysis of transplantation outcome and IBD activity

Inflammatory bowel diseases (IBD) is a systemic disorder with possible renal involvement, yet data regarding the outcome of kidney transplantation (KT) in those patients, and IBD course post KT, are scarce. In this retrospective analysis, we studied the outcome of 12 IBD kidney recipients (seven Crohn's disease, five ulcerative colitis; primary kidney disease was IgA nephropathy in five, polycystic disease in four), compared to two control groups: matched controls and a cohort of recipients with similar kidney disease. During a follow-up period of 60.1 (11.0-76.6) months (median, interquartile range), estimated 5-year survival was 80.8 vs. 96.8%, with and without IBD, respectively (P = 0.001). Risk of death with a functioning graft was higher with IBD (HR = 1.441, P = 0.048), and with increased age (HR = 1.109, P = 0.05). Late rehospitalization rate was higher in IBD [incidence rate ratio = 1.168, P = 0.030], as well as rate of hospitalization related to infection [1.42, P = 0.037]. All patients that were in remission before KT, remission was maintained. Patients that were transplanted with mild or moderate disease remained stable or improved with Infliximab or Adalimumab treatment. In conclusion, IBD is associated with an increased risk of mortality, hospitalization because of infection and late rehospitalization after KT. Clinical course of IBD is stable after KT.

A comprehensive review and update on ulcerative colitis. Dis Mon 2019;65:100851. [PMID: 30837080 DOI: 10.1016/j.disamonth.2019.02.004]

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disorder of the colon that causes continuous mucosal inflammation extending from the rectum to the more proximal colon, with variable extents. UC is characterized by a relapsing and remitting course. UC was first described by Samuel Wilks in 1859 and it is more common than Crohn's disease worldwide. The overall incidence and prevalence of UC is reported to be 1.2-20.3 and 7.6-245 cases per 100,000 persons/year respectively. UC has a bimodal age distribution with an incidence peak in the 2nd or 3rd decades and followed by second peak between 50 and 80 years of age. The key risk factors for UC include genetics, environmental factors, autoimmunity and gut microbiota. The classic presentation of UC include bloody diarrhea with or without mucus, rectal urgency, tenesmus, and variable degrees of abdominal pain that is often relieved by defecation. UC is diagnosed based on the combination of clinical presentation, endoscopic findings, histology, and the absence of alternative diagnoses. In addition to confirming the diagnosis of UC, it is also important to define the extent and severity of inflammation, which aids in the selection of appropriate treatment and for predicting the patient's prognosis. Ileocolonoscopy with biopsy is the only way to make a definitive diagnosis of UC. A pathognomonic finding of UC is the presence of continuous colonic inflammation characterized by erythema, loss of normal vascular pattern, granularity, erosions, friability, bleeding, and ulcerations, with distinct demarcation between inflamed and non-inflamed bowel. Histopathology is the definitive tool in diagnosing UC, assessing the disease severity and identifying intraepithelial neoplasia (dysplasia) or cancer. The classical histological changes in UC include decreased crypt density, crypt architectural distortion, irregular mucosal surface and heavy diffuse transmucosal inflammation, in the absence of genuine granulomas. Abdominal computed tomographic (CT) scanning is the preferred initial radiographic imaging study in UC patients with acute abdominal symptoms. The hallmark CT finding of UC is mural thickening with a mean wall thickness of 8 mm, as opposed to a 2-3 mm mean wall thickness of the normal colon. The Mayo scoring system is a commonly used index to assess disease severity and monitor patients during therapy. The goals of treatment in UC are three fold-improve quality of life, achieve steroid free remission and minimize the risk of cancer. The choice of treatment depends on disease extent, severity and the course of the disease. For proctitis, topical 5-aminosalicylic acid (5-ASA) drugs are used as the first line agents. UC patients with more extensive or severe disease should be treated with a combination of oral and topical 5-ASA drugs +/- corticosteroids to induce remission. Patients with severe UC need to be hospitalized for treatment. The options in these patients include intravenous steroids and if refractory, calcineurin inhibitors (cyclosporine, tacrolimus) or tumor necrosis factor-α antibodies (infliximab) are utilized. Once remission is induced, patients are then continued on appropriate medications to maintain remission. Indications for emergency surgery include refractory toxic megacolon, colonic perforation, or severe colorectal bleeding.

