Factors predicting the outcome of disease activity assessment in Crohn's disease

Disease activity assessment in IBD: clinical indices and biomarkers fail to predict endoscopic remission

BACKGROUND

In the current management paradigm, mucosal healing is preferred over clinical remission as a therapeutic end point in inflammatory bowel disease (IBD) because of the benefits engendered with respect to durability of remission. Colonoscopy, however, is not suitable for regular disease monitoring, and routine clinical assessment is often inaccurate with respect to endoscopic disease activity. The current investigation set out to characterize the relationship that exists between endoscopically determined IBD activity and clinical and biochemical measures of disease severity and to determine clinically useful thresholds for use in clinical practice.

METHODS

Patients attending for colonoscopy with known or suspected IBD were recruited. Clinical disease activity was recorded as per the Harvey-Bradshaw Index for Crohn's disease or the simple clinical colitis activity index for ulcerative colitis. Endoscopic activity was recorded using the simple endoscopic score for Crohn's disease or the modified Baron score for ulcerative colitis. Receiver operating characteristic analysis determined the predictive value and optimal predictive thresholds for clinical and biomarker data.

RESULTS

The Harvey-Bradshaw Index was not able to distinguish active from inactive Crohn's disease. The sensitivity, specificity, and positive and negative predictive values of simple clinical colitis activity index to detect endoscopic active disease were 43%, 96%, 94%, and 51%, respectively. Any elevation of C-reactive protein or fecal calprotectin was predictive of active mucosal disease, however, no lower threshold could be identified that predicted disease in remission.

CONCLUSIONS

C-reactive protein and fecal calprotectin are useful for the identification of endoscopically active IBD, but normal results do not confirm endoscopic remission.

Smoking behaviour modifies IL23r-associated disease risk in patients with Crohn's disease

BACKGROUND AND AIM

The etiology of Crohn's disease (CD) implicates both genetic and environmental factors. Smoking behavior is one environmental risk factor to play a role in the development of CD. The study aimed to assess the contribution of the interleukin 23 receptor (IL23R) in determining disease susceptibility in two independent cohorts of CD, and to investigate the interactions between IL23R variants, smoking behavior, and CD-associated genes, NOD2 and ATG16L1.

METHODS

Ten IL23R single-nucleotide polymorphisms (SNPs) were genotyped in 675 CD cases, and 1255 controls from Brisbane, Australia (dataset 1). Six of these SNPs were genotyped in 318 CD cases and 533 controls from Canterbury, New Zealand (dataset 2). Case-control analysis of genotype and allele frequencies, and haplotype analysis for all SNPs was conducted.

RESULTS

We demonstrate a strong increased CD risk for smokers in both datasets (odds ratio 3.77, 95% confidence interval 2.88-4.94), and an additive interaction between IL23R SNPs and cigarette smoking. Ileal involvement was a consistent marker of strong SNP-CD association (P ≤ 0.001), while the lowest minor allele frequencies for location were found in those with colonic CD (L2). Three haplotype blocks were identified across the 10 IL23R SNPs conferring different risk of CD. Haplotypes conferred no further risk of CD when compared with single SNP analyses.

CONCLUSION

IL23R gene variants determine CD susceptibility in the Australian and New Zealand population, particularly ileal CD. A strong additive interaction exists between IL23R SNPs and smoking behavior resulting in a dramatic increase in disease risk depending upon specific genetic background.

The clinical utility of health-related quality of life screening in a pediatric inflammatory bowel disease clinic

BACKGROUND

Adjusting to symptom flares, treatment regimens, and side effects places youth with inflammatory bowel disease (IBD) at increased risk for emotional and behavioral problems and adverse disease outcomes. Implementation of psychosocial screening into clinical practice remains a challenge. This study examines the clinical utility of health-related quality of life (HRQOL) screening in predicting disease outcome and healthcare utilization.

METHODS

One hundred twelve youth of 7 to 18 years diagnosed with IBD and their parents. Youth completed standardized measures of HRQOL and depression. Parents completed a proxy report of HRQOL. Pediatric gastroenterologists provided the Physician Global Assessment. Families were recruited from a pediatric gastroenterology clinic. Retrospective chart reviews examined disease outcome and healthcare utilization for 12 months after baseline measurement.

