Tag Archives: Crohn’s disease

Delays in diagnosing Crohn’s disease

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Delayed diagnosis remains a problem in Crohn’s disease (Inflamm Bowel Dis 2012; 18: 496-505).  This study included a total of 1591 IBD patients (932 CD, 625 UC, 34 indeterminate colitis) from the Swiss IBD cohort study (SIBDCS).

  • Diagnostic delay in CD patients was significantly longer compared to UC patients (median 9 versus 4 months, P < 0.001).
  • 75% of CD patients were diagnosed within 24 months compared to 12 months for UC and 6 months for IC patients.
  •  Independent risk factors for long diagnostic delay in CD (>24 months)  included age <40 years at diagnosis (odds ratio [OR] 2.15, P = 0.010) and ileal disease (OR 1.69, P = 0.025)
  • In UC patients, nonsteroidal antiinflammatory drug (NSAID intake (OR 1.75, P = 0.093) and male gender (OR 0.59, P = 0.079) were associated with long diagnostic delay (>12 months)

Diagnostic delay has been a problem for quite a long time; in children, delays can worsen growth failure.  In 1988, Kanof et al reported that decreased height velocity preceded the diagnosis of CD in 88% of their patients (pediatric cohort). In addition, 42% of their population had a reduction in height velocity before intestinal symptoms were noted.

Especially when there is not a lot of colonic disease, a high degree of suspicion needs to be maintained.  This is not difficult for pediatric gastroenterologists.  For pediatricians and family physicians, the increased availability of biomarkers (Biomarkers identify patients who benefit and how) should be helpful in reducing diagnostic delays.

Additional blog entries and references:

  • Kanof ME, Lake AM, Bayless TM. Decreased height velocity in children and adolescents before the diagnosis of Crohn’s disease. Gastroenterology.1988; 95 :1523– 1527.
  • Differentiating ulcerative colitis from Crohn disease in children and young adults: report of a working group of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the Crohn’s and Colitis Foundation of America.  North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition, Colitis Foundation of America, Bousvaros A, Antonioli DA, Colletti RB, Dubinsky MC, Glickman JN, Gold BD, Griffiths AM, Jevon GP, et al.J Pediatr Gastroenterol Nutr. 2007 May; 44(5):653-74.

Upper endoscopy useful for identifying Crohn’s disease

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In a large pediatric study, the value of upper endoscopy in detecting Crohn’s disease (CD) is evident (JPGN 2012: 54: 753-57).

While the majority of pediatric patients with suspected inflammatory bowel disease probably undergo both upper endoscopy and colonoscopy, the added value of upper endoscopy remains unclear.  In this retrospective study with 171 pediatric patients (70 with CD, 33 with UC, 68 Non-IBD), 11% of children with CD had the diagnosis established based “solely” on the finding of granulomatous inflammation in upper intestinal tract (along with clinical symptoms).

Other key findings:

  • Presence of histologic gastric inflammation in CD patients compared to control patients was significantly higher (p<0.0001) but not significantly higher compared to UC patients (p=0.19).
  • Duodenal inflammation was highly suggestive of CD compared with both UC and non-IBD patients.  This occurred in 19% of CD patients compared with 0% and 1% in the other groups respectively.
  • 21 children (30%) had granulomas identified in upper GI tract (19 in stomach).  In 8 (11%), the diagnosis was changed based on this finding.  Prior to histology, the tenative diagnosis: 2 UC, 4 IC, 2 non-IBD.
One curious finding was a the presence of “perianal abscess/fistula” with similar frequency in CD patients and UC patients based on their Table 2 Patient Characteristics.
Additional references:
  • -IBD 2009; 15: 1101-4.  Presence of UGI disease in IBD.
  • -JPGN 2007; 44: 653.  NASPGHAN report on discriminating/labelling UC vs. Crohn’s.
  • -JPGN 2002; 35: 636-40. Advocates panendoscopy for all new IBD.  Granulomas in 28% of EGDs & 71% of UC pts c some abnl on EGD; 82% Crohn’s c abnl EGD.
  • -JPGN 2005; 41: abstract 181 (page 549).  UGI identified granulomas in 15% that were not identified elsewhere.
  • -JPGN 2004; 39: 257-61. Diagnostic role of EGD for pediatric IBD.
  • Magnetic resonance enterography for Crohn’s disease

Quantifying Risk of PML with Natalizumab

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Given the limited number of treatment options for inflammatory bowel disease, when Natalizumab became available, there was a great deal of enthusiasm.  This quickly diminished as reports of progressive multifocal leukoencephalopathy (PML) emerged.  So far, I have not prescribed this agent.