IL-10 polymorphisms +434T/C, +504G/T, and -2849C/T may predispose to tubulointersititial nephritis and uveitis in pediatric population

BACKGROUND

Tubulointerstitial nephritis (TIN) and uveitis syndrome (TINU) are likely to be autoimmune diseases. Based on previous studies, adults with isolated idiopathic uveitis have polymorphisms in interleukin 10 (IL-10) and tumor necrosis factor α (TNF-α) genes. We aimed to evaluate the presence of IL-10 and TNF-α polymorphisms in a nationwide cohort of pediatric TIN/TINU patients.

METHODS

Single nucleotide polymorphisms in IL-10 (+434T/C, +504G/T, -1082G/A, -2849C/T) and in TNFα (-308G/A, -238G/A, -857C/T) genes were genotyped in 30 well-defined pediatric patients with idiopathic TIN/TINU syndrome. Control group frequencies for these SNPs were obtained from 393 independent Finnish subjects.

RESULTS

The homozygous minor allele in IL-10 +434T (rs2222202) and IL-10+504G (rs3024490) was found in all patients with TIN or TINU syndrome while the frequency of these minor alleles in the control population was 44% and 23%, respectively (p <0.001). In IL-10 SNP -2849 (rs6703630) a significant difference was found with genotype TT in all patients (p = 0.004) and in subgroups with TINU syndrome (p = 0.017) and TINU syndrome with chronic uveitis (p = 0.01) compared to reference population. There were no statistical differences in any of the studied TNF-α genotypes between TIN/TINU patients and control population.

CONCLUSIONS

A significant difference in the frequency of IL-10+434T and +504G alleles was found between TIN/TINU patients and control population. Genotype -2849TT was more frequently present in patients with TINU syndrome than in the reference subjects. Genetic variation in the inflammatory mediators may predispose to autoimmune nephritis and uveitis.

Trends and Factors Associated with Hospitalization Costs for Inflammatory Bowel Disease in the United States

BACKGROUND

Few studies have addressed recent trends in hospitalization costs for inflammatory bowel disease (IBD).

OBJECTIVE

We explored trends and described patient and hospital factors associated with hospitalization costs for IBD.

METHODS

Using data from the 2003-2014 National Inpatient Sample for adults aged ≥ 18 years, we estimated costs using multivariable linear models and assessed linear trends by time periods using piecewise linear regressions.

RESULTS

In 2014, there were an estimated 56,290 hospitalizations for Crohn's disease (CD), with a mean cost of US$11,345 and median cost of US$7592; and 33,585 hospitalizations for ulcerative colitis (UC), with a mean cost of US$13,412 and median cost of US$8873. Higher costs were observed among Hispanic [adjusted cost ratio (ACR) = 1.07; 95% confidence interval (CI) = 1.00-1.14; p = 0.04] or other non-Hispanic (ACR = 1.09; 95% CI = 1.02-1.17; p = 0.01) CD patients than for non-Hispanic White CD patients. For UC patients, higher costs were observed among men (ACR = 1.09; 95% CI = 1.05-1.13; p < 0.001) compared with women and among patients aged 35-44 years, 45-54 years, and 55-64 years compared with those aged 18-24 years. Among all patients, factors associated with higher costs included higher household income, more comorbidities, and hospitals that were government nonfederal versus private, were large versus small, and were located in the West versus Northeast regions. From 2003 to 2008, total costs increased annually by 3% for CD (1.03; 95% CI = 1.02-1.05; p < 0.001) and 4% for UC (1.04; 95% CI = 1.02-1.06; p < 0.001), but remained unchanged from 2008 to 2014.

CONCLUSIONS

The findings are important to identify IBD patients with higher hospitalization costs and to inform policy plans on hospital resource allocation.

Tubulointerstitial Nephritis

Tubulointerstitial nephritis (TIN) is a cause of acute kidney injury in children characterized histologically by an inflammatory cell infiltrate in the kidney interstitium. The most common causes of TIN in children include medications, infections, inflammatory disorders, and genetic conditions. TIN typically presents with nonoliguric acute kidney injury and may be associated with systemic symptoms, including fever, rash, and eosinophilia. The long-term prognosis is generally favorable, with full kidney recovery; however, some patients may develop progressive chronic kidney disease. Immunosuppressive therapy may be indicated for severe or prolonged disease.

