Microalbuminuria in inflammatory bowel disease

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.

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.

Serum amyloid protein A in inflammatory bowel disease: from bench to bedside

Inflammatory bowel diseases (IBD) is featured by gastrointestinal inflammation and a disease course with alternating recurrence and remission. The global burden caused by IBD has significantly boosted in recent years, necessitating treatment optimization. Serum amyloid A (SAA) is a class of 104 amino acid conservative acute-phase proteins, which is essential in immune-mediated inflammatory processes, like IBD. The SAA monomeric structure is composed of four α-helical regions and a C-terminal amorphous tail. Its disordered structure enables multiple bindings to different ligands and permits multiple functions. It has been proven that SAA has dual roles in the inflammatory process. SAA stimulates the pro-inflammatory cytokine expression and promotes the pathogenic differentiation of TH17 cells. In addition, SAA can remove toxic lipids produced during inflammatory responses and membrane debris from dead cells, redirect HDL, and recycle cholesterol for tissue repair. In IBD, SAA acts on gut epithelium barriers, induces T-cell differentiation, and promotes phagocytosis of Gram-negative bacteria. Owing to the tight connection between SAA and IBD, several clinical studies have taken SAA for a biomarker for diagnosis, assessing disease activity, and predicting prognosis in IBD. Furthermore, 5-MER peptide, a drug specifically targeting SAA, has shown anti-inflammatory effects in some SAA-dependent animal models, providing novel insights into the therapeutic targets of IBD.

Fecal and Urinary Adipokines as Disease Biomarkers

The use of biomarkers is of great clinical value for the diagnosis and prognosis of disease and the assessment of treatment efficacy. In this context, adipokines secreted from adipose tissue are of interest, as their elevated circulating levels are associated with a range of metabolic dysfunctions, inflammation, renal and hepatic diseases and cancers. In addition to serum, adipokines can also be detected in the urine and feces, and current experimental evidence on the analysis of fecal and urinary adipokine levels points to their potential as disease biomarkers. This includes increased urinary adiponectin, lipocalin-2, leptin and interleukin-6 (IL-6) levels in renal diseases and an association of elevated urinary chemerin as well as urinary and fecal lipocalin-2 levels with active inflammatory bowel diseases. Urinary IL-6 levels are also upregulated in rheumatoid arthritis and may become an early marker for kidney transplant rejection, while fecal IL-6 levels are increased in decompensated liver cirrhosis and acute gastroenteritis. In addition, galectin-3 levels in urine and stool may emerge as a biomarker for several cancers. With the analysis of urine and feces from patients being cost-efficient and non-invasive, the identification and utilization of adipokine levels as urinary and fecal biomarkers could become a great advantage for disease diagnosis and predicting treatment outcomes. This review article highlights data on the abundance of selected adipokines in urine and feces, underscoring their potential to serve as diagnostic and prognostic biomarkers.

Urinary chemerin as a potential biomarker for inflammatory bowel disease

Purpose

Systemic levels of the adipokine chemerin are elevated in different inflammatory conditions such as inflammatory bowel disease (IBD). In IBD, chemerin protein expression in colon mucosa is induced and serum chemerin levels are increased. Aim of this study was to identify chemerin protein in human feces and/or urine and to evaluate a possible association with IBD activity.

Materials and methods

Feces and urine of 40 patients with IBD and the respective sera of 34 patients were collected. Chemerin levels were analyzed by immunoblot in feces and urine samples. In addition, enzyme-linked immunosorbent assay (ELISA) was used to measure chemerin in all urine, feces and serum samples of the patients and in urine of 17 healthy controls.

Results

Chemerin was not detectable in 80% of the human feces samples by ELISA. Chemerin in human urine was detected by immunoblot and ELISA. Compared to serum levels, urinary concentration was about 6,000-fold lower. Urinary chemerin did not differ between patients with ulcerative colitis (n = 15) and Crohn's disease (n = 25). Urinary chemerin was not related to its serum levels, did not correlate with serum C-reactive protein level and negatively correlated with serum creatinine. Of note, urinary chemerin of patients with a fecal calprotectin > 500 μg/g was significantly higher compared to patients with lower calprotectin levels and compared to healthy controls. Serum creatinine did not differ between the patient groups.

Conclusion

Urinary chemerin might present a novel non-invasive biomarker for monitoring IBD severity and clinical course.

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

Background

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

Methods

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

Results

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

Conclusions

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

Co-existing sickle cell anaemia and inflammatory bowel disease: case report and review of the literature

Sickle cell anaemia (SCA) is a chronic haemolytic anaemia associated with vaso-occlusive painful crises which may affect several systems including the gastro-intestinal system, resulting in abdominal pain. The concurrence of inflammatory bowel disease and haemoglobinopathy is rare. No previously reported concurrent cases of both SCA and ulcerative colitis (UC) in sub-Saharan Africa were found in the literature. A 16-year-old girl with concurrent SCA and UC is presented. She was admitted to University College Hospital, Ibadan with a 1-year history of recurrent peri-umbilical pain and bloody stools. These symptoms were mainly attributed to SCA at the referring hospital, and she was managed for chronic tropical diarrhoea without a remarkable clinical response. This case illustrates the concurrent presentation of SCA and ulcerative colitis which led to the missed and delayed diagnosis of ulcerative colitis.

Urinary levels of pro-fibrotic transglutaminase 2 (TG2) may help predict progression of chronic kidney disease

Renal clinical chemistry only detects kidney dysfunction after considerable damage has occurred and is imperfect in predicting long term outcomes. Consequently, more sensitive markers of early damage and better predictors of progression are being urgently sought, to better support clinical decisions and support shorter clinical trials. Transglutaminase 2 (TG2) is strongly implicated in the fibrotic remodeling that drives chronic kidney disease (CKD). We hypothesized that urinary TG2 and its ε-(γ-glutamyl)-lysine crosslink product could be useful biomarkers of kidney fibrosis and progression. Animal models: a rat 4-month 5/6th subtotal nephrectomy model of CKD and a rat 8-month streptozotocin model of diabetic kidney disease had 24-hour collection of urine, made using a metabolic cage, at regular periods throughout disease development. Patients: Urine samples from patients with CKD (n = 290) and healthy volunteers (n = 33) were collected prospectively, and progression tracked for 3 years. An estimated glomerular filtration rate (eGFR) loss of 2-5 mL/min/year was considered progressive, with rapid progression defined as > 5 mL/min/year. Assays: TG2 was measured in human and rat urine samples by enzyme-linked immunosorbent assay (ELISA) and ε-(γ-glutamyl)-lysine by exhaustive proteolytic digestion and amino acid analysis. Urinary TG2 and ε-(γ-glutamyl)-lysine increased with the development of fibrosis in both animal model systems. Urinary TG2 was 41-fold higher in patients with CKD than HVs, with levels elevated 17-fold by CKD stage 2. The urinary TG2:creatinine ratio (UTCR) was 9 ng/mmol in HV compared with 114 ng/mmol in non-progressive CKD, 1244 ng/mmol in progressive CKD and 1898 ng/mmol in rapidly progressive CKD. Both urinary TG2 and ε-(γ-glutamyl)-lysine were significantly associated with speed of progression in univariate logistic regression models. In a multivariate model adjusted for urinary TG2, ε-(γ-glutamyl)-lysine, age, sex, urinary albumin:creatinine ratio (UACR), urinary protein:creatinine ratio (UPCR), and CKD stage, only TG2 remained statistically significant. Receiver operating characteristic (ROC) curve analysis determined an 86.4% accuracy of prediction of progression for UTCR compared with 73.5% for UACR. Urinary TG2 and ε-(γ-glutamyl)-lysine are increased in CKD. In this pilot investigation, UTCR was a better predictor of progression in patients with CKD than UACR. Larger studies are now warranted to fully evaluate UTCR value in predicting patient outcomes.

