Menstrual Blood versus Endometrial Biopsy in Detection of Genital Tuberculosis by Using Nested Polymerase Chain Reaction in an Endemic Region

Female Genital Tuberculosis

Female genital tuberculosis (FGTB) is an important cause of morbidity and infertility worldwide. Mycobacterium tuberculosis most commonly spreads to the genital tract from a focus elsewhere in the body and affects the bilateral fallopian tubes and/or endometrium. Many patients with FGTB have indolent disease and are only diagnosed after evaluation for infertility. Women may present with menstrual irregularities, lower abdominal or pelvic pain, or abnormal vaginal discharge. Given the low sensitivity of diagnostic tests, various composite reference standards are used to diagnose FGTB, including some combination of endoscopic findings, microbiological or molecular testing, and histopathological evidence in gynecological specimens. Early treatment with a standard regimen of a 2-month intensive phase with isoniazid, rifampin, ethambutol, and pyrazinamide, followed by a 4-month continuation phase with isoniazid and rifampin, is recommended to prevent irreversible organ damage. However, even with treatment, FGTB can lead to infertility or pregnancy-related complications, and stigma is pervasive.

Diagnosis of urogenital tuberculosis by multiplex-nested PCR targeting mpt64 (Rv1980c) and IS6110: comparison with multiplex PCR and GeneXpert® MTB/RIF

A multiplex-nested PCR (M-nested PCR) targeting mpt64 (Rv1980c) + IS6110 was designed to detect Mycobacterium tuberculosis (Mtb) DNA within urine (n = 35), endometrial biopsies (n = 22) and menstrual blood (n = 3) of male/female UGTB patients, and results were compared with M-PCR using the same targets. Detection limit of the purified Mtb DNA was found to be 1 fg by M-nested PCR, which was 10⁶ -fold lower than M-PCR. Moreover, sensitivities of 100% and 81·8% were obtained in confirmed (n = 5) and clinically suspected UGTB (n = 55) cases, respectively, by M-nested PCR, with a specificity of 97·1% (n = 70). Sensitivities attained by M-nested PCR were significantly higher (p < 0·05) than M-PCR in both clinically suspected and total UGTB (n = 60) cases. To confirm the true PCR-negative results, an internal amplification control, that is, human β-globin gene (hbb) was incorporated in the M-nested PCR/M-PCR assays, wherein all the clinical specimens (positive/negative for mpt64/IS6110) were found to be positive for hbb. Some UGTB specimens (n = 35) were also subjected to GeneXpert® MTB/RIF assay that revealed a significantly lower (p < 0·001) sensitivity (17·1 vs 88·6%) than M-nested PCR, although high specificity (100%) was attained with GeneXpert. After validating the results in a higher number of UGTB specimens, our M-nested PCR may be translated into an attractive diagnostic kit.

Insight into diagnosis of female genital tuberculosis

INTRODUCTION

Female genital tuberculosis (TB) is a common manifestation of extrapulmonary TB (EPTB) with varied clinical presentations, i.e. infertility, pelvic pain and menstrual irregularities. Diagnosis of female genital TB is challenging predominantly due to paucibacillary nature of specimens and inconclusive results obtained by most of the routine laboratory tests.

AREAS COVERED

This review has briefly summarized the epidemiology, clinical features and transmission of female genital TB. Commonly used laboratory tests include bacteriological examination (smear/culture), tuberculin skin testing, interferon-γ release assays, imaging, laparoscopy/hysteroscopy and histopathological/cytological observations. Further, utility of nucleic acid amplification tests (NAATs), like loop-mediated isothermal amplification, PCR, multiplex-PCR, nested PCR, real-time PCR and GeneXpert® could significantly improve the detection of female genital TB.

EXPERT OPINION

Currently, there is no single test available for the efficient diagnosis of female genital TB, rather a combination of tests is being employed, which yields moderate diagnostic accuracy. The latest modalities developed for diagnosing pulmonary TB and other clinical EPTB forms, i.e. aptamer-linked immobilized sorbent assay, immuno-PCR (I-PCR), analysis of circulating cell-free DNA by NAATs, and identification of Mycobacterium tuberculosis biomarkers within extracellular vesicles of bodily fluids by I-PCR/nanoparticle-based I-PCR, may also be exploited to further improve the diagnosis of female genital TB.

Comparison of Polymerase Chain Reaction (PCR), Microbiological and Histopathological Observations in the Diagnosis of Endometrial Tuberculosis

BACKGROUND

Female genital tuberculosis often faces diagnostic challenges due to the asymptomatic nature of the disease. Our study aims at comparing the microbiological and histopathological results with PCR in diagnosing genital tuberculosis in endometrial curettage specimens.

METHODS

Around 139 patients with diverse gynaecological complaints were recruited for the study, and endometrial curettage specimens were collected. The specimens were subjected to microbiological culture and staining, histopathological examination and PCR to look for the presence of M. tuberculosis. Statistical analyses of the PCR results include calculating sensitivity, specificity, positive and negative prediction values and positive and negative likelihood ratios.

RESULTS

PCR yielded a detection rate of 41.7% (58/139) when compared to the microbiology (2.15%) and histopathology results (1.43%). PCR with hsp65 and cfp10, in combination, detected 20% of the cases. Statistical analyses were suggestive that PCR with hsp65 showed a higher sensitivity and specificity of 50% and 92.59% respectively.

CONCLUSION

The results obtained in this study suggest that for a definitive diagnosis, combinations of the results from various diagnostics techniques can only be considered.

Case report of pelvic tuberculosis resulting in Asherman's syndrome and infertility

Approximately one-third of the world’s population is infected with Mycobacterium tuberculosis, and it is a leading cause of infertility in endemic countries. The global incidence of tuberculosis (TB) is growing at approximately 0.4% per year, and much faster in sub-Saharan Africa. TB causing fertility is rare in developed countries. We present a case of genital tuberculosis causing Asherman’s syndrome and resultant infertility. The patient is a 34-year-old P0 who presented to care after a prolonged period of secondary amenorrhea and infertility. She underwent a hysterosalpingogram which demonstrated no free spill and a diagnostic hysteroscopy which had findings of mottled endometrium. Pathology returned positive for Mycobacterium tuberculosis. The patient was treated with 9 months of antituberculous therapy. While she has not yet succeeded in becoming pregnant, the patient has started to notice cyclic spotting, indicating possible return of menses. This case highlights the importance of TB treatment and considering TB in patients who present with unexplained infertility.