Category Archives: inflammatory bowel disease

Screening for subclinical PSC in IBD?

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In children with IBD, elevated liver enzymes raise the concern for primary sclerosing cholangitis (PSC).  PSC is thought to develop in up to 5% of patients with IBD.  To look more closely at this issue, a group of investigators examined 73 children (median age 12 years) with IBD with MRCP to look for evidence of PSC (JPGN 2012; 55: 308-13).

The majority of these patients had an MRCP at the time of an MRE; this was ordered independently from specific laboratory or clinical factors.  On average, the date for MRCP was about one year after the date of diagnosis.  In this group, 49 (67%) had Crohn’s disease (CD), 19 (26%) had indeterminate colitis (IC), and 5 (6.8%) had ulcerative colitis (UC) [In the results section, the authors state a discrepancy from previous: 47 with CD, 18 with IC, and 8 with UC.]

11 (15%) children had PSC-type lesions identified by MRCP.  6 of these patients had CD, 3 had IC, and 2 had UC.  Among the PSC group, 5 had abnormal AST & ALT, 4 had abnormal GGT, and 1 had abnormal bilirubin at time of diagnosis & similar numbers were present at the time of MRCP.  A much lower percentage of the non-PSC group (n=62), had abnormal LFTs.  Though, at time of MRCP, 9 (14.5%) had abnormal ALT.

An editorial in the same issue (page 238), concludes that “screening for PSC by MRCP in all of the newly diagnosed patients with IBD seems promising.”  Really?  Given a lack of therapeutic options, I don’t think identifying preclinical PSC makes any sense.  An exception would be in patients with persistent liver test abnormalities to avoid attributing this to medication toxicity.

Previous RELATED BLOG ENTRies

Challenges with primary sclerosing cholangitis | gutsandgrowth

Colonic disease and PSC | gutsandgrowth

Additional reference:

-Hepatology 2009; 50: 808-14.  High-dose ursodeoxycholic acid not effective for PSC (worsened outcomes noted)

According to the study which you would never qualify for…

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When I give patients advice on treatment, I rely on well-designed studies to help select the medications/treatments that are most likely to be effective.  It is interesting to ponder how applicable these studies are and how closely they reflect the patient population that I’m seeing.  A recent article indicates that in a tertiary referral center for inflammatory bowel disease, the majority of patients would be excluded from participation in these studies (Clin Gastroenterol Hepatol 2012; 10: 1002-07).

These authors performed a retrospective cohort study of patients presenting to the Mount Sinai Medical Center between January 2008 and June 2009.  For Crohn’s disease (CD) patients, the authors selected 7 published randomized control trials of biological therapy for patients with moderate-severe disease (ACCENT 1, CLASSIC 1, CHARM, PRECISE 1, ENCORE, ENACT, and SONIC).  For Ulcerative Colitis (UC), they selected ACT 1 and ACT 2 trials for moderate-severe UC.

Only 31.1% of 206 patients with IBD would have been eligible to participate in any of the selected RCTs.  The average age of their patients was about 35 and did not differ significantly among patients who would qualify compared to those who would not.

Among the CD patients, the inflammatory phenotype was most likely to qualify; 37 patients with inflammatory disease behavior would have been eligible.  While only 54% (37 of 68) of the inflammatory phenotype would have qualified, this accounted for 86% of the total population who would have qualified (only 34% of the entire CD cohort would have been eligible for study participation).

Among the UC patients, there were no disease characteristics or demographics associated with eligibility; that is, there was a similar distribution of disease extents, Mayo scores, disease duration, gender, and age among the patients who qualified and those who did not.

Reasons for exclusion: stricturing or penetrating disease, steroid dosing, comorbities, concomitant therapies, or prior exposure to biologics.

The authors note that the results from this study mirror that from similar studies with other chronic diseases including rheumatoid arthritis, chronic obstructive pulmonary diseases, and congestive heart failure.

When the authors looked at the trial-ineligible patients, 60% had a response to biological therapy. The response rates for ineligible patients (compared to eligible patients) were lower for CD patients but not for UC patients (Figure 2 in study).

