Mesalazine induced interstitial nephritis

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.

IgA nephropathy associated with Crohn's disease

The relationship between IgA nephropathy (IgAN) and Crohn’s disease was reported. IgAN is the most common primary glomerulonephritis and one of the leading causes of chronic kidney disease and end-stage renal failure, and up to 50% of cases progressed to end-stage renal disease within 25 years after IgAN diagnosis. However, specific and effective therapeutic strategies are still lacking. In this review, we discuss the possibility of the mechanism involved in IgAN associated with Crohn’s disease based on the findings of basic and clinical studies. Although the etiology of IgAN associated with Crohn’s disease is not permanent and various factors are thought to be involved, the stabilization of the disease condition of Crohn’s disease is believed to help treat IgAN.

Efficacy and Safety of Sulfasalazine Suspension in Children With Ulcerative Colitis

BACKGROUND

Sulfasalazine (SZ) is commonly used to treat pediatric ulcerative colitis (UC). SZ can be compounded into a suspension form which is beneficial for children with difficulty swallowing a pill. Despite being utilized for over 40 years, there is a lack of published data on the efficacy and safety of SZ suspension in children with UC. Recently, third-party payors have begun refusing to pay for SZ suspension due to lack of data.

METHODS

In this retrospective study, we reviewed the electronic medical records of patients ages <18 years diagnosed with UC from June 1999 to December 2019 at Boston Children's Hospital and treated with SZ suspension as a first-line agent. We obtained demographics, clinical, and endoscopic data to measure outcomes at 1 year and long term.

RESULTS

Of 57 patients treated with SZ suspension, 52 (91%) had a follow-up and 26 of 52 (50%) remained in steroid-free remission at 1 year. Two patients were switched to SZ tablets due to nonmedical reasons and 11 (21%) required rescue treatment (2 infliximab, 1 tacrolimus, 8 6-mercaptopurine/azathioprine) within a year. Three required colectomy within a year and 5 in long term. Four (8%) developed nonserious adverse reactions and switched to 5-aminosalicylates (5-ASA) by 1 year. The median duration of long-term follow-up was 36 months (range, 2-205 months) with 28 requiring treatment escalation in long term.

CONCLUSIONS

SZ suspension is a safe and effective treatment for UC in children with difficulty swallowing a pill. The 1-year remission rate on this treatment is comparable to 5-ASA utilized in children.

Crohn's disease may promote inflammation in IgA nephropathy: a case-control study of patients undergoing kidney biopsy

Intestinal immunity has been closely associated with the pathogenesis and progression of renal diseases, a relationship known as the "gut-kidney axis." To determine the association between immunoglobulin A nephropathy (IgAN) and Crohn's disease (CD), a clinico-pathological study was performed on patients who had IgAN with CD (CD-IgAN) and without CD (NOS-IgAN). We enrolled 29 patients diagnosed with IgAN via renal biopsy at the Tokyo Yamate Medical Center from 2009 to 2017. The patients were divided into CD-IgAN (n = 18) and NOS-IgAN (n = 11) and evaluated for clinical and pathological findings. IgA subclasses and galactose-deficient IgA1 (Gd-IgA1) were examined via immunohistochemistry using formalin-fixed paraffin-embedded sections from renal biopsy. Our results showed no significant difference in the extent of mesangial IgA subclasses or Gd-IgA1 deposition according to the presence or absence of CD. Pathologically, however, those with CD-IgAN had remarkably higher percentage of global glomerulosclerosis and extent of interstitial fibrosis and tubular atrophy (IF/TA) compared to those with NOS-IgAN. Moreover, the extent of macrophage infiltration in the glomerulus and interstitium was significantly higher in CD-IgAN than in NOS-IgAN. Clinically, the CD-IgAN group had significantly worse responsiveness to steroid treatment compared to the NOS-IgAN group. In conclusion, the similar immunological characteristics of deposited IgA molecules in the glomeruli between the CD-IgAN and NOS-IgAN groups might suggest their etiological similarity. However, a renal pathology showing advanced glomerular and tubulointerstitial sclerosis accompanying increased macrophage infiltration and highly resistant clinical features in patients with CD-IgAN suggests that some pathophysiological factors in CD, including abnormal intestinal immunity, may promote and activate the inflammatory process in IgAN via undetermined mechanisms.

5-ASA induced interstitial nephritis in patients with inflammatory bowel disease: a systematic review

Background

Acute interstitial nephritis (AIN) is an important cause of kidney injury accounting for up to 27% of unexplained renal impairment. In up to 70% of cases, drugs, including aminosalicylates, are reported as the underlying cause. Following two recent paediatric cases of suspected mesalazine induced AIN within our own department, we performed a systematic review of the literature to address the following question: In patients with inflammatory bowel disease (IBD), is interstitial nephritis associated with 5-aminosalicylate (5-ASA) treatment? Our primary objective was to identify the number of cases reported in the literature of biopsy-proven 5-ASA induced interstitial nephritis, in children and adults with IBD. We also aimed to identify which variables influence the onset, severity and recovery of 5-ASA interstitial nephritis.

