Can diabetes mellitus modify the plasma concentrations of rifampicin in patients under treatment for tuberculosis?

Abstract Rifampicin is a key component of treatment for tuberculosis and its efficacy is determined by the blood levels attained after therapeutic doses. However, there is a high variability of rifampicin blood levels that is related to both the patient and the formulation used. To date, the effect of diabetes mellitus on the plasma levels of rifampicin was low exploited, which could be relevant either by the significant increase of the comorbidity worldwide as by the probable influence of diabetes on the rifampicin exposure. The study aims to evaluate whether diabetes mellitus contribute to the variation of the maximum concentration of rifampicin in patients with tuberculosis treated with a daily dose of 10 mg/kg. Rifampicin and glycated hemoglobin were measured by high-performance liquid chromatography, and blood glucose by spectrophotometry. A total of 62 male patients were included in the study, and 26 presented diabetes mellitus. Rifampicin plasma levels in 2-h plasma samples collected at day 61 ranged from 3 µg/mL to 14.2 µg/mL. Drugs levels were similar between diabetic and non-diabetic patients and were not correlated with blood glucose and glycated hemoglobin. Moreover, a high percentage of patients in both groups presented low levels of rifampicin.

Expresión diferencial de micro-ARN circulantes en pacientes con tuberculosis activa y latente / Differential expression of circulating micro-RNAs in patients with active and latent tuberculosis

RESUMEN Objetivo: El objetivo del estudio fue analizar la expresión diferencial de miR-21, miR-29a, miR-99b y miR-155 en muestras de suero de pacientes con tuberculosis (TB) latente y TB activa respecto a contro les sanos. Materiales y métodos: Se utilizaron 28 muestras de suero (nueve con TB activa, diez con TB latente y nueve controles sanos) para el análisis de expresión génica mediante RT-qPCR con Primers y sondas TaqMan. Se calculó la expresión diferencial por el método de Livak utilizando un gen norma lizador (RNU-48). Resultados: Se halló una sobreexpresión de miR-155 en personas con tuberculosis latente, respecto a los controles sanos (0,63 vs. 0,01; valor de p=0,032). Conclusión: El miR-155 podría ser considerado un biomarcador para diferenciar TB latente de enfermedad activa. Se requieren estudios con mayores tamaños muestrales para corroborar nuestros hallazgos.

ABSTRACT Objectives: To analyze the differential expression of miR-21, miR-29a, miR-99b and miR-155 in serum samples from patients with latent tuberculosis (TB) and active TB compared to healthy controls. Mate rials and Methods: We used 28 serum samples (9 with active TB, 10 with latent TB and 9 healthy con trols) for the analysis of gene expression by RT-qPCR with Primers and TaqMan probes. The differential expression was calculated by the Livak method using a normalizing gene (RNU-48). Results: Overex pression of miR-155 was found in people with latent tuberculosis, compared to healthy controls (0.63 vs. 0.01; p value = 0.032). Conclusion: The miR-155 could be considered a biomarker to differentiate latent TB from active disease. Studies with larger sample sizes are required to corroborate the findings.

Mycobacterium tuberculosis complex bacteremia among HIV and non-HIV patients in a Mexican tertiary care center

ABSTRACT Objectives: To determine the factors associated with Mycobacterium tuberculosis complex-positive blood culture. Methods: Case-control study. Sociodemographic, clinical and laboratory data were collected from 2000 to 2015. Results: We reviewed medical records of 533 patients with culture-proven tuberculosis, of whom 27.2% (145/533) had blood culture available. Patients with mycobacteremia presented more frequently with abdominal tuberculosis, body mass index <18 kg/m2, and had lower hemoglobin and albumin levels. No differences were observed regarding HIV status. Conclusions: Few studies have reported on the characteristics associated with Mycobacterium tuberculosis complex bacteremia, especially among Human Immunodeficiency Virus-negative patients. Out of 145 tuberculosis-infected patients with blood culture results available, 21 turned out positive. Anemia, hypoalbuminemia, and a body mass index < 18 kg/m2 were associated with mycobacteremia.

