Renal manifestations in inflammatory bowel disease: a systematic review

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.

Rare and severe adverse events in children with inflammatory bowel disease: analysis of data from the PIBD-SETQuality Safety Registry

BACKGROUND

Rare and severe adverse events can occur in children with inflammatory bowel disease (IBD), and the relationship with disease or drug treatment is often uncertain. We aimed to establish a method of reporting adverse events of interest in children with IBD, allowing for estimates of incidence rates with comparison between different regions, and, if possible, to compare with published data on rates of adverse events in children overall.

METHODS

For this analysis, we used data from the Paediatric Inflammatory Bowel Disease Network for Safety, Efficacy and Treatment and Quality improvement of care (PIBD-SETQuality) Safety Registry, which collects data on multiple rare and severe adverse events in children younger than 19 years with IBD. Overall, the registry collected data on ten prespecified rare and severe adverse events in children with IBD, as established by a panel of paediatric IBD experts, via reports from paediatric gastroenterologists at participating hospitals between Nov 1, 2016, and March 31, 2023. Reporting physicians, who could only be paediatric gastroenterologists or IBD nurses reporting on behalf of paediatric gastroenterologists, were recruited through invitations sent to both national and international IBD networks and at conferences. Once per month, participating paediatric gastroenterologists received an email with an anonymous and unique link to an online survey asking them to report whether any of ten rare and severe adverse events had occurred in a patient in their paediatric-IBD population in the previous month. Prevalent or retrospective rare and severe adverse events were excluded, as were events occurring in children with an unconfirmed diagnosis of IBD or for whom inflammatory colitis was part of a monogenic immunodeficiency disorder. Duplicates and events that did not meet the definitions and criteria were excluded. Physicians could also report other, non-categorised adverse events if they considered them rare and severe. In case of no response, up to two reminders were sent for each per-month survey. Annual denominator data surveys were sent to obtain the total number of person-years for the estimation of incidence rates, which were calculated via Poisson regression models.

FINDINGS

Responses were gathered from 220 paediatric gastroenterologists from 167 centres. 121 centres were in Europe, 23 centres were in North America, 17 centres were in Asia, and six centres were in Oceania. Combined, the total population with paediatric IBD consisted of an estimated 30 193 children with 114 528 person-years of follow-up. 451 adverse events were initially reported. After excluding and reorganising adverse events, 402 were eligible; 261 (65%) were categorised and 141 (35%) were non-categorised. The most frequently reported adverse events were venous-thromboembolic events (n=66), renal failure (n=43), opportunistic infections (n=42), and cancer (n=33). Haemophagocytic lymphohistiocytosis (n=4) and liver failure (n=3) were the least frequently reported adverse events. Incidence rates per 10 000 person-years were 5·50 (95% CI 4·25-6·97) for venous-thromboembolic events, 3·75 (2·74-4·99) for renal failure, 3·67 (2·67-4·89) for opportunistic infection, and 2·88 (2·01-3·98) for cancer. Of 66 venous-thromboembolic events, 31 (47%) involved cerebral venous sinus thrombosis at an incidence rate of 2·71 (95% CI 1·86-3·77).

INTERPRETATION

The PIBD-SETQuality Safety Registry enabled us to identify incidence rates of rare and severe adverse events in children with IBD. Our findings can guide physicians and enhance awareness of the incidence of adverse events in children with IBD that are considered to be rare.

FUNDING

EU Horizon 2020 Research and Innovation Programme.

Pomegranate seed oil mitigates liver and kidney damage in an experimental colitis model: Modulation of NF-κB activation and apoptosis

Pomegranate seed oil, extracted from pomegranate seeds, is a slightly fragrant yellow oil with a mild odor. Pomegranate seed oil is the main source of punicic acid (conjugated linolenic acid). Punicic acid is a long-chain omega-5 polyunsaturated fatty acid and a conjugated α-linolenic acid molecule. This acid is thought to provide many health benefits. This study evaluated the potential of pomegranate seed oil to attenuate damage to liver and kidney tissues in an acetic acid-induced colitis model. 32 male Sprague-Dawley rats were divided into 4 groups: control, colitis, 0.4 ml/kg, and 0.8 ml/kg pomegranate seed oil treatment after colitis. At the end of the experiment, histopathological and immunohistochemistry analyses of liver and kidney tissues were performed. Pomegranate seed oil treatment reduced damage in liver and kidney tissues, suppressed NF-κB activation, and regulated apoptosis. These findings support the potential effects of pomegranate seed oil against extraintestinal symptoms of colitis through its anti-inflammatory, and anti-apoptotic properties.

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.

Prevalence of Extraintestinal Manifestations in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Inflammatory bowel disease (IBD) is a multisystem disease impacting various body systems including musculoskeletal, ocular, skin, hepatobiliary, pulmonary, cardiac, and haematological systems. The extraintestinal manifestations of IBD are frequent, common in both ulcerative colitis (UC) and Crohn's disease (CD), and impact the morbidity and mortality of patients.

