Assessment of urine analysis for the diagnosis of tuberculosis

A rare presentation of disseminated tuberculosis: Prostatic abscess

Involvement of the prostate by tuberculosis (TB) occurs rarely and tuberculosis prostate abscess is an even rarer occurrence. It has been reported in immunocompromised patients, mainly human immunodeficiency virus seropositive individuals. We are reporting a case of tuberculosis prostatic abscess in an immunocompetent patient with relapse of TB.

Urogenital Tuberculosis

Urogenital tuberculosis is the second most frequent form of extrapulmonary tuberculosis. Starting with a pulmonary focus, 2 to 20% of patients develop urogenital tuberculosis through hematogenous spread to the kidneys, prostate, and epididymis; through the descending collecting system to the ureters, bladder, and urethra; and through the ejaculatory ducts to the genital organs. Urogenital tuberculosis occurs at all age ranges, but it is predominant in males in their fourth and fifth decades. It is a serious, insidious disease, generally developing symptoms only at a late stage, which leads to a diagnostic delay with consequent urogenital organ destruction; there are reports of patients with renal failure as their initial clinical presentation. Although the condition has been long recognized by nephrologists, urologists, and infectious disease specialists, urogenital tuberculosis is still largely unknown. Even when suggestive findings such as hematuria, sterile pyuria, and recurrent urinary infections are present, we rarely remember this diagnostic possibility. Greater knowledge of the features of urogenital tuberculosis then becomes relevant and should emphasize the importance of an early diagnosis.

Urine-Based Nested PCR for the Diagnosis of Mycobacterium tuberculosis: A Comparative Study Between HIV-Positive and HIV-Negative Patients

Background

While tuberculosis (TB) can be diagnosed by microscopy and culture, the sensitivity of Ziehl-Neelsen staining is variable and culture results require 4 - 8 weeks to be determined. Polymerase chain reaction (PCR) and its modifications, including nested PCR, might be promising methods for the rapid diagnosis of TB.

Objectives

This study aimed to evaluate the performance of nested PCR on urine samples of human immunodeficiency virus (HIV)-positive and -negative patients with different manifestations of clinical TB.

Methods

In a prospective study, three early-morning urine samples from 100 patients with pulmonary TB (PTB) or extrapulmonary TB (EPTB) were evaluated using a molecular target with insertion element IS6110, specific to the Mycobacterium tuberculosis genome, and nested PCR was performed. The results were analyzed with SPSS version 22.

Results

A total of 100 patients, including 74 (74%) with PTB and 26 (26%) with EPTB, were enrolled. Positive smears were seen in 38 patients (38%). Lymph nodes were the most commonly involved organ in 14 of the 26 (53.8%) EPTB patients (13.5%). Seven (23.1%) of the EPTB patients were HIV-positive. Urine PCR was positive in only 28 patients (28%). Seven HIV-positive patients with PTB showed positive urine PCR results. Moreover, PCR results were positive in only one of the seven HIV-positive subjects with EPTB. Positive PCR results were found in 20 of the 73 HIV-negative patients (27.4%) and in 8 of the 27 HIV-positive patients (29.6%). Therefore, there was no significant difference between the HIV-negative and HIV-positive patients for urine PCR (sensitivity 29.6%, specificity 72.6%; positive and negative predictive values 28% and 72%, respectively; P = 0.138).

Conclusions

Nested PCR showed the same sensitivity in HIV-positive and HIV-negative patients. It can be applied as a rapid technique for the diagnosis of TB.

Urinary tuberculosis: a cohort of 79 adult cases

We aimed to investigate the demographic, clinical, diagnostic, treatment and outcome features of patients with urinary tuberculosis (UTB). Patients with UTB admitted to seven separate centers across Turkey between 1995 and 2013 were retrospectively evaluated. The diagnosis of UTB was made by the presence of any clinical finding plus positivity of one of the following: (1) acid-fast bacilli (AFB) in urine, (2) isolation of Mycobacterium tuberculosis, (3) polymerase chain reaction (PCR) for M. tuberculosis, (4) histopathological evidence for TB. Seventy-nine patients (49.36% male, mean age 50.1 ± 17.4 years) were included. Mean time between onset of symptoms and clinical diagnosis was 9.7 ± 8.9 months. The most common signs and symptoms were hematuria (79.7%), sterile pyuria (67.1%), dysuria (51.9%), weakness (51.9%), fever (43%) and costovertebral tenderness (38%). Cystoscopy was performed in 59 (74.6%), bladder biopsy in 18 (22.8%), kidney biopsy in 1 (1.26%) and nephrectomy in 12 (15.2%) patients. Histopathological verification of UTB was achieved in 12 (63.1%) patients who undergone biopsy and in 100% of those undergone nephrectomy. Mycobacterium tuberculosis was isolated in the urine of 50 (63.3%) cases. Four-drug standard anti-TB treatment was the preferred regimen for 87.3% of the patients. Mean treatment duration was 10.5 ± 2.7 months. Deterioration of renal function occurred in 15 (18.9%) patients two of whom progressed to end-stage renal disease and received hemodialysis. Only one patient died after 74-day medical treatment period. Cases with UTB may present with non-specific clinical features. All diagnostic studies including radiology, cyctoscopy and histopathology are of great importance to exclude UTB and prevent renal failure.