Due to its efficacy for multiple sclerosis and IBD, there has been continued interest in understanding the risk for PML (NEJM 2012; 366: 1870-80, editorial pg 1938-39).

Key findings:

  • 212 cases of PML among 99,571 patients treated with natalizumab (2.1 cases per 1000)
  • Three main risk factors: positive JC-virus antibody, previous use of immunosuppressants, and receiving natalizumab more than 2 years

Patients who were negative for anti-JC virus antibodies had an incidence of 0.09 cases or less per 1000 patients.  Among patients who test positive for anti-JC virus antibodies, the risk remained <1 per 1000 patients if no use of immunosuppressants and 2 per 1000 if prior use of immunosuppressants during the first two years of therapy.  The risks were five-fold higher after 2 years in both groups.

While the risks are becoming more clear, the benefits of natalizumab are fairly well-established for multiple sclerosis.  Natalizumab decreased the annualized rate of relapse among patients with relapsing–remitting multiple sclerosis by 68%.

Additional references:

  • -NEJM 2009; 361: 1067, 1075, 1081.  Asymptomatic detection of JC virus common in urine noted in patients Rx’d with natalizumab (19% baseline to 63% on Rx); actual leukoencephalopathy ~1/1000 patients.
  • -Gastroenterol 2007; 132: 1672.  ENCORE trial.
  • -JPGN 2007; 44: 185. n=31 children/adolescents.  55% response, 29% remission; dosed at 3mg/kg.
  • -IBD 2007; 13: 2.  n=79.  Trial of combination natalizumab & infliximab.
  • -NEJM 2006; 354: 899, 911, 924.  Natalizumab slows progression of MS.  Risk of PML due to JC virus 1:1000 in 18 months of Rx.
  • -NEJM 2005; 353: 1912/1965.  Natalizumab not significantly effective for Crohn’s in this study
  • -NEJM 2005; 353: 362, 369, 375, 414.  3 cases of PML associated with Natalizumab
  • -JPGN 2004; 39: S49 [abstract 0107].  Natalizumab in 38 adolescents was effective (Hyams et al).
  • -Gastroenterol 2004; 126: 1574-81. review.  Natalizumab benefitted subjects with elevated CRP. (dosing 300mg every 4 weeks.)
  • -NEJM 2003; 24-32 & 68.  Natalizumab improved response rates in pts c Crohn’s dz (similar to infliximab).  Drug blocks alpha4 integrins which are required for lymphocytes to enter the intestine.
  • -Gastroenterol 2001; 121: 268-74. Infusion of 3mg/kg decreases CDAI in Crohn’s dz.

Improve Care Now

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Several years ago, “ImproveCareNow” Network was established with a goal of improving the quality of care children with inflammatory bowel disease. https://improvecarenow.org/ (http://www.youtube.com/watch?v=beG2eMROWqg)

Documentation of some outcomes of this effort have now been published (Pediatrics 2012; 129: e1030-e1041).  In this study from six U.S. centers, data from 843 children with Crohn’s disease and Ulcerative Colitis were available.  Centers were eligible to participate if they did not have extensive quality improvement (QI) experience and if they were able to enroll >75% of their IBD patients.  During the course of the study (2007-2010), there were increases in the proportion of patients with measurement of thiopurine methyltransferase (TPMT) before initiation of thiopurines, increased percentage of individuals receiving an appropriate thiopurine dosage, and an increased percentage of patients with inactive disease.  In Crohn’s disease, the number with inactive disease changed from 55% to 68%; in ulcerative colitis, the number increased from 61% to 72%.  

