Comparison of the CapitalBio™Mycobacterium RT-PCR detection test and Xpert MTB/RIF assay for diagnosis of renal tuberculosis.

The purpose of this study is to compare the efficiency difference between CapitalBio™Mycobacterium real-time polymerase chain reaction (RT-PCR) detection test and Xpert MTB/RIF assay for the diagnosis of renal tuberculosis (TB). We analyzed 117 samples collected between July 1, 2018, and October 31, 2019, from patients with suspected renal TB to determine the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of the CapitalBio™ Mycobacterium RT-PCR detection test for renal TB and to evaluate its diagnostic accuracy compared with Xpert MTB/RIF assay. Five cases were excluded from this study because of incomplete data. Taking clinical diagnosis as the gold standard, for the Xpert MTB/RIF assay, the sensitivity was 87.95% (78.96-94.07%), specificity 96.55% (82.24-99.91%), PPV 98.65% (92.70-99.97%), NPV 73.68% (56.90-86.60%), and AUC 0.92 (0.86-0.96). For the CapitalBio™Mycobacterium RT-PCR detection test, the overall sensitivity was 84.34% (74.71-91.39%), specificity 93.10% (77.23-99.15%), PPV 97.22% (90.32-99.66%), NPV 67.50% (50.87-81.43%), and AUC 0.89(0.81-0.94). The diagnostic efficiency of the CapitalBio™Mycobacterium RT-PCR detection test was similar to that of the Xpert MTB/RIF assay in patients with renal TB. Hence, the CapitalBio™Mycobacterium RT-PCR detection test presents a valuable alternative for the diagnosis of renal TB.

Early Diagnosis of Tuberculosis-Associated IgA Nephropathy with ESAT-6.

IgA nephropathy (IgAN) is the most common cause of primary renal diseases worldwide, and the early secreted antigenic target of 6 (ESAT-6) which was secreted by Mycobacterium tuberculosis (MTB) may be involved in the development and progression of IgAN. This study aimed to investigate the role of ESAT-6 for early diagnosis of IgAN caused by MTB infection. From 2011 to 2014, 21 patients with renal tuberculosis (RTB), 25 with IgAN, and 46 with IgAN infected with MTB (IgAN/MTB) were enrolled. Serum levels of antibodies against Mycobacterium tuberculosis antigen 85A (Ag85A) were measured by ELISA. Urine culture and phage amplified biologically assay were performed to detect MTB. HE staining was used to observe the morphological changes in kidney tissues. Immunohistochemistry was applied to detect the expression of ESAT-6. Immunofluorescence staining was conducted to detect IgA1. Positive rates of serum anti-Ag85A antibody and urine culture for MTB were higher in the RTB and IgAN/MTB groups than those in the IgAN group. The positive rates of plaques were also higher in RTB and IgAN/MTB groups than the positive rate in the IgAN group. By contrast, the positive rate of ESAT-6 was lower in the IgAN group than that in the RTB group or the IgAN/MTB group, whereas the expression levels of IgA1 were higher in the IgAN and IgAN/MTB groups, compared with the RTB group. Our findings suggest that ESAT-6 and IgA1 may be helpful for early diagnosis of IgAN caused by MTB infection.

[Isolation frequency of the Mycobacterium genus in urine samples]. / Frecuencia de aislamiento del género Mycobacterium en muestras de orina.

Kidney infections caused by Mycobacterium genus are torpid and chronic evolution. In this study were analyzed 177 urine samples (included 110 from HIV patients) received between January 2006 and July 2014 in the National Reference Laboratory of Tuberculosis at Tropical Medicine Institute "Pedro Kourí" (IPK). The results were 17 isolates Mycobacterium tuberculosis, and 30 isolates of nontuberculous mycobacteria were detected. This study confirms the diagnostic importance of these infections especially in HIV/AIDS patients.

Is Urinary Lipoarabinomannan the Result of Renal Tuberculosis? Assessment of the Renal Histology in an Autopsy Cohort of Ugandan HIV-Infected Adults.

