Nephrolithiasis in patients with inflammatory bowel disease in the community

Risk relationship between inflammatory bowel disease and urolithiasis: A two-sample Mendelian randomization study

BACKGROUND

The causal genetic relationship between common parenteral manifestations of inflammatory bowel disease (IBD) and urolithiasis remains unclear because their timing is difficult to determine. This study investigated the causal genetic association between IBD and urolithiasis using Mendelian randomization (MR) based on data from large population-based genome-wide association studies (GWASs).

METHODS

A two-sample MR analysis was performed to assess the potential relationship between IBD and urolithiasis. Specific single nucleotide polymorphism data were obtained from GWASs, including IBD (n = 59957) and its main subtypes, Crohn's disease (CD) (n = 40266) and ulcerative colitis (UC) (n = 45975). Summarized data on urolithiasis (n = 218792) were obtained from different GWAS studies. A random-effects model was analyzed using inverse-variance weighting, MR-Egger, and weighted medians.

RESULTS

Genetic predisposition to IBD and the risk of urolithiasis were significantly associated [odds ratio (OR), 1.04 (95% confidence interval [CI], 1.00-.08), P = 0.01]. Consistently, the weighted median method yielded similar results [OR, 1.06 (95% CI, 1.00-1.12), P = 0.02]. The MR-Egger method also demonstrated comparable findings [OR, 1.02 (95% CI, 0.96-1.08), P = 0.45]. Both funnel plots and MR-Egger intercepts indicated no directional pleiotropic effects between IBD and urolithiasis. CD was strongly associated with it in its subtype analysis [OR, 1.04 (95% CI, 1.01-1.07), P = 0.01], and UC was also causally associated with urolithiasis, although the association was not significant [OR, 0.99 (95% CI, 0.95-1.03), P = 0.71].

CONCLUSION

A unidirectional positive causal correlation was identified between IBD and urolithiasis, with varying degrees of association observed among the different subtypes of IBD. Recognizing the increased incidence of urolithiasis in patients with IBD is crucial in clinical practice. Early detection and surveillance of IBD, improved patient awareness, adoption of preventive strategies, and promotion of collaborative efforts among healthcare providers regarding treatment methodologies are vital for improving patient outcomes.

Sleep and circadian rhythm disturbance in kidney stone disease: a narrative review

The circadian rhythm generated by circadian clock genes functions as an internal timing system. Since the circadian rhythm controls abundant physiological processes, the circadian rhythm evolved in organisms is salient for adaptation to environmental change. A disturbed circadian rhythm is a trigger for numerous pathological events. Recently, accumulated data have indicated that kidney stone disease (KSD) is related to circadian rhythm disturbance. However, the mechanism between them has not been fully elucidated. In this narrative review, we summarized existing evidence to illustrate the possible association between circadian rhythm disturbance and KSD based on the epidemiological studies and risk factors that are linked to circadian rhythm disturbance and discuss some chronotherapies for KSD. In summary, KSD is associated with systemic disorders. Metabolic syndrome, inflammatory bowel disease, and microbiome dysbiosis are the major risk factors supported by sufficient data to cause KSD in patients with circadian rhythm disturbance, while others including hypertension, vitamin D deficiency, parathyroid gland dysfunction, and renal tubular damage/dysfunction need further investigation. Then, some chronotherapies for KSD were confirmed to be effective, but the molecular mechanism is still unclear.

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.

Causal effects of inflammatory bowel diseases on the risk of kidney stone disease: a two-sample bidirectional mendelian randomization

BACKGROUND

Existing epidemiological observational studies have suggested interesting but inconsistent clinical correlations between inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), and kidney stone disease (KSD). Herein, we implemented a two-sample bidirectional Mendelian randomization (MR) to investigate the causal relationship between IBD and KSD.

METHODS

Data on IBD and KSD were obtained from Genome-Wide Association Studies (GWAS) summary statistics and the FinnGen consortium, respectively. Strict selection steps were used to screen for eligible instrumental SNPs. We applied inverse variance weighting (IVW) with the fix-effects model as the major method. Several sensitivity analyses were used to evaluate pleiotropy and heterogeneity. Causal relationships between IBD and KSD were explored in two opposite directions. Furthermore, we carried out multivariable MR (MVMR) to obtain the direct causal effects of IBD on KSD.

RESULTS

Our results demonstrated that CD could increase the risk of KSD (IVW: OR = 1.06, 95% CI = 1.03-1.10, p < 0.001). Similar results were found in the validation group (IVW: OR = 1.05, 95% CI = 1.01-1.08, p = 0.013) and in the MVMR analysis. Meanwhile, no evidence of a causal association between UC and KSD was identified. The reverse MR analysis detected no causal association.

CONCLUSIONS

This MR study verified that CD plays a critical role in developing kidney stones and that the effect of UC on KSD needs to be further explored.

Risk of Nephrolithiasis in Patients with Inflammatory Bowel Disease Receiving Biologic Treatment

INTRODUCTION

Inflammatory bowel disease is a chronic inflammatory disorder of the gastrointestinal tract. Biologic drugs target specific molecules in the body's immune system to control inflammation. Recent studies have suggested a potential link between their use and an increased risk of nephrolithiasis. We conducted a study to further investigate this association.

METHODS

The study used multiple logistic regression analysis to assess the association between the use of biologic drugs and nephrolithiasis. A p-value of <0.05 was considered statistically significant. SAS 9.4 was used for statistical analysis.