This study shows significant progress in these patients and the potential benefit of a more-structured approach.  However, some of the improvements in these outcomes may not be to process improvements. 

Study limitations:

  • The study does not document the rate of inactive disease in non-participating centers; thus there is not an adequate control population.  Given more widespread use of biologic therapies, this may account for much of the improvement in outcomes.   In fact, the study does not describe the percentage of patients receiving thiopurines or biologic agents.
  • The use of the physician global assessment (PGA) as indicative of disease activity.  The authors acknowledge that “PGA ….is a relatively subjective measure.”  A more reliable measure of disease activity like a stool calprotectin, endoscopy, or imaging study improvement would have been helpful.  
  • Better documentation or better outcomes? It is not clear whether some of the improvement reflects better documentation or improved care delivery.

Despite the limitations of this study, it is a good starting point.  The goal of improving the care of patients is shared by almost all physicians.  One way to start making a difference is measuring specific outcomes and targeting specific goals/checklists. Going forward with QI there are many QI hurdles: 

  • Defining optimal care is nearly impossible, there are few trials comparing efficacy & difficult to judge risk/benefit ratio of many therapies.
  • Difficulty selecting appropriate outcome measures -indications for hospitalization and surgery are not clear-cut in many cases.  Surgery may be an appropriate treatment rather than a negative outcome. 
  • Risk adjustment is an imperfect science.

Goals with Quality Improvement:

  • Plan-Do-Study-Act cycles.
  • Learning from high-performing centers -benchmarking

Warranted vs unwarranted variations:
Unwarranted: selecting inadequate dosing of medications, failure to check for TB before remicade/biologics, failure to consider drug interactions, failure to discuss options with families
Warranted: variation due to differences in disease (eg budesonide for ileitis but not pancolitis), variation driven by patient preferences (eg. using NG instead of corticosteroids)

“When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind” –Lord Kelvin 1883

“Not everything that counts can be counted, and not everything that can be counted counts.” –Albert Einstein

Additional references on quality improvement:

  • Free Self Management Handbook endorsed by ImproveCareNow:

https://improvecarenow.org/patients/self-management-handbook

  • -JPGN 2009; 49: 272.  Review of quality measures/history.
  • -Kohn LT, et al. To Err is Human: Building Safer Health System.  Nat’l Academy Press; 2000
  • -Crossing the quality chasm.  Wash DC: Nat’l Academy Press; 2001.
  • -Clin Gastro & Hep 2010; 8: 709.  Quality indicator sets in cirrhosis.
  • -J Pediatr 2005; 146: 744-50.  Bucuvalas JC et al.  Adjusting calcinerin inhibitor dosing
  • -IBD guidelines: www.cincinnatichildrens.org/svc/alpha/health-policy/ev-based/ibd.htm
  • -JPGN 2009; 49: 297.  Variation in care in pediatric Crohn disease. (Our center participated in this study)
  • -J Pediatr 2009; 154: 582.  Ventilator assoc pneumonia reduced w bundle of hand hygiene, elevated HOB, not changing ventilator circuits except when soiled & mouth care
  • -“The Learning Curve”(Atul Gawande) in The Best American Essays 2003 -some CF ctrs outperform, extending life expectancy ~14yrs.
  • -” A Surgeons Notes on Performance-Atul Gawande
    -NEJM 2007; 357: 2652.  Nice editorial.
  • www.icsi.org
  • www.qualityforum.org
  • www.ambulatoryqualityalliance.org
  • www.ncqa.org
  • www.cms.hhs.gov/hospitalqualityinit

Comments from lead author forwarded to blog:

Thanks for including our recent paper in your blog.  I agree with the study limitations as you mentioned, but wanted to put a couple of things in context.  We actually thought very hard about the issue of a control group, and specifically how to determine what the remission rate would be without the intervention.  We could not come up with a reasonable comparator (very few people/groups outside of ICN even know what the remission rate of their population is).  One very rough measure (which we did not feel was legitimate to include) is the rate of remission for new sites as they are joining the collaborative.  Established sites with complete participation have better outcomes than newer sites or sites that participate less fully, suggesting that at least a significant portion of the effect is due to the QI intervention rather than secular trend.  As far as the objective measures for outcomes, I know you realize that we are not able to mandate specific objective evaluations for a QI/observational research study, so we may never be able to use mucosal healing (for example) as our measure of remission.  However you probably noticed in the paper that we did demonstrate improvements in objective measures including sPCDAI, PUCAI and use of corticosteroids.  Certainly improvements in process measures may have been due in part to better documentation, but it is unlikely that objective outcome measures improved due to documentation. Thanks again for sharing our work with your audience.

Biomarkers identify patients who benefit and how

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Fecal calprotectin and serum CRP levels are helping to identify which patients benefit most from biologic therapies, how frequently to dose individuals and how well inflammation correlates with changes in CDAI.  Several abstracts from ACG highlight these issues:

Abstract #1175: Fecal calprotectin concentration and clinical remission in patients with active Crohn’s disease treated with certolizumab pegol: results from PRECiSE 1 (Sandborn W et al).

Abstract #1164: Baseline C-reactive protein is associated with disease progression in  patients with Crohn’s disease (Colmbel J-F et al).

Abstract #1165: Association of baseline C-reactive protein with maintenance of remission in patients with moderate to severe Crohn’s disease treated with adalimumab (Sandborn W et al)

Abstract 1175 uses a post hoc analysis of patients with active Crohn’s disease (CD) who were treated with certolizumab or placebo for 26 weeks.  Baseline calprotectin concentrations were higher in patients who achieved remission.  Another interesting finding of this study was that placebo patients did not have improvement in calprotectin levels.  So, even though some patients  had improvement in CDAI scores, indicating subjective improvement, inflammatory activity did not decline.  This is another indicator of how flawed a CDAI is for indicating the effectiveness of an IBD therapy.

Abstract 1164 looked at 238 patients with moderate to severe CD who were randomized to placebo arm in the CHARM study.  These patients were given open-label adalimumab for induction (80 mg week 0, 40 mg week 2) followed by blinded weekly placebo treatment from weeks 4-56 with a switch to open-label adalimumab after week 12 for a disease flare.  Higher baseline CRP levels in patients with moderate or severe CD were associated with higher disease scores after four weeks and after one year.  This suggests that a patient with higher CRP is more likely to have disease progression without adequate treatment.

Abstract 1165 examined the relationship between CRP and remission in CHARM patients. In the high baseline CRP group, 39 patients received adalimumab every other week, 28 weekly, and 34 received placebo.  In the low baseline CRP group, there were 42 every other week patients, 33 weekly, and 39 placebo patients.  In the high baseline CRP group, remission rates were 50% higher in the weekly treatment group compared to the every other week group.  Patients with low baseline CRP had similar results when treated weekly versus every other week.  Thus, patients with high baseline CRP are more likely to benefit from dose escalation and low CRP patients are more likely to have coexistent issues contributing to their symptoms (eg. IBS).

One other caveat: CRP production is geneticallly-determined and some patients do not make CRP in spite of active inflammation.

Related blog entries:

Food as medicine

Speed matters

Additional calprotectin references:

  • -IBD 2010; 16: 482. Calprotectin correlated with inflammation of ileum after pouch creation in children.
  • -IBD 2009; 12: 1851. Calprotectin was the only marker to correlate with endoscopic activity; n=134.
  • -JPGN 2009; 48: 48. Good sensitivity/specificity of calprotectin & lactoferrin. Up to 96% sensitivity & specificity.
  • -Clin Gastro & Hep 2008; 6: 1218. Lack of correlation between clinical symptoms and fecal biomarkers. However, biomarkers do correlate with mucosal/endoscopic disease. n=164.
  • -IBD 2008; 14: 1392. Monitoring IBD activity level c calprotectin & lactoferrin; n=15.
  • -IBD 2008; 14: 1229. Clinical utility in assessing histological relapse in kids. n=73 over 8yrs…may allow avoidance of invasive tests; cut off of 275mcg/gm had 97% sensitivity/neg pred value 85% pos pred value/specificity at predicting relapse.
  • -IBD 2008; 14: 669. Fecal calprotectin good at predicting relapse in pediatric IBD w cutoff of 400.