Antineutrophil cytoplasmic antibodies in Chinese patients with tuberculosis

Abstract INTRODUCTION: Based on reports, infection with Mycobacterium tuberculosis is believed to induce the development of antibodies that are considered to be biological indicators for the diagnosis of some other diseases. However, conflicting results have been published regarding the presence of antineutrophil cytoplasmic antibodies (ANCAs) in patients with tuberculosis. We aim to study the seroprevalence of ANCA in a population of Chinese patients with tuberculosis, which may lead to the misdiagnosis of vasculitic disorders. METHODS: The study was conducted from January 2016 to May 2017 to evaluate the presence of ANCA in 103 Chinese patients using indirect immunofluorescent assay. An enzyme-linked immunosorbent assay was performed for anti-myeloperoxidase (MPO) and anti-proteinase 3 (PR3) detection. RESULTS: Perinuclear ANCA (p-ANCA) was detected in 4.8% (5/103) of patients, whereas cytoplasmic ANCA (c-ANCA) was not detected; 1.9% (2/103) of patients with tuberculosis was positive for anti-MPO antibodies, and none had anti-PR3 antibodies. Both anti-MPO-positive patients were diagnosed with ANCA-associated vasculitides. CONCLUSIONS: ANCA positivity may be more related to vasculitis and immunological disorders than to a M. tuberculosis infection. Therefore, to improve diagnostic accuracy, patients with M. tuberculosis who are ANCA positive should be investigated for concurrent diseases, including the effects of drugs. Therefore, even in tuberculosis epidemic area, ANCA seropositivity, detected by ELISA, is still more suggestive of ANCA-associated vasculitides.

Glutaraldehyde test for the rapid diagnosis of pulmonary and extra-pulmonary tuberculosis in an area with high tuberculosis incidence

BACKGROUND Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide. The primary method for controlling TB is the rapid and accurate identification of infected individuals. Immune response exploitation represents one of the main methods used for early TB diagnosis; however, few studies have reported that whole blood originating from TB-infected patients gels faster in the presence of aldehyde than blood originating from healthy subjects, which is the focus of the current study. OBJECTIVES The study objectives are to determine the diagnostic value of a glutaraldehyde test (GT) in pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (EPTB) and to assess its performance compared with light-emitting diode fluorescence microscopy (LED-FM). MATERIALS AND METHODS This study included 272 specimens (176 suspected PTB specimens and 96 suspected EPTB specimens). Of the 272 patients, 98 patients had TB infection confirmed by culture (64 PTB cases and 34 EPTB cases), and 174 patients had no TB infection. The gold standard technique (culture) was used as reference to verify the GT's performance. RESULTS The GT showed a high sensitivity (96.9%) and specificity (82.1%) for PTB with a good positive predictive value (PPV = 75.6%) and negative predictive value (NPV = 97.9%). For EPTB, the GT showed a sensitivity of 91.2% and a specificity of 77.4%, with PPV = 68.9% and NPV = 94.1%. LED-FM had lower sensitivities for PTB (65.6%) and EPTB (42.1%) and an excellent specificity of 100%, with PPV = 100% and NPV = 100%. CONCLUSION We concluded that GT is rapid, easy, simple and cost-effective and does not require qualified personnel with a specific background or sophisticated equipment like molecular biology or mycobacterium-specific genotyping techniques. These qualities make the GT attractive for use in low- and high-income countries in addition to other conventional methods, particularly culture, which continues to be the gold standard.