Characterization of the Effect of Renal Impairment on Upadacitinib Pharmacokinetics

Upadacitinib is a novel selective Janus kinase 1 inhibitor developed for treatment of rheumatoid arthritis and other autoimmune diseases. The objective of this study was to assess the pharmacokinetics and safety of a single upadacitinib dose in subjects with normal renal function and in subjects with renal impairment. A total of 24 subjects between the ages of 18 and 75 years were assigned to 1 of 4 renal function groups based on estimated glomerular filtration rate (normal, mild, moderate, severe; N = 6/group). A single 15-mg dose of upadacitinib extended-release formulation was administered under fasting conditions. Serial plasma and urine samples were assayed to evaluate the effect of renal impairment on upadacitinib exposure through regression analysis and analysis of covariance. The primary analysis was the regression analysis of upadacitinib exposures versus estimated glomerular filtration rate. The point estimates for upadacitinib plasma exposure ratios (90% confidence interval [CI]) in subjects with mild, moderate, and severe renal impairment were 1.18 (90%CI, 1.06-1.32), 1.33 (90%CI, 1.11-1.59), and 1.44 (90%CI, 1.14-1.82) for area under the plasma concentration-time curve and 1.06 (90%CI, 0.92-1.23), 1.11 (90%CI, 0.88-1.40), and 1.14 (90%CI, 0.84-1.56) for maximum observed plasma concentration, respectively, relative to subjects with normal renal function based on the regression analysis. The analysis of covariance categorical analysis provided consistent results. Upadacitinib was well tolerated by all subjects, and no safety issues were identified in subjects with renal impairment. Renal impairment has a limited effect on upadacitinib pharmacokinetics. This is in agreement with the known limited role of urinary excretion in upadacitinib elimination. Based on the limited impact on exposure, no dose adjustment is necessary for upadacitinib in subjects with impaired renal function.

Pediatric Inflammatory Bowel Diseases: Should We Be Looking for Kidney Abnormalities?

BACKGROUND

Kidney disease has been reported in adults with inflammatory bowel disease (IBD) and is regarded an extraintestinal manifestation or more rarely a side effect of the medical treatment.

METHODS

In this cross-sectional study we describe the extent of kidney pathology in a cohort of 56 children with IBD. Blood and urine samples were analyzed for markers of kidney disease and ultrasonography was performed to evaluate pole-to-pole kidney length.

RESULTS

We found that 25% of the patients had either previously reported kidney disease or ultrasonographic signs of chronic kidney disease. The median kidney size compared with normal children was significantly reduced. In a multivariate linear mixed model, small kidneys significantly correlated with the use of infliximab, whereas the use of enteral nutritional therapy was associated with larger kidneys.

CONCLUSION

Children with IBD are at risk of chronic kidney disease, and the risk seems to be increased with the severity of the disease.

Hemin reduces inflammation associated with TNBS-induced colitis

Purpose

Hemin is a heme-oxygenase inducer, which can confer anti-inflammatory, cytoprotective, and antiapoptotic effects. These properties are beneficial therapeutical effects to inflammatory bowel disease (IBD). IBD is a worldwide health problem characterized by chronic inflammation of intestinal epithelium, which promotes intestinal and extraintestinal symptomatology. Current treatment only induces and maintains the patient in remission and results in many side effects. The research of other pharmacologic approaches is crucial to the treatment of IBD. The aim of this study is to evaluate the effect of hemin in the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model.

Materials and methods

Male CD-1 mice with TNBS-induced colitis were treated with a daily dose of hemin 5 mg/kg body weight/day and 10 mg/kg body weight/day intraperitoneal, during 4 days. The evaluated parameters were fecal hemoglobin, alkaline phosphatase (ALP), myeloperoxidase, tumor necrosis factor-α, interleukin (IL)-1β, IL-10, histopathologic analysis, urea, creatinine, and alanine aminotransferase.

Results

The hemin-treated mice presented a decrease in fecal hemoglobin, ALP, and proinflammatory cytokine concentrations compared to the TNBS group. Histopathology analysis confirmed the decrease in lesion extension produced by hemin.

Conclusion

These findings suggest that hemin treatment reduces hemorrhagic focus, intestinal damage, tissue inflammation, and lesion extension associated with experimental colitis.

Renal Manifestations of Inflammatory Bowel Disease

Renal and urinary involvement has been reported to occur in 4% to 23% of inflammatory bowel disease (IBD) patients. Parenchymal renal disease is rare and most commonly affects glomerular and tubulointerstitial compartments. The most common findings on renal biopsy of IBD patients are IgA nephropathy and tubulointerstitial nephritis. Overall morbidity of IBD-related renal manifestations is significant, and there is often only a short window of injury reversibility. This, along with subtle clinical presentation, requires a high index of suspicion and routine monitoring of renal function. There are no established guidelines for the optimal screening and monitoring of renal function in IBD patients.