[Investigation and management of genito-urinary tuberculosis]

Genito-urinary tuberculosis is the fourth most common manifestation of the disease, but it is often underestimated by clinicians because of few and non-specific symptoms and insidious disease course. The most common urinary findings are multiple ureteral stenosis. The most common genital involvement is an epididymal nodule for men and a chronic salpingitis for women. The definite diagnosis of genito-urinary tuberculosis is obtained on the basis of culture studies. Due to the paucibacillary nature of the disease, especially of genital location in woman, a probable or presumptive diagnosis is frequently considered with several parameters including radiological imaging (abdominal CT-scan, pelvic ultrasound, pelvic MRI). Endoscopic and surgical procedures are frequently required to obtain specimens for histopathologic and bacteriological studies. Medical treatment is the method of choice, with a combination of four drugs, namely isoniazid, rifampicin, ethambutol and pyrazinamide, followed by a two-drug regimen, for a total of six month duration. Surgery might be indicated in complicated genito-urinary tuberculosis (decreased renal function, infertility, urologic complaints).

An IMS/ATP Assay for the Detection of Mycobacterium tuberculosis in Urine

Background. Although sputum smears are the gold standard for diagnosis of tuberculosis, sensitivity in HIV/TB coinfection cases is low, indicating a need for alternative methods. Urine is being increasingly evaluated. Materials and Methods. A novel method for detecting Mycobacterium tuberculosis (MTB) in synthetic urine using a combined IMS/ATP assay was evaluated. Preliminary work established standard ATP conditions and the sensitivity and specificity of the MTB antibody. Eighty-four blinded samples in four replicate assays were evaluated for the presence of MTB using labeled immunomagnetic beads for capture. Beads were separated, washed, and resuspended in broth and added to a microtiter plate. Bioluminescent output was measured and signal-to-noise ratios were calculated. All samples were plated on Middlebrook 7H10 agar or trypticase soy agar to determine limit of detection and recoveries. Results and Conclusions. MTB was distinguished from common bacteriuria isolates and other nontarget bacteria by its ATP results. IMS/ATP successfully detected 19 of 28 samples of MTB in synthetic urine with a limit of detection of 10⁴ CFU/ml. Sensitivity and specificity were 67.9% and 82.1%, respectively. This assay offers a possible rapid screening method for HIV-positive patients with suspected coinfection to improve MTB diagnosis.

Can tissue PCR augment the diagnostic accuracy in genitourinary tract tuberculosis?

PURPOSE

Conventional methods like smear and culture for Mycobacterium tuberculosis are of limited sensitivity and specificity. Histopathological examination (HPE) for the tissues obtained gives inconclusive diagnosis in the absence of caseous necrosis or stained acid-fast bacilli. This study was conducted to determine the utility of tissue PCR for diagnosing tuberculosis of the genitourinary tract (GUTB) and its comparative evaluation with HPE.

PATIENTS AND METHODS

A prospective study was conducted from January 2006 to August 2009 with 78 tissue specimens (renal, prostate, epididymis, penile and soft tissue) from patients with clinically suspected GUTB. All the samples were processed for both PCR and histopathology.

RESULTS

In 68 (87.1%) samples, results for both PCR and HPE were coinciding. False positivity and false negativity was observed in 5.1% (4/78) and 7.6% (6/78) samples, respectively. With HPE as the gold standard, PCR has shown sensitivity of 87.5% (95% CI 80.1; 91.9) and specificity of 86.7% (95% CI 74.9; 93.8) and positive agreement between two tests was observed as significant (0.7). PCR results were obtained within a mean period of 3.4 days while those of HPE were obtained in 7.2 days.

CONCLUSIONS

Tissue PCR is a sensitive and specific method for obtaining early and timely diagnosis of GUTB. Application of tissue PCR results can augment the diagnostic accuracy in histopathologically labelled granulomatous inflammations.

Tuberculous pericarditis: a diagnostic quandary

Tuberculous pericarditis is uncommon in the Western world, and can prove a diagnostic quandary in that confirmation of the diagnosis and culture of mycobacteria can be difficult. We present a case of tuberculous pericarditis where endobronchial ultrasound-guided transbronchial needle biopsy of a pathological lymph node provided the diagnosis after other methods of investigation had proved futile.

Urine for the diagnosis of tuberculosis: current approaches, clinical applicability, and new developments

PURPOSE OF REVIEW

Urine is increasingly being investigated as a convenient clinical sample for the identification of mycobacterial products for the diagnosis of tuberculosis. The available literature on mycobacterial lipoarabinomannan (LAM) and urine mycobacterial DNA is reviewed.

