Several features distinguish Crohn’s from intestinal tuberculosis
MedWire News: Indian researchers have identified several features that distinguish Crohn’s disease (CD) from intestinal tuberculosis and developed a scoring system to aid with this.
Blood in stools, focally enhanced colitis, and involvement of the sigmoid colon all suggested the presence of CD, they report in the American Journal of Gastroenterology.
In countries such as India that are endemic for tuberculosis, distinguishing this disease from CD can be difficult and is of prime concern as treatment differs significantly, explains the team from the All India Institute of Medical Sciences in New Delhi.
To investigate further, they studied 53 patients with intestinal tuberculosis and 53 with CD who attended their gastroenterology clinic.
In univariate analysis, CD was more commonly associated with longer duration of disease, chronic diarrhea, blood in stool, perianal disease, extra-intestinal manifestations, involvement of left colon, skip lesions, aphthous ulcers, cobblestoning, longitudinal ulcers, focally enhanced colitis, and microgranulomas than intestinal tuberculosis.
In contrast, partial intestinal obstruction, constipation, presence of nodular lesions, and both a higher number and larger granulomas were significantly more common in intestinal tuberculosis patients than those with CD.
Independent predictors for intestinal tuberculosis were blood in stool (odds ratio [OR]=0.1, weight loss (OR=9.8), histologically focally enhanced colitis (OR=0.1) and involvement of sigmoid colon (OR=0.07).
Using this information, the team developed a scoring system that ranged from 0.3 to 9.3, with a higher score predicting a greater likelihood of intestinal tuberculosis.
A cut-off of 5.1 gave a sensitivity of 83%, a specificity of 79%, and the overall discriminatory ability of the model was 91%.
In a validation model of 40 patients, the corresponding values were 90% and 60%, and 89%.
Govind Makharia and colleagues conclude: “Although there are similarities between CD and intestinal tuberculosis, these two can be differentiated on the basis of a combination of clinical manifestations, endoscopic features, and histological features.”
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By Anita Wilkinson