Tumor-Induced Osteomalacia in a Patient with Crohn's Disease: A Case Report and Approach to Investigating Hypophosphatemia.

Introduction: Hypophosphatemia occurs commonly in inflammatory bowel disease (IBD) patients and can cause considerable morbidity. The differential diagnoses in IBD include nutritional causes and hypophosphatemia induced by some formulations of intravenous iron infusions. Case Presentation: We present the case of a 37-year-old man with active Crohn's disease, presenting with difficulty walking and fractures of the vertebrae and calcaneus. He had long-standing hypophosphatemia. Nutritional causes for hypophosphatemia were considered in the first instance given the presence of chronic diarrhea and vitamin D deficiency; however, there was minimal response to appropriate supplementation with oral phosphorous and vitamin D. Iron infusion-induced hypophosphatemia was then considered, but the nadir phosphate level preceded any iron infusion. Therefore, work-up was undertaken for less common causes. He was ultimately diagnosed with tumor-induced osteomalacia, caused by excess fibroblast growth factor 23 (FGF23) secretion from a phosphaturic mesenchymal tumor about the knee. He had complete resolution of symptoms and biochemical abnormalities following successful resection of the tumor. Conclusion: This case illustrates the approach to investigation of hypophosphatemia in IBD patients. If the time course and response to phosphate supplementation are not as expected for nutritional or iron infusion-induced hypophosphatemia, less common causes should be considered.

Viral Enteric Infections in Acute Severe Ulcerative Colitis.

BACKGROUND AND AIMS: Excluding superimposed enteric infection is critical in the management of acute severe ulcerative colitis [ASUC]. Whilst infection with Clostridium difficile and cytomegalovirus have been shown to increase colectomy and mortality rates, no data exist regarding the impact of common viral enteropathogens in ASUC. Our aim was to determine if viral enteric infection in ASUC alters the severity or outcomes of these episodes. METHODS: This was a retrospective review of cases presenting to a large tertiary centre. Data were obtained from an in-house, prospectively maintained inflammatory bowel disease database. We identified all ASUC cases treated between October 2015 and January 2021 and compared those testing positive for adenovirus 40/41, human rotavirus or norovirus GI by faecal multiplex polymerase chain reaction [PCR] to those testing negative. RESULTS: We identified 147 patients with ASUC and faecal multiplex PCR testing for viral pathogens. In total, 22/147 patients [14.9%] tested positive, two of whom tested positive for two viruses. The infected and non-infected cohorts did not differ significantly with regard to admission C-reactive protein [81.7 vs 76.6, p = 0.77], Mayo endoscopic subscore [2.4 vs 2.3, p = 0.43], length of hospital admission [7.9 vs 7.9 p = 0.99], requirement for rescue therapy [59% vs 56%, p = 0.75] or colectomy rate [4.5% vs 4.1%, p = 0.69]. CONCLUSIONS: Infection with viral enteropathogens was common in our ASUC cohort, but did not appear to affect disease severity at presentation, the need for rescue therapy or the success rate of rescue therapy.

Markers of Systemic Inflammation in Acute Attacks of Ulcerative Colitis: What Level of C-reactive Protein Constitutes Severe Colitis?

BACKGROUND AND AIMS: The erythrocyte sedimentation rate [ESR] as a component of the Truelove and Witts Criteria [TWC] is the traditional inflammatory marker used for the assessment of ulcerative colitis [UC] activity. However, the C-reactive protein [CRP] is preferentially used in contemporary clinical practice. We aimed to determine the equivalent CRP cut-off for an ESR of  >30 mm/h in patients presenting with acute severe UC. METHODS: Clinical and pathological data were prospectively collected from 163 presentations of severe UC. A CRP cut-off corresponding to an ESR of  >30 mm/h was determined using confusion matrices. A validation cohort of 128 presentations was prospectively collected and analysed. RESULTS: A CRP cut-off of ≥12 mg/L generated an 85% positive predictive value [PPV] with a sensitivity of 95% and an accuracy of 82% for having a paired ESR of  >30 mm/h. There were no statistically significant differences between groups determined by the traditional ESR versus the new CRP-based criterion in the presenting faecal calprotectin, Mayo endoscopic subscore, or the rates of intravenous corticosteroid therapy failure and colectomy-by-discharge. Applying the CRP  ≥12 mg/L criterion to a validation cohort of 128 presentations generated a PPV of 83% and a sensitivity of 94%. CONCLUSIONS: The proposed CRP  ≥12 mg/L cut-off is an inclusive, sensitive, and very practical alternative to ESR as part of the TWC for defining UC presentation severity. It demonstrated similar performance characteristics to the classical ESR criterion when used for the assessment of acute UC disease activity. These findings were confirmed in a validation cohort.