Methods

Embase and PubMed databases were searched from inception to 07/10/20. Search terms had three main themes: “inflammatory bowel disease”, “interstitial nephritis” and “aminosalicylates”. Studies were included if they reported an outcome of AIN, confirmed on biopsy, suspected to be secondary to a 5-ASA drug in those with IBD. A narrative synthesis was performed.

Results

Forty-one case reports were identified. Mesalazine was the most frequently reported aminosalicylate associated with AIN (95%). The median duration of treatment before AIN was diagnosed was 2.3 years (Interquartile Range (IQR) 12–48 months). The median rise in creatinine was 3.3 times the baseline measurement (IQR 2.5–5.5). Aminosalicylate withdrawal and steroids were the most frequently used treatments. Despite treatment, 15% of patients developed end-stage renal failure.

Conclusions

AIN is a serious adverse drug reaction associated with aminosalicylates, with mesalazine accounting for most reports. The current guidance of annual monitoring of renal function may not be sufficient to identify cases early. Given the severity of AIN and reports in the literature that early treatment with steroids may be beneficial, we would recommend at least 6 monthly monitoring of renal function.

PROSPERO registration number CRD42020205387.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00687-y.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Risk of renal cancer in patients with inflammatory bowel disease: A pooled analysis of population-based studies

BACKGROUND

Currently, newer epidemiological studies report the association between inflammatory bowel disease (IBD) and risk of renal cancer (RCa). Thus, we conducted a meta-analysis to determine whether IBD patients were associated with RCa risk.

METHODS

Various medical databases were searched from inception to April 2020. Standardized incidence ratio (SIR) or relative risk (RR) with corresponding 95% confidence intervals (CIs) were pooled. The meta-analysis was completed by STATA version 14.2.

RESULTS

A total of 421 articles were identified, and 11 studies met the inclusion criteria. Data from 9 cohort studies showed a significantly increased risk of RCa in IBD patients (pooled SIR: 1.53; 95%CI: 1.25-1.80; I² = 42.4%), especially for patients with Crohn's disease (CD) (pooled SIR: 1.95; 95%CI: 1.45-2.44; I² = 39.9%). We did not observe a significantly increased risk of RCa in patients with ulcerative colitis (UC) (pooled SIR: 1.31; 95%CI: 0.94-1.67; I² = 48.0%) when compared to the background population. Only 2 case-control studies reported the results of RCa risk, showing no significant difference between IBD group and IBD-free group (pooled RR: 1.64; 95%CI: 0.52-5.22; I² = 77.9%).

CONCLUSIONS

Our findings indicate that IBD patients with special reference to CD patients have a significantly higher risk of RCa. Further studies are warranted to enable definite conclusions to be drawn.

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.

Mesalazine Induces Oxidative Stress and Cytochrome c Release in Isolated Rat Heart Mitochondria: An Analysis of Cardiotoxic Effects

Mesalazine is widely used in the management of inflammatory bowel disease. Previous studies reported that mesalazine-induced cardiotoxicity is a rare, potentially fatal complication. Mitochondria play an important role in myocardial tissue homeostasis. Deterioration in mitochondrial function will eventually lead to cardiomyocyte death and consequently cardiovascular dysfunction. The aim of the current study was to investigate the effects of mesalazine on rat heart mitochondria. Rat heart mitochondria were isolated by mechanical lysis and differential centrifugation. Parameters of mitochondrial toxicity including succinate dehydrogenase (SDH) activity, reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP) collapse, mitochondrial swelling, and cytochrome c release were evaluated. Results revealed that mesalazine induced a concentration- and time-dependent rise in mitochondrial ROS formation, inhibition of SDH, MMP collapse, mitochondrial swelling, and cytochrome c release in rat heart mitochondria. These results indicate that the cardiotoxic effects of mesalazine are most likely associated with mitochondrial dysfunction and ROS formation, which finally ends in cytochrome c release signaling and induction of apoptosis.

Inflammatory bowel disease in patients undergoing renal biopsies

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sulfasalazine induces mitochondrial dysfunction and renal injury

Sulfasalazine is a commonly used drug for the treatment of rheumatoid arthritis and inflammatory bowel disease. There are several cases of renal injury encompass sulfasalazine administration in humans. The mechanism of sulfasalazine adverse effects toward kidneys is obscure. Oxidative stress and its consequences seem to play a role in the sulfasalazine-induced renal injury. The current investigation was designed to investigate the effect of sulfasalazine on kidney mitochondria. Rats received sulfasalazine (400 and 600 mg/kg/day, oral) for 14 consecutive days. Afterward, kidney mitochondria were isolated and assessed. Sulfasalazine-induced renal injury was biochemically evident by the increase in serum blood urea nitrogen (BUN), gamma-glutamyl transferase (γ-GT), and creatinine (Cr). Histopathological presentations of the kidney in sulfasalazine-treated animals revealed by interstitial inflammation, tubular atrophy, and tissue necrosis. Markers of oxidative stress including an increase in reactive oxygen species (ROS) and lipid peroxidation (LPO), a defect in tissue antioxidant capacity, and glutathione (GSH) depletion were also detected in the kidney of sulfasalazine-treated groups. Decreased mitochondrial succinate dehydrogenase activity (SDA), mitochondrial depolarization, mitochondrial GSH depletion, increase in mitochondrial ROS, LPO, and mitochondrial swelling were also evident in sulfasalazine-treated groups. Current data suggested that oxidative stress and mitochondrial injury might be involved in the mechanism of sulfasalazine-induced renal injury.

