1. A Aljebreen, MD, Assistant Professor, department of Medicine, KKUH
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 Crohn’s 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.

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, p

7. Al-Karawi. J Clin Gastroenterol 1995; 20: 225-232.
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:

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
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) Intestinal TB (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 Jun;38(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 Jun;38(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 1998;93: 606–609.
Gastrointest Endosc 2004;59:362-8.

16. Typical transverse ulcer

17. Gastrointest Endosc 2004;59:362-8.

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.

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 CD 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 2002;97:1446 –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 Crohn’s disease specimens.
Moreover, in the tissues of intestinal tuberculosis with granulomas similar to those of Crohn’s 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 2002;97:1446 –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. Makhania et al. Digestive disease & Science. Jan 2007
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 Crohn’s 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.