Diagnostic Utility of Target Genes 19 kDa Gene, TRC4 Element, MPB64 Gene and 32 kDa Gene in the Diagnosis of Female Genital Tuberculosis

A BSTRACT Background: The prevalence, morbidity and mortality due to tuberculosis are high worldwide, particularly in developing countries. The extra-pulmonary tuberculosis is a diagnostic challenge due to paucibacillary nature. The female genital tuberculosis, a chronic disease, presents with atypical symptoms mimicking other gynecological conditions. A combination of tests is required to diagnose extra-pulmonary tuberculosis, including female genital tuberculosis. This study was conducted to evaluate the diagnostic utility of 19 kDa gene, TRC4 element, MPB64 gene and 32 kDa gene by polymerase chain reaction in the diagnosis of female genital tuberculosis. Methods: A total of 240 genitourinary samples were collected from suspected cases of female genital tuberculosis. All the samples were subjected to microscopy for acid-fast bacilli, mycobacterial culture by BacT/ALERT 3D and real-time polymerase chain reaction targeting 19 kDa gene, TRC4 element, MPB64 gene and 32 kDa gene. Results: The majority of the patients belonged to younger age group of less than 30 years (69%). The majority of the patients were underweight, having less than 19 of body mass index (48%). On analysis of assay performance, all four genes showed 100% specificity, while sensitivity was found to be highest for 19 kDa gene, followed by 32 kDa gene, MPB64 gene and TRC4 element. Conclusion: Polymerase chain reaction targeting multiple genes can play an important role in the rapid and accurate diagnosis of female genital tuberculosis. The most effective target gene for diagnosis of female genital tuberculosis is 19 kDa gene as compared to 32 kDa gene, MPB64 gene and TRC4 element.