METHODS

The Embase, Embase classic, and PubMed databases were searched between January 1979 and December 2021. A random effects model was performed to find the pooled prevalence of joint, ocular, and skin extraintestinal manifestations of UC and CD.

RESULTS

Fifty-two studies were included that reported on 352 454 patients. The prevalence of at least 1 joint, ocular, or skin extraintestinal manifestation in all IBD, UC, and CD was 24%, 27%, and 35% respectively. The prevalence between UC and CD were similar for pyoderma gangrenosum and axial joint manifestations. Ocular manifestations were found to be more common in CD than in UC. Peripheral joint manifestations and erythema nodosum were found to be more common in CD than UC.

DISCUSSION

To our knowledge, this is the first meta-analysis that reports on the prevalence of at least 1 joint, ocular, or skin extraintestinal manifestation in IBD. Our results are largely consistent with figures and statements quoted in the literature. However, our findings are based on significantly larger cohort sizes. Thus, our results have the potential to better power studies and more accurately counsel patients.

Inflammatory Bowel Disease With Chronic Kidney Disease and Acute Kidney Injury

INTRODUCTION

It remains unclear whether inflammatory bowel disease is associated with long-term risk of chronic kidney disease (CKD) and acute kidney injury (AKI) in the general population.

METHODS

A total of 417,302 participants, including 2,940 patients with ulcerative colitis and 1,261 patients with Crohn's disease, without previous CKD and AKI at baseline (2006-2010) from the UK Biobank were included. The study outcomes included incident CKD and AKI, ascertained by self-report data and data linkage with primary care, hospital admissions, and death registry records. Analysis was conducted in 2022.

RESULTS

During a median follow-up of 12.5 years, 13,564 and 14,331 participants developed CKD and AKI, respectively. Compared with the hazard ratio for non-inflammatory bowel diseases, the hazard ratios for CKD and AKI related to inflammatory bowel diseases were 1.57 (95% CI=1.37, 1.79) and 1.96 (95% CI=1.74, 2.20) after adjustments for age, sex, and race and were 1.32 (95% CI=1.15, 1.51) and 1.70 (95% CI=1.51, 1.91) after further adjustments for biological, behavioral, and socioeconomic factors in addition to mental health and self-rated health. Similar results were found for patients with Crohn's disease (adjusted hazard ratio=1.38 (95% CI=1.09, 1.75) for CKD and 1.62 [95% CI=1.30, 2.02] for AKI) and those with ulcerative colitis (adjusted hazard ratio=1.29 (95% CI=1.09, 1.51) for CKD and 1.71 [95% CI=1.49, 1.97] for AKI) in the fully adjusted models. Genetic risks of kidney diseases did not significantly affect the association of inflammatory bowel disease with incident CKD and AKI (both p-interactions>0.05). The association between inflammatory bowel disease and the risk of incident CKD (p-interaction=0.010) and AKI (p-interaction<0.001) were stronger in younger participants than in older participants.

CONCLUSIONS

Inflammatory bowel disease was associated with higher risks for CKD and AKI, independent of genetic risks of kidney diseases.

Association between inflammatory bowel disease, nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease: A propensity score-matched analysis of US nationwide inpatient sample 2016-2018

OBJECTIVES

The incidence and prevalence of inflammatory bowel disease (IBD), mainly including ulcerative colitis (UC) and Crohn's disease (CD), are increasing globally. We aimed to evaluate the potential association between IBD and nephrolithiasis, tubulointerstitial nephritis, and chronic kidney disease (CKD).

METHODS

Data of hospitalized adults ≥20 years of age were extracted from the U.S. National Inpatient Sample (NIS) during 2016-2018. Patients with UC, CD, or CKD were identified through the International Classification of Diseases, Tenth Revision (ICD-10) codes. Propensity score matching (PSM) analysis (1:1) was conducted to balance the characteristics between groups. Logistic regression analyses were performed to determine the relationships between UC or CD and kidney conditions.

RESULTS

Three cohorts were included for analysis after PSM analysis. Cohorts 1, 2 and 3 contained 235 262 subjects (117 631 with CD or without IBD), 140 856 subjects (70 428 with UC or without IBD), and 139 098 subjects (69 549 with CD or UC), respectively. Multivariate analysis revealed that compared to non-IBD individuals, CD patients were significantly associated with greater odds for nephrolithiasis (adjusted odds ratio [aOR] 2.25, 95% confidence interval [CI] 2.08-2.43), tubulointerstitial nephritis (aOR 1.31, 95% CI 1.24-1.38), CKD at any stage (aOR 1.28, 95% CI 1.24-1.32), and moderate-to-severe CKD (aOR 1.22, 95% CI 1.17-1.26), while UC was associated with a higher rate of nephrolithiasis. Compared to UC, CD was associated with higher odds for all such kidney conditions.

CONCLUSIONS

Patients with CD are more likely to have nephrolithiasis, tubulointerstitial nephritis, CKD at any stage, and moderate-to-severe CKD compared to non-IBD individuals.