Gastrointestinal involvement and its association with the risk for nephritis in IgA vasculitis

Background:

We analysed clinical and biochemical parameters in predicting severe gastrointestinal (GI) manifestations in childhood IgA vasculitis (IgAV) and the risk of developing renal complications.

Methods:

A national multicentric retrospective study included children with IgAV reviewed in five Croatian University Centres for paediatric rheumatology in the period 2009–2019.

Results:

Out of 611 children, 281 (45.99%) had at least one GI manifestation, while 42 of 281 (14.95%) had the most severe GI manifestations. Using logistic regression several clinical risk factors for the severe GI manifestations were identified: generalized rash [odds ratio (OR) 2.09 (95% confidence interval (CI) 1.09–4.01)], rash extended on upper extremities (OR 2.77 (95% CI 1.43–5.34)] or face [OR 3.69 (95% CI 1.42–9.43)] and nephritis (IgAVN) [OR 4.35 (95% CI 2.23–8.50)], as well as lower values of prothrombin time (OR 0.05 (95% CI 0.01–0.62)], fibrinogen [OR 0.45 (95% CI 0.29–0.70)] and IgM [OR 0.10 (95% I 0.03–0.35)]] among the laboratory parameters. Patients with severe GI involvement more frequently had relapse of the disease [OR 2.14 (CI 1.04–4.39)] and recurrent rash [OR 2.61 (CI 1.27–5.38)]. Multivariate logistic regression found that the combination of age, GI symptoms at the beginning of IgAV and severity of GI symptoms were statistically significant predictors of IgAVN. Patients in whom IgAV has started with GI symptoms [OR 6.60 (95% CI 1.67–26.06)], older children [OR 1.22 (95% CI 1.02–1.46)] with severe GI form of IgAV (OR 5.90 (95% CI 1.12–31.15)] were particularly high-risk for developing IgAVN.

Conclusion:

We detected a group of older children with the onset of GI symptoms before other IgAV symptoms and severe GI form of the IgAV, with significantly higher risk for acute and chronic complications of IgAV.

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.

Relationship between Microalbuminuria and Disease Activity in Patients with Ulcerative Colitis

BACKGROUND

Introducing a non-invasive method for determining disease activity is important in patients with ulcerative colitis (UC). So in this study, we aimed to assess the association between disease activity index and microalbuminuria in patients with UC.

METHODS

In the present cross-sectional study, 84 patients with UC were selected. The disease activity was calculated by the partial Mayo clinic score. Microalbuminuria was assessed using the immunoturbidimetric method in a first-voided sample in the morning in two consecutive days and the mean of these two measurements was reported as urinary microalbumin level. Serum C reactive protein (CRP), erythrocyte sedimentation rate (ESR), and fecal calprotectin were measured respectively using conventional turbidimetric immunoassay, Westergren method, and ELISA methods.

RESULTS

The mean age of the participants was 40.01 ± 12.85 years, 60.8% of them were female and 53.5% had microalbuminuria. The frequency of microalbuminuria was significantly higher in patients with active compared with inactive inflammatory bowel disease (IBD). There were significant differences between the patients with active and inactive disease regarding CRP, ESR, and calprotectin (p < 0.001). Moreover, there was a strong correlation between microalbuminuria and CRP (r = 0.89, p < 0.001), ESR (r = 0.92, p < 0.001), and calprotectin (r = 0.91, p < 0.001).

CONCLUSION

Microalbuminuria could be used as a non-invasive marker of disease activity in patients with UC.

Association of Urinary Albumin:Creatinine Ratio with Outcome of Children with Sepsis

Objective

The aim of the study was to investigate the association of urinary albumin:creatinine ratio (ACR) with regard to the outcome of sepsis patients and to study the trends of ACR with severity of disease, organ dysfunction, microcirculation status, the use of inotrope, and mechanical ventilation use, and length of pediatric intensive care unit (PICU) stay.

Materials and methods

In the prospective observational study, the patients with varying categories of sepsis admitted in the PICU with stay >24 hours were enrolled consecutively. Urine samples were collected at the time of admission (ACR1), 12 hours (ACR2), and 24 hours (ACR3).

Results

One hundred and thirty-eight patients including 56 cases of sepsis, 31 of severe sepsis, 22 of septic shock, and 29 of multiorgan dysfunction syndrome (MODS) cases were analyzed. There were 29 (21%) deaths. ACR (median, IQR) was significantly higher in nonsurvivors [ACR1 198.9 (111.2–329.4) vs 124.5 (59.37–294.5), p 0.03], [ACR2 213.8 (112.5–350) vs 117.8 (62.6–211.9) p 0.008], [ACR3 231.8 (99.9–441.2 vs 114.4 (44.1–240.3), p 0.005]. The ACR is increased progressively with the increasing severity of sepsis (p < 0.001). The performance of ACR operative characteristics was compared with that of PRISM and PELOD scores. In deceased, ACR was significantly correlated with blood pH, lactate, and base deficit. A cutoff value of ACR 102.7 mg/g had sensitivity 86.2%, specificity 40.4%, positive predictive value 27.8%, and negative predictive value 91.7%. The use of inotropes, mechanical ventilation (>48 hours), and mortality was significantly higher in patients with ACR >102 mg/g. The probability of death varied from 17.6 to 19% in the first 24 hours of admission. ACR was significantly cheaper as compared to PRISM score and PELOD score estimations.

Conclusion

Urinary ACR, a cost-effective tool, correlates with the severity of sepsis and associated morbidity and mortality in children.

How to cite this article

Sachdev A, Raheja K, Gupta N, Chugh P. Association of Urinary Albumin:Creatinine Ratio with Outcome of Children with Sepsis. Indian J Crit Care Med 2020;24(6):465–472.

Elevated urinary orosomucoid excretion as a novel biomarker in Crohn's disease

BACKGROUND

Laboratory markers are essential tools in the follow-up of patients with Crohn's disease (CD). Our aim was to investigate urinary concentrations of orosomucoid in relation to the inflammatory activity of CD and to compare it with clinical indices and conventional laboratory parameters.

MATERIALS AND METHODS

Blood and urine samples of 86 patients (55 adults and 31 children) with CD and 68 healthy individuals (38 adults and 30 children) as controls were analysed. Patients were categorized according to their clinical scores (Harvey-Bradshaw Index [HBI] or Pediatric Crohn's Disease Activity Index [PCDAI]). Urinary orosomucoid (u-ORM) was determined by automated immune turbidimetric assay, and values were referred to urinary creatinine (u-ORM/u-CREAT, mg/mmol).