While stringent criteria for eligibility limit the external validity of the study results, these criteria are in place for multiple reasons.  Less rigid selection criteria would require larger study populations, longer duration studies, and greater costs.

The issue of study applicability is even a bigger problem in pediatrics.  This is primarily due to fewer high quality studies in children. As such, many clinical judgements require extrapolation from adult studies.

Related blog post:

Interpreting industry-funded studies

What is the risk of colon cancer in IBD?

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Some recent studies have shown that colorectal cancer complicating IBD may not be as common as previously thought or may be decreasing in incidence (Gastroenterology 2012; 143: 375-81 & Gastroenterology 2012; 143: 382-89 ).

The first study used a nationwide cohort of 47,374 Danish patients with IBD over a 30-year period.  During a 178 million person-years of follow-up evaluation, 268 patients with ulcerative colitis (UC) and 70 patients with Crohn’s disease (CD) developed colorectal cancer (CRC).  The risk was comparable to the general population (RR 1.07)!  Furthermore, the relative risk for CRC decreased over sequential time periods: 1.34  (1979-88) to 0.57 (1999-2008).

Increased risk:

  • UC diagnosed in childhood or adolescence
  • longer disease duration
  • patients with primary sclerosing cholangitis

Their conclusion, ‘the overall risk of CRC in patients with UC has decreased markedly over time and no longer exceeds that of the general population, at least in the first decade after diagnosis.”  And, based on their data, patients with Crohn’s disease are not at increased risk for CRC.

The second study from California used a large Kaiser Permanente database from 1998-June 2010.  29 cancers were identified in CD (n=5603) and 53 in UC (n=10,895) patients.  The incidence per 100,000 for CRC was 75 for CD, 76 for UC, and 47 for general population.

These authors conclude that there is an increased risk of CRC in a community-based IBD population between 1998-2010 despite advances in medical treatment.

To understand the discrepancy of these reports, the same issue provides an editorial (page 288).  My take is that the current incidence of CRC is lower than in previous reports but that the risk factors identified in the Danish cohort (see above) likely remain important.

Additional references:

  • -Gastroenterol 2009; 136: 718. 22% of cancers occurred before recommended surveillance in adults (only 9% if exclusion of patients who had IBD and cancers diagnosed at same time).
  • Colon Cancer Survival Calculator http://www.mayoclinic.com/calcs-Gastro 2010; 138: 207-2177 (entire issue)
  • -JAMA 2009; 302: 649. Aspirin use likely increases survival after dx of colon cancer. Commentary-Gastro 2010;138: 2012.
  • -NEJM 2009; 361: 2449. molecular basis of colorectal cancer
  • -Gut 2008; 57: 1246. IBD and colon cancer
  • -IBD 2007; 4: 367. 5ASA Rx did not reduce rate of cancer in large study of UC/CD -review of 18,000 colorectal cancer cases. IBD increased risk of CRC 6-7-fold..
  • -Clin Gastro & Hep 2006; 4: 1346. aminosalicylates reduce CRC.
  • -Gastroenterol 2006; 130: 1030, 1039, 1350. 600 patients followed for 35 yrs: CRC by colitis duration: 2.5% @ 20yrs, 7.6% @ 30yrs, 10.8% @ 40yrs. 5 year survival was 73% among those with cancer. 2nd study showed main CRC risk in UC pts is among those with extensive colitis.
  • -Clin Gastro & Hepatol 2004; 2: 1088. Lower cancer risk in this cohort, n=1460. CRC 0.4 @10yrs, 1.1% @ 20yrs, 2.1% @ 30yrs. Lower CRC may be due to more surgery in Rx failures & use of 5-ASA.
  • -Clinical perspectives in Gastro 1999; 2: 9 & 25. (review) surveillance/ overview take 4 bx q10cm. start p 8yrs in pancolitis & 15yrs for left-sided dz. Cancer risk: ~5% at 20yrs + 1%/yr p 20yrs in pancolitis.
  • -Gastroenterol 2003; 125: 1311. Advancement of dysplasia to cancer in UC.