OBJECTIVE: The detection of urinary lipoarabinomannan (LAM), a mycobacterial cell wall component, is used to diagnose tuberculosis (TB). How LAM enters the urine is not known. To investigate if urinary LAM-positivity is the result of renal TB infection we correlated the outcomes of urinary LAM-antigen testing to renal histology in an autopsy cohort of hospitalized, Ugandan, HIV-infected adults. METHODS: We performed a complete autopsy, including renal sampling, in HIV-infected adults that died during hospitalization after written informed consent was obtained from the next of kin. Urine was collected postmortem through post-mortem catheterisation or by bladder puncture and tested for LAM with both a lateral flow assay (LFA) and an ELISA assay. Two pathologists assessed the kidney histology. We correlated the LAM-assay results and the histology findings. RESULTS: Of the 13/36 (36%) patients with a positive urinary LAM ELISA and/or LFA, 8/13 (62%) had renal TB. The remaining 5 LAM-positive patients had disseminated TB without renal involvement. Of the 23 LAM-negative patients, 3 had disseminated TB without renal involvement. The remaining LAM-negative patients had no TB infection and died mostly of fungal and bacterial infections. LAM LFA had a sensitivity of 81% and specificity of 100% to diagnose TB at any location, and the LAM ELISA a sensitivity of 63% and a specificity of 100%. 54% (7/13) LAM LFA-positive patients were not on anti-TB treatment at the time of death. CONCLUSION: Renal TB infection explained LAM-positivity in the majority of patients. Patients with disseminated TB without renal involvement can also be diagnosed with LAM. This suggests that other mechanisms that lead to urinary LAM-positivity exist in a minority of patients.

Diagnóstico bacteriológico de tuberculosis renal: experiencia del Laboratorio Regional de Tuberculosis de la provincia de Córdoba

Dada la considerable incidencia de tuberculosis renal entre enfermos con tuberculosis pulmonar, nos propusimos estudiar la frecuencia de esta asociación en pacientes atendidos en centros de salud públicos y privados de Córdoba a lo largo del período 1997-2009. Se tomó en consideración la incidencia según el sexo y las especies del complejo Mycobacterium tuberculosis identificadas. El análisis de 948 muestras de orina de 383 pacientes indicó tuberculosis renal en 24 casos (6,3 %), con presencia mayoritaria de Mycobacterium tuberculosis (95,8 %) y presencia de Mycobacterium bovis en 4,2 % de los casos. La asociación tuberculosis renal-tuberculosis pulmonar activa se encontró en 6 casos. En esta investigación quedó demostrada la importancia del cultivo seriado de muestras de orina y la conveniencia de cultivar en medios sólidos y líquidos. Asimismo, el aislamiento de Mycobacterium bovis pone de relieve la importancia de usar el medio Stonebrink junto con el medio de Lowenstein-Jensen. El medio líquido no tuvo un aporte significativo al diagnóstico de tuberculosis renal; sin embargo, el cultivo de muestras seriadas aumentó la sensibilidad de la detección.

Bacteriological diagnosis of renal tuberculosis: an experience at the Regional Tuberculosis Laboratory in Córdoba province, Argentina. Given the incidence of renal tuberculosis in patients suffering of pulmonary tuberculosis, we seek to study both the frequency of this association in diagnosed cases of renal tuberculosis and the Mycobacterium tuberculosis complex species that were identified (period 1997-2009), observing its incidence by sex, demonstrating the importance of serial culture of urine samples and evaluating the convenience of using solid and liquid media. The analysis of urine samples from 383 patients indicated renal tuberculosis in 24 cases; in most cases, (95.8 %) Mycobacterium tuberculosis complex species prevailed, whereas the presence of Mycobacterium bovis accounted for 4.2 % of the cases. The association of pulmonary and renal tuberculosis was found in 6 cases. The isolation of Mycobacterium bovis indicates the importance of including Stonebrink medium along with Lowenstein- Jensen medium. The liquid medium made no significant contribution to the diagnosis of renal tuberculosis, but indeed, cultivating serial samples increases sensitivity.

[Bacteriological diagnosis of renal tuberculosis: an experience at the regional tuberculosis laboratory in Córdoba Province, Argentina]. / Diagnóstico bacteriológico de tuberculosis renal: experiencia del Laboratorio Regional de Tuberculosis de la provincia de Córdoba.