RESULTS

U-ORM/u-CREAT values were seven times higher in children with active CD (0.50 vs 0.07 mg/mmol, P < 0.001) and two times higher in adults (0.32 vs 0.14 mg/mmol, P = 0.01) compared with patients with inactive disease. U-ORM/u-CREAT showed good correlation with conventional inflammatory markers (hs-CRP, serum ORM; P < 0.01) and activity indices (HBI, P = 0.018; PCDAI, P < 0.001). U-ORM/u-CREAT had similar discriminative performance to hs-CRP and serum ORM in the differentiation of active from inactive paediatric CD patients.

CONCLUSIONS

Our findings suggest that u-ORM/u-CREAT might serve as a valuable additional marker in the follow-up of CD patients, especially in children for whom the non-invasive sampling is a further advantage.

The Gut-Kidney Axis: Putative Interconnections Between Gastrointestinal and Renal Disorders

Diabetic kidney disease (DKD) is a devastating condition associated with increased morbidity and premature mortality. The etiology of DKD is still largely unknown. However, the risk of DKD development and progression is most likely modulated by a combination of genetic and environmental factors. Patients with autoimmune diseases, like type 1 diabetes, inflammatory bowel disease, and celiac disease, share some genetic background. Furthermore, gastrointestinal disorders are associated with an increased risk of kidney disease, although the true mechanisms have still to be elucidated. Therefore, the principal aim of this review is to evaluate the impact of disturbances in the gastrointestinal tract on the development of renal disorders.

The predictive value of proteinuria in acute pancreatitis

BACKGROUND/OBJECTIVES

Acute pancreatitis has a highly variable clinical course. Early and reliable predictors for the severity of acute pancreatitis are lacking. Proteinuria appears to be a useful predictor of disease severity and outcome in a variety of clinical conditions. This study aims to investigate the predictive value of proteinuria on admission for the severity of acute pancreatitis compared with other commonly used predictors; the APACHE II score, Modified Glasgow score and C-reactive protein (CRP).

METHODS

This is a post-hoc analysis of 64 patients admitted with acute pancreatitis treated in one teaching hospital, who participated in a previous randomized trial. Proteinuria was defined as a Protein/Creatinine (P/C) ratio >23 mg/mmol. The primary endpoint was severe acute pancreatitis. Secondary endpoints included infectious complications, need for invasive intervention, ICU stay and in-hospital mortality.

RESULTS

Proteinuria was present in 30/64 patients (47%). Eleven patients (17%) had severe acute pancreatitis. There was no difference in incidence of severe acute pancreatitis between patients with and without proteinuria: 6/30 patients (20%) versus 5/34 patients (15%) respectively (p = 0.58). Likewise, the occurrence of infectious complications, need for intervention and ICU stay and mortality did not differ significantly (p = 0.58, p = 0.99, p = 0.33 and p = 0.60 respectively). The diagnostic performance of the P/C ratio for the prediction of severe pancreatitis was inferior to the Modified Glasgow score (p = 0.04) and CRP (p = 0.03).

CONCLUSION

Proteinuria on admission does not seem to be a reliable predictor for disease severity in acute pancreatitis. The diagnostic performance of the P/C ratio is inferior to the Modified Glasgow score and CRP.

High prevalence of fatigue in inflammatory bowel disease: A case control study

BACKGROUND AND AIMS

Many outpatients with Inflammatory Bowel Disease (IBD) complain about fatigue, even in a quiescent disease. The aim of this study is to examine prevalence of fatigue in IBD outpatients and define possible determinants of fatigue.

METHODS

A case-control study was conducted in consecutive IBD outpatients, with Lynchsyndrome gene carriers (Lynch) as a control group. Demographics, laboratory results and Harvey Bradshaw Index (HBI) were obtained from medical records. Subjective fatigue was measured by the revised Piper Fatigue Scale (PFS). Mean PFS scores were compared between groups. Secondly, possible determinants of fatigue were assessed.

RESULTS

Three hundred patients were enrolled. 74% returned the questionnaires (117 CD; 55 UC; and 50 Lynch). Demographics were not different between groups. Mean overall PFS is 4.03. PFS score in IBD patients was significantly higher compared to Lynch. Mean (SD) PFS score was 4.8 (2.09) for CD, 4.2 (2.3) for UC versus 1.9 (2.03) for Lynch (P<0.01). Fatigue was present in 40% of the IBD patients in remission. HBI was positively, but not significantly, correlated with PFS scores (r=0.37).

CONCLUSION

We found a high prevalence of fatigue in IBD patients, compared to a control group, even in a quiescent disease. None of the studied determinants was significantly associated with fatigue.

Potential urinary biomarkers of disease activity in Crohn's disease

OBJECTIVE

Measurement of the immunoreactive urinary albumin (ir-uAlb) concentration by immunological methods was found to be an effective method to identify disease activity in Crohn's disease (CD). Recently a size-exclusion (SE) high performance liquid chromatography (HPLC) method was developed to measure both ir-uAlb and non-immunoreactive urinary albumin (total, t-uAlb). We aimed to follow-up one of our CD patients with frequent remissions and exacerbation phases comparing the changes of disease activity parameters and the concentration of ir-uAlb and t-uAlb. The surprising results led us to perform measurements in greater depth.

MATERIAL AND METHODS

Concentration of ir-uAlb was measured by immunoturbidimetry (IT) and t-uAlb by SE-HPLC. Albumin peak of SE-HPLC was collected and applied to a reversed-phase (RP) HPLC and to gel-electrophoresis. Eluted peaks of RP-HPLC and identified bands of gel-electrophoresis were analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS).

RESULTS

The concentration of t-uAlb was 15 times higher than that of the ir-uAlb during active state. The RP-HPLC and the gel-electrophoresis separation proved that albumin peak by size-exclusion consists of three different peaks. MALDI-TOF/MS measurements identified α1-acid-glycoprotein and Zn-α2-glycoprotein as major, and albumin as minor protein.

CONCLUSIONS

Peak of albumin of SE-HPLC contains a significant amount of glycoprotein during the active phase of CD, which could not be detected in remission. Urinary α1-acid-glycoprotein and/or Zn-α2-glycoprotein could be an ideal disease activity biomarker of CD.

Ulcerative colitis practice guidelines in adults: American College Of Gastroenterology, Practice Parameters Committee

Guidelines for clinical practice are aimed to indicate preferred approaches to medical problems as established by scientifically valid research. Double-blind placebo controlled studies are preferable, but compassionate-use reports and expert review articles are used in a thorough review of the literature conducted through Medline with the National Library of Medicine. When only data that will not withstand objective scrutiny are available, a recommendation is identified as a consensus of experts. Guidelines are applicable to all physicians who address the subject regardless of specialty training or interests and are aimed to indicate the preferable but not necessarily the only acceptable approach to a specific problem. Guidelines are intended to be flexible and must be distinguished from standards of care, which are inflexible and rarely violated. Given the wide range of specifics in any health-care problem, the physician must always choose the course best suited to the individual patient and the variables in existence at the moment of decision. Guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee and approved by the board of trustees. Each has been intensely reviewed and revised by the Committee, other experts in the field, physicians who will use them, and specialists in the science of decision analysis. The recommendations of each guideline are therefore considered valid at the time of composition based on the data available. New developments in medical research and practice pertinent to each guideline will be reviewed at a time established and indicated at publication to assure continued validity. The recommendations made are based on the level of evidence found. Grade A recommendations imply that there is consistent level 1 evidence (randomized controlled trials), grade B indicates that the evidence would be level 2 or 3, which are cohort studies or case-control studies. Grade C recommendations are based on level 4 studies, meaning case series or poor-quality cohort studies, and grade D recommendations are based on level 5 evidence, meaning expert opinion.

