Multiplex Polymerase Chain Reaction for diagnosis of gastrointestinal tuberculosis

Abstract

Background and Aim To evaluate the role of multiplex polymerase chain reaction (PCR) for diagnosis of gastrointestinal tuberculosis (GITB). Methods This was a prospective observational study conducted from July 2015 to November 2016 at a tertiary care teaching institution in north India. Fifty individuals with clinically suspected GITB and older than 18 years of age were recruited. Patients underwent radiological investigations, esophagogastroduodenoscopy, or colonoscopy as clinically indicated. Multiple biopsies for tissue diagnosis and PCR were taken. All specimens were subjected to Ziehl Neelsen staining, histopathology, and multiplex PCR using specific primers for genes IS6110, MPB64, and Protein b. The performance of the assay was assessed using a composite reference standard for diagnosis of tuberculosis. It comprised a combination of clinical characteristics and microbiological methods, including smear, Bactenecin (BACTEC) culture, histopathology, and response to antitubercular therapy. Results A final diagnosis of tuberculosis was made in 32 cases (Duodenal‐4, Ileo‐colonic‐28). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of histopathology for the diagnosis of tuberculosis was 28.12, 100, 100, and 43.9%, respectively. The sensitivity, specificity, PPV and NPV of BACTEC Mycobacteria Growth Indicator Tube (MGIT) culture for the diagnosis of tuberculosis was 9.3, 100, 100, and 38.29%, respectively. The sensitivity, specificity, PPV, and NPV of multiplex PCR for the diagnosis of tuberculosis was 87.5, 100, 100, and 86.2%, respectively. Conclusion Multiplex PCR using specific primers for genes IS6110, MPB64, and Protein b had a higher sensitivity compared to conventional techniques for the diagnosis of GITB.

Pathological and DNA-based Detection of Tracheobronchial Tuberculosis in China

“…MPCR was performed by using specific primers to amplify IS6110 segment and MPB64 gene, which respectively had amplicon sizes of 123 and 240 bp. 7 Statistical analyses were performed using Microsoft Excel (version 2010) software. Categorical variables were described as frequencies and percentages, while quantitative variables were expressed as the mean ± standard deviation (SD).…”

Recent advances in the diagnosis of intestinal tuberculosis

“…Using this technique, more than one target gene sequence in a clinical specimen can be amplified in a single tube. Several studies have tried to apply this examination to establish the diagnosis of intestinal tuberculosis and compare it with other conventional examinations including simple PCR examination [ 23 , 24 ].…”

Gastrointestinal tuberculosis: A systematic review of epidemiology, presentation, diagnosis and treatment

“…[ 92 ] The presence of distinctive granulomas in the intestinal biopsy can help establish the diagnosis of GITB with a sensitivity, specificity, positive predictive value and negative predictive value of 28-58%, 69-100%, 64-100% and 41-65%, respectively [ Figure 5 ]. [ 55 94 95 96 97 ]…”

“…[ 97 99 100 ] Similarly, the sensitivity, specificity, PPV and NPV of AFB culture on biopsy are 9-35%, 100%, 100% and 38-63%, respectively [ Figure 7 ]. [ 55 94 97 ] PCR on intestinal biopsy shows a high rate of positivity between 50 and 95%. [ 50 53 55 ] The sensitivity, specificity, PPV and NPV of PCR on biopsy are 50-71%, 79-100%, 86-100% and 60-68%, respectively.…”

“…[ 101 ] Nevertheless, use of multiple targets in multiple PCR tests improved the sensitivity, specificity, PPV and NPV to 78- 88%, 98-100%, 97-100% and 77-98%, respectively [ Figure 7 ]. [ 94 98 102 ] The use of other gene amplification techniques like nucleic acid amplification test called GenXpert-MTB/RIF has been used as an alternative to PCR for rapid diagnosis. The reported sensitivities and specificity ranges between 8 and 96%, and 2 and 100%, respectively [ Figure 7 ].…”