RESULTS

Linear regressions, controlling for demographic and disease parameters, revealed that baseline measurement of youth and parent proxy-reported HRQOL predicted the number of IBD-related hospital admissions, gastroenterology clinic visits, emergency department visits, psychology clinic visits, telephone contacts, and pain management referrals over the next 12 months. Disease outcome was not significant.

CONCLUSIONS

Lower HRQOL was predictive of increased healthcare utilization among youth with IBD. Regular HRQOL screening may be the impetus to providing better case management and allocating resources based on ongoing care needs and costs. Proactive interventions focused on patients with poor HRQOL may be an efficient approach to saving on healthcare costs and resource utilization.

Chronic pain in inflammatory bowel disease: characteristics and associations of a hospital-based cohort

BACKGROUND

Chronic pain (CP) is a common symptom in patients with inflammatory bowel disease. This study aimed to examine its prevalence, severity, clinical associations, and impact on psychological well-being and to identify patient factors that independently predict the presence of severe/disabling pain.

METHODS

One hundred and twenty consecutive patients with inflammatory bowel disease attending a hospital-based clinic provided information through questionnaires on quality of life, mood disturbance, and functional gut symptoms. Those who had CP (pain occurring every day for 3 months within the past 6 months) provided additional information on the pain's intensity and associated disability and management and coping strategies.

RESULTS

Forty-six patients (38%) had CP, most commonly in the abdomen (91%), and they had higher disease activity, reduced quality of life, and more depression and anxiety and took more paracetamol and opiates than those without. These indices were worse in the subgroup of 23 with moderate-severe pain/disability. Criteria for irritable bowel syndrome were met in 70% of those with pain irrespective of its severity. Multivariate analysis identified 4 independent associations with moderate-severe pain/disability: active disease (odds ratio, 49 [95% confidence intervals, 1.6-1455]), catastrophizing tendency (35 [3-228]), medication belief score (0.05 [0.005-0.55], and depression score (1.80 [1.02-3.17]).

CONCLUSIONS

CP has major effects on quality of life and functional and social outcomes. Active disease and maladaptive coping strategies and negative attitudes and beliefs toward symptoms are independently associated with more severe pain. Management strategies should move the focus away from analgesic dependence toward psychosocial intervention and nonpharmacologic therapy.

Mucosal improvement in patients with moderate to severe postoperative endoscopic recurrence of Crohn's disease and azathioprine metabolite levels

BACKGROUND

The value of azathioprine metabolites (6-thioguanine nucleotides [6-TGN]) in monitoring clinical treatment response is still controversially discussed. Data regarding thiopurine metabolite levels and endoscopic improvement are lacking.

METHODS

Data were analyzed post hoc from a 1-year, multicenter, double-blind, double-dummy, randomized trial comparing azathioprine 2.0 to 2.5 mg/kg per day versus mesalamine 4 g/d in a subset of 23 postoperative patients with Crohn's disease (CD) treated with azathioprine and having moderate-to-severe endoscopic recurrence according to a modified 6-grade score. Red blood cell (RBC) concentrations of 6-TGN, 6-methyl-mercaptopurine ribonucleotides (6-MMPR), and 6-methyl-thioguanine nucleotides (6-MTGN) were indicated as follows: area under the concentration-time curve, average concentration (C av), and concentration at the final study visit.

RESULTS

Overall, 74% of patients showed an improvement in the modified endoscopic score (P = 0.022). Median endoscopic score reduced from 4 at the baseline to 2 at the final visit. Patients with a high C av for 6-TGN (≥ 193 pmol/8 × 10(8) RBC; P = 0.017) or 6-MTGN (≥ 79.2 pmol/8 × 10(8) RBC; P = 0.035) significantly improved in endoscopic score, and the improvement in endoscopic score correlated with C av for 6-TGN (r = -0.51; P = 0.013). For concentration at the final visit, higher values for 6-TGN (≥ 142 pmol/8 × 10(8) RBC; P = 0.017) were associated with a better postoperative score. Sensitivity analysis revealed a significant correlation between 6-TGN (area under the concentration-time curve) and postoperative endoscopic improvement.