Imbalance of Th17 and Treg in peripheral blood mononuclear cells of active tuberculosis patients

Abstract Objective: Maintaining a right balance between Th17 and Treg might be critical to the immunopathogenesis of active tuberculosis (TB). This study aimed to assess whether the Th17/Treg balance is altered in active TB patients. Methods: 250 study subjects (90 active TB patients, 80 latent TB subjects, and 80 healthy controls) were recruited for the study. The expression of Th17 and Treg in peripheral blood mononuclear cells (PBMCs) in the 250 subjects was investigated by flow cytometry. Plasma levels of cytokines IL-17 and IL-10, which are related to Th17 and Treg, respectively, were determined by ELISA. Results: The percentages of Th17 and Treg in PBMCs from active TB patients were significantly higher than those from latent TB or control groups (Th17: 4.31 ± 1.35% vs. 1.58 ± 0.71% or 1.15 ± 0.49%, p < 0.05; Treg: 11.44 ± 2.69% vs. 7.54 ± 1.56% or 4.10 ± 0.99%, p < 0.05). The expression of IL-17 and IL-10 was significantly increased in active TB patients in comparison to that in latent TB or control groups (IL-17: 16.85 ± 9.68 vs. 7.23 ± 5.19 or 8.21 ± 5.51 pg/mL, p < 0.05; IL-10: 28.70 ± 11.27 vs. 20.25 ± 8.57 or 13.94 ± 9.00 pg/mL, p < 0.05). Conclusions: Our study demonstrated an altered balance of Treg/Th17 in active TB patients, with higher percentages of Th17 and Treg in PBMCs. Further research on this imbalance may offer a new direction for TB treatment.

Ratio of monocytes to lymphocytes in peripheral blood in patients diagnosed with active tuberculosis

Objective: The ratio of monocytes to lymphocytes in peripheral blood could reflect an indi- vidual's immunity to Mycobacterium tuberculosis. The objective of this study was to evaluate the relationship between ratio of monocytes to lymphocytes and clinical status of patients with active tuberculosis. Methods: This was a retrospective review of data collected from the clinical database of The Fifth People's Hospital of Wuxi, Medical College of Jiangnan University. A total of 419 patients who had newly diagnosed active tuberculosis and 108 cases from 419 patients with tuberculosis therapy either near completion or completed were selected. Controls were 327 healthy donors. Results: Median ratio of monocytes to lymphocytes was 0.36 (IQR, 0.22-0.54) in patients before treatment, and 0.16 (IQR, 0.12-0.20) in controls (p < 0.001). Ratio of monocytes to lymphocytes <9% or >25% was significant predictors for active tuberculosis (OR = 114.73, 95% CI, 39.80-330.71; OR = 89.81, 95% CI, 53.18-151.68, respectively). After treatment, the median ratio of monocytes to lymphocytes recovered to be nearly normal. Compared to other patients, patients with extrapulmonary tuberculosis and of age >60 years were more likely to have extreme ratio of monocytes to lymphocytes (AOR = 2.57, 95% CI, 1.08-6.09; AOR = 4.36, 95% CI, 1.43-13.29, respectively). Conclusions: Ratio of monocytes to lymphocytes <9% or >25% is predictive of active tuberculosis. .

Proteomic Profiling of Serum from Patients with Tuberculosis

BACKGROUND: Effective treatment and monitoring of tuberculosis (TB) requires biomarkers that can be easily evaluated in blood samples. The aim of this study was to analyze the serum proteome of patients with TB and to identify protein biomarkers for TB. METHODS: Serum samples from 26 TB patients and 31 controls were analyzed by using nano-flow ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry in data-independent mode, and protein and peptide amounts were calculated by using a label-free quantitative approach. The generated data were analyzed by using principal component analysis and partial least squares discriminant analysis, a multivariate statistical method. RESULTS: Of more than 500 proteins identified, alpha-1-antitrypsin was the most discriminative, which was 4.4 times higher in TB patients than in controls. Peptides from alpha-1-antitrypsin and antithrombin III increased in TB patients and showed a high variable importance in the projection scores and coefficient in partial least square discriminant analysis. CONCLUSIONS: Sera from patients with TB had higher alpha-1-antitrypsin levels than sera from control participants. Alpha-1-antitrypsin levels may aid in the diagnosis of TB.