C-reactive protein references:

  • -J Pediatr 2011; 159: 340. CRP helps identify IBD.
  • -Clin Gastro & Hepatology 2011; 9: 421. CRP predicts response to IFX. n=718. those with high CRP had 91% response vs 83% in pts with NL CRP.
  • -Gastro 2004; 126: 1574-81. Crohn’s review. High CRP suggests likely response to anti-TNFα treatment.
  • -JPGN 2004; 38: 509-12. CRP more reliable than ESR for IBD.
  • -NEJM 1999; 340: 448. Review on acute phase reactants. CRP better than ESR as ESR is an indirect measure (resistance of plasma, due to fibrinogen, to the falling of RBCs) & broader range for CRP.

Magnetic resonance enterography for Crohn’s disease

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Magnetic resonance enterography (MRE) has increasingly been recognized as an effective way to characterize small bowel disease in Crohn’s disease (Inflamm Bowel Dis 2012; 18: 520-28).

In this retrospective pediatric study, 95 patients with Crohn’s disease underwent MRE from 2006-2009.  As expected, terminal ileal disease was the most common site of involvement with 54%; this was followed by ileum with 19%, and jejunum with 17%.  Other findings included solitary jejunal inflammation (3.7%), small bowel stenosis (1.9%) fistula (1%), and abscess (1%).  Specific evidence of inflammation included contrast enhancement, bowel wall thickening or derangement of bowel wall shape.  The images in the article are excellent.

The main advantage of MRE over CT enterography (CTE) is the lack of ionizing radiation.  In addition, MRE can better detect soft tissue contrast suggestive of bowel wall edema.  This helps distinguish acute from chronic inflammation.  Obtaining an MRE is technically more challenging and more costly.  The youngest patient in the study was seven; though the authors note that the youngest patient they have performed MRE was six.

Additional references:

  • More imaging needed?
  • -JPGN 2010; 51: 603.  MRE for suspected IBD.  Useful in pediatric Crohn’s disease.
  • -IBD 2009; 15: 1635. U/S compared favorably with endoscopy in correlating postoperative recurrence with Crohn’s.
  • -Clin Gastro Hepatol 2006; 3: 1221. MRI as accurate in evaluating ileocolonic disease with flareups as endoscopy.
  • -IBD 2004; 10: 452-61. U/S was very helpful in identifying disease and complications.

Drug levels for inflammatory bowel disease

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In many conditions, drug levels are helpful to make sure the patient receives an adequate dose for the indication.  When we treat infections or seizures, drug levels predict the effectiveness of the medication and allow dosing adjustments to improve responses as well as to lower toxicity. Drug levels are helpful in inflammatory bowel disease (IBD) as well.  Drug levels may help with thiopurine dosing and with infliximab (IFX) dosing.

Infliximab (IFX) levels can guide therapy (Scand J Gastroeneterol 2011; 46: 310-18). This study examined 106 patients (85 with CD and 21 with UC) over a ten-year period. In this cohort, patients received concurrent hydrocortisone, acetaminophen, and cetirizine to prevent acute reactions and to try to limit anti-infliximab antibodies (ATI), also called anti-human antichimeric antibodies (HACA).  Infusion intervals ranged from 4-12 weeks.

69% of Crohn’s patients maintained response to IFX and 48% of UC patients.  Infliximab trough levels were significantly increased among patients who maintained their response.  A cutoff value of 0.5 μg/mL was defined as clinically relevant for IFX trough concentrations for Crohn’s patients and for UC the cutoff was 0.8 μg/mL .  Trough levels below this cutoff were 86% sensitive and 85% specific for identifying loss of response.  The overall accuracy for the test was 87% in identifying loss of response.