RESULTS

The final sample consisted of 22,895 cases, among which 5603 (24.51%) were receiving at least one biologic drug. The biologic drugs received were as follows: Adalimumab 2437 (10.66%), Infliximab 1996 (8.73%), Vedolizumab 1397 (6.11%), Ustekinumab 1304 (5.70%); Tofacitinib, 308 (1.35%); Certolizumab, 248 (1.08%); and Golimumab, 121 (0.53%). There were 1780 (7.74%) patients with Nephrolithiasis: 438 (8.0%) patients were receiving biologic treatment. We found that the use of Vedolizumab (OR = 1.307, 95% CI 1.076-1.588, p = 0.0071) increased the odds of Nephrolithiasis by 31%.

CONCLUSION

Vedolizumab use was associated with an increased risk of nephrolithiasis. The use of two or more biologic drugs also increased the risk compared to no biologic treatment.

Urolithiasis in patients with inflammatory bowel disease: A systematic review and meta-analysis of 13,339,065 individuals

BACKGROUND

This study aimed to summarize the current literature regarding the prevalence of renal stones in patients with inflammatory bowel disease (IBD). Moreover, we aimed to evaluate the risk factors of urolithiasis in patients with IBD and the difference between patients with IBD and healthy controls in terms of urinary profile.

METHODS

On February 23, 2022, a computerized search was conducted on PubMed, OVID via MEDLINE, Web of Science, and Scopus using relevant keywords. Three independent reviewers performed 2-stage screening and data extraction. The National Institutes of Health tools were employed for quality assessment. Review Manager 5.4 software was used to calculate the mean difference (MD) between IBD patients and non-IBD in terms of urine profile using the Inverse-variance model and to estimate the odds ratio of reported risk factors for renal stones with the Generic Inverse-Variance model.

RESULTS

Thirty-two articles (n = 13,339,065 patients) were included. The overall prevalence of renal stones in patients with IBD was 6.3%, 95% Confidence interval (4.8%-8.3%). The prevalence of urolithiasis was more common in Chron's disease vs Ulcerative colitis (7.9% vs 5.6%) and in old studies (1964-2009) than in more recent studies (2010-2022) (7.3% vs 5.2%), respectively. Compared to non-IBD patients, patients with IBD were associated with significantly lower urine volume (MD = -518.84 mL/day, P < .00001), calcium 24-hour urine (MD = -28.46 mg/day, P < .0001), citrate 24-hour urine (MD = -144.35 mg/day, P < .00001), sodium 24-hour urine (MD = -23.72 mg/day, P = .04), and magnesium 24-hour urine (MD = -33.25 mg/day, P < .00001).

CONCLUSION

The overall prevalence of renal stones in patients with IBD was comparable to the general population. Patients with Chron's disease were associated with a higher prevalence of urolithiasis compared to Ulcerative colitis. Drugs that induce renal calculi should be stopped in high-risk patients.

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.

Secondary oxalate nephropathy and kidney transplantation

PURPOSE OF REVIEW

Secondary hyperoxaluria is associated with poor kidney allograft outcomes after the kidney transplant. Calcium oxalate (CaOx) deposition is common in early allograft biopsies leading to acute tubular necrosis and poor kidney allograft function. Though treatment options for secondary hyperoxaluria are limited, it is crucial to identify patients at increased risk of oxalate nephropathy after the transplant.

RECENT FINDINGS

Recent data suggest that significant changes in renal replacement therapies and dietary modifications in high-risk patients can prevent kidney allograft damage from the calcium oxalate deposition leading to improve allograft outcomes.

SUMMARY

The accurate and timely diagnosis of secondary oxalate nephropathy in kidney transplant recipients is paramount to preserving graft function in the long-term. This review will discuss the incidence, risk factors, prevention, and management of oxalate nephropathy in the kidney allograft.

Dietary advice for patients with bowel-related conditions and malabsorption

PURPOSE

To explain the pathophysiology of kidney stone formation and appropriate dietary recommendations in inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD) and after bariatric surgery, focusing on the current literature.

METHODS

A narrative review methodology was performed. A literature search was conducted using PubMed, MEDLINE, and Google Scholar. Studies on the relationship between IBD or bariatric surgery and the risk of kidney stone formation were included.

RESULTS

Dietary composition has a critical role in urinary stone formation. Nutritional factors such as fluid intake, dietary protein, carbohydrates, oxalate, and calcium contribute to the risk of stone formation. Bowel-related malabsorptive conditions (IBD, after bariatric surgery, etc.) are associated with an increased risk of kidney stone formation due to metabolic and physiological changes such as hyperoxaluria, hypocitraturia, and decreased fluid intake or absorption. While the risk is lower in restrictive bariatric surgeries, the risk of kidney stone formation increases, especially after malabsorptive procedures. Dietary recommendations for these patients could profit alleviate urinary changes and reduce the risk of kidney stones.

CONCLUSION

Bowel-related malabsorptive conditions such as IBD and bariatric surgery are associated with an increased risk of kidney stones. Appropriate dietary recommendations can improve urinary metabolic changes and reduce kidney stone formation and the possibility of stone-related surgery.

Risk factors for developing hyperoxaluria in children with Crohn's disease

BACKGROUND

For the purpose of a better understanding of enteric hyperoxaluria in Crohn's disease (CD) in children and adolescents, we investigated the occurrence and risk factors for development of hyperoxaluria in those patients.

METHODS

Forty-five children with CD and another 45 controls were involved in this cross-sectional study. Urine samples were collected for measurement of spot urine calcium/creatinine (Ur Ca/Cr), oxalate/creatinine (Ur Ox/Cr), and citrate/creatinine (Ur Citr/Cr) ratios. Fecal samples were also collected to detect the oxalyl-CoA decarboxylase of Oxalobacter formigenes by PCR. Patients were classified into 2 groups: group A (with hyperoxaluria) and group B (with normal urine oxalate excretion). The disease extent was assessed, and the activity index was calculated.