Correlation between the response to Mycobacterium tuberculosis antigens and the tuberculin skin test in patients with rheumatoid arthritis in Colombia / Correlación de la respuesta a antígenos de Mycobacterium tuberculosis y la prueba cutánea de tuberculina en pacientes con artritis reumatoide

Introduction. Rheumatoid arthritis patients under treatment with anti-TNF-α are at a high risk of developing active tuberculosis, and therefore, screening for latent tuberculosis infection is recommended before anti-TNF-α therapy. Objective. To compare the tuberculin test and IFNγ production induced by culture filtrate proteins(CFPs) and Mycobacterium tuberculosis-specific CFP-10 antigens in rheumatoid arthritis patients. Materials and methods. An analytic transversal study was conducted in rheumatoid arthritis patients treated at Hospital Universitario San Vicente Fundación between January and December 2007. IFNγ production in response to CFPs and CFP-10 was measured in the supernatants of whole blood cultures and evaluated for correlations with tuberculin reactivity. The degree of concordance between both tests was also established. Results. Forty-five patients were included, of which 14 (31.1%) had a tuberculin reaction of ≥10 mm of induration, 9 (20%) produced IFNγ in response to CFP-10, and 7 were positive for both tests. The correlation between tests was r=0.53 (IC 95%:0.28-0.72), and the global concordance between tests was80%, with a Kappa coefficient of 0.48 (IC95%:0.20-0.76). Conclusions. Only two tuberculin (-)/CFP-10+ "anergic" patients were observed. By contrast, six tuberculin +/CFP-10(-) "tuberculin false-positive" patients were observed. These data suggest that the tuberculin test is not an appropriate tool for determining the need for tuberculosis prophylaxis.

Introducción. Los pacientes con artritis reumatoide bajo tratamiento con anti-TNFα están en alto riesgo de desarrollar tuberculosis activa, por lo cual se recomienda hacer la tamización para infección latente de tuberculosis, antes de iniciar el tratamiento. Objetivo. Comparar la prueba de tuberculina y la producción de IFNγ inducida por antígenos CFP (Culture Filtrate Protein) y antígenos específicos de Mycobacterium tuberculosis (CFP-10) para el diagnóstico de infección latente de tuberculosis en pacientes con artritis reumatoide. Materiales y métodos. Se llevó a cabo un estudio transversal analítico en pacientes con artritis reumatoide atendidos en el Hospital Universitario San Vicente Fundación, entre enero y diciembre de 2007, a los cuales se les determinó la producción de IFNγ en respuesta a CFP y CFP-10 en sobrenadantes de cultivos de sangre total, y se correlacionó con la reacción en la prueba de tuberculina. Además, se estableció el grado de concordancia entre ambas pruebas. Resultados. Se incluyeron 45 pacientes, de los cuales, 14 (31,1 %) tuvieron un diámetro de induración ≥10 mm (tuberculina positiva), nueve (20 %) produjeron IFNγ en respuesta a CFP-10, y siete fueron positivos para ambas pruebas. La correlación entre las pruebas fue de r=0,53 (IC95%: 0,28-0,72) y la concordancia global entre pruebas fue de 80 %, con un coeficiente kappa de 0,48 (IC95%: 0,20-0,76). Conclusiones. Solo se observaron dos pacientes con tuberculina positiva y CFP-10 positivo "anérgicos" y se encontraron seis pacientes con tuberculina positiva y CFP-10 negativa "falsos positivos para tuberculina", lo cual sugiere que la prueba de la tuberculina no es la más adecuada para indicar profilaxis para tuberculosis.

Co-Immunization of Plasmid DNA Encoding IL-12 and IL-18 with Bacillus Calmette-Guerin Vaccine against Progressive Tuberculosis