Outcomes of dietary management approaches in active ulcerative colitis: A systematic review.

BACKGROUND & AIMS: The dietary management of active ulcerative colitis (UC) is currently poorly understood. Due to the lack of clinical guidelines for this population, diet choice may be based on the personal judgement of the clinician, and without sound evidence. The aim of this systematic review was to appraise the current literature on the dietary management of individuals with active UC, in both inpatient and outpatient settings, to determine if clinical outcomes differ by diet prescription. METHOD: PUBMED, CINAHL, EMBASE, Web of Science and SCOPUS were comprehensively searched during March and April 2020. Eligible trials recruited adults with active UC comparing different methods of dietary management, including enteral nutrition (EN), total parenteral nutrition (TPN), elimination diets and standard oral diets, in both the inpatient and outpatient settings. RESULTS: 10 studies met inclusion criteria of this qualitative synthesis. No difference was found between EN, TPN and bowel rest in terms of disease activity measures when compared to a standard oral diet. The results of this study also showed promising potential for the use of elimination diets in the outpatient setting with four studies finding a significant difference in disease activity measures between the intervention diet and control. CONCLUSION: There is no strong evidence to support the use of any specific dietary prescription to improve clinical outcomes for individuals with active UC. A number of low quality studies suggest benefit of following an elimination diet, however, additional high quality studies are required before any more specific recommendations can be made.

Development and evaluation of a risk assessment tool to improve clinical triage accuracy for colonoscopic investigations.

BACKGROUND: Gastroenterology Departments at hospitals within Australia receive thousands of General Practitioner (GP)-referral letters for gastrointestinal investigations every month. Many of these requests are for colonoscopy. This study aims to evaluate the performance of the current symptoms-based triage system compared to a novel risk score using objective markers. METHODS: Patients with lower abdominal symptoms referred by their GPs and triaged by a Gastroenterology consultant to a colonoscopy consent clinic were recruited into the study. A risk assessment tool (RAT) was developed using objective data (clinical, demographic, pathology (stool test, FIT), standard blood tests and colonoscopy outcome). Colonoscopy and histology results were scored and then stratified as either significant bowel disease (SBD) or non-significant bowel disease (non-SBD). RESULTS: Of the 467 patients in our study, 45.1% were male, the mean age was 54.3 ± 13.8 years and mean BMI was 27.8 ± 6.2. Overall, 26% had SBD compared to 74% with non-SBD (42% of the cohort had a normal colonoscopy). Increasing severity of referral symptoms was related to a higher triage category, (rectal bleeding, P = 2.86*10-9; diarrhoea, P = 0.026; abdominal pain, P = 5.67*10-4). However, there was no significant difference in the prevalence of rectal bleeding (P = 0.991) or diarrhoea (P = 0.843) for SBD. Abdominal pain significantly reduced the risk of SBD (P = 0.0344, OR = 0.52, CI = 0.27-0.95). Conversely, the RAT had a very high specificity of 98% with PPV and NPV of SBD prediction, 74% and 77%, respectively. The RAT provided an odds ratio (OR) of 9.0, 95%CI 4.29-18.75, p = 2.32*10-11), higher than the FIT test (OR = 5.3, 95%CI 2.44-11.69, p = 4.88*10-6), blood score (OR = 2.8, 95%CI 1.72- 4.38, p = 1.47*10-5) or age (OR = 2.5, 95%CI 1.61-4.00, 5.12*10-5) independently. Notably, the ORs of these individual objective measures were higher than the current practice of symptoms-based triaging (OR = 1.4, 95%CI 0.88-2.11, p = 0.153). CONCLUSIONS: It is critical that individuals with high risk of having SBD are triaged to the appropriate category with the shortest wait time. Here we provide evidence that a combination of blood markers, demographic markers and the FIT test have a higher diagnostic accuracy for SBD than FIT alone.

