Diagnosis of Crohn’s disease in India where tuberculosis is widely prevalent

Table 1 Demographic, clinical and laboratory features

Characteristics	CD (n = 26)	GITB (n = 26)	P value
Demographic features
Age (range), yr	36.6 ± 8.6 (6-79)	37.2 ± 9.6 (18-78)	NS
Sex (male:female) ratio	16:10	15:11	NS
Clinical features
Duration of symptoms (range), mo	58.1 ± 9.8 (8-240)	7.2 ± 3.4 (2-24)	S
Chronic diarrhoea, n (%)	18 (69.2)	9 (34.6)	S
Hematochezia, n (%)	8 (30.7)	1 (3.8)	S
Fever, n (%)	6 (23.1)	18 (69.2)	S
Weight loss, n (%)	18 (69.2)	19 (73.1)	NS
Abdominal pain, n (%)	17 (65.4)	22 (84.6)	NS
Intestinal obstruction, n (%)	5 (19.2)	3 (11.5)	NS
Growth retardation, n (%)	2 (7.7)	0 (0)	NS
Ascites, n (%)	2 (7.7)	9 (34.6)	S
Abdominal lump, n (%)	2 (7.7)	4 (15.4)	NS
Extra-intestinal features, n (%)	16 (61.5)	6 (23.1)	S
Laboratory/radiological features
Anaemia, n (%)	15 (57.7)	7 (26.9)	S
Hypoproteinemia, n (%)	11 (42.3)	9 (34.6)	NS
ESR (range) mm at 1 h	54.7 ± 12.2 (10-104)	59.7 ± 13.6 (19-110)	NS
Pulmonary infiltration/fibrosis, n (%)	1 (3.8)	10 (38.4)	S
Abdominal lymphadenopathy, n (%)	3 (11.5)	11 (42.3)	S
Generalized lymphadenopathy, n (%)	0 (0)	2 (7.7)	NS

Table 2 Morphological, histological, microbiological, serological and treatment-related features n (%)

Characteristics	CD	GITB	P value
	(n = 26)	(n = 26)
Sites of involvement
Oesophagus	0 (0)	1 (3.8)	NS
Stomach	0 (0)	2 (7.7)	NS
Duodenum	1 (3.8)	2 (7.7)	NS
Jejunum	2 (7.7)	1 (3.8)	NS
Ileum	16 (61.5)	20 (76.9)	NS
Ileo-cecal valve	20 (76.9)	21 (80.7)	NS
Right colon	18 (69.2)	21 (80.7)	NS
Left colon	10 (38.4)	5 (19.2)	NS
Rectum	8 (30.7)	5 (19.2)	NS
Anal and perianal region	2 (7.7)	1 (3.8)	NS
Endoscopic and/or surgical findings
Skip lesions	6 (23.1)	2 (7.7)	NS
Deep linear/serpiginous ulcers	15 (57.7)	6 (23.1)	S
Aphthous ulcers	9 (34.6)	5 (19.2)	NS
Stricture	8 (30.7)	5 (19.2)	NS
Cobble-stone appearance	15 (57.7)	6 (23.1)	S
Pseudo polyps	9 (34.6)	5 (19.2)	NS
Neoplasm-like appearance	0 (0)	2 (7.7)	NS
Fistula	3 (11.5)	0 (0)	NS
Histological features
Granuloma	8 (30.7)	15 (57.7)	NS
Caseation	0 (0)	9 (34.6)	S
Confluence	0 (0)	6 (23.1)	S
Interpreted as IBD by pathologist	10 (38.4)	3 (11.5)	S
Interpreted as TB by pathologist	0 (0)	13 (50)	S
Interpreted as non-specific chronic inflammation by pathologist	16 (61.6)	10 (38.4)	NS
AFB smear/culture positivity	0 (0)	6 (23.1)	S
TB PCR positivity	0 (0)	17 (65.4)	S
Serological features
p-ANCA	1 (3.8)	1 (3.8)	NS
c-ANCA	1 (3.8)	0 (0)	NS
IgA ASCA	10 (38.4)	6 (23.1)	NS
IgG ASCA	10 (38.4)	11 (42.3)	NS
Treatment-related factors
Recurrence after surgery, n/total patients underwent surgery (%)	7/9 (77.7)	0/4 (0)	S
Number of patients previously treated with ATT (without any response)	9 (34.6)	-	-
Complete response to ATT	-	26 (100)	-

Table 3 Sensitivity, specificity and accuracy in diagnosis of CD or GITB

Parameters	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Accuracy (%)
Factors predicting CD
Clinical score (fever, hematochezia, diarrhoea and duration of symptoms)	80.7	88.4	87.5	82.1	84.62
Co-existing deep linear/ serpiginous ulcers and/or Cobble-stone appearance	69.2	65.3	66.6	72	67.3
Pathologist reporting as IBD	38.4	88.4	76.9	58.9	63.4
Recurrence of disease after surgery	77.7	100	100	66.6	42.3
Factors predicting GITB
Co-existing pulmonary lesions and/or abdominal lymphadenopathy	57.6	88.4	83.3	67.6	73.1
Pathologist reporting as TB	50	100	100	66.6	75
Granuloma on histology	57.6	69.2	65.2	62	63.4
TB PCR positive	65.3	100	100	74.2	82.6
Smear and/or culture positive for AFB	23	100	100	56.5	61.5
Complete response to ATT	100	100	100	100	100