TB or CD?

1
TB or CD?

• A Aljebreen, MD, Assistant Professor, department
  of Medicine, KKUH

Colrectum Forum 2007
2
Overview

• TB and CD epidemiology
• How to diagnose?

3
Introduction

• In geographical regions where both intestinal
  tuberculosis (TB) and Crohns disease (CD)
  coexist, the differential diagnosis of these two
  conditions poses a challenge to clinicians.
• The ultimate course of these two disorders is
  different.
• Intestinal TB is entirely curable, provided that
  the diagnosis is made early enough and
  appropriate treatment is instituted.
• In contrast, CD is a progressive relapsing
  illness.
• Unfortunately, it is difficult to differentiate
  intestinal TB from CD because of similar
  clinical, pathological, radiological, and
  endoscopic findings.

4
(No Transcript)
5
(No Transcript)
6
Epidemiology of TB

• Annual incidence rates of extrapulmonary
  tuberculosis have been increasing to 4.7 cases
  per 100,000 population in 1997 in Saudi Arabia.
• Extrapulmonary TB represented 28.2 of all
  reported TB cases.
• Abdominal TB accounted for 16 of all
  extrapulmonary TB in 2 large series from Riyadh
  and Jeddah.

Ministry of Health. Tuberculosis. Annual Health
Report, 1997. p. 46-49.
7
Epidemiology of TB

• Gastrointestinal TB was the 2nd most common type
  of TB after pulmonary disease among 820 patients
  with TB between 1982 and 1990 (small bowel
  involvement in 34 of them)

Al-Karawi. J Clin Gastroenterol 1995 20
225-232.
8
CD in Saudi Arabia

• Very scarce data
• It was considered an area without IBD
• 1982, the first 2 cases reported.
• In 2003, Al-Ghamdi reported the first study about
  CD where they collected 77 cases from 1983-2002.
• Concluded there was a definite increase in the
  incidence of CD
• At KKUH we have collected 79 new IBD cases within
  the last 2 years
• So, there is a definite surge of IBD

Al-Ghamdi et al, WJG 2003
9
Extrapulmonary TB difficult to diagnose??

• Several forms of extrapulmonary TB lack any of
  the localizing symptoms or signs.
• Cutaneous anergy to PPD was noted in 35-50 of
  patients.
• No clinical or radiological evidence of pulmonary
  TB could be found in up to one 3rd of these
  patients.

10
Diagnosis intestinal TB or CD

• They can present exactly with same clinical
  pictures (same age group, symptoms and signs)
• Same radiological findings and same endoscopic
  findings
• Mostly with same pathological findings
• So how can we make the diagnosis?

11
? Other features

• History of previous TB
• CXR findings of TB
• The tuberculin skin test is less helpful, because
  a positive test does not necessarily mean active
  disease.
• Perianal fistulae and extraintesitnal
  manifestations of CD
• If all negative any other clues??

12
Multiple attempts!!

• Endoscopic findings?
• Laproscopic findings?
• Histological findings?
• PCR?
• Empirical TB?

13
Endoscopic diagnosis?

• CD (4 parameters)
• Anorectal lesions,
• longitudinal ulcers,
• aphthous ulcers, and
• cobblestone appearance
• Intestinal TB (4 parameters)
• involvement of fewer than four segments,
• a patulous ileocecal valve,
• transverse ulcers, and
• scars or pseudopolyps

Endoscopy. 2006 Jun38(6)592-7.
14
Endoscopic diagnosis?

• Lee et al hypothesized that a diagnosis of
  Crohn's disease could be made when the number of
  parameters characteristic of Crohn's disease was
  higher than the number of parameters
  characteristic of intestinal tuberculosis, and
  vice versa.
• Making these assumptions, the diagnosis of either
  intestinal tuberculosis or Crohn's disease would
  have been made made correctly in 77 of our 88
  patients (87.5 ), incorrectly in seven patients
  (8.0 ), and would not have been made in four
  patients (4.5 ).