PURPOSE: Bacillus Calmette-Guerin (BCG) vaccine has widely been used to immunize against tuberculosis, but its protective efficacy is variable in adult pulmonary tuberculosis, while it is not efficiently protective against progressive infection of virulent Mycobacterium tuberculosis strains. In this study, the protective effects of plasmid DNA vaccine constructs encoding IL-12 or IL-18 with the BCG vaccine were evaluated against progressive infection of M. tuberculosis, using mouse aerosol challenge model. MATERIALS AND METHODS: Plasmid DNA vaccine constructs encoding IL-12 or IL-18 were constructed and mice were immunized with the BCG vaccine or with IL-12 DNA or IL-18 DNA vaccine constructs together with the BCG vaccine. RESULTS: The BCG vaccine induced high level of interferon gamma (IFN-gamma) but co-immunization of IL-12 or IL-18 DNA vaccine constructs with the BCG vaccine induced significantly higher level of IFN-gamma than a single BCG vaccine. The BCG vaccine was highly protective at early stage of M. tuberculosis infection, but its protective efficacy was reduced at later stage of infection. The co-immunization of IL-12 DNA vaccine constructs with the BCG vaccine was slightly more protective at early stage of infection and was significantly more protective at later stage infection than a single BCG vaccine. CONCLUSION: Co-immunization of IL-12 DNA vaccine with the BCG vaccine induced more protective immunity and was more effective for protection against progressive infection of M. tuberculosis.

Latent tuberculosis infection in individuals with human immunodeficiency virus infection: comparison of tuberculin skin test to the anti TB-IgM antibodies

To determine Latent Tuberculosis Infection [LTBI] prevalence and compare TST results to the anti TB-IgM anti bodies [ATIA] for the diagnosis of LTBI in HIV infected individuals. Sixty two randomized sampled HIV infected subjects from an addict treatment center in Ahvaz southwest Iran underwent TST, using 5 TU of purified protein derivative, and measuring ATIA. Data were analyzed in SPSS [version 16, USA]. Of 62 participants, 34 [54.8%] had positive result for TST, whereas 6 [9.7%] had positive ATIA. Overall concordance between TST and ATIA was 45.2% [Kappa= 0.37, p = 0.32]. In subjects with positive test results by either TST or ATIA, only 4.8% had positive test results by both tests. Discordant results were found in 54.8% of subjects. Positive results for both tests in subjects categorized in two groups [above and below 200 CD4-cell/mm3] had no significant difference [P>0.05]. LTBI prevalence among HIV infected individuals in studied area is higher than other parts of the world. TST is a useful test for LTBI diagnosis and prefer to ATIA. Concordance between TST and ATIA is low

Significance of appropriate sampling in the diagnosis of tuberculosis [TB] - a comparison of different techniques

After years of decline, tuberculosis [TB] has re-emerged as a serious public health problem worldwide causing significant mortality and morbidity in developing countries like Pakistan, where the estimated incidence of TB is 181 per 10000. The present prospective study was conducted in Shalamar Hospital Lahore from January 2007 to October 2009. The objective was to compare the PCR results of specific site samples and blood of the same TB patient to see the validity of PCR results based on blood samples. Clinical samples obtained from 205 patients of suspected TB [pulmonary or extra-pulmonary] were subjected to ZN smear examination, LJ medium culture, and PCR test by amplifying 541 fragment of Mycobacterium tuberculosis complex genome. A highly significant difference was seen in the test results clone on samples obtained from specific site according to disease and blood samples of the same patient infected with pulmonary or extra-pulmonary tuberculosis. The sensitivity of different tests was found to be significantly different, which was 67.32 percent for PCR test, 27.81 percent for LJ medium culture and 12.20 percent for ZN smear examination. However, there was no significant difference between different tests as far as specificity was concerned. PCR test sensitivity in pulmonary and extra-pulmonary clinical samples was 77.15 and 61.6 percent respectively, being significantly higher, when compared with sensitivity of other tests. The mean detection time for M. tuberculosis was 24 days by LJ medium culture and less than 1 day by .smear examination and PCR test. We concluded that the PCR test is more sensitive than ZN smear examination and LJ medium culture for the diagnosis of TB in pulmonary and extra-pulmonary clinical samples. To get more accurate results PCR for TB diagnosis should be done on specific site samples. Blood samples are not appropriate for the diagnosis of TB by PCR when the PCR is clone on TB genomic DNA