Chronic tubulointerstitial nephritis induced by 5-aminosalicylate in an ulcerative colitis patient: a rare but serious adverse event

The 5-aminosalicylate is widely prescribed in inflammatory bowel disease patients. Its potential for renal damage has been seldom described. We report a case of a 23-year-old man who started 5-aminosalicylate after being diagnosed with ulcerative colitis. One year after, a significant decline on his creatinine clearance was noted, however, at that time, he was on an acute flare of his bowel disease and the 5-aminosalicylate dose was increased. Six months later, his renal function kept worsening and, on drug-induced toxicity suspicion, 5-aminosalicylate was halted and a kidney biopsy demonstrated a chronic tubulointerstitial nephritis. Steroids and azathioprine were started leading to partial recovery and stabilisation of his renal function. Physicians who prescribe 5-aminosalicylate to patients with inflammatory bowel disease should be aware of this adverse event.

Do gastroenterologists monitor their patients taking 5-amino-salicylates following initiation of treatment

BACKGROUND

5-Amino salicylate (5-ASA) medications may rarely be associated with a significant decline in renal function and interstitial nephritis. British Society of Gastroenterology guidelines advise regular renal function monitoring for patients taking these drugs.

AIM

To assess whether gastroenterologists in Kent were following best practice guidelines regarding the monitoring of their patients on 5-ASA therapy.

METHODS

Using longitudinal community and regional pathology databases for the Kent population, our renal unit regularly screens a total population of 300 000 for evidence of renal disease. The data extracted are analysed using an automated computerised system to identify patients requiring intervention for kidney disease. All patients taking 5-ASA medication were identified from a population of 300 000. The pathology database was studied to identify the patients on 5-ASA treatment and whether they had had renal function tests.

RESULTS

800 adult patients were identified taking 5-ASA therapy. 612 patients received 5-ASAs for 3 months or more, and these were included in the final analysis. 293 patients had no renal function checks while on treatment. 79 patients had renal function tests less than once every 4 years and 36 patients once every 2-4 years. 204 patients had renal function measurements in 50% or more of years of treatment, of whom 116 were checked every year. Some patients were started on treatment with abnormal results at baseline and some with identified kidney disease continued on their 5-ASAs.

CONCLUSIONS

The majority of patients receiving 5-ASA compounds do not have regular renal function monitoring. Clinicians are failing to follow best practice guidelines.

Drug-induced nephrotoxicity in inflammatory bowel disease

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

Renal manifestations and complications of inflammatory bowel disease

Renal manifestations and complications are not rare in patients with inflammatory bowel disease (IBD) and may present as nephrolithiasis, amyloidosis, tubulointerstitial nephritis, and glomerulonephritis. Symptoms of renal impairment are not always specific and since the underlying bowel disease is preponderant, renal function deterioration may be underestimated. Additionally, medical treatment of patients with IBD such as aminosalicylates, cyclosporine, and tumor necrosis factor-α inhibitors can cause renal complications, although direct correlation to bowel disease is not always clear. The well-documented renal manifestations and complications of IBD, as well as the possible renal side effects of new drugs, emphasize the need for periodic evaluation of renal function. New markers of renal function may facilitate early diagnosis and unravel the complex mechanisms responsible for kidney damage. The purpose of this review is to summarize the renal manifestations and complications as well as the markers of renal function utilized in IBD, attempting to shed more light on the pathophysiology of renal damage in IBD.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

5-Aminosalicylates and effects on renal function in patients with Crohn's disease

BACKGROUND

Case reports concerning irreversible renal failure caused by 5-aminosalicylates (5-ASA) have been published. The aim of this study was to investigate the effect of long-term use of 5-ASA on renal function in patients with Crohn's disease (CD).

METHODS

This was a retrospective survey in 200 consecutive outpatients with CD. Endogenous creatinine clearance (ECC) was estimated from serum creatinine with the Cockroft and Gault formula. The first ECC was chosen close to the start of 5-ASA and the second was the most recent ECC available.

RESULTS

In 153 patients (59 men and 94 women), sufficient data were available for analysis. The interval between ECCs was 11 years, with a mean exposure to 5-ASA of 8.6 years. The cumulative dose of 5-ASA amounted to 9 kg. The ECC declined 0.3 +/- 5 mL/min/yr (from 100 +/- 25 to 92 +/- 28 mL/min; P < 0.01). In a multiple linear regression model, duration of the interval was a significant predictor for change in ECC (P < 0.0001), but cumulative dose of 5-ASA was not predictive (P = 0.30). No interstitial nephritis was reported, and in the 8 patients with the largest decline in ECC, comorbidity causing renal function impairment was present.