RESULTS

According to the activity index, 30 patients (66.7%) had mild disease and 13 patients (28.9%) had moderate disease. There was no significant difference in Ur Ox/Cr ratio regarding the disease activity index. O. formigenes was not detected in 91% of patients in group A while it was detected in all patients in group B (p < 0.001). By using logistic regression analysis, the overall model was statistically significant when compared to the null model, (χ² (7) = 52.19, p < 0.001), steatorrhea (p = 0.004), frequent stools (p = 0.009), and O. formigenes (p < 0.001).

CONCLUSION

Lack of intestinal colonization with O. formigenes, steatorrhea, and frequent stools are the main risk factors for development of enteric hyperoxaluria in CD patients. Identifying risk factors facilitates proper disease management in future studies. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Renal and Urological Disorders Associated With Inflammatory Bowel Disease

Renal and urinary tract complications related to inflammatory bowel disease (IBD) have been relatively understudied in the literature compared with other extraintestinal manifestations. Presentation of these renal manifestations can be subtle, and their detection is complicated by a lack of clarity regarding the optimal screening and routine monitoring of renal function in IBD patients. Urolithiasis is the most common manifestation. Penetrating Crohn's disease involving the genitourinary system as an extraintestinal complication is rare but associated with considerable morbidity. Some biologic agents used to treat IBD have been implicated in progressive renal impairment, although differentiating between drug-related side effects and deteriorating kidney function due to extraintestinal manifestations can be challenging. The most common findings on renal biopsy of IBD patients with renal injury are tubulointerstitial nephritis and IgA nephropathy, the former also being associated with drug-induced nephrotoxicity related to IBD medication. Amyloidosis, albeit rare, must be diagnosed early to reduce the chance of progression to renal failure. In this review, we evaluate the key literature relating to renal and urological involvement in IBD and emphasize the high index of suspicion required for the prompt diagnosis and treatment of these manifestations and complications, considering the potential severity and implications of acute or chronic loss of renal function. We also provide suggestions for future research priorities.

Urinary manifestations in African American and Caucasian inflammatory bowel disease patients: a retrospective cohort study

Background

Inflammatory bowel diseases (IBD), like ulcerative colitis (UC) and Crohn’s disease (CD), are associated with urinary extra-intestinal manifestations, like urolithiasis and uncomplicated urinary tract infections (UTIs). The literature reviewed for this study identifies an increased association of CD and urolithiasis against the general population as well as UC. Furthermore, the rates in which urinary comorbidities manifest have not been well characterized in cross-race analyses. The purpose of this study is to establish the prevalence of common urinary extra-intestinal manifestations in CD and UC and to further determine at what rate these affect the African American and Caucasian populations.

Methodology

This is a retrospective cohort study using de-identified data collected from a research data base that included 6 integrated facilities associated with one tertiary healthcare center from 2012 to 2019. The electronic chart records for 3104 Caucasian and African American IBD patients were reviewed for frequency of urolithiasis and uncomplicated UTI via diagnosed ICD-10 codes. Comparison between data groups was made using multivariate regressions, t-tests, and chi square tests.

Results

Our study included 3104 patients of which 59% were female, 38% were African American, and 43% were diagnosed with UC. Similar proportions of UC and CD diagnosed patients developed urolithiasis (6.0% vs 6.7%, p = 0.46), as well as uncomplicated UTIs (15.6% vs. 14.9%, p = 0.56). Similar proportions of African American and Caucasian patients developed urolithiasis (5.4% vs 7.0%, p = 0.09), but a higher proportion of African Americans developed uncomplicated UTIs (19.4% vs 12.6%, p ≤ 0.001).

Conclusion

We found similar rates of urolithiasis formation in both UC and CD in this study. Furthermore, these rates were not significantly different between African American and Caucasian IBD populations. This suggests that UC patients have an elevated risk of urolithiasis formation as those patients with CD. Additionally, African Americans with IBD have a higher frequency of uncomplicated UTI as compared to their Caucasian counterparts.

Extra-Intestinal Manifestations of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with extra-intestinal manifestations (EIMs) that tend to parallel intestinal activity and have a debilitating effect on the quality of life. EIMs primarily affect the joints, skin, and eyes with less frequent involvement of the liver, kidney, and pancreas. This article reviews the prevalence of musculoskeletal, dermatological, ocular, and other manifestations in IBD and their coalition with underlying intestinal inflammation. EIMs occurring independently of intestinal activity are managed by targeted therapies, categorical regimens, and specific treatments. On the other hand, EIMs paralleling the bowel activity are carefully monitored while the IBD is brought under control. Since the etiology of the disease is responsible for the development of the EIMs, the research scrutinizes the identified pathogenic mechanisms that tend to involve genetic susceptibility, aberrant self-recognition, and autoantibodies directed against organ-specific antigens shared by intestinal and extra-intestinal organs. This article also provides an overview of the epidemiology, clinical features, diagnostic modalities, and management of the EIMs associated with IBD.

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.

Microbial genetic and transcriptional contributions to oxalate degradation by the gut microbiota in health and disease

Over-accumulation of oxalate in humans may lead to nephrolithiasis and nephrocalcinosis. Humans lack endogenous oxalate degradation pathways (ODP), but intestinal microbes can degrade oxalate using multiple ODPs and protect against its absorption. The exact oxalate-degrading taxa in the human microbiota and their ODP have not been described. We leverage multi-omics data (>3000 samples from >1000 subjects) to show that the human microbiota primarily uses the type II ODP, rather than type I. Furthermore, among the diverse ODP-encoding microbes, an oxalate autotroph, Oxalobacter formigenes, dominates this function transcriptionally. Patients with inflammatory bowel disease (IBD) frequently suffer from disrupted oxalate homeostasis and calcium oxalate nephrolithiasis. We show that the enteric oxalate level is elevated in IBD patients, with highest levels in Crohn's disease (CD) patients with both ileal and colonic involvement consistent with known nephrolithiasis risk. We show that the microbiota ODP expression is reduced in IBD patients, which may contribute to the disrupted oxalate homeostasis. The specific changes in ODP expression by several important taxa suggest that they play distinct roles in IBD-induced nephrolithiasis risk. Lastly, we colonize mice that are maintained in the gnotobiotic facility with O. formigenes, using either a laboratory isolate or an isolate we cultured from human stools, and observed a significant reduction in host fecal and urine oxalate levels, supporting our in silico prediction of the importance of the microbiome, particularly O. formigenes in host oxalate homeostasis.