CONCLUSIONS

Our post hoc analysis from a double-blind, randomized trial suggests that higher RBC 6-TGN levels are associated with endoscopic improvement in patients with severe postoperative endoscopic recurrence of CD. Thus, our study provides first evidence on the utility of monitoring of thiopurine metabolites to achieve mucosal response in CD.

Unfavourable outcome for women in a study of health-related quality of life, social factors and work disability in Crohn's disease

OBJECTIVE

The aim was to describe health-related quality of life (HRQL) and social factors, sickness and disability variables in a large population-based cohort of patients with Crohn's disease (CD).

METHODS

HRQL was measured with Short Form-36 in 497 adult patients with CD at three outpatient clinics. Comparisons were made with age-sex-matched background population and with ulcerative colitis (UC). Social factors, employment, sickness compensation and disability pension for CD were compared with national population registers.

RESULTS

CD had a greater negative effect on HRQL than did UC. This difference was more pronounced for women. Compared with background population, patients with CD had lower educational level, and had a two-fold rise in long-term sickness and disability pension rate. Women with CD had higher rates of sickness and disability than men with CD and were more often living single, though procreation was not affected.

CONCLUSION

This study characterized the burden of CD in a large population-based cohort. CD had higher impact on HRQL, compared with UC. Women with CD had worse outcome in subjective health status, but not in objective assessment of disease activity. Women also had higher rates of sickness, disability pension and single living. The mechanism underlying the sex-related inequalities in outcome for CD warrants further elucidation.

Crohn's disease activity index does not correlate with endoscopic recurrence one year after ileocolonic resection

BACKGROUND

Crohn's disease clinical trials utilize the Crohn's Disease Activity Index (CDAI) to measure primary endpoint assessments of clinical recurrence and remission. We evaluated the extent of agreement between clinical recurrence/remission as defined by the CDAI and endoscopic recurrence 1 year after intestinal resection for Crohn's disease (CD).

METHODS

Twenty-four CD patients who had been randomly assigned to a postoperative clinical trial had 1 year clinical, endoscopic, and histological assessment for disease recurrence. The primary endpoint was the extent of agreement between endoscopic recurrence and clinical recurrence 1 year after intestinal resection for CD. Secondary endpoints were extent of agreement between endoscopic recurrence and the surrogate markers of CD activity, i.e., histological activity, sedimentation rate, and C-reactive protein (CRP).

RESULTS

Twelve of the 24 patients (50%) were in endoscopic remission (i0, i1) and 12 (50%) had endoscopic recurrence (i2, i3, or i4). There was good agreement between endoscopy and histological activity scores (intraclass correlation coefficient = 0.53, kappa coefficient = 0.58). In contrast, there was little to no relationship between endoscopy and CDAI scores; median CDAI scores for endoscopy scores of i0/i1, i2, i3, and i4 were 118, 76, 156, and 78, respectively (P for trend = 0.88). The kappa coefficient (of agreement) between endoscopy score ± 2 and CDAI score ± 150 was 0.12 (exact P = 0.68), indicating poor agreement. Similarly, there was no consistent association observed between endoscopy scores and mean CRP and ESR values at week 54.

CONCLUSIONS

The CDAI shows poor agreement with endoscopic recurrence 1 year after intestinal resection. Endoscopic recurrence should be the primary endpoint of future postoperative studies and ileocolonoscopy the gold standard test to detect postoperative recurrence.

The burden of inpatient costs in inflammatory bowel disease and opportunities to optimize care: a single metropolitan Australian center experience

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) causes significant morbidity, frequently resulting in hospital admission and resection surgery. However, little is known about: 1. how IBD patients' inpatient healthcare utilisation compares to other inpatients and 2. whether there are potentially modifiable factors which may influence this.

METHODS

Over five months a cohort of admitted IBD patients were acquired and each assigned five admitted, age and gender matched controls at a single tertiary center. Data compared over 15 months included: total cumulative length of stay (TLoS), number of admissions (index and subsequent re-admissions), inpatient costs, care complexity (defined by relative stay index [RSI]), and disease-specific factors amongst the IBD cohort. Data were confirmed by case notes review.