Albuminuria in hematopoietic cell transplantation patients: prevalence, clinical associations, and impact on survival

Chronic kidney disease (CKD) is common after hematopoietic cell transplantation (HCT). We prospectively measured the urinary albumin:creatinine ratio (ACR) in 142 patients. Total (intact) monomeric albumin was determined by liquid chromatography of untreated urine samples collected weekly to day 100 after HCT. Albuminuria was defined as ACR (mg/g creatinine) > 30; proteinuria, as ACR >300. Cox and logistic regression analyses evaluated ACR as a risk factor for clinical events. The prevalence of albuminuria was 37% at baseline, 64% at day 100, and 50% at 1 year. Proteinuria occurred in 4% of patients at baseline, in 15% at day 100, and in 4% at 1 year. Characteristics associated with albuminuria include age, sex, donor type, hypertension, and sinusoidal obstruction syndrome (SOS). Albuminuria was associated with an increased risk of acute graft-versus-host disease (aGVHD) and bacteremia, but not acute kidney injury (AKI). Albuminuria at day 100 was associated with CKD at 1 year (odds ratio = 4.0; 95% confidence interval [CI] = 1.1 to 14.6). Nonrelapse mortality (NRM) risk was elevated (hazard ratio = 6.8; 95% CI = 1.1 to 41.5) in patients with overt proteinuria at day 100. Albuminuria occurs frequently after HCT and is correlated with aGVHD, bacteremia, hypertension, and progression of renal disease. Proteinuria at day 100 is associated with an 6-fold increased risk of NRM by 1 year after HCT.

Renal effects of long-term treatment with 5-aminosalicylic acid

BACKGROUND

A number of case reports link the use of 5-aminosalicylic acid (5-ASA) to interstitial nephritis in patients with inflammatory bowel disease (IBD).

OBJECTIVE

To investigate whether the long-term use of 5-ASA has harmful effects on renal function in patients with IBD.

METHODS

A retrospective analysis of 171 consecutive outpatients with Crohn's disease or ulcerative colitis was conducted. Serum creatinine levels and body weight were measured before and after treatment to calculate the creatinine clearance (CrCl) rate.

RESULTS

In 171 patients (93 women, 78 men), the mean (+/- SD) dose of 5-ASA was 3.65+/-0.85 g/day with a cumulative dose of 11+/-7.7 kg over an interval of 8.4+/-5.9 years. Serum creatinine concentrations increased from 76.8 micromol/L to 88.7 micromol/L (n=171; P<0.0001) and the CrCl rate fell significantly from 104.6 mL/min to 93.1 mL/min (n=81; P<0.0001). There was one case of interstitial nephritis reported. Treatment groups included mesalamine (74.3%), sulfasalazine (15.2%) and combination (sulfalsalazine/mesalamine [10.5%]) with treatment durations of 7.2+/-4.5, 12.3+/-8.7 and 11.2+/-6.7 years, respectively. The duration of treatment was the most important covariate for change in CrCl and when analyzed by treatment group, those treated with sulfasazine had a strong correlation (r=-0.54, P=0.0145), while nonsignificant in the mesalamine group (r=0.06, P=0.7017). The decline in CrCl was negatively correlated with the pretreatment CrCl rate (r=-0.34; P=0.0024) and positively correlated with the mean daily dose of 5-ASA (r=0.32; P=0.0034).

CONCLUSION

The present study is the first to demonstrate a significant dose- and treatment duration-dependant decline in CrCl. The risks need to be further evaluated because 5-ASA is widely used for long-term maintenance therapy in patients with IBD.

Does the urinary excretion of alpha1-microglobulin and albumin predict clinical disease activity in ulcerative colitis?

INTRODUCTION

There remains some difficulty in determining disease activity during the development of inflammatory bowel disease (IBD). The excretion levels of some inflammatory response molecules increase as a result of the onset of this disease. We studied urinary alfa-1-microglobulin (alpha1-MG) and albumin levels in patients with active and inactive ulcerative colitis (UC) and investigated whether we could use these parameters as an activity index.

METHODS

The study was carried out at Gazi University Faculty of Medicine, Nephrology and Gastroenterology Departments, between December 2003 and March 2006. In total, 35 patients (male/female: 16/19, mean age: 38.3+/-2.4 years) and 13 healthy controls (male/female: 6/7, mean age: 35.8+/-2.8 years) were enrolled in the study. Nineteen patients had symptoms of active disease and the remaining 16 patients had inactive disease.

RESULTS

There was a significant difference in serum C-reactive protein (CRP), urinary albumin excretion, and alpha1-MG excretion levels between patients and controls. Patients with active disease had significantly higher serum CRP and alpha1-MG levels than those with inactive disease and controls. Patients with active disease had higher microalbuminuria levels than inactive patients, but this difference was not statistically significant. Urinary albumin and alpha1-MG excretion did not correlate with serum CRP levels.

CONCLUSION

The present study suggests that, as with CRP, urinary levels of albumin and alpha1-MG increase during the active period of UC. During the inactive period, concentrations of these parameters are comparable to controls. The measurement of alpha1-MG and/or microalbuminuria could provide information on disease severity and response to treatment.

Selective white cell apheresis reduces relapse rates in patients with IBD at significant risk of clinical relapse

BACKGROUND

We assessed whether selective granulocyte and monocyte/macrophage adsorption apheresis maintained clinical remission in asymptomatic inflammatory bowel disease (IBD) patients at significant risk of clinical relapse.

METHODS

Sixty asymptomatic patients (age 18-70 years) with IBD (in clinical remission) with fecal calprotectin over 250 microg/g (which defines those at risk of clinical relapse with >80% specificity and sensitivity) were recruited for this open-label, prospective, randomized, controlled study. Twenty-nine underwent selective leukocytapheresis, undergoing 5, once weekly, out-patient sessions. Thirty-one had unchanged maintenance treatment and acted as controls. Follow-up for a clinical relapse was 6 months. The secondary outcome variable was the time to relapse.

RESULTS

The number of patients who remained in clinical remission at 6 months was significantly lower in controls (32.3%) than in the apheresis (72.4%) group (P = 0.0023, Fisher's exact test). The time to first relapse was significantly earlier in the control group (99 +/- 73 days) as compared with the apheresis group (161 +/- 44 days) (log-rank test; P = 0.0004). Mild and transient headache was reported by 16 of the 29 (55%) for up to 3 hours, but no serious side effects were observed.