Pathophysiology and Treatment of Enteric Hyperoxaluria

Enteric hyperoxaluria is a distinct entity that can occur as a result of a diverse set of gastrointestinal disorders that promote fat malabsorption. This, in turn, leads to excess absorption of dietary oxalate and increased urinary oxalate excretion. Hyperoxaluria increases the risk of kidney stones and, in more severe cases, CKD and even kidney failure. The prevalence of enteric hyperoxaluria has increased over recent decades, largely because of the increased use of malabsorptive bariatric surgical procedures for medically complicated obesity. This systematic review of enteric hyperoxaluria was completed as part of a Kidney Health Initiative-sponsored project to describe enteric hyperoxaluria pathophysiology, causes, outcomes, and therapies. Current therapeutic options are limited to correcting the underlying gastrointestinal disorder, intensive dietary modifications, and use of calcium salts to bind oxalate in the gut. Evidence for the effect of these treatments on clinically significant outcomes, including kidney stone events or CKD, is currently lacking. Thus, further research is needed to better define the precise factors that influence risk of adverse outcomes, the long-term efficacy of available treatment strategies, and to develop new therapeutic approaches.

Risk factors for urolithiasis in patients with Crohn's disease

OBJECTIVE

To study the risk factors for urolithiasis in patients with Crohn's disease.

METHODS

This retrospective study included 1071 patients with Crohn's disease who were treated at a single center. Data pertaining to the following variables were analyzed: sex; age; type of Crohn's disease; number of intestinal resections; residual small intestine length; ileostomy; history of glucocorticoid therapy; and duration of Crohn's disease treatment.

RESULTS

Of the 1071 patients, 34 (28 male and six female) had urolithiasis (urolithiasis group) and 1037 (711 male and 326 female) did not (non-urolithiasis group). The median residual small intestine length measured in the urolithiasis group (280.0 cm) was significantly shorter than that in the non-urolithiasis group (342.5 cm; P < 0.01). Significantly more patients in the urolithiasis group (14/34) received steroid medication than those in the non-urolithiasis group (213/1037; P < 0.01). On multivariate analysis, male sex (odds ratio 3.15; P < 0.05), history of glucocorticoid therapy (odds ratio 3.07; P < 0.05), and shorter residual small intestine length (odds ratio 0.99; P < 0.01) were risk factors for the development of urolithiasis in patients with Crohn's disease.

CONCLUSION

Our results suggest that male sex, history of glucocorticoid therapy, and shorter residual small intestine length are risk factors for urolithiasis in patients with Crohn's disease.

Urolithiasis in complicated inflammatory bowel disease: a comprehensive analysis of urine profile and stone composition

PURPOSE

To evaluate the impact of extensive surgery on urine profile, serum exams and stone composition of complicated IBD patients.

METHODS

Patients with IBD and a history of total proctocolectomy (TPC) with fecal diversion (end ileostomy or ileal pouch anal anastomosis-IPAA) were selected. Only patients with at least one complete 24-h urine profile were included. A case-control study was performed selecting patients with kidney stone disease in a random way who had also at least on complete 24-h urine profile. Case and controls were matched for age, gender, and body mass index (BMI). Groups were compared to urine profile, serum exams and stone composition.

RESULTS

Sixty-eight patients were enrolled in this study, 34 patients with IBD who underwent TPC and had diagnosis of kidney stones and 34 matched patients with only kidney stones. IBD patients had a significantly lower urine volume, urine citrate and urine sodium. Regarding serum exams, only serum bicarbonate was statistically significant lower. In both groups, calcium oxalate stone was the most common.

CONCLUSION

Patients with IBD with TPC and kidney stones have a low urine volume and low urine citrate as main risk factors for kidney stone formation. As seen in the general population, calcium oxalate is the most common stone composition.

Inflammatory Bowel Diseases Are Associated With an Increased Risk for Chronic Kidney Disease, Which Decreases With Age

BACKGROUND & AIMS

It is not clear what factors affect risk of chronic kidney disease (CKD) in patients with inflammatory bowel disease (IBD); increased risk has been inconsistently associated with use of 5-aminosalicylates (5-ASAs). We aimed to calculate the relative hazard of CKD among patients with IBD, adjusted for CKD risk factors, and to determine whether IBD medications are associated with change in estimated glomerular filtration rate (eGFR).

METHODS

We performed a retrospective cohort study of data from The Health Improvement Network. Patients with IBD (n = 17,807) were matched for age, sex, and practice to individuals without IBD (n = 63,466). The relative hazard of CKD, stages 3 through 5D, in patients with IBD was calculated using a Cox proportional hazards model adjusted for common CKD risk factors. We also evaluated the association of 5-ASAs, azathioprine, and methotrexate with change in eGFR using a longitudinal model.

RESULTS

After we controlled for risk factors associated with CKD, we found IBD to be associated with development of CKD in patients 16-77 years old. As patient age increased, the adjusted hazard ratio for CKD decreased monotonically, from 7.88 (95% CI, 2.56-24.19) at age 16 to 1.13 (95% CI, 1.01-1.25) at age 77. In the longitudinal analysis, exposure to 5-ASAs or methotrexate was not associated with change in eGFR, whereas azathioprine was associated with a slightly higher eGFR (0.32 mL/min/1.73 m²; 95% CI, 0.16-0.48).