NSAIDs and IBD

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While data has shown that nonsteroidal antiinflammatory drugs (NSAIDs) may worsen established IBD, whether these medications may serve as a trigger for IBD is less clear. One recent study indicates that NSAIDs may raise the risk of developing IBD (Ann Intern Med 2012; 156: 350-9).

This study examined the risk by using data from the Nurses Health Study which included 76,795 women.  Aspirin and NSAID use were self-reported.

Results:

  • “123 incident cases of CD and 117 cases of UC occurred over 18 years and 1,295,317 person-years of follow-up”
  • Frequent NSAIDs users (at least 15 days per month) had “increased risk for both CD (absolute difference in age-adjusted incidence, 6 cases per 100,000 person-years [95% CI, 0 to 13]; multivariate hazard ratio, 1.59 [CI, 0.99 to 2.56])”
  • And “UC (absolute difference, 7 cases per 100,000 person-years [CI, 1 to 12]; multivariate hazard ratio, 1.87 [CI, 1.16 to 2.99])”
  • There was no association with acetaminophen or aspirin within the same cohort.  This lessens the possibility of a false association; if subjects were treating GI symptoms, it is likely that an association would have been seen with all analgesics

The authors conclude that any absolute risk is low and therefore more important in understanding mechanism rather than in altering clinical use of these medications.

Link to abstract: Aspirin, nonsteroidal anti-inflammatory drug use, and risk for Crohn …

Additional NSAID references:

  • Gastroenterol 1966; 51: 430.  Sentinel article describing NSAID GI risk.
  • Gastroenterol 2008; 134: 1224.  Use of NSAIDs and risk prevention.
  • Clin Gastro & Hep 2007; 5: 1040. Long term effects of NSAIDs similar to COX-2 selective agents on small bowel mucosal damage (62% had abnormalities vs 50% of COX-2)
  • Clin Gastro & Hep 2006; 4: 1082 & 1090. Consensus on gastroprotection with NSAIDs.
  • Clin Gastro & Hep 2006; 4: 196.  NSAIDs worsen IBD.
  • Clin Gastro & Hep 2003; 1: 160.  Ileitis due to NSAIDs.

Adding Methotrexate to anti-TNF therapy

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While new therapies are emerging for inflammatory bowel disease as noted in recent blog entries on Vedolizumab and Tofacitinib, many patients have refractory disease and require management with available treatments.  One strategy in this situation has been to add methotrexate (Inflamm Bowel Dis 2012; 18: 1488-92).

This case series from the Mayo clinic reported their experience with 14 pediatric Crohn’s patients (10 males) who had methotrexate added to anti-TNF therapy.

Clinical remission was achieved in 50% (PCDAI <15) within 6 weeks with methotrexate (dose: 15 mg/meter squared –average dose 17.5mg SC weekly).  All patients received folate supplementation (1 mg daily). In this study, the average duration of methotrexate use was only 8.2 months & average followup was only 10 months.

Discussion notes that prior to methotrexate all patients had active disease despite anti-TNF therapy & most had received thiopurines. Most patients tolerated methotrexate. Four patients had Clostridium difficile infection; two cases were de novo.  Even after treatment of the infection, patients with Clostridium difficile were refractory to methotrexate treatment.

Of the initial 14 patients, two patients had severe nausea; this resulted in medication discontinuation in one patient and dose reduction in another patient.  No liver or kidney toxicity was identified.

Patients who did not respond to methotrexate, subsequent care including the following: three had surgery, one received tacrolimus/corticosteroids, one received natalizumab, one received certolizumab, and one received adalimumab/corticosteroids (while awaiting screening for certolizumab).

A prospective study of methotrexate is needed to confirm the its effectiveness in refractory Crohn’s and to determine long-term safety and efficacy.