CONCLUSIONS

This study represents a new approach to the treatment of IBD by targeting a group of asymptomatic patients for treatment who are at significant risk of relapse based on high fecal calprotectin concentrations. Selective leukocytapheresis significantly reduced the number of, and increased the time to, clinical relapse in these patients without serious side effects.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CLINICAL SIGNIFICANCE

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

Microalbuminuria and comparison of serologic testing for exposure to Borrelia burgdorferi in nonclinical Labrador and Golden Retrievers

Canine Lyme disease is caused by the spirochete Borrelia burgdorferi after transmission by an Ixodes tick, typically resulting in joint pain, fever and lethargy. Lyme nephritis is a poorly characterized syndrome associated with severe glomerular and tubular renal injury and poor clinical outcome in young to middle-aged dogs positive for exposure to B. burgdorferi. The aims of this study were to identify associations between natural exposure to B. burgdorferi and the presence of microalbuminuria in nonclinical young Labrador and Golden Retrievers and to compare two commonly used serologic tests available to document B. burgdorferi exposure: the Western blot and the commercial point-of-care C6 peptide enzyme-linked immunosorbent assay (ELISA) tests. Microalbuminuria was assessed using a commercial point-of-care ELISA specific for canine albumin. Blood and urine samples from 268 asymptomatic Labrador and Golden Retrievers were included. Of these, 18.7% were positive for B. burgdorferi exposure according to the C6 ELISA; 21.2% were positive for natural exposure to B. burgdorferi and 11.5% for vaccinal antibodies according to the Western blot. The agreement rate was 93% between the two tests (kappa = 0.78, P < 0.0001) for natural exposure. Urine from 6.1% of the dogs was positive for microalbuminuria. There was no association between microalbuminuria and exposure to B. burgdorferi based on results of a Western blot (P = 0.57) or C6 ELISA (P = 0.53). Microalbuminuria is likely not a consequence of B. burgdorferi exposure in young nonclinical Labrador and Golden Retrievers.

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

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

Urinary excretion of alpha1-microglobulin and albumin in acute myocardial infarction. Correlation with plasma concentrations of troponin I and C-reactive protein

OBJECTIVES

Microalbuminuria associated with myocardial infarction (MI) is normally ascribed to glomerular factors, but could just as well involve pathophysiological processes located in other parts of the nephron, e.g. proximal tubules where plasma albumin normally filtered through the glomerulus is almost completely reabsorbed. The aims of this study were to establish whether impaired tubular reabsorption of filtered albumin contributes to microalbuminuria during MI, and whether the urinary excretion of protein relates to plasma levels of C-reactive protein (CRP) and troponin I.

MATERIAL AND METHODS

We monitored plasma CRP and troponin I as well as the urinary excretion of albumin and alpha1-microglobulin, a low-molecular-weight plasma protein and marker of tubular proteinuria, in 18 patients with MI.

RESULTS AND CONCLUSIONS

The urinary excretion of alpha1-microglobulin and albumin was significantly elevated in nine patients, and the urinary excretion of the two proteins correlated significantly. A decrease in tubular reabsorption of albumin may thus be at least one of the causative factors underlying microalbuminuria during MI. The plasma levels of CRP and troponin I were also significantly higher in this group of nine patients, and correlated with urinary protein excretion, suggesting an interrelationship between inflammatory response and tubular dysfunction. Extrarenal inflammatory processes seem to affect renal tubular function, thereby contributing to microalbuminuria during MI.

Microalbuminuria in the intensive care unit: Clinical correlates and association with outcomes in 431 patients*

OBJECTIVE

Comparison of urine albumin within 6 hrs of intensive care unit (ICU) admission with demography, clinical classification, outcome, inotrope/vasopressor requirement, clinical assessment of mortality risk, and Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores.

DESIGN

Urine albumin-creatinine ratio (ACR) was measured on ICU admission (ACR 1) and after 4-6 hrs (ACR 2).

SETTING

A 17-bed general ICU in a university teaching hospital.

PATIENTS

Unselected medical (206) and surgical (225) patients recruited prospectively.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Bedside urine ACR was measured by nurses using a Bayer DCA 2000 analyzer and expressed in mg/mmol (reference range <2.3). ACR 1 in medical and surgical patients was 15.5 (12.4-19.5) and 8.2 (5.9-11.1) mg/mmol, respectively (p = .0002), and ACR 2 was 9.0 (5.8-12.5) and 4.6 (3.6-5.3), respectively (p < .0001). For all patients, median (95% confidence interval) ACR fell from 11.2 (8.7-13.2) to 5.4 (4.7-6.8) mg/mmol 4-6 hrs after ICU admission (p < .0001). ACR 1 for nonsurvivors (n = 90) and survivors (n = 341) was 16.1 (11.2-21.3) and 8.8 (6.9-11.9), respectively (p = .0002) and ACR 2, 12.4 (8.2-18.9) and 4.8 (3.9-5.4), respectively (p < .0001). In both medical and surgical patients who died on the ICU, median ACR failed to decrease significantly following admission. ACR1 and ACR 2 were higher in patients who required inotropic or vasopressor support and correlated with duration of therapy. ACR 1 and 2 were inversely correlated with mean Po2/Fio2 ratio 48 hrs after ICU admission and positively correlated with duration of mechanical ventilation and ACR 1 with ICU stay. ACR 2 predicted mortality and ACR 1 inotrope requirement independent of clinical mortality risk assessment and APACHE II and SOFA scores.

CONCLUSIONS

Urine albumin changes rapidly within the first 6 hrs following ICU admission and predicts ICU mortality and inotrope requirement as well as or better than APACHE II and SOFA scores. Serial urine albumin measurement may provide a means of monitoring the microvascular effects of systemic inflammation.

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

AIM: To investigate whether microproteinuria in patients with inflammatory bowel disease (IBD) is associated with the disease activity or the treatment with 5-aminosalicylic acid (5-ASA).

METHODS: We prospectively studied microproteinuria in 86 consecutive patients with IBD, 61 with ulcerative colitis (UC) and 25 with Crohn’s disease (CD), before as well as 2 and 6 months after their inclusion in the study. Forty-six patients received 5-ASA for a period of 28.8 months (range 1-168 mo). Microalbuminuria (mALB) and urine levels of the renal tubular proteins β₂-microglobulin (β₂mGLB) and β-N-acetyl-D-glucosamidase (β-NAG) as well as the creatinine clearance were determined in a 12-h overnight urine collection. Tumor necrosis factor-α (TNF-α) serum levels were also measured.

RESULTS: A total of 277 measurements (194 in UC patients and 83 in CD patients) were performed. The prevalence of abnormal microproteinuria in UC and CD patients was 12.9% and 6.0% for mALB, 22.7% and 27.7% for β₂mGLB, and 11.3% and 8.4% for β-NAG, respectively. mALB was not associated with IBD activity. β₂mGLB and β-NAG urine levels were correlated to UC activity (UCAI: P<0.01; UCEI: P<0.005). mALB in UC patients and β-NAG urine levels in CD patients were related to TNF-α serum levels. An association was noticed between microproteinuria and smoking habit. Treatment with 5-ASA was not correlated to the severity of microproteinuria or to the changes of creatinine clearance.

CONCLUSION: Microproteinuria is mainly associated with UC and its activity but not affected by 5-ASA.

Microalbuminuria is associated with impaired glomerular permselectivity in lymphoma patients

Slightly increased urinary albumin excretion is frequently found in patients with lymphoma and other malignancies but the pathophysiological mechanisms have yet to be clarified. In this study, parameters of renal function in lymphoma patients with microalbuminuria were evaluated. Sixty-seven patients with histologically proven diffuse large B-cell lymphoma were included in the study at diagnosis. Urinary albumin excretion was measured by immunoturbidimetry and microalbuminuria was defined as an excretion rate between 20 and 200 microg/min. Glomerular function was further estimated by renal clearance of creatinine and IgG, and the IgG/IgG4 charge selectivity index. Tubular function was evaluated by renal clearance of beta(2)-microglobulin. The median value of IgG clearance was increased in the microalbuminuric patients (0.22 versus 0.18 microl/min; p = 0.03). The median selectivity index was significantly lower in patients with microalbuminuria (1.0 versus 2.2; p<0.0001). Urinary albumin excretion was correlated with both the renal clearance of IgG (p<0.0001) and the selectivity index (p<0.0001). These data suggest that a slightly elevated level of urinary albumin excretion in a population of patients with aggressive lymphoma reflects altered glomerular permselectivity probably due to a defect in charge selectivity. The glomerular sieving dysfunction may be associated with an inflammatory response to the malignancy. Further studies are needed to validate the clinical impact of the renal parameters in lymphoma patients.