Multiple Complications of Crohn's Disease and the Need for Early and Continuous Multidisciplinary Undertaking

Crohn's disease is an inflammatory disease that typically affects the bowels but can also have many different extraintestinal manifestations. One of those complications is immunoglobulin A nephropathy (IgAN), which is one of the most encountered renal lesions in the setting of Crohn's disease. Another point of focus for Crohn's patients is the risk of cancer, with a higher risk of colorectal cancer but also extraintestinal neoplasia such as hepatobiliary, hematological, and urinary tract neoplasia. We present the case of a young patient suffering from long-term Crohn's disease and subsequent IgAN leading to end-stage kidney disease and hemodialysis. The patient was diagnosed young and had undergone multiple surgeries and different treatments in various countries. He then presented in our center already with advanced chronic renal failure from IgAN that was unknown due to poor multidisciplinary follow-up. Shortly after starting hemodialysis, he developed a large abdominal mass, first thought to result from Crohn's-related fistula. This mass turned out to be a urachal adenocarcinoma, a rare type of bladder cancer with an especially poor prognosis. It is not known whether this type of cancer is associated with either Crohn's disease or IgAN, and no such association has been previously described. The treatment of urachal cancer usually relies on surgery, with the addition of chemotherapy in some cases. Unfortunately for our patient, his case was already so advanced at the moment of diagnosis that he was excluded from curative treatment and quickly passed away thereafter. This case illustrates many important aspects of the rigorous follow-up that is needed for Crohn's patients, with regular check-ups, screening investigations, and the need for multidisciplinary evaluation. Furthermore, it describes the development of a rare type of cancer in the setting of Crohn's disease and IgAN, with no prior established link between these different pathologies.

A spurious elevation of serum creatinine level in a patient with Crohn's disease without histologic kidney damage: a case report and review of the literature

Patients with inflammatory bowel disease (IBD) are prone to develop kidney injury. Renal involvement in IBD patients is usually diagnosed by the measurement of serum creatinine and the estimation of the glomerular filtration rate. We describe a patient with IBD who presented with large fluctuations in his serum creatinine level (~3.0-fold) without significant histologic abnormalities and with a normal cystatin C level. This appears to be related to a high-protein diet and intermittent fasting. Even though the impact of a high-protein diet on mild elevations of the serum creatinine level has been described, large fluctuations in serum creatinine from diet alone, as seen in this case, have never been reported, raising the question about the potential contribution of inflamed bowel on gut absorption or metabolism of creatinine. This case highlights the importance of a detailed history, including the dietary habits, when encountering a patient with increased serum creatinine level, and careful interpretation of serum creatinine in a patient with a creatinine high-protein diet or underlying IBD.

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.

Rosiglitazone Does Not Affect the Risk of Inflammatory Bowel Disease: A Retrospective Cohort Study in Taiwanese Type 2 Diabetes Patients

Human studies on the effect of rosiglitazone on inflammatory bowel disease (IBD) are still lacking. We investigated whether rosiglitazone might affect IBD risk by using the reimbursement database of Taiwan's National Health Insurance to enroll a propensity-score-matched cohort of ever users and never users of rosiglitazone. The patients should have been newly diagnosed with diabetes mellitus between 1999 and 2006 and should have been alive on 1 January 2007. We then started to follow the patients from 1 January 2007 until 31 December 2011 for a new diagnosis of IBD. Propensity-score-weighted hazard ratios were estimated with regards to rosiglitazone exposure in terms of ever users versus never users and in terms of cumulative duration and cumulative dose of rosiglitazone therapy for dose-response analyses. The joint effects and interactions between rosiglitazone and risk factors of psoriasis/arthropathies, dorsopathies, and chronic obstructive pulmonary disease/tobacco abuse and the use of metformin were estimated by Cox regression after adjustment for all covariates. A total of 6226 ever users and 6226 never users were identified and the respective numbers of incident IBD were 95 and 111. When we compared the risk of IBD in ever users to that of the never users, the estimated hazard ratio (0.870, 95% confidence interval: 0.661-1.144) was not statistically significant. When cumulative duration and cumulative dose of rosiglitazone therapy were categorized by tertiles and hazard ratios were estimated by comparing the tertiles of rosiglitazone exposure to the never users, none of the hazard ratios reached statistical significance. In secondary analyses, rosiglitazone has a null association with Crohn's disease, but a potential benefit on ulcerative colitis (UC) could not be excluded. However, because of the low incidence of UC, we were not able to perform detailed dose-response analyses for UC. In the joint effect analyses, only the subgroup of psoriasis/arthropathies (-)/rosiglitazone (-) showed a significantly lower risk in comparison to the subgroup of psoriasis/arthropathies (+)/rosiglitazone (-). No interactions between rosiglitazone and the major risk factors or metformin use were observed. We concluded that rosiglitazone has a null effect on the risk of IBD, but the potential benefit on UC awaits further investigation.

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.