CONCLUSIONS

The mean decline in ECC of 0.3 mL/min/yr in patients with CD does not exceed the decline expected from physiologic aging. Furthermore, the cumulative dose of 5-ASA was not a predictor for change in renal function. However, as interstitial nephritis caused by 5-ASA may rarely occur, we still advocate measurements of serum creatinine before and during treatment.

Experience of 5-aminosalicylate nephrotoxicity in the United Kingdom

AIM

To study 5-aminosalicylate nephrotoxicity in patients with inflammatory bowel disease in the UK.

METHODS

A detailed postal questionnaire was sent to all 1298 names in the British Society of Gastroenterology database and 290 consultant members of the Renal Association. The British Society of Gastroenterology reported new cases monthly, the Renal Association 6 monthly. Results were expressed as estimated glomerular filtration rate.

RESULTS

Retrospective study: cases--British Society of Gastroenterology:Renal Association 202:87, aged 15-76 years. Median peak (range) creatinine (British Society of Gastroenterology:Renal Association) - 300:301 (78-1200) micromol/L. Prospective study - 59 cases, median age 52 years (M:F ratio: 47:12). Median pre-treatment estimated glomerular filtration rate: 76.9 (123.9-39), at diagnosis 28.4 (80.5-3.6, creatinine range: 92-1361 micromol/L), recovery 46.8 [111.2-end stage renal failure] mL/min/1.73 m2. Recovery of renal function was significantly improved for patients treated for < 12 months [n = 10, median recovery estimated glomerular filtration rate 70.5 (92-26.9) vs. > 12 months 38.4 (111.2-end stage renal failure) mL/min/1.73 m2, P = 0.028].

CONCLUSIONS

Regular monitoring of renal function may allow earlier detection of nephrotoxicity, particularly during the first year of therapy. Based on an inflammatory bowel disease prevalence in the United Kingdom of 412 x 10(5) with about 50% on treatment, we estimate that the incidence of clinical nephrotoxicity in patients taking 5-aminosalicylate therapy is approximately one in 4000 patients/year.

Comparison of two different daily dosages (2.4 vs. 1.2 g) of oral mesalazine in maintenance of remission in ulcerative colitis patients: 1-year follow-up study

BACKGROUND

Mesalazine as maintenance therapy in ulcerative colitis is used worldwide and has been proven to be effective. However, the optimal dosage remains to be defined.

AIM

To establish whether daily treatment with 2.4 g of oral mesalazine is more effective than 1.2 g in preventing disease relapse.

METHODS

A total of 156 patients with ulcerative colitis in remission were randomly treated for 1 year with 2.4 (n = 80) or 1.2 (n = 76) g/day of mesalazine. Activity of disease was assessed by periodical clinical, endoscopic and histological examinations.

RESULTS

After 12 months, 24 of 80 patients (30%) on 2.4 g and 20 of 76 patients (26%) on 1.2 g were still in remission (P = N.S.). Patients in 2.4 g group remained in remission for a longer time than those in 1.2 g group (P < 0.001). Among clinical variables considered in the study, course of disease prior to enrollment (< or = 3 or > 3 relapses/year) was found to influence response to therapy.

CONCLUSIONS

A daily dosage of 2.4 g of oral mesalazine seems to better at preventing and delaying relapses of ulcerative colitis than 1.2 g. The course of disease seems to be crucial in choosing the optimal dosage of mesalazine in a maintenance regimen.

Interstitial nephritis from mesalazine: case report and literature review

We report a new case of biopsy-confirmed mesalazine-induced interstitial nephritis in an 18-year-old male with ulcerative colitis. His renal function improved with drug discontinuation and corticosteroid treatment. An English literature review revealed an additional 22 cases of this complication that, taken together, showed (1) a male predominance, (2) an absence of specific symptoms or findings on urinalysis, (3) a 61% frequency of residual chronic renal insufficiency with 13% of patients developing end-stage renal disease, and (4) an apparent favorable response to steroid therapy. We conclude that patients receiving 5-aminosalicylates should be routinely monitored with serum creatinine measurements to prevent this uncommon but potentially serious adverse drug reaction.

Inflammatory bowel disease and the eye

Inflammatory bowel disease includes Crohn's disease and ulcerative colitis, and is characterized by chronic inflammation of the intestines. The advances in understanding of the inflammatory process have resulted in improved treatment of inflammatory bowel disease. The systemic complications of inflammatory bowel disease involve many organs, eyes included. The ophthalmic complications are usually of inflammatory origin. Some of these complications, like scleritis, may reflect overall disease activity. Treatment of intestinal inflammation-either medical or surgical-usually helps resolution of ophthalmic complications. This review describes recent developments in the diagnosis and management of the inflammatory bowel disease and its ophthalmic complications.