Acute interstitial nephritis due to mesalazine. Case Report

A case of mesalazine-induced acute interstitial nephritis (AIN) in a 41-year-old patient with ulcerative colitis (UC) is reported here. Clinical symptoms such as fever and arthralgia, and laboratory findings such as eosinophilia and renal failure suggested AIN, which was confirmed by biopsy. With withdrawal of mesalazine and intravenous methylprednisolone the patient's renal function was recovered. It is observed that early discontinuation of mesalazine is associated with amelioration of interstitial nephritis in most patients, so the recommendation is that patients receiving mesalazine should undergo routine monitoring of renal function. Delayed diagnosis may lead to permanent renal function impairment.

Effect of granulocyte and monocyte adsorption apheresis on urinary albumin excretion and plasma endothelin-1 concentration in patients with active ulcerative colitis

BACKGROUND/AIM

Increases in microalbuminuria and endothelin (ET-1) are involved in the development of ulcerative colitis (UC) and in its progress. Because granulocyte and monocyte adsorption apheresis has proven to be useful in the treatment of UC, we examined whether urinary albumin excretion and plasma ET-1 concentrations are altered and whether granulocyte and monocyte adsorption apheresis affects the concentrations of these two factors in patients with active UC.

METHODS

Twenty patients with active UC and 20 age-matched healthy volunteers (our hospital staffs) were included in this study. UC patients were randomly divided into two treatment groups: a granulocyte and monocyte adsorption treatment group (n = 10) and a conventional treatment group (n = 10). The urine albumin/creatinine ratio, plasma ET-1 concentration and tumor necrosis factor (TNF)-alpha were determined before and after treatment and compared between 2 treatment groups. The 10 adsorption treatment patients underwent 5 consecutive weekly apheresis sessions, each of 60 min duration at a flow rate of 30 ml/min.

RESULTS

The urine albumin/creatinine ratio in UC patients (6.4 +/- 2.2 mg/mmol) were higher than that in healthy subjects (1.0 +/- 0.7 mg/mmol, p < 0.01). In addition, the plasma ET-1 level in UC patients (3.5 +/-1.5 pg/ml) was higher than that in healthy subjects (0.8 +/- 0.4 pg/ml, p < 0.01). Plasma TNF-alpha was detected in UC patients (18.8 +/- 8.4 pg/ml), but not in healthy subjects. The urine albumin/creatinine ratio was highly correlated with the plasma ET-1 level (r = 0.62; p < 0.01) and plasma TNF-a level (r = 0.66, p < 0.01). Granulocyte and monocyte adsorption apheresis reduced the urine albumin/ creatinine ratio from 6.6 +/- 2.4 to 1.8 +/- 0.6 mg/mmol (p < 0.01), reduced the plasma ET-1 level from 3.7 +/- 1.6 to 1.4 +/- 0.6 pg/ml (p < 0.05) and reduced the plasma TNF-alpha from 19.2 +/- 8.6 to 3.8 +/- 1.2 pg/ml (p < 0.01). Conventional treatment did not affect these factors.

CONCLUSION

Our data suggest that increases in the urine albumin/creatinine ratio, ET-1 and TNF-alpha play an important role in active UC and that granulocyte and monocyte adsorption apheresis is effective in ameliorating such increases.

Mediators of inflammation correlate with microalbuminuria in patients with non-Hodgkin's lymphoma

Recent studies have demonstrated a high frequency of minor glomerular leakage of albumin in cancer patients. Pathogenic mechanisms of increased urinary albumin excretion (UAE) in malignancies remain to be clarified. We have attempted to identify whether microalbuminuria in lymphoma patients is associated with inflammatory mediators and the acute-phase response. UAE, urinary excretion of beta2-microglobulin and IgG, and serum levels of interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha) and C-reactive protein (CRP) were determined in 113 patients with newly diagnosed non-Hodgkin's lymphoma. We demonstrated a high frequency of microalbuminuria (>or= 20 microg/min) and UAE correlated strongly with serum levels of CRP, IL-6 and TNF-alpha. UAE, CRP, IL-6 and TNF-alpha were significantly higher in patients with advanced disease stage, B symptoms and in high-risk patients according to the International Prognostic Index. Urinary excretion of beta2-microglobulin was unaffected in patients with increased UAE. However, UAE was significantly correlated with urinary excretion of IgG, suggesting an altered size selectivity of the glomerular filtration barrier. This is the first study that shows a direct correlation between microalbuminuria and proinflammatory cytokines in malignancies, indicating a pathogenic relationship between inflammation and glomerular leakage of albumin. Future efforts should focus on the pathophysiological cause-effect mechanisms and larger studies are needed to confirm the clinical significance of UAE.

Elevated serum values of procollagen III peptide (PIIIP)in patients with ulcerative colitis who will develop pseudopolyps

AIM: To assess the impact of procollagen III peptide as a marker of collagenesis in the development of pseudopolyps in patients with ulcerative colitis.

METHODS: Development of pseudopolyps was monitored in 25 patients with ulcerative colitis classified according to Powell-Tuck index as mild (n = 12) or moderate (n = 13) form of disease. Patients with a mild form of disease were treated with oral mesalazine medication (2-4 g/day) and local mesalazine preparation (suppository). Patients with a moderate form of disease received oral mesalazine medication (2-4 g/day), local mesalazine preparation (suppository) and local methylprednisolone at an initial dose of 60 mg/day, followed by dose tapering. How many significant variables (previously determined by analysis of variance) were elevated in the groups with and without pseudopolyp developement was observed. ROC analysis for calculation of new index was made.

RESULTS: Serum values of procollagen III peptide (PIIIP), C-reactive protein (CRP) and C4 complement component (C4) were statistically significantly lower in the group of patients free from pseudopolyp development than those who developed one or more pseudopolyps (0.45 ± 0.12 vs 1.42 ± 0.70, P < 0.0027; 7.6 ± 4.7 vs 17.8 ± 9.17, P < 0.035; and 0.46 ± 0.11 vs 0.34 ± 0.16, P < 0.068, respectively) at endoscopic conrtrols with patohistologically samples during 13 months. There were no statistically significant differences in the values of C3, ceruloplasmin and IgM between the two groups (P > 0.05). Discrimination function analysis yielded highest standardized cannon coefficients for PIIIP (0.876), CRP (0.104), C3 (-0.534) and C4 (0.184) (P < 0.036). The elevation in two of three laboratory variables (PIIIP, CRP and C4) reached sensitivity of 93% and specificity of 90% in the development of pseudopolyps.

CONCLUSION: It is proposed that an increase in two of the three laboratory parameters (PIIIP, CRP and C4) could improve the accuracy of prediction of the development of pseudopolyps. When using PIIIP, CRP and C4 on decision making, the positive predictive value and accuracy were 90% and 92%, respectively.