RESULTS

There were 102 IBD patients and 510 controls (median age 44 years, 57% female). IBD patients had more re-admissions (mean 1.72 vs 1.55, p=0.002) and longer TLoS (median 6.8 vs 3.4 days, p<0.0001) than controls. Both median cumulative cost of inpatient healthcare and RSI were also higher in IBD compared to controls ($7052 vs $5470 and RSI 362% vs 293%, each p<0.008). IBD patients seen by a gastroenterologist prior to their index admission had fewer re-admissions (mean 1.37 vs 2.02, p=0.016,) and tended to have lower total cumulative inpatient costs than those without prior Gastroenterologist review (median $6439 vs $9479, p=0.069).

CONCLUSIONS

IBD patients have significantly greater inpatient healthcare utilization, complexity and costs than age and gender matched, hospitalized controls. Prior gastroenterologist care in IBD may reduce subsequent admission rates, and inpatient-related costs.

Faecal calprotectin in children with clinically quiescent inflammatory bowel disease

OBJECTIVE

The use of faecal calprotectin as a surrogate marker for intestinal inflammation is emerging. However, the data on faecal calprotectin during maintenance therapy in children with inflammatory bowel disease, IBD, are sparse. Our aim was to study faecal calprotectin levels in paediatric IBD during clinically quiescent disease and to investigate if high levels were associated with a flare-up of the disease.

SUBJECTS AND METHODS

Faecal calprotectin level was measured in 72 children with paediatric IBD in clinical remission (median age 13 years). Of these, 37 children had been in clinical remission for more than a year, 20 for 6-12 months and 15 for 3 to <6 months. The clinical outcome of the patients was followed up to the first relapse or up to 12 months.

RESULTS

When in clinical remission, 35% (25/72) of the children had normal faecal calprotectin (<100 microg/g) and 13% (9/72) a very high level (>1000 microg/g) while not reporting symptoms. A clinical relapse occurred in 35% (25/72) during the subsequent 12 months. When in clinical remission, the predictive value of faecal calprotectin for an overt relapse was low ranging from 0.396 to 0.429 for faecal calprotectin values >100 microg/g or >1000 microg/g, respectively. The negative predictive value was 0.75 for values <100 microg/g.

CONCLUSIONS

In paediatric IBD, subjective symptoms and clinical assessment associate poorly with the levels of faecal calprotectin. During maintenance medication in colonic disease, the probability of staying in clinical remission for a subsequent year is high if faecal calprotectin value is low.

Adverse clinical phenotype in inflammatory bowel disease: a cross sectional study identifying factors potentially amenable to change

BACKGROUND AND AIM

A significant proportion with inflammatory bowel disease (IBD) exhibit an adverse clinical phenotype reflected in endpoints like surgery and hospitalizations. We sought to identify clinico-demographic factors associated with these adverse consequences that may be amenable to change.

METHODS

Over 6 months IBD patients visiting a metropolitan center were prospectively identified and given a comprehensive survey addressing patient knowledge, mental health and satisfaction with medical care along with other clinical data. Logistic regression analyses assessed for associations between clinico-demographic variables and adverse clinical endpoints (previous surgery [ever] and/or recent inpatient admission over a 16 month observation period).

RESULTS

Of 256 IBD patients, 162 responded (response rate 63%); 95 (59%) had Crohn's disease (CD), 63 (40%) ulcerative colitis (UC), four indeterminate colitis; 53% were female. Factors associated with a greater likelihood of hospitalization included moderate/severe disease activity, psychological co-morbidity, numbers of medications and outpatient visits (odds ratio [OR] 7.09 [2.83-17.76], 4.13 [1.25-13.61], 1.26 [1.03-1.54], 1.17 [1.00-1.37] respectively; all P < 0.05). Post-surgical patients were more likely to have CD, more currently active disease and longer disease duration (OR 8.55 [2.43-29.4], 3.52 [1.26, 9.87], 1.14 [1.08, 1.21] respectively; all P < 0.02), yet were less likely to have previously seen a gastroenterologist, OR 0.25 [0.08-0.76] (P = 0.01).

CONCLUSIONS

'At risk' patients (those previously operated, with ongoing disease activity, dissatisfaction and/or psychological comorbidities) may benefit from early identification and more intensive management. Specialist gastroenterology care appears to be under-utilized in operated patients yet may reduce future IBD morbidity.