Patient information on methotrexate (from my office website):  Methotrexate

Related blog entries:

Drug levels for inflammatory bowel disease

Methotrexate and liver toxicity

Additional methotrexate references:

-IBD 2011; 17: 2521. Methotrexate therapy: ~25% remission at 1yr, 16% at 2yrs.. n=93.
-JPGN 2011;53: 389. n=64. Supports use of zofran for 1st few months to prevent nausea.
-JPGN 2010; 51: 714. Use of MTX after thiopurines. n=27. 48% in remission at 6 months.
-JPGN 2009; 48: 526. Use in pediatric CD, n=25. 64% response

Adalimumab for children with Crohn’s disease

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While adalimumab has been used in children with refractory Crohn’s disease, there has not been a lot of available data.  However, this situation has improved with the publication of the “IMAgINE 1” study (Hyams JS et al, Gastroenterology 2012; 143: 365-74).

This study enrolled 192 pediatric (6-17 yr-old) patients with moderate to severe Crohn’s disease; patients had PCDAI >30 and had failed conventional therapy with the exception of infliximab.  Approximately 45% in both groups had received prior treatment with infliximab.  The study started as an open-label induction followed by double-blind randomization into either a high-dose or low-dose maintenance phase.

Dosing:  For open label, patients >40 kg received 160 mg at week 0 and 80 mg at week 2.; patients <40 kg, received 80 mg at week 0 and 40 mg at week 2.

For maintenance, high dose was considered 40 mg every other week (eow) if >40 kg, and 20 mg eow if <40 kg.  Low dose was 20 mg and 10 mg respectively based on weight.

Results: 152 of 188 patients completed 26 week study period; 4 patients did not complete induction period.  At week 26, 63 patients (33.5%) were in clinical remission.  The high-dose remission response was 38.7% which was not statistically different from the 28.4% response in the low-dose group.

At week 52, there was a statistically improved response rate in the high-dose group 41.9% compared with low-dose group 28.4%; at the week 52 point, the remission rates were 33.3% compared with 23.2% respectively (p=0.1).  Among patients who were at least 13, it is noted that the overall CDAI clinical remission rate was 51% (week 26) and 36% (week 52) which are comparable to adult data from CHARM study.

Based on previous infliximab: Patients who had prior infliximab did not respond as favorably as infliximab-naive patients.  In the high dose group, the clinical remission at week 26 was 56.9% for infliximab-naive group compared to 16.7% for infliximab-experienced.  Similarly, the infliximab-naive response was higher, 68.6% compared with 47.6% for the infliximab-experienced.

Safety: “No new safety signals were detected.” Yet, 101 of 192 patients had adverse events during open label period, including 2 serious infections (which resolved & patients completed study).  Eight serious infections were noted during double-blind period.  Other safety problems included hepatic-related events in 9 of 188 patients, injection site reactions in 19 patients, hematologic adverse events in 8 patients, and 8 allergic reactions.  There were no reports of malignancy, congestive heart failure, lupus-like syndrome or demyelinating disease.

In both the high-dose and low-dose group, switching to weekly therapy instead of eow was allowed and commonly occurred: 48/95 in low-dose & 35/93 in high-dose.

Reasons for discontinuation: In both groups, drug discontinuation was frequent.  In the low-dose group, 37 patients stopped therapy.  In 18, this was due to lack of efficacy.  The other reasons included adverse effects in 10, protocol violation in 4, withdrew consent in 4, and lost to followup in 1.  In the high-dose group, 27  stopped therapy.  In 11, this was due to lack of efficacy; 12 had adverse effects, 2 withdrew consent, and 1 had protocol violation.

Another recent article (Inflamm Bowel Dis 2012; 18: 685-90) indicates that the annual risk of loss of response to adalimumab was 18% per year of followup.  This study involved 380 CD patients with an average age of 38 years.  This study also showed that there was a significant difference between patients naive to anti-TNF therapy and those who had prior anti-TNF therapy:  8% loss of response per year of followup compared with 22% respectively.