Also, ATIs were significantly higher in CD patients who had lost response to infliximab.  Patients who had been “re-treated,” were significantly more likely to have developed ATIs.  “Re-treated” was defined as having interruption of IFX treatment more than 6 months.

These specific cutoff values apply to the radioimmunoassay technique for measuring IFX and ATI.  These values may not extrapolate to ELISA assays.  At the same time, the findings suggest a practical approach in patients with symptoms while receiving IFX:

  • Check IFX level (at trough or at 4 weeks)
  • If low level and no ATI, likely to respond to dose escalation
  • If low level but positive for ATI, not likely to respond to dose escalation
  • Do not assume symptoms are due to drug failure; reassess with imaging &/or scope. Consider alternate etiologies (eg infections, stricture, celiac, IBS).
  • Cotherapy with an immunomodulator reduces ATIs and boosts levels of IFX.
More usage of IFX and ATI levels is likely; however, cost issues preclude frequent measurements.

Additional references:

  • Only one chance to make first impression.  Previous blog entry on use of infliximab.
  • -Clin Gastro & Hepatology 2011; 9: 395. Do not assume symptoms are due to drug failure -reassess with imaging &/or scope. Consider alternate etiologies (eg infections, stricture, celiac, IBS). Check IFX level –if >12 @ 4weeks or >1.4 mcg/mL at trough –>predicts good response.  If +HACA, ~90% response with alternative TNF.  In those with low level, 86% responded to dose escalation.
  • -DDW 2011, Abstract #772. If loss of response to IFX, **confirm active dz (labs, scope) & not due to CDT. **check HACA –if +, only 10-20% chance of responding to dose escalation; better chance of responding to similar agent **check IFX week 4 level, if low (& neg HACA) then 90% respond to dose escalation
  • -NEJM 2010; 362:1383-1395. SONIC study.  Patients with moderate-to-severe Crohn’s disease who were treated with infliximab plus azathioprine or infliximab monotherapy were more likely to have a corticosteroid-free clinical remission than those receiving azathioprine monotherapy.
  • -Gut 2010; 59: 49-54. Trough IFX levels in UC. n=115. Antibody status can only be measured at trough levels. Undetectable trough level (<1.4 mcg/mL) associated with lower remission (15% vs 69%) and lower endoscopic response (28% vs 76%) & higher colectomy rate (55% vs. 7%).
  • -Gastroenterology 2010; 139: 344 (review of above Gut article). Similar to Crohn’s disease: 82% remission with detectable trough vs 6% w/o detectable level.
  • –Lancet 354 (9194): 1932–9. doi:10.1016/S0140-6736(99)05246-0. PMID 10622295.”Infliximab (chimeric anti-tumour necrosis factor alpha monoclonal antibody) versus placebo in rheumatoid arthritis patients receiving concomitant methotrexate: a randomised phase III trial. ATTRACT Study Group”.
  • -Am J Gastroenterol 2010; 105: 1133-39. If lack/loss of response, may need dose escalation with humira or Cimzia (q2weeks):
  • -IBD 2011; 17: 141-51. Loss of response to biologics.
  • -Gastro & Hep 2008; 4: 12. “primary nonresponse can be determined after 2 doses” in table reiterating AGA consensus guidelines. 85% of responders show benefit by 2weeks & all responders benefit c/in 6 weeks (Am J Gastro 2001; 96: S303). Worsening Sx despite infliximab indicates need to look for stricture, infxn, etc.
  • -Clin Gastro & Hep 2006; 4: 1248. Clinical remission associated with measurable infliximab troughs; thus, if no measurable trough, increase dose or shorten interval. If level detected & no response, unlikely to respnd to TNF class. Also, concurrent immunomodulators were not helpful.
  • -Am J Gastro 2010; 105: 2617 (Oussalah et al). 2-3yrs 41% IFX failure in UC. withdrawal of AZA increase loss of response –7x more likely
  • -Am J Gastro ; 105: 1133-40. n=155. 23% ATI -92% respond to med change, 17% respond to dose change. Level <12 @ 4weeks, 86% respond to dose change
  • -Gut 2010; 59: 1363. n=121. Co-treatment helped reduce complications & flares relative to monotherapy (& azathioprine appeared to be more effective than methotrexate).