Endoscopy. 2006 Jun38(6)592-7.
15
Endoscopic findings TB

• In tuberculosis patients, transverse ulcers with
  surrounding hypertrophic mucosa and multiple
  erosions were usual colonoscopic findings.

Am J Gastroenterol 199893 606609. Gastrointest
Endosc 200459362-8.
16
Typical transverse ulcer
17
Gastrointest Endosc 200459362-8.
18
Radiology

• SBFT reveals a thickened bowel wall with
  distortion of the mucosal folds and ulcerations.
• CT may show preferential thickening of the
  ileocecal valve and medial wall of the cecum and
  massive lymphadenopathy with central necrosis.
• Calcified mesenteric lymph nodes and an abnormal
  chest film are other findings that aid in the
  diagnosis of intestinal tuberculosis.

19
(No Transcript)
20
At surgery TB

• Reduced largely since introduction of colonoscopy
• Indications
• Mass lesions associated with the hypertrophic
  form, because they can lead to luminal compromise
  with complete obstruction.
• Surgery also may be necessary when free
  perforation, confined perforation with abscess
  formation, or massive hemorrhage occur.
• Findings
• The bowel wall appears thickened with an
  inflammatory mass surrounding the ileocecal
  region.
• The serosal surface is covered with multiple
  tubercles.
• The mesenteric lymph nodes frequently are
  enlarged and thickened.

21
Histologically

• Intestinal TB granulomas are
• Large,
• multiple,
• confluent with
• caseation
• Ulcers lined by epitheliod histiocytes
• CD
• Fissuring ulcer,
• lymphoid aggregates,
• transmural inflammation, and
• Infrequent, small, noncaseating granulomas.

Am J Gastroenterol 2002971446 1451. Pulimood
et al. Gut 1999
22

• Multiple confluent granulomas, one of which
  exhibits necrosis.
• There is almost no infiltration of neutrophils.

23
PCR rapid and accurate?

• The positivity rate by PCR in 39 intestinal
  tuberculosis specimens was 64.1 (25/39), but was
  zero by PCR in 30 Crohns disease specimens.
• Moreover, in the tissues of intestinal
  tuberculosis with granulomas similar to those of
  Crohns disease, there were 71.4 (10/14)
  positive by PCR, and there were 61.1 (11/18)
  positive in intestinal tuberculosis tissues
  without granulomas.

Am J Gastroenterol 2002971446 1451.
24
Empirical anti-TB

• If intestinal TB still possibility, give 4-6
  weeks of anti-TB
• 30 of CD patietns at China receives anti-TB
  before final diagnosis
• ? Saudi

25
ASCA?

• ASCA (IgG and IgA) does not differentiate between
  CD and intestinal TB
• No correlation between ASCA and duration,
  location and behaviour of CD and intestinal TB

Makhania et al. Digestive disease Science. Jan
2007
26
Microbiology

• Finding Acid-fast bacilli in one third of
  patients.
• The organism also can be recovered in a culture
  of the involved tissues (up to 50 of pts but
  need 8 weeks)

27
Horvath et al, AJG 1998
28
Intestinal TB when to call?

• The definitive diagnosis of intestinal
  tuberculosis is made by
• identification of the organism in tissue, either
  by direct visualization with an acid-fast stain,
• by culture of the excised tissue, or
• by a PCR assay.

29
Presumptive diagnosis

• can be established in
• A patient with active pulmonary tuberculosis and
  radiologic and clinical findings that suggest
  intestinal involvement.
• Response to anti-TB

30
Summary

• In geographical regions where both intestinal
  tuberculosis (TB) and Crohns disease (CD)
  coexist, the differential diagnosis of these two
  conditions poses a challenge to clinicians.
• Unfortunately, it is difficult to differentiate
  intestinal TB from CD because of similar
  clinical, pathological, radiological, and
  endoscopic findings.
• Although attempts have been made to distinguish
  them, there are still no specific differential
  diagnostic methods up to now.
• Polymerase chain reaction (PCR) assay, which
  allows highly specific and sensitive detection of
  Mycobacterium tuberculosis has been developed (9
  11), and may provide a novel means for
  differentiating between these two conditions.