New Tests in New Tests in GastroenterologyGastroenterology

Stephen Bridger

ACB Meeting 10/11/2005

GastroenterologyGastroenterology

Too Busy– Too Many patients

IBS 14 - 24% of adult population, + 28% of referrals to GI clinics

– Too Many Investigations Doubling of endoscopy workload in last 10 yrs

Non Specific nature of GI symptoms Even alarm symptoms such as rectal bleeding common (1 in 7

adults/week) + poorly predictive of significant GI pathology

Unable to predict which of our chronic patients will relapse and when.

“Would you mind very much if I went in before you? You’ve only a sore throat and I’ve diarrhoea”

Lundberg JO et al. (2005) Technology Insight: calprotectin, lactoferrin and nitric oxide as novel markers of inflammatory bowel disease

Nat Clin Pract Gastroenterol Hepatol 2: 96–102 doi:10.1038/ncpgasthep0094

CalprotectinCalprotectin

35 KDa Calcium and Zinc binding protein found in neutrophils, monocytes, and macrophages

Up to 60% of the total cytosolic protein content of neutrophils

First Described in 1980 Initially called L1 protein Antimicrobial and Anti-tumour activity reduces local zinc concentrations, and inhibits zinc

dependent metalloproteinases

Clinical UseClinical Use

Resists metabolic degradation measured in stool, plasma, CSF, sputum, amniotic

fluid Stool samples can be sent by post, then frozen and

batch analysed Approx £10 per test Upper limit of normal in stool is 10mg/l As little as 5gm stool sample required

Clinical UsesClinical Uses

extensively validated, showing consistent abnormalities in patients with IBD, colorectal carcinoma, and nonsteroidal enteropathy

Proposed as a useful outpatient screening test for organic small bowel or colorectal pathology. May be particularly useful in children.

Proposed as an IBD monitoring test, can predict steroid refractory disease, or which “well patients” are likely to relapse. Potential for monitoring the efficacy of new therapeutic regimes.

General BackgroundGeneral Background

Levels relatively unaffected by GI bleeding need > 100mls of blood per day to increase

calprotectin level by 6mg/l In active Crohn’s disease, levels of calprotectin up

to 40,000 mg/l reported

Guidelines for the investigation of

chronic diarrhoea, Gut 2003 “Stool markers of gastrointestinal

inflammation such as lactoferrin and, more recently, calprotectin, are of considerable research interest but, as yet, these have not

been introduced into clinical practice.”

A simple method for assessing intestinal inflammation in Crohn's disease

Tibble et al Gut 2000

22 patients: fecal calprotectin compared with 4 day 111Indium White Cells– Good correlation (r = 0.8 , P<0.0001)

116 patients with known Crohn’s disease, calprotectin was compared with healthy controls

220 consecutive patients attending a GI clinic, 31 newly diagnosed Crohn’s disease, 159 patients with IBS...

Calprotectin: Crohn’s versus Controls

Calprotectin compared with CRP

Use of surrogate markers of inflammation and Use of surrogate markers of inflammation and Rome criteria to distinguish organic from Rome criteria to distinguish organic from

nonorganic intestinal diseasenonorganic intestinal diseaseTibble et al Gastroenterology 2002Tibble et al Gastroenterology 2002

Prospective study: 602 new GI referrals 4 Gastroenterologists blinded to the results

of calprotectin and permeability, other investigations determined by Physicians

263 patients diagnosed with organic disease

Referral SymptomsReferral Symptoms

Calprotectin Levels in the Calprotectin Levels in the Different Diagnostic GroupsDifferent Diagnostic Groups

Sensitivity/Specificity for Organic Sensitivity/Specificity for Organic and Non-Organic Diseaseand Non-Organic Disease

Sensitivity Specificity

Calprotecin >10mg/L

89 79

Positive RomeCriteria

85 71

CRP > 5.0 mg/L 50 81

ESR > 10mm/Hr

58 72

Odds Ratios for Organic and Odds Ratios for Organic and Non-organic DiseaseNon-organic Disease

OR PPV NPV

Calprotecin >10mg/L

27.8(17.6 – 43.7)

0.76 0.89

CRP > 5mg/L 4.2(2.9 – 6.1)

.67 0.68

ESR >10mm/Hr

3.2(2.2 – 4.6)

0.62 0.69

L/R > 0.05 8.9(5.8 – 14)

0.56 0.89

+’ve RomeCriteria

13.3(8.9 – 20)

0.86 0.69

Diagnostic accuracy of fecal calprotectin in Diagnostic accuracy of fecal calprotectin in distinguishing organic causes of chronic distinguishing organic causes of chronic

diarrhoea from IBS: A prospective study in diarrhoea from IBS: A prospective study in adults and children. adults and children.