Vitamin D, IBD, and Causality

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The importance of vitamin D has been noted in this blog previously (Common to be “D-ficient” ).  Now a study implicates vitamin D as a risk factor for developing inflammatory bowel disease, especially for Crohn’s disease (Gastroenterology 2012: 142: 482-89).  It is known that vitamin D influences innate immunity.  As such, it may play a role in the susceptibility to Crohn’s disease (CD) and Ulcerative colitis (UC).

This prospective study included 72,719 women (age 40-73) enrolled in the Nurses’ Health Study.  Research subjects completed an assessment of diet and lifestyle along with 25-hydroxy vitamin D [25(OH)D] levels.  The 25(OH)D levels were predicted; this prediction was based on a validated model which included vitamin D intake, sun exposure, race, and body mass index (J Natl Cancer Inst 2006; 98: 451-9).  This model was validated against directly measured 25(OH)D levels.

During nearly 1.5 million person-years of followup, 122 incident cases of CD and 123 cases of UC occurred.  The adjusted hazard ratio (HR) for the highest quartile of 25(OH)D was 0.54 for CD and 0.65 for UC compared to the lowest quartile.  Compared with a level less than 20, the highest quartile HR was 0.38 for CD and 0.57 for UC.

In addition, the authors identified a significant inverse association between dietary supplemental vitamin D and UC; an insignificant reduction in CD risk was noted with dietary intake.  Although it is difficult to determine causality, these data convincingly show that ‘healthy’ levels of vitamin D are associated with a lower risk of IBD.

Rifaximin for Crohn’s disease?

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Rifaximin (Xifaxan®) shows promise as a new treatment for Crohn’s disease (Gastroenterology 2012; 142: 473-81).  Rifaximin is an oral medication with minimal systemic absorption; it has a good track record in a number of GI indications, including bacterial gastroenteritis (traveler’s diarrhea), bacterial overgrowth in irritable bowel disease, and hepatic encephalopathy.  There are a few reasons why rifaximin would be considered a good candidate treatment for Crohn’s disease:

  • The pathophysiology of Crohn’s disease involves interaction of adherent bacteria to the intestinal mucosa and with the immune system
  • Other antimicrobials have shown benefit for Crohn’s disease
  • Animal models do not manifest Crohn’s disease when in a bacteria-free environment

In this study of 402 patients with moderate-to-severe Crohn’s disease, a multicenter randomized double-blind trial examined efficacy and safety of rifaximin at doses of 400mg, 800mg, and 1200mg twice daily.  The primary end point was remission based on Crohn’s Disease Activity Index (CDAI).

At the end of the 12-week treatment period, 62% of the 800mg group were in remission compared to 43% of the placebo group.  This difference was maintained 12 weeks afterwards with 45% maintaining remission compared with 43% of patients receiving placebo.  When looking at the other dosing regimens, at 12 weeks, 54% of the 400mg group and 47% of the 1200mg group were in remission based on CDAI.

Clinical response, but not remission, occurred in 56% of placebo patients compared with 63% for 400mg patients, 72% for 800mg patients, and 57% of 1200mg patients.  This trial may have been hampered by patient selection in that the placebo response was high.  This may be due to the fact that ~50% of patients had a low CRP value at baseline.

Safety was good in all patient groups.  However, one rifaximin-treated patient developed C difficile infection.

The fact that a clear dose response was not evident suggests the need for more studies.