Related blog entries:

TNF-α antagonists and infections

CHOOSE TNF TRIAL

Disease modifying treatment in IBD

Only one chance to make first impression

TNF antagonists and UC

Adalimumab references:

  • -Gut 2011:  Gut doi:10.1136/gut.2010.221127. Use in induction of remission in UC. Reinisch W, et al. Adalimumab for induction of clinical remission in … – Gut – BMJ
  • -Aliment Pharmacol Ther 2010; 32: 1228-39. CHOICE trial. adalimumab effective in pts failing prior IFX.
  • -Gastroenterol 2009; 137: 1628. n=168.  71% & 67% of pts responded by weeks 4 & 12.  61% demonstrated sustained benefit. (in IFX failure pts). Of 156 pts, 65% needed to step up to 40mg weekly and 60 eventually stopped adalimumab due to loss of response.  Lower trough levels associated with loss of effectiveness & often with antibodies to adalimumab (present in 9.2% of pts).
  • -IBD 2011; 17: 2512.  n=50.  62% of pts develop skin reactions: eczema, acne-like dermatitis, psoriasis-like (6 of 50).  Adalimumab d/c’d in 22%.  Message -see dermatologist
  • -Lofberg et al. Am J Gastro 2008; 103: S418 (abstract 1069) Care study. -n=945. Humira at week 20 -remissions in 52% of pts naive to biologics, in 46% who prev responded to IFX & became intolerant, in 40% who prev responded to IFX and lost response, and 36% of pts with primary non-response to IFX.
  • -IBD 2008; 14: S1 Abrstarct 0002. Humira in TNF-naive patients with Crohn’s disease. Decreases hospitalizations. (12 month: 12.7% vs 20.3% in placebo group) Adult dosing: Induction 160mg, then 80mg in 2 weeks, then 40mg every 2 weeks.
  • -IBD 2008; 14: 1683. Response to adalimumab in 10 children.
  • -Gastro 2008; 135: 1493. n=778. mod-to severe Crohn had less hospitalizations (decreased ~60%) and surgery if Rx’d w Humira. 40mg eo week or qweek post 80/40 induction
  • -NEJM 2008; 359: 810. Use in pediatric JRA -helpful.
  • -JPGN 2008; 47: 19. n=15 pediatric patients. Complete or partial response in 64%.
  • -Gastro 2007; 132: 52. CHARM Trial. n=778. 40mg weekly c 47% response at week 26 (17% placebo) & 41% @ week 52 (12% placebo); works nearly as well in pts c prev inliximab as naive pts. Rapid onset ~c/in 2 weeks
  • -Clin Gastro & Hep 2006; 4: 1199-1213. Excellent review. Suggested dosing: 20mg every other week if 20-25kg, 25mg every other week if 25-30kg, 30mg every other week if 30-40kg, 35mg every other week if 40-55kg,  40mg every other week if >55kg, and increase to weekly dosing if needed
  • -JPGN 2008; 46: 1208, 226. pediatric case report and review of CHARM
  • -Gastro 2006; 130: 323-333. CLASSIC-I Trial, n=299. 36% 4-week response to 160mg/80mg week 0/subsequent week 2 (vs. 12% of placebo) All pts naive to anti-TNF Rx.

Adalimumab Injection Pain

  • –Suggestions from GI bulletin board. 1)you let the Humira Pen sit out for about 30 minutes prior to administering the medication, so that it appears clear and not foggy, that it greatly reduces pain at the site. 2) the pain disappeared after adding bicarbonate to the Humira. By trial and error, our nurse found that 0.15cc of bicarbonate is the minimum amount that yields a good effect.
  • -Lidocaine with adalimumab. Abstract reference: AF Ayala, Rosanne S.Groh, Brandt P.Robbins, Lisa M.Scalzi, Lizabeth Bingham, C. April TI The addition of injectable lidocaine to adalimumab results in decreased injection site pain and increased acceptance of therapy. 72nd Annual Scientific Meeting of the American-College-of-Rheumatology/43rd Annual Scientific Meeting of the Association-of-Rheumatology-Health-Professionals. CY OCT 24-29, 2008 CL San Francisco, CA. They used 0.2 ml 1% lidocaine into prefilled adalimumab syringe. We’ve tried this with a few patients and it seems to work well.
  • -Pt developed a “shot blocker” that is a bristle brush with a central hole for the syringe. The brush diffuses the pain from the Humira injection. Click the link below for a youtube video he created.
  • -http://www.youtube.com/watch?v=nfL95YRlTjY

Vedolizumab -another new IBD treatment

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Occasionally a parent will express concern that their child may run out of effective treatments for inflammatory bowel.  At this time, there are a limited number of effective therapies. If a patient develops reactions or antibodies to medications and/or does not have a clinical response, then the options become quite limited.

