Fluorescent quantitative PCR of Mycobacterium tuberculosis for differentiating intestinal tuberculosis from Crohn's disease

Abstract

Intestinal tuberculosis (ITB) and Crohn's disease (CD) are granulomatous disorders with similar clinical manifestations and pathological features that are often difficult to differentiate. This study evaluated the value of fluorescent quantitative polymerase chain reaction (FQ-PCR) for Mycobacterium tuberculosis (MTB) in fecal samples and biopsy specimens to differentiate ITB from CD. From June 2010 to March 2013, 86 consecutive patients (38 females and 48 males, median age 31.3 years) with provisional diagnoses of ITB and CD were recruited for the study. The patients' clinical, endoscopic, and histological features were monitored until the final definite diagnoses were made. DNA was extracted from 250 mg fecal samples and biopsy tissues from each patient. The extracted DNA was amplified using FQ-PCR for the specific MTB sequence. A total of 29 ITB cases and 36 CD cases were included in the analysis. Perianal disease and longitudinal ulcers were significantly more common in the CD patients (P<0.05), whereas night sweats, ascites, and circumferential ulcers were significantly more common in the ITB patients (P<0.05). Fecal FQ-PCR for MTB was positive in 24 (82.8%) ITB patients and 3 (8.3%) CD patients. Tissue PCR was positive for MTB in 16 (55.2%) ITB patients and 2 (5.6%) CD patients. Compared with tissue FQ-PCR, fecal FQ-PCR was more sensitive (X2=5.16, P=0.02). We conclude that FQ-PCR for MTB on fecal and tissue samples is a valuable assay for differentiating ITB from CD, and fecal FQ-PCR has greater sensitivity for ITB than tissue FQ-PCR.

The diagnostic value of polymerase chain reaction for Mycobacterium tuberculosis to distinguish intestinal tuberculosis from crohn's disease: A meta-analysis

“…Therefore, a total of only nine articles were eligible for further analysis. [ 4 14 15 21 22 23 24 25 26 ] The study selection process is shown in Figure 1 , and the basic characteristics of the selected studies are presented in Table 1 .…”

“…However, in the literature, there are limited data on the use of fecal samples for detecting MTB DNA to distinguish ITB from CD. Two eligible articles using fecal samples[ 4 21 ] reported sensitivities of 0.83 and 0.79 and respective specificities of 0.92 and 0.89. In addition, Balamurugan et al .…”

“…[ 1 ] Clinical, radiological, endoscopic, and histologic findings are similar between the two disorders, and these disorders have common underlying pathologies. [ 2 3 ] The overall resurgence of TB,[ 4 ] which was probably caused by the pandemic of human immunodeficiency virus (HIV) infection and the large wave of population migration,[ 5 ] has led to an increase in ITB. As the sixth most common presentation of extrapulmonary TB, ITB is observed in 11% of extrapulmonary TB patients.…”

Endoscopic features and treatment response have better prediction rate than clinical symptoms/signs in distinguishing Crohn's disease and intestinal tuberculosis

“…A study that used fecal samples reported TB PCR results positive for IS6110 sequence in 79% of ITB patients and in 5% of CD patients, and concluded that fecal TB PCR combined with TB culture of mucosa biopsy specimen was a good test to distinguish the two diseases [26]. The fluorescent quantitative TB PCR using fecal samples had greater sensitivity than that using tissue samples [27].…”

Meta-Analytic Bayesian Model For Differentiating Intestinal Tuberculosis from Crohn's Disease

“…This differentiation is also increasingly a problem in countries where ITB is not common, but rapidly growing immigrant populations from areas of high ITB prevalence make ITB an important diagnostic possibility. A definite diagnosis of ITB depends on methods that have unsatisfactorily low sensitivities, including 5.3–37.5% for acid-fast bacilli tissue staining (1–3), 23–46% for mycobacterial culture (4,5), and 36.4–67.9% for PCR (3,4,6–8). Therefore, ITB still cannot be confidently excluded even when all the above results are negative, thus the current Asia-Pacific guidelines recommend 8–12 weeks of empirical antituberculosis treatment for patients with diagnostic uncertainty, owing to the potentially fatal complications if immunosuppressive agents are wrongly prescribed to ITB patients (9).…”