CONCLUSIONS

In a retrospective study of more than 80,000 persons, we found that IBD is associated with increased risk of CKD, and the hazard ratio is highest among younger patients. Commonly used non-biologic therapeutic agents were not associated with lower eGFR.

A prediction model of Nephrolithiasis Risk: A population-based cohort study in Korea

Purpose

Well-validated risk prediction models help to stratify individuals on the basis of their disease risks and to guide health care professionals in decision-making. The incidence of nephrolithiasis has been increasing in Korea. Racial differences in the distribution of and risk for nephrolithiasis have been reported in Asia but no population-specific nephrolithiasis models have been developed. We aimed to develop a simplified nephrolithiasis prediction model for the Korean population by using data from general medical practice.

Materials and Methods

This was a prospective, population-based cohort study in Korea. A total of 497,701 participants from the National Health Insurance Service–National Sample Cohort (NHIS-NSC) were enrolled from 2002 to 2010. A Cox proportional hazards model was used.

Results

During a median follow-up time of 8.5 years (range, 2.0–8.9 years) and among 497,701 participants, there were 15,783 cases (3.2%) of nephrolithiasis. The parsimonious model included age, sex, income grade, alcohol consumption, body mass index, total cholesterol, fasting blood glucose, and medical history of diseases. The Harrell's C-statistic was 0.806 (95% confidence interval [CI], 0.790–0.821) and 0.805 (95% CI, 0.782–0.827) in the derivation and validation cohorts, respectively.

Conclusions

The results of the present study imply that nephrolithiasis risk can be predicted by use of data from general medical practice and based on predictors that clinicians and individuals from the general population are likely to know. This model comprises modifiable risk factors and can be used to identify those at higher risk who can modify their lifestyle to lower their risk for nephrolithiasis. This study also offers an opportunity for external validation or updating of the model through the incorporation of other risk predictors in other settings.

Inflammatory bowel diseases: time of diagnosis, environmental factors, clinical course, and management - a follow-up study in a private inflammatory bowel disease center (2003-2017)

BACKGROUND

The governmental program of Brazilian Unified National Health System has already published studies on the incidence of inflammatory bowel diseases (IBD), but up until now, there have been no epidemiological studies in private centers in Brazil. However, these diseases tend to affect people from a higher socioeconomic class, mainly in the capital of MS state that has the third highest GDP in Brazil.

OBJECTIVES

The aim was to analyze an observational, descriptive study of an IBD database in a private center including: the side, behavior of the disease and medical management, the association of extra-intestinal manifestations, and the main clinical symptoms which led to the investigation and diagnosis of IBD.

PATIENTS AND METHODS

A cohort study was developed in which data of all patients with IBD were analyzed with SPSS software in a constructed electronic database.

RESULTS

Of 329 patients, 212 (64.4%) had Crohn's disease (CD) and 117 (35.6%) had ulcerative colitis (UC). Average age at diagnosis of CD was 36.19 (±14.33) and of UC was 41.61 (±15.37). An amount of 50.05% of the patients with CD and 72.7% (P<0.001) with UC were female. We have observed that concerning the first symptoms, diahrrea and blood feces corresponded to 70% in UC while in CD 50% of the patients presented diahrrea with blood feces, loss of weight corresponded to 50% and only diahrrea 25%. (P<0.001). Anti-TNFs corresponded to 56.2% being more frequent in CD 0.001%. CD patients used biologic therapy and antibiotics more frequently than those with UC. In conclusion, IBD is also frequent in private health care centers in Brazil; women are most affected. Symptoms such as diarrhea and bleeding, as well as diarrhea and weight loss, must be taken as warning signs to investigate for inflammatory disease. The use of biologic therapies is frequent in referral centers when patients have severe disease.

[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.

Altered uric acid metabolism in isolated colonic Crohn's disease but not ulcerative colitis

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) have higher incidence of developing nephrolithiasis. Increased uric acid production induced by Saccharomyces cerevisiae exacerbates colitis in mice. We aimed to evaluate the association between serum uric acid level and disease activity in IBD population.

METHODS

Four hundred and thirty-five patients enrolled in Jinling Hospital from January 1, 2015 to August 31, 2017 were included in the retrospective study. Clinical parameters were collected and compared with non-IBD matched controls (n = 51). Serum uric acid to creatinine ratio (UA/Cr) was used as a biomarker for uric acid metabolism. Sixty-five active IBD patients were longitudinally studied to investigate the UA/Cr before and after therapy. Linear mixed models were estimated for Crohn's disease (CD) group to explore the relationship between UA/Cr and other parameters.

RESULTS

Uric acid to creatinine ratio was significantly correlated with Crohn's disease activity index (ρ = 0.184, P = 0.002) and Harvey Bradshaw index (ρ = 0.154, P = 0.010) and C-reactive protein (ρ = 0.591, P < 0.001) in CD group. Colonic CD and anti-Saccharomyces cerevisiae antibody (ASCA) positive CD had an increased UA/Cr compared with L1, L3, and ASCA negative CD (P = 0.027, P = 0.0013, and P = 0.043, respectively). A significant decrease in UA/Cr was observed after induction therapy in active CD (P = 0.0002) but not in ulcerative colitis (P = 0.076).

CONCLUSION

Uric acid to creatinine ratio correlated with disease activity in CD. Colonic CD and ASCA positive CD had an increased UA/Cr. Effective treatment for CD patients lowered UA/Cr. Uric acid metabolism might be a novel aspect to investigate disease activity of IBD.