Against this backdrop, it is encouraging that new medical treatments are being tested, including Vedolizumab (Inflamm Bowel Dis 2012; 18: 1470-79).

The cited study reports the experience of using Vedolizumab in a randomized controlled phase 2 dose-ranging study in 46 patients (9 placebo, 37 vedolizumab).

Vedolizumab is “a gut-selective monoclonal antibody that antagonizes α4β7 integrin on select subsets of leukocytes binding to MAdCAM-1 on gut vascular endothelium.”  Many have considered vedolizumab to be similar to natalizumab, except it is considered  gut-specific and therefore should not increase the risk of progressive multifocal leukoencephalopathy (PML).  By altering the immune surveillance/lymphocyte tracking of the GI tract and not the brain, theoretically there should not be an increased risk of PML.

Another previous limitation of vedolizumab in small studies was the development of human antihuman antibodies (HAHA) –no joke!  HAHA occurred in up to 44% of patients in previous studies and were associated with reduced efficacy.  As a consequence, a new formulation of vedolizumab has been developed with presumably reduced  immunogenicity.

In the cited study, patients between 18-70 were recruited to receive one to three doses of vedolizumab (2, 6, or 10 mg/kg) or placebo.

Results:

  • Over 50% of vedolizumab-treated patients maintained a clinical response between days 29-253 whereas placebo response ranged between 22-33%.
  • This study was not powered for efficacy; however, the treated patients did have reduced fecal calprotectin.  At baseline, the calprotectin in the treatment groups averaged 405 μg/g and by day 113 had reduced to 54 μg/g.  In contrast, placebo group started with calprotectin of 310 μg/g and dropped to 192 μg/g during same time period.
  • HAHA were detected in 4 (11%)

According to a presentation at DDW (GEMINI I trial), more than 2500 patients have been treated in trials with vedolizumab.  None has developed PML. Encouraging results for efficacy (dosing 300mg IV q4weeks) were also noted; 1 year clinical remission noted in 45% of treated patients compared with 14% of placebo group. Digestive Disease Week 2012 – Vedolizumab Scores on Safety …)

Results of vedolizumab for Crohn’s disease are expected soon as well.

Related blog entries:

Quantifying Risk of PML with Natalizumab

Tofacitinib –a JAK Inhibitor for UC

CHOOSE TNF TRIAL

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While most physicians consider drug efficacy as the most important factor in choosing therapy, this is not always the determinant factor in patient choice.

The “CHOOSE TNF TRIAL” (Inflamm Bowel Dis 2012; 18: 1523-30) was a prospective survey of 100 adult patients with Crohn’s disease who were naive to anti-TNF therapy (infliximab, adalimumab, certolizumab).

Most important to patients:

  • Ease of use 69%
  • Time for therapy 34%
  • Time between applications 31%
  • Evidence for efficacy 19%
  • Fear of syringes 10%

Patient choice: Adalimumab preferred in 36%, certolizumab in 28%, and infliximab in 25%

While patient concerns need to be considered, others have shown that physician opinion is an important factor for patient decisions (J Rhemumatol 2008; 35: 618-24).  The discussion notes that “three anti-TNF drugs used in inflammatory bowel disease treatment have not been compared side-by-side in clinical trials.”  Thus far in pediatrics, infliximab is the only TNF approved for clinical use; as such, the other anti-TNF agents have been used primarily when infliximab loses effectiveness.

