Distinguishing intestinal tuberculosis from Crohn's disease (CD) is difficult, although studies have reported clinical, endoscopic, imaging, and laboratory findings that help to differentiate these two diseases.
Dr Peter Higgins and colleagues from Michigan, USA produced estimates of the predictive power of these findings and construct a comprehensive model to predict the probability of intestinal tuberculosis vs. CD.
The research team conducted a systematic literature search for studies differentiating intestinal tuberculosis from CD in MEDLINE, PUBMED, and EMBASE from inception until 2015.
|The sensitivity for diagnosis of intestinal tuberculosis was 91%|
|American Journal of Gastroenterology|
The team performed 55 distinct meta-analyses to estimate the odds ratio of each predictive finding.
Estimates with a significant difference between CD and intestinal tuberculosis, and low to moderate heterogeneity were incorporated into a Bayesian prediction model incorporating the local pretest probability.
The team included 38 studies comprizing 2,117 CD, and 1,589 intestinal tuberculosis patients in the analyses.
Findings in the model that favored CD included male gender, hematochezia, perianal disease, intestinal obstruction, and extraintestinal manifestations.
The extraintestinal manifestations included endoscopic findings of longitudinal ulcers, cobblestone appearance, luminal stricture, mucosal bridge, and rectal involvement, pathological findings of focally enhanced colitis, and computed tomographic enterography findings of asymmetrical wall thickening, intestinal wall stratification, comb sign, and fibrofatty proliferation.
Findings that significantly favored intestinal tuberculosis included fever, night sweats, lung involvement, and ascites, endoscopic findings of transverse ulcers, patulous ileocecal valve, and cecal involvement.
Pathological findings of confluent or submucosal granulomas, lymphocyte cuffing, and ulcers lined by histiocytes; a computed tomographic enterography finding of short segmental involvement; and a positive interferon-γ release assay favored intestinal tuberculosis.
The team validated a model by gender, clinical manifestations, endoscopic, and pathological findings in 49 patients.
The research team found that the sensitivity, specificity, and accuracy for diagnosis of intestinal tuberculosis were 91%, 93%, and 92%, respectively.
Dr Higgins' team commented, " A Bayesian model based on the meta-analytic results is presented to estimate the probability of intestinal tuberculosis, and CD calibrated to local prevalence."
"This model can be applied to patients using a publicly available web application."