Evaluation of renal function following treatment with 5-aminosalicylic acid derivatives in patients with ulcerative colitis

BACKGROUND

A number of cases of nephrotoxicity have been reported in patients with inflammatory bowel disease taking oral 5-aminosalicylic acid (5-ASA).

AIM

To evaluate the effects of 9 months of therapy with mesalazine or olsalazine on renal function in patients with ulcerative colitis in remission.

METHODS

Forty patients with ulcerative colitis in complete remission for 6 months were randomized to either olsalazine (n=20) or mesalazine (n=20 for nine months). Thirty-six of the 40 patients were on prior salicylate therapy. Disease activity was the measure ofclinical efficacy and was assessed by the Harvey-Bradshaw Index (HBI). Laboratory efficacy measurements included glomerular filtration rate (GFR), microalbuminuria, urinary gluthathione S-transferase (GST) and serum C-reactive protein (CRP). Safety analysis consisted of documentation of adverse events and laboratory values.

RESULTS

There was no significant reduction in the GFR overall on therapy. The levels of GFR adjusted for baseline were similar in the two treatment groups after 3, 6 and 9 months. A significantly higher percentage of mesalazine-treated patients experienced drug related adverse events, all of a minor nature. The incidence of adverse events causing early withdrawal was similar in the two treatment groups.

CONCLUSION

Treatment with mesalazine or olsalazine for 9 months had no significant impact on GFR.

Renal tubular injury is present in acute inflammatory bowel disease prior to the introduction of drug therapy

BACKGROUND

5-aminosalicylic acid (5-ASA) has been associated with renal complications in inflammatory bowel disease. Renal function is typically monitored using serum creatinine; however, significant disease may predate increases in creatinine.

AIMS

To identify whether markers of early renal disease (urinary albumin, alpha-1-microglobulin [alpha-1-M] and N-acetyl-beta-D-glucosaminidase [NAG], and serum cystatin C) are useful in the assessment of renal function in inflammatory bowel disease patients receiving 5-ASA.

METHODS

Twenty-one patients with a new diagnosis of inflammatory bowel disease were investigated. Samples were taken at diagnosis, and at 3-monthly intervals after the commencement of 5-ASA, for 1 year.

RESULTS

Mean creatinine clearance was 100 mL/min and did not change following treatment. Inflammatory bowel disease was not associated with albuminuria. Urinary N-acetyl-beta-D-glucosaminidase and alpha-1-microglobulin at diagnosis were increased in 10 (48%) and 11 (52%) patients, respectively: treatment was not associated with consistent changes in urinary protein excretion. There was a significant correlation between cystatin C and creatinine clearance both at diagnosis (r=-0.533, P=0.0275) and combining the initial and follow-up data (r=-0.601, P < 0.01), but not between creatinine and creatinine clearance (P > 0.05).

CONCLUSIONS

Tubular proteinuria is an extra-intestinal manifestation of inflammatory bowel disease irrespective of 5-ASA treatment. Tubular proteins are not useful predictors of an adverse renal response to 5-ASA. Serum cystatin C may be an improved marker of glomerular filtration rate in this setting.

Soluble adhesion molecules in inflammatory bowel disease

BACKGROUND

Soluble adhesion molecules are elevated in a number of inflammatory conditions.

AIMS

To investigate the correlation of soluble intercellular adhesion molecule-1 (sICAM-1) and sE-selectin with the activity of inflammatory bowel disease (IBD).

METHODS

sICAM-1 and sE-selectin were measured by an enzyme-linked immunosorbent assay (ELISA) in 53 patients with ulcerative colitis (UC) and 38 patients with Crohn's disease (CD).

RESULTS

Patients with active UC and CD had significantly higher sICAM-1 than patients with inactive disease and controls. Patients with pancolitis had significantly higher levels than patients with distal colitis. There was a significant difference in sE-selectin levels between patients with active CD and control sICAM-1. sE-selectin did not correlate with the Harvey Bradshaw index (HBI). C-reactive protein (CRP) and microalbuminuria were better markers than sICAM-1 or sE-selectin which correlated with serum tumour necrosis factor (TNF)-alpha.

CONCLUSION

sICAM-1 and sE-selectin are elevated in the serum of patients with IBD but CRP and microalbuminuria reflect clinical disease activity more accurately. This study does not support the routine use of soluble adhesion molecules as disease activity markers in IBD.

Increased urinary nitrite, a marker of nitric oxide, in active inflammatory bowel disease

BACKGROUND

Nitric oxide (NO) production is increased in inflammatory bowel disease (IBD), and measurement of NO metabolites may be useful for monitoring disease activity.

AIMS AND OBJECTIVES

To characterise urinary nitrite levels, a stable metabolite of NO, in IBD and to evaluate its potential as a marker of disease activity.

METHODS

Twelve-hour urinary nitrites were measured by the microplate assay method in 46 patients with IBD (active; n = 32). Urinary samples from 16 healthy individuals served as controls.

RESULTS

Increased levels of urinary nitrites were found in patients with active IBD compared with those with inactive IBD. Twenty-eight out of 32 patients (87.5%) with active IBD had detectable levels of nitrite in their urine as compared with 2/14 (14.3%) patients with inactive IBD. None of the 16 healthy controls had detectable urinary nitrite. Twelve-hour urinary nitrite in active compared with inactive IBD: 5 0.7 versus 0.1+/-0.04 micromol (P < 0.05). There was good correlation between urinary nitrite and some markers of disease activity in IBD such as C-reactive protein and microalbuminuria but not with erythrocyte sedimentation rate.

CONCLUSIONS

Increased levels of nitrite were detected in urine of patients with active IBD, consistent with increased NO synthesis. This simple assay may be exploited as a potential marker of disease activity in IBD.

Minimal renal dysfunction in inflammatory bowel disease is related to disease activity but not to 5-ASA use

BACKGROUND

Conflicting data exist about proteinuria in inflammatory bowel diseases. It is still unclear whether the occurrence of proteinuria in inflammatory bowel disease patients is an extra-intestinal manifestation of disease or the result of adverse effects to medication, especially to aminosalicylates (ASA).

METHODS

A total of 95 patients (51 with Crohn's disease and 44 with ulcerative colitis) were enrolled in the study. Disease activity was assessed by Crohn's Disease Activity Index (CDAI) or the Truelove index, respectively. Urine was collected over 24 h and protein excretion of specific marker proteins for tubular (alpha 1-microglobulin-alpha 1-MG) and glomerular (albumin-Alb, Immunoglobulin G-IgG) dysfunction was measured using a highly sensitive immunoluminometric assay.

RESULTS

Out of 51 Crohn's disease patients, 20 showed elevated urinary alpha 1-MG. The amount of alpha 1-MGuria was strongly correlated to the CDAI (r=0.6, P < 0.001). Only four Crohn's disease patients showed slightly elevated values for glomerular proteins in urine. Similar results were obtained for ulcerative colitis: whereas only two ulcerative colitis patients showed albuminuria, tubular proteinuria was detected in 28 out of 44 ulcerative colitis patients. Proteinuria was strongly dependent on disease activity (P < 0.01) but was not related to ASA treatment.

CONCLUSIONS

Proteinuria of tubular marker proteins occurs in the majority of inflammatory bowel disease patients and is related to disease activity rather than to ASA treatment. Tubular proteinuria seems to reflect a renal extra-intestinal manifestation of inflammatory bowel disease and may serve as a new relevant marker of disease activity.