No dose-dependent tubulotoxicity of 5-aminosalicylic acid: a prospective study in patients with inflammatory bowel diseases

BACKGROUND AND AIMS

Elevated levels of renal tubular markers in the urine are found in 20-30% of patients with chronic inflammatory bowel diseases. We investigated whether this reflects a dose-dependent tubulotoxicity of 5-aminosalicylic acid (5-ASA).

PATIENTS AND METHODS

In an open, prospective, multicenter study 18 patients with Crohn's disease and 29 with ulcerative colitis were treated with 3 g 5-ASA or more daily as the sole drug for 6 weeks. Clinical activity (CDAI, CAI) and renal tubular markers [beta-N-acetyl-D-glucosaminidase (beta-NAG) and other proteins in urine] were monitored. We examined whether the proportion of patients with elevated beta-NAG is more than 15% higher (absolute difference) than that prior to treatment.

RESULTS

The proportion decreased from 19.2% to 12.8% in the intention-to-treat analysis (n=47) and from 24.3% to 13.5% in the per-protocol analysis (n=37), which was not more than 15% higher than at baseline. Mean CDAI decreased from 222 to 146 and mean CAI from 7.3 to 3.1 (intention-to-treat analysis). Response to therapy was shown by 61% of patients with Crohn's disease and 66% of patients with ulcerative colitis. The cumulative dose of 5-ASA was not correlated with beta-NAG level in the urine.

CONCLUSION

This study largely rules out that 5-ASA at 3 g or higher per day for 6 weeks induces renal tubular damage. Elevated renal tubular markers reflect inflammatory activity or an extraintestinal manifestation of inflammatory bowel diseases.

Oral and topical 5-aminosalicylic acid (mesalazine) in inducing and maintaining remission in mild-moderate relapse of ulcerative colitis: one-year randomised multicentre trial

BACKGROUND

The association of oral 5-aminosalicylic acid (mesalazine) and enema is effective in treatment of mild-moderate forms of ulcerative colitis. However no study has been aimed at determining optimal duration of this association in active ulcerative colitis.

AIM

To determine whether longer duration of therapy: 1. increases the rate of patients achieving remission, and 2. reduces relapse rate during the maintenance period in patients in remission.

PATIENTS AND METHODS

A total of 149 patients, (89 male, 60 female), were randomly assigned to a regimen with 5-aminosalicylic acid tablets 2.4 g/day associated with 5-aminosalycilic enema 2 g/day for a 4-week (n = 73) or 8-week regimen (n = 76). After this acute therapy, patients were submitted to clinical, endoscopic and histological examinations and those in remission were assigned to a follow-up (maintenance) period with oral mesalazine alone at a dosage of 1.2 g/day. A clinical visit, including laboratory tests, at 6 months and an endoscopic-histological control at 12 months were carried out to exclude symptoms and endoscopic-histological signs of activity. Relapse of disease, i.e., presence of clinical symptoms or abnormal laboratory tests, was confirmed by endoscopy and histology.

RESULTS

At end of acute phase, clinical, endoscopic and histological remission was comparable in the two groups: 42/76 (55%), in the 4-week, and 47/73 patients (64%), in the 8-week regimen. No difference was found stratifying patients according to extension of disease. Of these 89 patients in remission, 75 (34 from 4-week regimen; 41 from 8-week regimen) completed 12 months' follow-up. At end of follow-up, a similar percentage of patients in the 4-week regimen (50%) and 8-week regimen (51%) were still in remission. No significant difference between cumulative relapse rates of the two groups was found. Stratifying patients according to extension of disease, in the 8-week regimen group, those with left-sided colitis showed a higher remission rate than that of patients with diffuse colitis (66% versus 35%, p < 0.05). All regimens were well tolerated by most patients during the entire study period.

CONCLUSIONS

An additional 4 weeks of topical treatment does not increase the remission rate in patients with mild-moderate active ulcerative colitis but seems to reduce the probability of relapse in patients with left-sided colitis.

Primary chronic interstitial nephritis in Crohn's disease

BACKGROUND & AIMS

In Crohn's disease, cases of interstitial nephritis with renal failure have been reported in connection with the use of mesalamine.

METHODS

We observed 4 patients with severe interstitial nephritis proven by examination of kidney biopsy specimens. Renal failure was discovered before or simultaneously with the diagnosis of Crohn's disease, and patients were not treated with mesalamine. Impairment of renal function progressed to end-stage renal failure in 3 of the 4 patients.

RESULTS

Our results show that the kidney can be an extraintestinal target of Crohn's disease.

CONCLUSIONS

Several unanswered questions remain concerning the frequency of interstitial nephritis in patients with Crohn's disease, as well as the exact role of mesalamine in the development of chronic interstitial nephritis.

Sulphasalazine and mesalazine: serious adverse reactions re-evaluated on the basis of suspected adverse reaction reports to the Committee on Safety of Medicines

BACKGROUND

5-aminosalicylates are extensively prescribed for the treatment of ulcerative colitis but have a wide range of described adverse effects.

AIMS

To determine whether serious adverse effect profiles differ for sulphasalazine and mesalazine.