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.

Granulocyte-macrophage colony-stimulating factor autoantibodies: a marker of aggressive Crohn's disease.

BACKGROUND: Neutralizing autoantibodies (Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF Ab) have been associated with stricturing ileal Crohn's disease (CD) in a largely pediatric patient cohort (total 394, adult CD 57). The aim of this study was to examine this association in 2 independent predominantly adult inflammatory bowel disease patient cohorts. METHODS: Serum samples from 742 subjects from the NIDDK IBD Genetics Consortium and 736 subjects from Australia were analyzed for GM-CSF Ab and genetic markers. We conducted multiple regression analysis with backward elimination to assess the contribution of GM-CSF Ab levels and established CD risk alleles and smoking on ileal disease location in the 477 combined CD subjects from both cohorts. We also determined associations of GM-CSF Ab levels with complications requiring surgical intervention in combined CD subjects in both cohorts. RESULTS: Serum samples from patients with CD expressed significantly higher concentrations of GM-CSF Ab when compared with ulcerative colitis or controls in each cohort. Nonsmokers with ileal CD expressed significantly higher GM-CSF Ab concentrations in the Australian cohort (P = 0.002). Elevated GM-CSF Ab, ileal disease location, and disease duration more than 3 years were independently associated with stricturing/penetrating behavior and intestinal resection for CD. CONCLUSIONS: The expression of high GM-CSF Ab is a risk marker for aggressive CD behavior and complications including surgery. Modifying factors include environmental exposure to smoking and genetic risk markers.

Crohn's disease and smoking: is it ever too late to quit?

BACKGROUND: Smoking increases CD risk. The aim was to determine if smoking cessation at, prior to, or following, CD diagnosis affects medication use, disease phenotypic progression and/or surgery. METHODS: Data on CD patients with disease for ≥5 yrs were collected retrospectively including the Montreal classification, smoking history, CD-related abdominal surgeries, family history, medication use and disease behaviour at diagnosis and the time when the disease behaviour changed. RESULTS: 1115 patients were included across six sites (mean follow-up-16.6 yrs). More non-smokers were male (p=0.047) with A1 (p<0.0001), L4 (p=0.028) and perianal (p=0.03) disease. Non-smokers more frequently received anti-TNF agents (p=0.049). (p=0.017: OR 2.5 95%CI 1.18-5.16) and those who ceased smoking prior to diagnosis (p=0.045: OR 2.3 95%CI 1.02-5.21) progressed to complicated (B2/B3) disease as compared to those quitting at diagnosis. Patients with uncomplicated terminal ileal disease at diagnosis more frequently developed B2/B3 disease than isolated colonic CD (p<0.0001). B2/B3 disease was more frequent with perianal disease (p<0.0001) and if i.v. steroids (p=0.004) or immunosuppressants (p<0.0001) were used. 49.3% (558/1115) of patients required at least one intestinal surgery. More smokers had a 2nd surgical resection than patients who quit at, or before, the 1st resection and non-smokers (p=0.044: HR=1.39 95%CI 1.01-1.91). Patients smoking >3 cigarettes/day had an increased risk of developing B2/B3 disease (p=0.012: OR 3.8 95%CI 1.27-11.17). CONCLUSION: Progression to B2/B3 disease and surgery is reduced by smoking cessation. All CD patients regardless of when they were diagnosed, or how many surgeries, should be strongly encouraged to cease smoking.

Inter-observer agreement for Crohn's disease sub-phenotypes using the Montreal Classification: How good are we? A multi-centre Australasian study.