Carroccio et al Clin Chem Jun 2003Carroccio et al Clin Chem Jun 2003

Prospective study 120 patients Raised Calprotecin levels predicted pts with

IBD with 100% sensitivity and 95% specificity Diagnostic accuracy higher in children Coeliac disease was the commonest cause of

false negatives

Fecal calprotectin - a useful screening test for Fecal calprotectin - a useful screening test for inflammation of the colon in children.inflammation of the colon in children.

Fagerberg et al DDW 2003Fagerberg et al DDW 2003

36 children : calprotectin prior to colonoscopy

22 of the children had colitis on Hxpath + endoscopic criteria: – Mean calprotectin 349 (15.4 - 1860 mg/L)

Sensitivity & Positive predictive value 95% Specificity of 93%

Fecal Calprotectin as an aid to Diagnosis in Fecal Calprotectin as an aid to Diagnosis in intestinal inflammationintestinal inflammation

Dolwani et al DDW 2003Dolwani et al DDW 2003

65 patients with abdo pain + diarrhoea All referred for Barium follow through 15 false negatives: 6 IBD, 4 IBS, 5

uncertain

Ba FT Normal Ba FT abnormal

Calprotectin < 60 33 1

Calprotectin > 60 15 16

Fecal Calprotectin in steroid dependent Colitis. Fecal Calprotectin in steroid dependent Colitis. An indicator of clinical responseAn indicator of clinical response

Atkinson DDW 2003Atkinson DDW 2003 27 patients with steroid dependent colitis in remission Calprotectin checked at 0, 8 and 16 weeks steroids reduced at 2 weekly intervals until relapse or

cessation Mean Calprotectin at Time Zero was 6 x higher in

those patients who Relapsed (P = 0.0009) “CPT may differentiate between pts with merely symptomatic

response and those with genuine mucosal healing- failure to lower CPT sufficiently may indicate the need for a trial of a different therapy”

Surrogate markers of intestinal inflammation are predictive of relapse in patients with

inflammatory bowel disease Gastroenterology 2000;119:15-22

Subclinical intestinal inflammation: An inherited abnormality in Crohn’s

disease relatives?Gastroenterology June 2003

Effect of Pentavac and MMR Effect of Pentavac and MMR vaccination on the intestinevaccination on the intestine

Gut 2002 816-17Gut 2002 816-17

109 consecutive infants attending an Iceland Vaccination clinic had fecal calpro taken 1 week prior and 2 and 4 weeks after Pentavac (12 months) and MMR (18 months)

No differences at any time of study “MMR very unlikely to cause ‘autistic

enterocolitis’”

Calprotectin versus FOB in Bowel Calprotectin versus FOB in Bowel CancerCancer

FOB screening in asymptomatic patients has reduced bowel ca mortality by 15-33%

Detection threshold about 2-4 mls of blood/100g stool but tumours bleed intermittently and polyps may not bleed at all

Sensitivity of FOB may be as low as 26%

Faecal Calprotectin and FOB tests in the Faecal Calprotectin and FOB tests in the diagnosis of colorectal carcinoma and diagnosis of colorectal carcinoma and

adenoma. Gut 2001 49(3):402-8adenoma. Gut 2001 49(3):402-8 3 FOBs and 1 stool calprotectin sample Three groups

– 96 Controls (healthy volunteers)– 62 consecutive patients with newly diagnosed

bowel cancer– 233 consecutive patients referred for

colonoscopy for polyp follow up, cancer surveillance, anaemia

Calprotectin vs FOBCalprotectin vs FOB

Dukes Stage

n median range +’ve by calprotectin

+’ve by FOB

A 10 62.5 7-933 90 20B 24 115 2-3770 88 46C 14 62 1.5-

314 86 100

D 14 132 10.5 - 3388 100 71

Faecal Calprotectin in the Different Faecal Calprotectin in the Different Diagnostic GroupsDiagnostic Groups

Fecal Calprotectin levels in a high risk Fecal Calprotectin levels in a high risk population for colorectal neoplasia population for colorectal neoplasia

Kronberg et al Gut 2000 (46) 795 -800Kronberg et al Gut 2000 (46) 795 -800

Calprotectin and CancerCalprotectin and Cancer

ConclusionsConclusions

Calprotectin has significant advantages over guaiac based FOB testing– Higher sensitivity for colorectal ca – More likely to detect patients with Dukes A + B– More likely to detect patients with rectal and

right sided tumours– Single test rather than 3 samples– No dietary restrictions

Conclusions 2Conclusions 2

Sensitivity >95% for detecting patients with IBD Failure to lower CPT predicts those patients with steroid

refractory disease (even if the patient has had a good symptomatic response to steroids)

Asymptomatic patients with IBD with CPT > 50mg/l have a 90% probability of relapse in the next 12 months

CPT reduction in IBD treated patients appears to correlate with endoscopic mucosal healing

CPT levels much more clinically useful in IBD than any of the currently used systemic immune tests (CRP, ESR, Igs, Plts)

The Future?The Future?

GI OPD screening– Organic versus non-organic– Investigate versus observe

Population based bowel cancer screening– Selected high risk groups

IBD monitoring Availability ?