METHODS

Analysis of suspected serious adverse reactions reported to the Committee on Safety of Medicines of the UK in 1991-1998. Adverse effect profiles were categorised for interstitial nephritis, pancreatitis, serious skin reactions, hepatitis and hepatic failure, and blood dyscrasias. Report rates were calculated using prescribing data from the Department of Health and compared for mesalazine and sulphasalazine. Further analysis was undertaken for sulphasalazine according to disease indication of inflammatory bowel disease or rheumatoid arthritis.

RESULTS

A total of 4.7 million prescriptions were dispensed for sulphasalazine compared with 2.8 million for mesalazine. Interstitial nephritis was only described for mesalazine, with 11.1 reports per million prescriptions. Pancreatitis was reported seven times as frequently for mesalazine (7.5 per million prescriptions) compared with sulphasalazine (1.1 per million prescriptions) (odds ratio (OR) 7.0; 95% confidence interval (CI) 2.6-18.6; p<0.001). There were no reports of serious skin disorders in patients prescribed sulphasalazine for inflammatory bowel disease. Blood dyscrasias were reported significantly more often in patients receiving sulphasalazine for rheumatoid arthritis than for inflammatory bowel disease (OR 5.31; 95% CI 2.6-11.0; p<0.001), and there was a similar trend for hepatic disorders.

CONCLUSIONS

Spontaneous reports suggest that within the five sets of disorders considered, there is no evidence to indicate a safety advantage of mesalazine over sulphasalazine in the treatment of inflammatory bowel disease. Pancreatitis and interstitial nephritis appear significantly more common with mesalazine, and advice on renal monitoring in patients who receive mesalazine may need reinforcing.

Sulphasalazine and 5-aminosalicylic acid in long-term treatment of ulcerative colitis: report on tolerance and side-effects

BACKGROUND

Use of sulphasalazine in ulcerative colitis patients is hampered by a variety of side-effects, including male infertility. 5-aminosalicylic acid is better tolerated and has been increasingly used to treat patients intolerant/allergic to sulphasalazine but it may also be associated with side-effects.

AIM

To evaluate tolerance of long-term treatment with sulphasalazine and 5-aminosalicylic acid in ulcerative colitis.

METHODS

Side-effects to sulphasalazine (2-3 g/day) and 5-aminosalicylic acid (1.2-2.4 g/day) were recorded in 685 patients: 410 patients received only sulphasalazine, 130 only 5-aminosalicylic acid, and 145 both drugs. In patients with side-effects to sulphasalazine, a desensitisation protocol (rechallenge) was attempted to improve tolerance, and patients still presenting side-effects after desensitisation were switched to 5-aminosalicylic acid. Male fertility was also assessed in 42 males on sulphasalazine and on 5-aminosalicylic acid.

RESULTS

Side-effects were observed in 110/555 patients (20%) on sulphasalazine and in 18/275 patients (6.5%) on 5-aminosalicylic acid during a median period of follow-up of 7 and 5 years, respectively. Desensitisation was achieved in 40% of patients intolerant to sulphasalazine. 5-aminosalicylic acid intake induced side-effects in 2/130 patients (1.5%) who had not taken sulphasalazine before versus 4/91 patients (4%) tolerating sulphasalazine and 12/54 patients (22%) intolerant/allergic to sulphasalazine, the difference in incidence of side-effects in the two latter groups being statistically significant (4.4% vs 20.8%, p=0. 001). Fertility was found to be affected in all patients on sulphasalazine but improved when put onto 5-aminosalicylic acid.

CONCLUSIONS

5-aminosalicylic acid should be considered the drug of choice in the treatment of ulcerative colitis bearing in mind that intolerance or allergy may occur in a few patients also on this drug.

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.

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.

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.

Review article: interstitial nephritis associated with the use of mesalazine in inflammatory bowel disease

5-Aminosalicylic acid (5-ASA) has replaced sulphasalazine as first line therapy for mild to moderately active inflammatory bowel disease and is widely used. A number of reports have linked oral 5-ASA therapy to chronic tubulo-interstitial nephritis and this relationship is now well established. Despite increasing recognition of the potential for this serious adverse event, guidelines for monitoring renal function in patients prescribed 5-ASA preparations are not widely employed. Whilst the incidence of this adverse event in the population of patients with inflammatory bowel disease treated with mesalazine is low, the morbidity in an affected individual is high with some cases progressing to end-stage renal disease. Routine monitoring of renal function is simple and inexpensive and could prevent this outcome. Based on the available data, serum creatinine should be estimated prior to commencing treatment, monthly for the first 3 months, 3-monthly for the next 9 months, 6-monthly thereafter and annually after 5 years of treatment.

Systemic levels of free 5-aminosalicylic acid depend on the nature of the 5-aminosalicyclic acid derivative and not on disease activity or extent in patients with inflammatory bowel disease

INTRODUCTION

Several new derivatives of sulphasalazine that make use of its active moiety, 5-aminosalicylic acid (5-ASA), have been introduced for the treatment of inflammatory bowel disease (IBD). In rats short term intravenous administration of 5-ASA has been associated with nephrotoxicity. A number of cases of nephrotoxicity have been reported recently in IBD patients taking oral maintenance treatment with 5-ASA compounds.