Additional Rifaximin References:

  • -NEJM 2011; 364: 22 (pg 81-editorial).  About 10% improvement over placebo in pts with IBS-D.  (see abstract below).  Effects lasted up to 3 months.
  • -JPGN 2009; 49: 400-04. helped symptoms in 61% of IBD pts. n=23 (12 w Crohn). dose 10-30mg/kg/day.
  • -Aliment Pharm Ther 2005; 22: 31-35. Use in SBBO. n=90; 1200mg/day x 7 days. NL glucose breath test in 60% (vs 17% in low dose group); no side effects.
  • -Ann Intern Med 2006; 145: 557-563. double-blind, randomized controlled trial, n=87 for IBS. 400mg tid x 10days. Rx resulted in greater IBS improvement, ~40% improvement vs 20% w placebo during 10 week study
  • -IBD 2006; 12: 335. open-label use of rifaximim (400mg BID) for 30 pts c UC flare on ASA products resulted in clinical remission in 23 of 30.
  • -J Infect 2011; 62: 34-38. Rx may lead to resistant staphylococci.
  • -Hepatology 2010; 52: 1484. Review.

Additional Crohn’s Antibiotic/Probiotic References:

  • -IBD 2009; 15; 17. 40% response to Cipro in treatment of peranal fistulas. n=25. No response to metronidazole.
  • -IBD 2008; 14: 1597, 1585. No proven role for probiotics and IBD except pouchitis (after Abx)
  • -Clin Gastro & Hep 2008; 6: 145. Pouch problems reviewed -excellent review.
  • -IBD 2006; 12: 335. open-label use of rifaximim (400mg BID) for 30 pts c UC flare on ASA products resulted in clinical remission in 23 of 30.
  • -Curr Med Res Opinion 2005; 8: 1165-70. Rx for traveler’s diarrhea.  May be useful for Crohn’s as well.
  • -Gastroenterology 2005; 128: 856. Use of ornidazole prophylaxis reduced recurrence p-op from 37.5% to 8%.
  • -IBD 2004; 10: 318-325. antibiotics & IBD review.
  • -Gastroenterology 2004; 127: 412-21. adherent-invasive E. coli associated with ileal mucosa in 22% of Crohn’s (n=63) ileal mucosa vs. 6% of controls (n=16); higher colonization noted in neo-terminal ileums (36%).

Pediatric capsule endoscopy experience

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Capsule endoscopy (CE) in pediatric gastroenterology has become a routine procedure.   The experience of our group is noted in a recent study (JPGN 2012; 54: 409-13).  In this study, our single pediatric center reviewed 284 CE procedures (277 patients) over a five-year period.  The youngest patient to swallow a capsule was 4.6 years old.  Twenty capsules were placed endoscopically, with the youngest & smallest patient being 3 years old (13.5kg).  A patency capsule was used in 23 patients.

Overall, the yield with CE was high. 205 (72%) had positive findings; 154 (54%) had small bowel findings.  The study also compared its data to pediatric and adult meta-analysis.  Similar to other pediatric studies, Crohn disease was the most common indication; in adult studies, CE is used mostly for occult GI bleeding and anemia.  CE procedures did not reach the colon in 65 (21%); 36 of these incomplete procedures had positive findings.

Capsule retention occurred in seven patients (2.4%) which is similar to the meta-analysis studies as well.  Six of the seven had surgery due to capsule retention, though one surgical procedure had been planned and capsule helped identify stricture site.  In addition, one of the seven was retrieved through a tight ileostomy.

Additional references:

  • -Gastroenteology 2010; 139: 1468. Predictions for upcoming advances.
  • -Gastroenterology 2009; 137: 1197. Strongest indication -obscure bleeding.
  • -JPGN 2009; 49: 196. Capsule retention in 5.2% in known IBD. overall 3 of 207 studies (1.4%) To date, >170,000 capsule studies worldwide.
  • -Gastrointest Endosc 2008; 68: 255-66. Authors recommend using CT/colonoscopy as primary investigations & reserving capsule only if negative initial evaluation. 17% of pts had asymptomatic partial small bowel obstruction -contraindicating use of capsule.
  • -Endoscopy 2008; 40: 30-35 & -IBD 2008; 14: 1287. Consider wireless capsule before IPAA in UC.
  • -IBD 2008; 14: 1219. Correlation of capsule & MRI enterolysis. Capsule detected more mucosal lesions.
  • -JPGN 2008; 47: 31. Capsule endoscopy may reclassify pediatric IBD
  • –Speed matters.  Additional references listed on this previous blog entry.