BACKGROUND: Crohn's disease (CD) exhibits significant clinical heterogeneity. Classification systems attempt to describe this; however, their utility and reliability depends on inter-observer agreement (IOA). We therefore sought to evaluate IOA using the Montreal Classification (MC). METHODS: De-identified clinical records of 35 CD patients from 6 Australian IBD centres were presented to 13 expert practitioners from 8 Australia and New Zealand Inflammatory Bowel Disease Consortium (ANZIBDC) centres. Practitioners classified the cases using MC and forwarded data for central blinded analysis. IOA on smoking and medications was also tested. Kappa statistics, with pre-specified outcomes of κ>0.8 excellent; 0.61-0.8 good; 0.41-0.6 moderate and ≤0.4 poor, were used. RESULTS: 97% of study cases had colonoscopy reports, however, only 31% had undergone a complete set of diagnostic investigations (colonoscopy, histology, SB imaging). At diagnosis, IOA was excellent for age, κ=0.84; good for disease location, κ=0.73; only moderate for upper GI disease (κ=0.57) and disease behaviour, κ=0.54; and good for the presence of perianal disease, κ=0.6. At last follow-up, IOA was good for location, κ=0.68; only moderate for upper GI disease (κ=0.43) and disease behaviour, κ=0.46; but excellent for the presence/absence of perianal disease, κ=0.88. IOA for immunosuppressant use ever and presence of stricture were both good (κ=0.79 and 0.64 respectively). CONCLUSION: IOA using MC is generally good; however some areas are less consistent than others. Omissions and inaccuracies reduce the value of clinical data when comparing cohorts across different centres, and may impair the ability to translate genetic discoveries into clinical practice.

Serious infections in patients with inflammatory bowel disease receiving anti-tumor-necrosis-factor-alpha therapy: an Australian and New Zealand experience.

BACKGROUND AND AIM: Anti-tumor-necrosis-factor-alpha (anti-TNF-α) medications are effective in inflammatory bowel disease (IBD), but have an increased risk of tuberculosis (TB) and serious infections. The aim of this study was to examine the Australian/New Zealand experience of serious infections and TB in IBD patients receiving anti-TNF-α therapy from 1999-2009. METHODS: Serious infections, defined as 'requiring hospital admission' and TB cases in patients receiving, or within 3 months following, anti-TNF-α therapy were analyzed across Australia and New Zealand. Patient demographics, IBD medications, duration of anti-TNF-α therapy, and infection details were collected. RESULTS: A total of 5562 IBD patients were managed across the centers. Of these, 489 (16.8%) Crohn's disease and 137 (5.2%) ulcerative colitis patients received anti-TNF-α therapy. There were three cases of latent TB that received prophylaxis prior to anti-TNF-α therapy. No cases of active TB were reported. Fourteen (2.2%) serious infections occurred. Seven occurred in patients receiving anti-TNF-α therapy for less than 6 months, including two cases of primary Varicella zoster (VZV), two cases of Pneumocystis jiroveci pneumonia, two cases of Staphylococcus aureus bacteremia, and one severe flu-like illness. Six patients were taking additional immunosuppressive medications. The other seven infections occurred after 6 months (mean 32.6 ± 24.3 months) and included one case of primary VZV, one flu-like illness, and five bacterial infections. All infections resolved with treatment. CONCLUSION: TB is a very rare complication of anti-TNF-α therapy in Australia and New Zealand. Serious infections are uncommon but early opportunistic infections with Pneumocystis jiroveci pneumonia suggest a need for vigilance in patients on multiple immunosuppressive medications. VZV vaccination prior to immunosuppressive therapy should be considered in VZV-naïve patients.

Anti-tumour necrosis factor-alpha treatment for perianal Crohn's disease in Australia.

OBJECTIVE: To examine the prevalence of perianal Crohn's disease (PCD) and the eligibility of PCD patients to access anti-tumour necrosis factor-alpha (anti-TNFalpha) treatment under current Australian Pharmaceutical Benefits Scheme (PBS) guidelines. DESIGN, SETTING AND PARTICIPANTS: A retrospective study of patients with Crohn's disease (CD) and PCD attending four large adult inflammatory bowel disease (IBD) centres in Australia between January 2004 and May 2008. Patients for whom anti-TNFalpha therapy was clinically indicated were assessed to determine whether they satisfied PBS criteria for subsidised medication. MAIN OUTCOME MEASURES: Prevalence of CD and PCD in patients attending different IBD centres; eligibility of PCD patients for PBS-subsidised anti-TNFalpha medication. RESULTS: Data were available on 3589 patients, representing about 6% of all patients with IBD in Australia. Of the 1815 patients with CD, 310 (17%) had PCD. Anti-TNFalpha therapy was deemed clinically indicated for 166 patients with PCD (54%), of whom 49 (30%) did not qualify for PBS-funded therapy. CONCLUSION: Thirty per cent of patients with clinically significant PCD currently do not have access to PBS-subsidised optimal medical treatment. We believe that PBS criteria should be extended to include this subgroup of IBD patients.