OBJECTIVE

To study the urinary and serum levels of acetylated 5-ASA (Ac-5-ASA) and the unacetylated 5-ASA (5-ASA) in patients with IBD maintained on sulphasalazine, olsalazine and mesalazine (pH dependent release form). We also sought correlation between levels of 5-ASA, clinical disease activity and extent of disease.

METHODS

We studied 79 patients (male, n = 30; female, n = 49) with established IBD [ulcerative colitis (UC), n = 48; Crohn's disease (CD), n = 31], 72 maintained on 5-ASA compounds (sulphasalazine = 27; olsalazine = 28; mesalazine = 17) and 7 patients were receiving no medication. Urinary and serum analysis of 5-ASA was performed by high performance liquid chromatography (HPLC). Clinical disease activity was quantified using simple index of Harvey and Bradshaw.

RESULTS

Patients receiving mesalazine had significantly higher levels of serum free 5-ASA compared to those who were receiving olsalazine and sulphasalazine (mesalazine mean +/- SEM; range; 2.84 +/- 1.21 (0.00-16.00) vs olsalazine 0.45 +/- 0.18 (0.00-16.20); mumol/L; p < 0.04; sulphasalazine 0.37 +/- 0.25 (0.00-3.74); p < 0.03). Similarly levels of urinary free 5-ASA were significantly higher in patients maintained on mesalazine compared to those on olsalazine or sulphasalazine (mesalazine 219 +/- 80.43 (0.00-1050) vs olsalazine 33.3 +/- 17.23 (0.00-317) mumol/L; p < 0.01; and sulphasalazine 15 +/- 8.86 (0.00-192); p < 0.05). However, no significant difference was observed in the levels of urinary free 5-ASA between olsalazine and sulphasalazine. No significant difference was observed in the levels of free-5-ASA in UC patients with left sided disease and those with extensive disease. Furthermore, no significant difference was observed in the levels of serum and urinary 5-ASA in CD patients with ileo-colic disease and colonic disease. Urinary and serum free-5-ASA did not correlate with the clinical disease activity.

CONCLUSION

Systemic absorption of 5-ASA from sulphasalazine and olsalazine is relatively low. However, pH-dependent mesalazine formulations may release their contents rapidly in the small intestine and proximal colon resulting in higher plasma and urinary concentrations of free 5-ASA. The effects of free 5-ASA on renal function in the human require further evaluation.

The systemic load and efficient delivery of active 5-aminosalicylic acid in patients with ulcerative colitis on treatment with olsalazine or mesalazine

BACKGROUND

There have been reports of nephrotoxic reactions in patients with ulcerative colitis treated with 5-aminosalicylic acid (5-ASA) preparations.

AIM

To compare the efficacy in delivery of active 5-ASA to the colon and the systemic load as the basis for potential long-term toxicity during treatment with olsalazine or mesalazine in patients with ulcerative colitis in remission.

PATIENTS AND METHODS

Fifteen patients with ulcerative colitis were treated with olsalazine or mesalazine, each for 7 days in an open, randomized, crossover design study. 5-ASA and acetyl-5-ASA (Ac-5-ASA) in plasma and urine were measured by high performance liquid chromatography.

RESULTS

The plasma concentration of 5-ASA was 1.2 +/- 0.1 micromol/L (mean +/- S.E.M.) for olsalazine and 8.0 +/- 1.9 micromol/L for mesalazine, while the plasma concentration of Ac-5-ASA was 2.8 +/- 0.2 micromol/L for olsalazine and 10.8 +/- 1.6 micromol/L for mesalazine. The amount of 5-ASA excreted in the urine was 68 +/- 30 micromol/24 h for olsalazine and 593 +/- 164 micromol/24 h for mesalazine. The amount of Ac-5-ASA in the urine was 1260 +/- 102 micromol/24 h for olsalazine and 3223 +/- 229 micromol/24 h for mesalazine. The urinary recovery of total 5-ASA plus Ac-5-ASA (as a percentage of the given dose) was 23 +/- 2.1% for olsalazine and 39 +/- 3.6% for mesalazine. The ratio between the plasma concentrations of mesalazine and olsalazine differed significantly both for 5-ASA (5.1) and Ac-5-ASA (3.6); for 5-ASA (9. 9) and Ac-5-ASA (2.6) in urine, and for the urinary recovery of total 5-ASA plus Ac-5-ASA (1.7). Moreover, in the mesalazine group there was a large variation in the individual plasma concentrations of 5-ASA and Ac-5-ASA, with maximal values 5-6-fold higher than that in the olsalazine group.

CONCLUSION

The systemic load of active 5-ASA is significantly higher for mesalazine than for olsalazine, when based on the dosages given and when calculated on an equimolar basis. Some of the patients in the mesalazine group showed unexpected high levels of plasma and urinary 5-ASA concentrations, a finding which may have long-term safety implications.