Given the incidence of renal tuberculosis in patients suffering of pulmonary tuberculosis, we seek to study both the frequency of this association in diagnosed cases of renal tuberculosis and the Mycobacterium tuberculosis complex species that were identified (period 1997-2009), observing its incidence by sex, demonstrating the importance of serial culture of urine samples and evaluating the convenience of using solid and liquid media. The analysis of urine samples from 383 patients indicated renal tuberculosis in 24 cases; in most cases, (95.8 %) Mycobacterium tuberculosis complex species prevailed, whereas the presence of Mycobacterium bovis accounted for 4.2 % of the cases. The association of pulmonary and renal tuberculosis was found in 6 cases. The isolation of Mycobacterium bovis indicates the importance of including Stonebrink medium along with Lowenstein- Jensen medium. The liquid medium made no significant contribution to the diagnosis of renal tuberculosis, but indeed, cultivating serial samples increases sensitivity.

[Complex radiologic diagnosis of renal tuberculosis]. / Kompleksnaia luchevaia diagnostika tuberkuleza pochek.

The paper analyzes a complex of physical, laboratory, and radiation studies in 71 patients with renal tuberculosis verified by the bacteriological urine test for Mycobacterium tuberculosis (MT) or postoperative histology. Ultrasound study, computed tomography, and excretory urotomography are not shown to be of informative value in diagnosing parenchymatous tuberculosis of the kidney. The diagnosis of this form of tuberculosis is made only on its clinical manifestations and positive urinary MT test. In all other forms of renal tuberculosis and its sequels, pathological changes can be detected on the basis of complex radiation techniques.

[A severe form of urinary tuberculosis in children]. / Forme grave de la tuberculose urinaire chez l'enfant.

Urinary tuberculosis is a rare disease in children. It poses major diagnostic problems because of clinical symptoms, which are often atypical and misleading. It causes serious lesions which are often multifocal and extensive, requiring complex surgical excision and urinary tract reconstruction. Prevention of this disease is based on generalized vaccination with BCG and adequate treatment of pulmonary tuberculosis. The authors report a case of urinary tuberculosis in a fourteen-year-old child who presented episodes of cystitis and hematuria refractory to treatment. The diagnosis, confirmed by the positive test for AFB in the urine was established late, at the stage of silent kidney and scleroatrophic bladder. The patient was treated with antituberculous chemotherapy (Isoniazid; Rifampicin, PZA) and nephro-ureterectomy with augmentation enterocystoplasty.

Resultados discordantes de la baciloscopia y el cultivo en el diagnóstico de laboratorio de la tuberculosis renal en Chile / Discordant results of direct microscopy and culture in the laboratory diagnosis of kidney tuberculosis in Chile

Entre enero y junio de 1990, 35 laboratorios de TBC de nivel II de Chile procesaron 13.295 muestras de orina mediante las técnicas de baciloscopia y el cultivo. Ciento cinco muestras de orina fueron positivas a la baciloscopia. De estas, 50 presentaron concomitantemente el cultivo positivo, sin embargo, en otras 49 muestras no hubo crecimiento microbacteriano. Catorce de los 35 laboratorios participantes comunicaron resultados discordantes. De 106 pacientes con exámenes de baciloscopias o cultivos positivos, 18 (17 por ciento) presentaron baciloscopia positiva y cultivo negativo. Nuestros resultados muestran que un número importante de muestras de orina presentan resultado discordante a la baciloscopia y el cultivo, afectando el dignóstico de laboratorio de la TBC renal.

[Urinary excretion of rifampicin in kidney failure when administered alone or together with isoniazid]. / Vydelenie rifampitsina s mochoi pri pochechnoi nedostatochnosti v usloviiakh izolirovannogo i sovmestnogo priema s izonizidom.

Rifampicin excretion with urine and its plasma levels were studied in 46 patients with nephrophthisis treated with rifampicin alone or in combination with isoniazid in doses of 8--10 mg/kg bw with regard to the degree of renal insufficiency. It was shown that excretion of rifampicin with urine decreased with progression of renal insufficiency and had no effect on its plasma levels. The combined use of isoniazid and rifampicin in a single dose was accompanied by a decrease in the latter's excretion with urine and different changes in its plasma concentration. The use of the two drugs for 4--6 weeks resulted in a further decrease in rifampicin excretion with urine not dependent on renal function and in decreased plasma levels of the antibiotic in 1/3 of patients. The findings indicate that the use of rifampicin in a dose less than 10 mg/kg of the body weight in patients with chronic renal insufficiency is not advisable. The absence of rifampicin in the urine specimens collected during the first hours on the 2nd day after its single use or its use for 4--6 weeks indicate that rifampicin does not accumulate in patients with renal insufficiency.