One drawback with injectable medications has been reduced adherence; up to 50% of patients fail to maintain regular injection interval; in addition, in patients who have had intravenous infusions (rather than patients who are naive) it is preferred over injections (Jay Popp, medical director of Janssen pharmaceuticals–personal communication).

As such, when patients receive infusions (eg. infliximab), closer followup and better adherence are more likely in comparison to injections.  This certainly improves efficacy.

Related blog entries:

TNF-α antagonists and infections

Disease modifying treatment in IBD

Only one chance to make first impression

How sensitive is Calprotectin?

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A recent article suggests that fecal calprotectin, while good, is not as good as endoscopy at detecting mucosal disease in pediatric Crohn’s disease (Inflamm Bowel Dis 2012; 18: 1493-97).

In this study, 60 consecutive children with new onset untreated Crohn’s disease (diagnosis based on Porto criteria -JPGN 2005; 41: 1-7) were enrolled in ESPGHAN growth study.  The data for this study was collected prospectively (21 investigators from multiple sites).  The calprotectin values were obtained prior to treatment.

Median fecal calprotectin values were 2198 μg/g in patients with isolated small bowel disease; this did not differ significantly from the value of 2400 μg/g in patients with colonic disease (with or without small bowel disease).

Fecal calprotectin was elevated in 95% of patients; this outperformed CRP (86%) and ESR (83%) as a marker for Crohn’s disease.  In the three children with normal calprotectin values, the serum inflammatory markers were normal in all three and two had minimal endoscopic findings.  The histology findings for these three children were not reported.

In my experience, fecal calprotectin has been very useful as a marker for Crohn’s disease and has helped identify some atypical cases by increasing my clinical suspicion.  I have had two patients with high calprotectin values who had normal-appearing mucosa with panendoscopy; they both had small bowel (jejunal) Crohn’s disease; one of these patients did have granulomas identified histologically.

While I realize that no test is perfect, I think additional studies are warranted to determine the actual sensitivity of this test for Crohn’s disease.  The sensitivity of calprotectin may yet be higher than the 95% reported in this study.

Related posts:

Biomarkers identify patients who benefit and how  Multiple additional calprotectin references with this link

Abatacept for IBD?

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Doesn’t work (Gastroenterology 2012; 143: 62-69).  While this study indicates that Abatacept was not effect for either Crohn’s disease (CD) or ulcerative colitis (UC), it was useful nevertheless.

In brief, the study examined four placebo-controlled trials of abatacept for induction and maintenance therapy in both CD and UC.  The induction studies included 451 CD patients and 490 UC patients.  The maintenance studies had 90 CD and 131 UC patients.

Results for induction:

  • CD: Clinical response: 17%, 10%, 15% for abatacept dosing of 30, 10, and 3 mg/kg.  Placebo 14%
  • UC: 21%, 19%, 20%  for abatacept dosing of 30, 10, and 3 mg/kg.  Placebo 29.5%

Results for maintenance:

  • CD: 24% abatacept vs 11% placebo
  • UC: 12.5% vs 14% placebo

The premise of this study was that T-cell activation requires co-stimulatory signaling via T cell CD28 and CD80 or CD86 on the antigen-presenting cell.  Abatacept (CTLA4-Ig) which is effective for psoriasis, rheumatoid arthritis, and juvenile idiopathic arthritis was thought to have potential; it blocks costimulation pathways involved in T-cell activation which was shown to be helpful in animal model of colitis.

So why did it not work?  The editorial in the same volume (pages 13-16) suggests the following possibilities:

  • Abatacept would be more likely to work when naive T cells are actively recruited into inflammation rather than memory T cells which are predominant in IBD
  • CD28-related pathways may not be important in IBD pathogenesis
  • Abatacept may have impeded Treg function in addition to preventing T-cell activation (explained in Fig 1D)
  • Blockade of CD28 pathways could have resulted in unfavorable changes in cytokine profiles from T-cell differentiation (Th1 vs Th2)

The implication of this study is that not all T-cell mediated inflammatory disease respond to the same treatment approaches.  The complexity of intestinal immune responses necessitates ongoing clinical studies to determine which promising therapies will be useful.