Renal lithiasis and inflammatory bowel diseases, an update on pediatric population

BACKGROUND AND AIM OF THE WORK

Historical studies have demonstrated that the prevalence of symptomatic nephrolithiasis is higher in patients with inflammatory bowel disease (IBD), compared to general population. The aim of the review was to analyze literature data in order to identify the main risk conditions described in literature and the proposed treatment.

METHODS

A research on the databases PubMed, Medline, Embase and Google Scholar was performed by using the keywords "renal calculi/lithiasis/stones" and "inflammatory bowel diseases". A research on textbooks of reference for Pediatric Nephrology was also performed, with focus on secondary forms of nephrolithiasis.

RESULTS

Historical studies have demonstrated that the prevalence of symptomatic nephrolithiasis is higher in patients with inflammatory bowel disease (IBD), compared to general population, typically in patients who underwent extensive small bowel resection or in those with persistent severe small bowel inflammation. In IBD, kidney stones may arise from chronic inflammation, changes in intestinal absorption due to inflammation, surgery or intestinal malabsorption. Kidney stones are more closely associated with Crohn's Disease (CD) than Ulcerative Colitis (UC) in adult patients for multiple reasons: mainly for malabsorption, but in UC intestinal resection may be an additional risk. Nephrolithiasis is often under-diagnosed and might be a rare but noticeable extra-intestinal presentation of pediatric IBD. Secondary enteric hyperoxaluria the main risk factor of UL in IBD, this has been mainly studied in CD, whether in UC has not been completely explained. In the long course of CD recurrent urolithiasis and calcium-oxalate deposition may cause severe chronic interstitial nephritis and, as a consequence, chronic kidney disease. ESRD and systemic oxalosis often develop early, especially in those patients with multiple bowel resections. Even if we consider that many additional factors are present in IBD as hypomagnesuria, acidosis, hypocitraturia, and others, the secondary hyperoxaluria seems to finally have a central role. Some medications as parenteral vitamin D, long-term and high dose steroid treatment, sulfasalazine are reported as additional risk factors. Hydration status may also play an important role in this process. Intestinal surgery is a widely described independent risk factor. Patients with ileostomy post bowel resection may have relative dehydration from liquid stool, which, added to the acidic pH from bicarbonate loss, is responsible for this process. In this acidic pH, the urinary citrate level excretion reduces. The stones most commonly seen in these patients contain uric acid or are mixed. In addition, the risk of calcium containing stones also increases with ileostomy. The treatment of UL in IBD involves correction of the basic gastrointestinal tract inflammation, restricted dietary oxalate intake, and, at times, increased calcium intake. Citrate therapy that increases both urine pH and urinary citrate could also provide an additional therapeutic benefit. Finally, patients with IBD in a pediatric study had less urologic intervention for their calculosis compared with pediatric patients without IBD.

Calcium Oxalate Differentiates Human Monocytes Into Inflammatory M1 Macrophages

Purpose

A number of hyperoxaluric states have been associated with calcium oxalate (CaOx) deposits in the kidneys. In animal models of stone disease, these crystals interact with circulating monocytes that have migrated into the kidney as part of innate immunity. Similarly, macrophages surround CaOx crystals in kidneys of patients excreting high levels of oxalate. We investigate the effect of this exposure and subsequent human immunological response in vitro.

Materials and methods

Primary human monocytes were collected from healthy donors and exposed to CaOx, potassium oxalate, and zinc oxalate (ZnOx). Cytokine production was measured with a multiplex ELISA. Quantitative reverse transcription-polymerase chain reaction was done to validate the mRNA profile expression. M1 macrophage phenotype was confirmed with immunofluorescence microscopy.

Results

Both primary monocytes and THP-1 cells, a human monocytic cell line, respond strongly to CaOx crystals in a dose-dependent manner producing TNF-α, IL-1β, IL-8, and IL-10 transcripts. Exposure to CaOx followed by 1 h with LPS had an additive effect for cytokine production compared to LPS alone, however, LPS followed by CaOx led to significant decrease in cytokine production. Supernatants taken from monocytes were previously exposed to CaOx crystals enhance M2 macrophage crystal phagocytosis. CaOx, but not potassium or ZnOx, promotes monocyte differentiation into inflammatory M1-like macrophages.

Conclusion

In our in vitro experiment, human monocytes were activated by CaOx and produced inflammatory cytokines. Monocytes recognized CaOx crystals through a specific mechanism that can enhance or decrease the innate immune response to LPS. CaOx promoted M1 macrophage development. These results suggest that monocytes have an important role promoting CaOx-induced inflammation.

Risk factors for gallstones and kidney stones in a cohort of patients with inflammatory bowel diseases

Background

Gallstones and kidney stones are known complications of inflammatory bowel diseases (IBD). Risk factors have been insufficiently studied and explanatory studies date back up to 30 years. It remains unclear, whether improved treatment options also influenced risk factors for these complications.

Objectives

Identifying risk factors for gallstones and kidney stones in IBD patients.

Methods

Using data from the Swiss Inflammatory Bowel Disease Cohort Study we assessed associations of diseases characteristics with gallstones and kidney stones in univariate and multivariate logistic regression analyses.

Results

Out of 2323 IBD patients, 104 (7.8%) Crohn’s disease (CD) and 38 (3.8%) ulcerative colitis (UC) patients were diagnosed with gallstones. Significant risk factors for gallstones were diagnosis of CD, age at diagnosis, disease activity and duration, NSAID intake, extra-intestinal manifestations and intestinal surgery. Kidney stones were described in 61 (4.6%) CD and 30 (3.0%) UC patients. Male gender, disease activity, intestinal surgery, NSAID usage and reduced physical activity were significant risk factors. Hospitalization was associated with gallstones and kidney stones. The presence of gallstones increased the risk for kidney stones (OR 4.87, p<0.001).

Conclusion

The diagnosis of CD, intestinal surgery, prolonged NSAID use, disease activity and duration and bowel stenosis were significantly associated with cholecystonephrolithiasis in IBD.