RECENT FINDINGS

The available data, despite being extracted from heterogeneous clinical populations and different clinical subgroups, indicate that urine LAM has little diagnostic utility in unselected tuberculosis suspects; however, test characteristics improve in HIV-infected patients, particularly those with advanced immunosuppression (CD4 cell count <200 cells/microl). Methodologies for urine PCR for detection of mycobacterial DNA vary across studies and focus is on standardizing assays with respect to specimen collection, assay design, and processing methodology.

SUMMARY

Both the urine LAM and PCR for mycobacterial DNA are being evaluated in different geographical settings. Urine LAM currently offers little utility for the diagnosis of tuberculosis in unselected populations. However, urine LAM appears promising as a diagnostic tool in HIV-infected patients with CD4 cell counts less than 200 cells/microl in different clinical settings. Further developmental studies are required to enhance the performance of the assays, and their usefulness over sputum microscopy in HIV-infected patients with advanced immunosuppression requires definition in large cohort studies.

Urine as an adjunct specimen for the diagnosis of active pulmonary tuberculosis

BACKGROUND

The diagnosis of pulmonary tuberculosis (PTB) is conventionally established by examination of three Ziehl-Neelsen stained smears; however, negative results do not preclude active TB. Since tubercle bacilli or their nucleic acids are also expected to be excreted through the kidneys, we assessed spot urine as a supplementary specimen for diagnosing PTB.

METHODS

A total of 164 respiratory specimens (147 sputum, 15 bronchoalveolar lavage, and two gastric lavage) from 81 suspected PTB cases were prospectively collected and processed. A total of 112 non-TB controls were also included in the study. For three consecutive days, morning urine specimens were collected from all patients and controls, and were processed for culture by BACTEC MGIT 960 (mycobacteria growth indicator tube) and Lowenstein-Jensen methods and for PCR by amplifying a 441-bp fragment of the hsp65 gene (Mycobacterium genus-specific) and a 786-bp fragment of the cfp32 gene (TB complex-specific).

RESULTS

Of the 81 patients suspected of having PTB, 46 (56.8%) were sputum culture-positive. Of these, 12 (26.1%) were also urine culture-positive for Mycobacterium tuberculosis. Of the 35 sputum culture-negative cases, three (8.6%) were urine culture-positive. The TB complex specific PCR (cfp32) was positive in 52.2% (24/46) of the bacteriologically-confirmed and 28.6% (10/35) of the bacteriologically-negative PTB patients. In none of the control subjects were urine culture or PCR found to be positive for M. tuberculosis.

CONCLUSIONS

Specific PCR and culture examination of spot urine samples from suspected PTB patients significantly improved the detection rate of PTB and should be encouraged in resource-limited settings and where multiple pulmonary specimens are not feasible.

Urogenital tuberculosis: update and review of 8961 cases from the world literature

The AIDS epidemic caused unexpected worldwide levels of tuberculosis, even in developed countries where the incidence used to be low. Patients with urogenital tuberculosis in developed countries have fewer specific symptoms and lower rates of delayed diagnoses compared with patients from other countries. As a result, the disease tends to be less serious, with more patients presenting without significant lesions of the upper urinary tract on diagnosis. These data point to a correlation of the timing of diagnosis with the severity of urogenital tuberculosis. A systematic search for urogenital tuberculosis, regardless of symptoms, is warranted for early detection.

Identification of HIV patients with active pulmonary tuberculosis using urine based polymerase chain reaction assay

BACKGROUND

Despite the increased dissemination of tuberculosis among HIV infected patients, the diagnosis is difficult to establish. Traditional microbiological methods lack satisfactory sensitivity. We have developed a highly sensitive and specific nested polymerase chain reaction (PCR) capable of detecting Mycobacterium tuberculosis DNA in urine specimens and have used this test to examine urine specimens from HIV patients with active pulmonary tuberculosis.

METHODS

Urine specimens from 13 HIV infected patients with microbiologically proven active pulmonary tuberculosis, 10 AIDS patients with non-tuberculous mycobacterial infection (documented by blood culture), 53 AIDS patients with no evidence of mycobacterial disease, and 80 healthy subjects (25 with positive skin test to purified protein derivative) were tested for M tuberculosis using PCR, acid fast staining (AFS), and culture.

RESULTS

Of the urine specimens from patients with active tuberculosis, all tested positive by PCR, two by culture, and none by AFS. No reactivity was observed in urine specimens from patients with non-tuberculous mycobacterial infection. Of the 53 AIDS patients without mycobacterial infection, one had a positive urine PCR. Normal subjects were all negative.

CONCLUSIONS

Urine based nested PCR for M tuberculosis may be a useful test for identifying HIV patients with pulmonary tuberculosis.