Feasibility of the Interferon-γ Release Assay for the Diagnosis of Genitourinary Tuberculosis in an Endemic Area

Abstract

PurposeTo evaluate the feasibility of the interferon-gamma release assay (IGRA) as a supplementary diagnostic tool for the diagnosis of genitourinary tuberculosis (GUTB).Materials and MethodsFifty-seven patients who were tested with the IGRA to diagnose GUTB were included. All patients had clinical or radiologic features suspicious for GUTB. Signs and symptoms included chronic dysuria with long-standing sterile pyuria, renal calcification with distorted renal calyces and contracted renal pelvis, and chronic epididymitis. Patients who had a history of tuberculosis in other organs were excluded. Tests including IGRA, urine acid-fast bacilli (AFB) stain and culture, urine tuberculosis polymerase chain reaction (UT-PCR), and radiological examinations were performed to confirm GUTB. The medical records of the patients were reviewed retrospectively.ResultsThe IGRA result was positive in 30 patients (52.6%). The results of the urine AFB stain and culture were positive in 5 patients (8.8%) and 7 patients (12.2%), respectively. The results of UT-PCR were positive in 9 patients (15.8%). The 7 patients who showed positive results in the urine AFB stain and culture also had positive results on the IGRA. A UT-PCR-negative patient was diagnosed with GUTB by positive results on both the IGRA and AFB stain and culture.ConclusionsThe IGRA might feasibly be used as a supplementary or screening tool for the diagnosis of GUTB in addition to urine AFB stain and culture. Further studies for statistical evaluation of its sensitivity, specificity, and efficacy are needed.

A case of testicular tuberculosis mimicking malignancy in a healthy young man

“…The laboratory tests to be considered in the diagnosis workup include a complete blood count (CBC), ESR, serum chemistry, and PCR [Hadadi, 2012;Kim et al 2013;Lamichaney et al 2014]. Tuberculin skin test (TST) and TB blood tests such as QuantiFERON-TB Gold are also useful in the diagnosis of tuberculosis.…”

A 68‐Year‐Old Woman with Recurrent Cystitis

“…Patients with GUTB can present with symptoms similar to bacterial urinary tract infection (UTI). The most common presenting symptoms include irritative voiding symptoms, flank pain and hematuria ( 13 ). Additionally, systemic symptoms, such as fever and weight loss, may be present but are typically rare.…”

Recent Trends in Diagnosis of Urogenital Tuberculosis

“…Immunological procedures such as IGRAs are widely employed for the early detection of UGTB cases. Notably, Kim et al [8] reported a sensitivity of 52.6% by Quantiferon-TB Gold in-Tube assay with the peripheral blood of both male and female UGTB patients using ESAT-6 (Rv3875), CFP-10 (Rv3874) and TB 7.7 as eliciting agents and proposed this test to be a supplementary tool along with urine smear/culture. On the other hand, enzyme-linked immunospot assay for interferon-γ production revealed a higher sensitivity of 86.4% but a lesser Future Microbiol.…”

“…Similarly, the most frequent sites for male UGTB are the epididymis and prostate followed by seminal vesicles and testicles originating from renal foci, which also lead to infertility [6]. Owing to asymptomatic nature and varied clinical presentations (ranging from vague urinary symptoms to chronic kidney disease) that mimic several urologic and genital diseases, diagnosis of UGTB is a daunting challenge [3].Smear/culture, histopathology, interferon-γ release assays (IGRAs), intravenous pyelography, laparoscopy and nucleic acid amplification tests (NAATs) are the main modalities employed in the diagnosis of UGTB [6][7][8], which have certain limitations. Smear microscopy and culture for Mycobacterium tuberculosis identification (on Lowenstein-Jensen medium or BACTEC-460/MGIT-960) are commonly used methods but they lead to poor sensitivities due to paucibacillary nature of specimens [7].…”

“…Smear/culture, histopathology, interferon-γ release assays (IGRAs), intravenous pyelography, laparoscopy and nucleic acid amplification tests (NAATs) are the main modalities employed in the diagnosis of UGTB [6][7][8], which have certain limitations. Smear microscopy and culture for Mycobacterium tuberculosis identification (on Lowenstein-Jensen medium or BACTEC-460/MGIT-960) are commonly used methods but they lead to poor sensitivities due to paucibacillary nature of specimens [7].…”