Etiopathogenesis of Nephrolithiasis in Ulcerative Colitis Patients with the Ileal Pouch Anal Anastomosis

BACKGROUND

Our previous study showed that nephrolithiasis is a common complication in ulcerative colitis patients after ileal pouch anal anastomosis (IPAA). However, the pathogenesis of nephrolithiasis in IPAA patients has not been studied. The aim of this study was to compare urine and serum metabolic compositions in IPAA patients with nephrolithiasis and controls with IPAA and no nephrolithiasis.

METHODS

Using cross-sectional study design, serum and 24-hour urine metabolic compositions were compared between IPAA patients with nephrolithiasis (the study group) and those without (the control group). Urinary supersaturation of calcium oxalate, calcium phosphate, and uric acid was calculated.

RESULTS

A total of 40 patients were enrolled in the study. There were no significant differences in serum electrolytes, vitamin D, parathyroid hormone, and kidney function tests between the study (n = 20) and control groups (n = 20). Patients in the study group were found to have a significantly higher 24-hour urine supersaturation of calcium oxalate (8.8 versus 5.0, P = 0.037) and calcium phosphate (0.61 versus 0.27, P = 0.028) as compared with controls. Nineteen (95%) patients in the study group were symptomatic due to nephrolithiasis with several requiring procedural intervention for treatment, including ureteroscopy in 3 (15%) patients, lithotripsy in 5 (25%) patients, and percutaneous surgery in 1 (5%) patient.

CONCLUSIONS

Ulcerative colitis-IPAA patients are at risk for the development of calcium oxalate and calcium phosphate stones. Nephrolithiasis is symptomatic in a majority of the patients and frequently requires procedural intervention for treatment.

Rheumatologic and extraintestinal manifestations of inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) often present as a complex inflammatory process wherein colon lesions (ulcerative colitis, UC) or widespread ulceration and fissure (Crohn's disease, CD) might be accompanied by ancillary extraintestinal manifestations (EIMs) that could involve almost every organ system, but also by autoimmune disorders ranging from psoriasis and rheumatoid arthritis to connective tissue diseases. Certain EIMs are more common related to the activity of the IBD (joint, skin, ocular and oral manifestations), other EIMs typically run a course independent of the IBD activity (hepatobiliary disorders) and some are non-specific disorders (osteoporosis and amyloidosis). This paper reviews the most common extraintestinal and rheumatologic manifestations of UC and CD. They may produce greater morbidity than the underlying intestinal disease and may even be the initial presenting symptoms of the IBD. Thus, early recognition of these manifestations should help guide therapy that will reduce overall morbidity in affected patients. Key Message A complete review on the most common extraintestinal and rheumatologic manifestations of ulcerative colitis and Crohn's disease.

Urolithiasis and crohn's disease

Objective:

To present an updated description of the relation between Crohn's disease (CD) and Urolithiasis.

Patients and Methods:

A literature search for English-language original and review articles was conducted in Medline, Embase, and Cochrane databases in the month of December 2014 for papers either published or e-published up to that date, addressing the association between CD and urolithiasis as its consequence. All articles published in English language were selected for screening based on the following search terms: “CD,” “renal calculus,” “IBD,” and “urolithiasis.” We restricted the publication dates to the last 15 years (2000–2014).

Results:

In total, 901 patients were included in this review of which 95 were identified as having CD and urolithiasis simultaneously, for a total of 10.5%. Average age was 45.07 years old, irrespective of gender. 28.6% of patients received some kind of medical intervention without any kind of surgical technique involved, 50% of patients were submitted to a surgical treatment, and the remaining 21.4% were submitted to a combination of surgical and medical treatment. Urolithiasis and pyelonephritis incidence ranged from 4% to 23% with a risk 10–100 times greater than the risk for general population or for patients with UC, being frequent in patients with ileostomy and multiple bowel resections. We found that urolithiasis occurred in 95 patients from a total of 901 patients with CD (10.5%); 61.81% in men and 38.19% in women. Stone disease seems to present approximately 4–7 years after the diagnosis of bowel disease and CaOx seems to be the main culprit.

Conclusions:

CD is a chronic, granulomatous bowel disease, with urolithiasis as the most common extraintestinal manifestation (EIM), particularly frequent in patients submitted to bowel surgery. This complication needs to be recognized and addressed appropriately, especially in patients with unexplained renal dysfunction, abdominal pain, or recurrent urinary tract infection. We believe this study to be an updated valuable review as most data related to this kind of EIM refers to articles published before 2000, most of them before 1990. These patients need to be followed up with a specific prevention plan to eliminate or mitigate the risk factors for stone disease, aiming at preventing its formation and its complications, preserving renal function, reducing morbidity, and ultimately improving their quality of life.

Renal Involvement in Inflammatory Bowel Diseases

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

Extraintestinal manifestations of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a systemic disease, and it not only affects the gastrointestinal tract, but also may show a variety of extraintestinal manifestations (EIMs). EIMs can involve multiple systems. This paper reviews the EIMs of IBD for a more comprehensive understanding of IBD to guide its clinical diagnosis and treatment.

Trends in pediatric urolithiasis: patient characteristics, associated diagnoses, and financial burden

BACKGROUND

The goal of this study was to examine national trends in hospitalization, emergency department (ED) utilization, secondary diagnoses, and charges associated with pediatric urolithiasis.

METHODS

Data were evaluated from the Kids' Inpatient Database of the Healthcare Costs and Utilization Project (HCUP) database from 1997 to 2012 and the HCUP National ED Sample from 2006 to 2011.