Surrogate markers of intestinal inflammation are predictive of relapse in patients with inflammatory bowel disease

BACKGROUND & AIMS

Prediction of relapse of inflammatory bowel disease has important implications for therapeutic strategies. We assessed whether measurement of intestinal permeability and inflammation could predict relapse of inflammatory bowel disease (IBD).

METHODS

Forty-three patients with Crohn's disease (CD) and 37 with ulcerative colitis (UC) in clinical remission provided a stool sample to be assayed for calprotectin (a neutrophil-specific marker), and patients with CD additionally underwent a small intestinal permeability test. Relapse was defined using clinical disease activity indices.

RESULTS

Twenty-five (58%) patients with CD and 19 (51%) with UC had a relapse over the 12-month period. Median calprotectin levels in the relapse groups (122 mg/L for CD, 123 mg/L for UC; normal <10 mg/L) differed significantly (P<0.0001) from those of the nonrelapse groups (41.5 mg/L for CD, 29.0 mg/L for UC). At 50 mg/L, the sensitivity and specificity of calprotectin for predicting relapse in all patients with IBD were 90% and 83%, respectively. Permeability in the CD patients who relapsed (median, 0.075; normal <0.04) differed significantly (P = 0. 004) from that in the nonrelapse group (median, 0.038). At the level of 0.05, the sensitivity and specificity of permeability in predicting relapse were 84% and 61%, respectively.

CONCLUSIONS

Fecal calprotectin predicts clinical relapse of disease activity in patients with CD and UC, whereas small intestinal permeability is a useful predictor of relapse in patients with small intestinal CD.

Altered IgG(4) renal clearance in patients with inflammatory bowel diseases. Evidence for a subclinical impairment of protein charge renal selectivity

BACKGROUND

A loss of intestinal glycosaminoglycans (GAGs) has been shown in inflammatory bowel diseases (IBD). Since GAGs are involved in the regulation of renal protein filtration and GAGs disruption is associated with anionic proteinuria, we examined whether changes in the selectivity of renal protein filtration occur in IBD.

METHODS

From 46 patients with IBD (17 with Crohn's disease (CD), and 29 with ulcerative colitis (UC)) and 21 healthy subjects, urine and serum samples were obtained. Albumin, total IgG and IgG(4) clearances were measured using sensitive methods. Serum p-ANCA and TNF-alpha were tested.

RESULTS

Median IgG(4) clearance was 0.041 ml/ min/10(-3) in patients with UC and 0.10 ml/ min/10(-3) in CD patients, both significantly higher than in controls (0.03 ml/min/10(-3)) (P<0.03). IgG(4) clearance was above the upper normal limit in 9/17 CD (53%) and in 10/29 UC (34.5%). Eighteen of 19 patients showing abnormal IgG(4) clearance were taking mesalazine. In patients on maintenance oral mesalazine, IgG(4) clearance was higher than that in patients off treatment (0.12 vs 0.03 ml/min/10(-3), P=0.04). No clinical/laboratory sign of renal dysfunction was documented in patients with altered IgG(4) clearance and maintained on mesalazine treatment.

CONCLUSION

Renal protein charge permselectivity is impaired in 40% of patients with IBD with no overt proteinuria. Our data suggest that altered IgG(4) clearance may represent a subclinical marker of renal involvement in IBD.

Renal tubular dysfunction in patients with inflammatory bowel disease treated with aminosalicylate

BACKGROUND

An increasing number of case reports indicate potential nephrotoxicity of 5-aminosalicylic acid (5-ASA), which shares similarities with the chemical structures of both phenacetin and acetylsalicylic acid.

AIM

In a point prevalence study the occurrence of sensitive indices indicative of early kidney malfunction was assessed in outpatients with inflammatory bowel disease.

METHODS

Routine indices of kidney function (creatinine clearance, urinary protein content, pH, electrolytes, and microscopy) were investigated in 223 patients with inflammatory bowel disease as well as sensitive markers of glomerular or tubular dysfunction (microproteinuria by SDS polyacrylamide gel electrophoresis (SDS-PAGE), urinary concentrations of N-acetyl-beta-D-glucosaminidase, alpha 1-microglobulin, gamma-glutamyltransferase (GGT), alkaline phosphatase (AP), and albumin). Histories of exposure to 5-ASA were assessed by questionnaire.

RESULTS

Patients receiving high amounts of 5-ASA, both actual as well as on a lifetime basis, showed an increased prevalence of tubular proteinuria by SDS-PAGE. Raised values for urinary AP and GGT indicate proximal tubular epithelial cells as the source. All other kidney function tests were normal. Analysis of covariates indicated strong associations between disease activity and size of 5-ASA doses as well as alterations in kidney tubular function.

CONCLUSION

The possibility exists that high doses of 5-ASA may be associated with proximal tubular proteinuria. This point prevalence study cannot dissect the possible impact of chronic inflammation from high dose 5-ASA treatment and further prospective studies are warranted.

Microalbuminuria correlates with intestinal histopathological grading in patients with inflammatory bowel disease

It has previously been shown that microalbuminuria is a useful disease activity marker for inflammatory bowel disease (IBD). Microalbuminuria correlates strongly with the markers of clinical and laboratory disease activity such as erythrocyte sedimentation rate (ESR), and C reactive protein (CRP). The aim of this study was to discover if microalbuminuria accurately reflects the intestinal inflammation by correlating it with intestinal inflammation using a standard histopathological grading system in patients with ulcerative colitis and Crohn's colitis. Forty two patients with IBD who had undergone endoscopic examination of the entire colon for the assessment of severity and extent of the disease (Crohn's colitis (n = 21), ulcerative colitis (n = 21)) were recruited to the study. Patients with small bowel Crohn's disease were not studied. Twenty four patients had left sided colonic disease and 18 patients had extensive colonic disease. Each patient's colonic biopsy specimens were scored blindly by a histopathologist and a composite score was compiled on the basis of the severity of changes in the enterocytes and crypts and the cellularity of the lamina propria. A clinical disease activity was obtained using the simple index of Harvey and Bradshaw. Microalbuminuria was measured in all patients by an immunoturbiditimetric method. ESR and CRP were also measured, as indicators of acute phase response in the same patients. It was found that patients with active IBD had higher concentrations of microalbuminuria compared with those patients in remission (median 222 micrograms/min (range 40-686 micrograms/min) v median 96 micrograms/min (range 30-376 micrograms/min); p < 0.001)). Significantly higher concentrations of microalbuminuria were also detected in patients with extensive colonic IBD compared with those patients with left sided disease (median 297 micrograms/min (range 132-686 micrograms/min) v median 101 micrograms/min (range 30-433 micrograms/min); p < 0.001)). A strong positive correlation was seen between microalbuminuria and intestinal histopathological score in IBD patient groups with left sided colitis (r = 0.77; p < 0.001) and extensive disease (r = 0.71; p < 0.01). The standard histopathological grading system correlated with the clinical disease activity (r = 0.64; p < 0.005) and CRP (r = 0.62; p < 0.02), however, it did not correlate with ESR. In conclusion, the strong correlation of microalbuminuria with a standard intestinal histopathological grading system suggests that microalbuminuria accurately reflects the severity of colonic inflammation in patients with Crohn's colitis and ulcerative colitis.