Renal and urologic complications of inflammatory bowel disease

Renal and urologic complications are not uncommon in patients with inflammatory bowel disease, and can be directly or indirectly related to the underlying disease process or its treatment. Many of these patients have asymptomatic disease, or the urinary symptoms are nonspecific or overshadowed by bowel symptoms. By the time a urinary complication is considered, significant disease progression or renal damage may have occurred. These risks necessitate a high degree of diligence and periodic urologic evaluation as part of the long-term management of patients with inflammatory bowel disease.

Renal papillary necrosis--40 years on

Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) are well recognized as a major class of therapeutic agent that causes renal papillary necrosis (RPN). Over the last decade a broad spectrum of other therapeutic agents and many chemicals have also been reported that have the potential to cause this lesion in animals and man. There is consensus that RPN is the primary lesion that can progress to cortical degeneration; and it is only at this stage that the lesion is easily diagnosed. In the absence of sensitive and selective noninvasive biomarkers of RPN there is still no clear indication of which compound, under what circumstances, has the greatest potential to cause this lesion in man. Attempts to mimic RPN in rodents using analgesics and NSAIDs have not provided robust models of the lesion. Thus, much of the research has concentrated on those compounds that cause an acute or subacute RPN as the basis by which to study the pathogenesis of the lesion. Based on the mechanistic understanding gleaned from these model compounds it has been possible to transpose an understanding of the underlying processes to the analgesics and NSAIDs. The mechanism of RPN is still controversial. There are data that support microvascular changes and local ischemic injury as the underlying cause. Alternatively, several model papillotoxins, some analgesics, and NSAIDs target selectively for the medullary interstitial cells, which is the earliest reported aberration, after which there are a series of degenerative processes affecting other renal cell types. Many papillotoxins have the potential to undergo prostaglandin hydroperoxidase-mediated metabolic activation, specifically in the renal medullary interstitial cells. These reactive intermediates, in the presence of large quantities of polyunsaturated lipid droplets, result in localized and selective injury of the medullary interstitial cells. These highly differentiated cells do not repair, and it is generally accepted that continuing insult to these cells will result in their progressive erosion. The loss of these cells is thought to be central to the degenerative cascade that affects the cortex. There is still a need to understand better the primary mechanism and the secondary consequences of RPN so that the risk of chemical agents in use and novel molecules can be fully assessed.

Normal ultrastructure of the kidney and lower urinary tract

The mammalian urinary tract includes the kidneys, ureters, urinary bladder, and urethra. The renal parenchyma is composed of the glomeruli and a heterogeneous array of tubule segments that are specialized in both function and structure and are arranged in a specific spatial distribution. The ultrastructure of the glomeruli and renal tubule epithelia have been well characterized and the relationship between the cellular structure and the function of the various components of the kidney have been the subject of intense study by many investigators. The lower urinary tract, the ureters, urinary bladder, and urethra, which are histologically similar throughout, are composed of a mucosal layer lined by transitional epithelium, a tunica muscularis, and a tunica serosa or adventitia. The present manuscript reviews the normal ultrastructural morphology of the kidney and the lower urinary tract. The normal ultrastructure is illustrated using transmission electron microscopy of normal rat kidney and urinary bladder preserved by in vivo perfusion with glutaraldehyde fixative and processed in epoxy resin.

Nephrotic syndrome from 5-ASA for ulcerative colitis? Complicated by carcinoma of the colon and sclerosing cholangitis

A patient with nephrotic syndrome had been treated with mesalazine for ulcerative colitis, and also had a carcinoma of the colon and sclerosing cholangitis. This seemingly unrelated series of complications gives us the opportunity to review the problem of nephropathy in ulcerative colitis.

Advanced and controlled drug delivery systems in clinical disease management

Advanced and controlled drug delivery systems are important for clinical disease management. In this review the most important new systems which have reached clinical application are highlighted. Microbiologically controlled drug delivery is important for gastrointestinal diseases like ulcerative colitis and distally localized Crohn's disease. In cardiology the more classic controlled release systems have improved patient compliance and decreased side effects. In the treatment of intractable pain the spinal and transdermal route is well documented. In neurology the flattened peak-through levels of antiepileptic drugs and anti Parkinson's drugs represents a more predictable kinetic profile. Tracheal delivery of corticosteroids and sympaticomimetics in asthma and Chronic Obstructive Pulmonary Disease is fully accepted in clinical practice: delivery by this route results in better efficacy and a better safety profile. In gynaecology the delivery of pulsatile hormones (LHRH) is used for pregnancy induction, while transdermal oestrogens are promising in the prevention of osteoporosis. In surgical practice the use of antibiotic impregnated bone cement and antibiotic impregnated biodegradable collagens is well established. To prevent infections intravascular catheters coated with heparin or antibiotics are used. In ophthalmology the Ocusert systems provide a controlled release of different drugs in the eye. Most spectacular is the clinical introduction of the first liposomal drugs; amfotericine B and daunorubicine. Liposomal formulations of these drugs have enhanced activity and decreased toxicity compared to conventional formulations.