RESULTS

Pediatric nephrolithiasis discharges increased by 18%, while ureterolithiasis discharges decreased by 17%. Hospital charges increased by 20% when accounting for inflation, despite an overall decrease in discharges by 2.5%. Female patients and those aged 15-17 years were more commonly affected. Pediatric ED visits increased by 9%. The most common secondary diagnoses during 2003-2009 were urinary tract infections (UTI) (13%), asthma (9%), epilepsy (4%), and paralysis (4%).

CONCLUSIONS

Decreased hospitalizations and increased ED visits indicate a shift to outpatient care. Inpatient health care charges associated with pediatric urolithiasis continue to rise. Comorbidities include UTI, asthma, epilepsy, attention deficit hyperactivity disorder (ADHD), and mood disorders. Because of the significant health care burden and the increased risk to children of developing long-term sequelae there is a strong need for increased research into the mechanism of this systemic inflammatory disease and improved therapeutic targets.

Incidence and Risk Factors for Urolithiasis in Patients with Crohn's Disease

BACKGROUND

The incidence of urinary tract calculi is thought to be higher in patients with inflammatory bowel disease (IBD) than that in the general population. However, few data are available about urolithiasis in patients with Crohn's disease (CD). We investigated the incidence of urolithiasis and the risk factors for urolithiasis in patients with CD.

METHODS

We examined the records of 387 patients with CD followed at Samsung Medical Center from July 2011 to June 2013. Evidence for the presence of calculi was obtained from radiologic findings (plain films, ultrasonography, or computed tomography), urinary colic symptoms, or a treatment history of urolithiasis after diagnosis of CD. Demographic variables, phenotype, concurrent medications, and previous CD-related surgery were analyzed.

RESULTS

Urinary tract calculi were found in 18 (4.7%) patients, which developed after the CD diagnosis. The incidence of urolithiasis in CD was 706 per 100,000 patient-years. Cox models with a time-dependent covariate showed that azathioprine (AZA)/6-mercaptopurine (6-MP) treatment (hazard ratio = 0.963; 95% CI: 0.931, 0.996; p = 0.030) was negatively associated with urolithiasis.

CONCLUSIONS

The annual incidence rate of urolithiasis in patients with CD was 0.7%. AZA/6-MP therapy was associated with a low risk of urolithiasis in these patients.

Urolithiasis and urinary tract infection among patients with inflammatory bowel disease: a review of US emergency department visits between 2006 and 2009

OBJECTIVE

To compare patients with inflammatory bowel disease (IBD) to a general population of urinary stone formers who present to US emergency departments with infected urolithiasis. Patients with IBD are at risk for both infection and stone formation, however studies investigating emergent urolithiasis presentations for this population are limited.

METHODS

Using the Nationwide Emergency Department Sample (2006-2009) we identified all patients presenting to the US emergency departments with a diagnosis of upper tract urolithiasis. We then described a subgroup with the concomitant diagnosis of IBD. We compared rates of urinary tract infection (UTI), sepsis, organ failure, admission, and mortality between the 2 groups. Using multivariate analysis, we determined whether or not IBD was a predictor of UTI, sepsis, and hospitalization.

RESULTS

Overall, 14,352 patients had concomitant IBD and urolithiasis. IBD patients with urolithiasis presented with infections (10.4% vs 9.1%; P <.001), sepsis (0.6% vs 0.2%; P <.001), and end-organ failure (6.3% vs 1.6%; P <.001) more frequently than non-IBD patients. They were also more likely to have characteristics independently associated with infection and sepsis, such as older age and female gender. In adjusted analyses, IBD was an independent predictor of infection (odds ratio [OR] = 1.3 [1.14-1.46]; P <.0001), sepsis (OR = 1.8 [1.09-2.92]; P <.0001), and admission (OR = 3.3 [3.04-3.64]; P <.0001).

CONCLUSION

IBD patients with urinary calculi have greater odds of UTI, renal failure, and sepsis compared to the general stone-forming population. The increased occurrence and severity of infected urolithiasis in this select group of patients warrants screening for stone disease, improved outpatient medical management, and early elective surgery for detected stones.

Is nephrolithiasis an unrecognized extra-articular manifestation in ankylosing spondylitis? A prospective population-based Swedish national cohort study with matched general population comparator subjects

Background

Ankylosing spondylitis (AS) is associated with several extra-articular manifestations. Nephrolithiasis (NL) has not been recognized as one of those, however, several factors known to increase the risk of NL are at play in AS patients. The objective was to estimate rates and predictors of NL in Swedish patients with AS compared to the general population.

Methods and Findings

We performed a prospective population-based nationwide cohort study based on linkage of data from Swedish registries. 8,572 AS patients were followed for 49,258 person-years (py) and 39,639 matched general population comparators were followed for 223,985 py. Patients were followed prospectively together with comparator subjects from January 2001 through December 2009. The first occurrence of NL during follow-up was the primary outcome. Hazard Ratios (HR) were used to compare these rates adjusting for comorbidities and treatment, and to assess predictors for NL. Mean age at study entry was 46 years (inter quartile range 36–56 years), 65% were males. Based on 250 vs. 466 NL events, the adjusted HR of NL in AS patients was 2.1 (95%CI 1.8 to 2.4). Predictors of NL within the AS group included prior diagnosis of inflammatory bowel disease (IBD) (HR 2.3; 95%CI 1.7 to 3.3), prior diagnosis of NL (HR 16.4; 95%CI 11.5 to 23.4), and patients receiving anti-TNF treatment (HR 1.6; 95%CI 1.2 to 2.1). Male sex was a risk factor for NL both in AS patients and in the general population.

Limitations

The risk for residual confounding and inability to study the chemical nature of NL were considered the main limitations of the study.

Conclusions

Patients with AS are at increased risk of NL, which may be considered a novel extra-articular manifestation. Previous history of NL, IBD, AS disease severity and male sex were identified as predictors of NL in AS.