Differentiation between intestinal tuberculosis and Crohn’s disease in endoscopic biopsy specimens by polymerase chain reaction

Abstract

OBJECTIVES: It is difficult to differentiate intestinal tuberculosis from Crohn’s disease because of similar clinical, pathological, radiological, and endoscopic findings. The purpose of this study was to investigate the value of polymerase chain reaction (PCR) assay in the differentiation intestinal tuberculosis from Crohn’s disease, and compare the histopathological features of endoscopic biopsy of the two disorders. METHODS: A total of 39 endoscopic biopsy specimens from patients with intestinal tuberculosis and 30 specimens from patients with Crohn’s disease were subjected to pathological analysis retrospectively, Ziehl-Neelsen stain, and PCR assay. RESULTS: Except for granuloma with caseation and confluence, which was the characteristic of intestinal tuberculosis, other pathological features of intestinal tuberculosis and Crohn’s disease were very similar or were difficult to find in endoscopic biopsy specimens. 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. CONCLUSIONS: Biopsy is of limited diagnostic value in the differentiation intestinal tuberculosis from Crohn’s disease, and PCR is valuable in the differentiation between intestinal tuberculosis and Crohn’s disease.