Correlation between serum tumor necrosis factor alpha levels and clinical severity of tuberculosis

This study verified the correlation between the serum levels of TNF alpha and different clinical forms of tuberculosis. We described a group of 24 patients presenting several clinical forms of tuberculosis and a control group of 13 healthy individuals. The levels of TNF alpha were measured by bioassay method. The levels of TNF-alpha had significant differences between the tuberculosis and control groups. The patients with abnormal chest X-Ray findings had higher TNF alpha levels (15328.48 ± 4602.19 pg/mL) when compared to patients with normal X-Rays (3353.18 ± 1495.29 pg/mL) (p<0.05). Patients that lost weight had higher TNF alpha levels (15468.54 ± 4580.54 pg/mL) than those that didn't loose weight (2904.98 ± 1367.89) (p<0.05). The levels of TNF alpha were higher in patients with a positive PPD skin test than in those with a negative PPD test (p<0.05). There was a positive correlation between patients' clinical severity and the serum levels of TNF alpha. In patients with successive measurements of TNF alpha, we observed that there was a drop in cytokine levels, and also a clinical improvement concomitantly. We concluded that there was a correlation between serum TNF alpha levels and chest X-Ray alterations, loss of weight, positive PPD skin test and clinical severity in patients with tuberculosis. There was evidence of a worse clinical outcome in patients with tuberculosis that presented higher TNF alpha serum levels.

Clinical and laboratory profile of patients with tuberculosis/HIV coinfection at a national referral centre: a case series

This case series describes the clinical and laboratory profile of 15 patients with tuberculosis [TB] HIV coinfection admitted to a referral centre in the Islamic Republic of Iran. Most of the patients [13] were male; the mean age was 36.9 years. Intravenous drug use was the route of transmission for all males and heterosexual intercourse for the 2 females; 12 patients had a history of imprisonment. All patients had pulmonary TB; 13 were smear-positive and all except 1 had atypical radiological presentation. Drug-induced hepatitis occurred in 3 patients and 12 had hepatitis C coinfection. Five patients died. The mean CD4 count was 229.2 [SD 199.5] cells/mm[3] and 78.6% had CD4 count < 350. TB may be an AIDS-defining illness in this country

Detection of M. tuberculosis in clinical samples of diversified nature by IS6110 based PCR.

Performance of the polymerase chain reaction technique based on IS6110 sequence was evaluated in clinical samples obtained from pulmonary and extrapulmonary cases of tuberculosis. One hundred and seventy two samples were processed for detection of M. tuberculosis by ZN stained smear examination, LJ medium culture, BACTEC radiometric culture and PCR tests amplifying 123bp region of IS6110 sequence. A significant difference was seen in the sensitivities of different tests, the figures being 83% for PCR test, 35.2% for smear examination, 47.16% for LJ culture and 53.45% for BACTEC culture (p < 0.05). However, no significant difference was found as far as specificity was concerned. PCR test sensitivity in. pulmonary and extrapulmonary clinical samples were 90.14% and 77.27% respectively and found to be significantly higher (p < 0.05) when compared with those of other tests. The mean detection time for M. tuberculosis was 24.03 days by LJ medium culture, 12.89 days by BACTEC culture and less than one day by PCR test. PCR based on IS6100 sequence is highly sensitive method for the early diagnosis of pulmonary and extrapulmonary tuberculosis.

Impact of Circulating TGF-beta and IL-10 on T Cell Cytokines in Patients with Asthma and Tuberculosis

Regulatory T cells, which stimulate or inhibit the effector functions of distinct T cell subsets, are critical in the control of the immune response. We investigated the effect of TGF-beta and IL-10 on T cell subsets according to the Th1/Th2 immune status. Sixty-two patients with asthma and 38 patients with pulmonary tuberculosis were included. Allergy skin tests, tuberculin tests, and chest radiography were performed. The levels of circulating IL-4, IFN-gamma, TGF-beta1, and IL-10 were measured using ELISA. The level of TGF-beta1 was higher in patients with asthma than in those with tuberculosis, but the IL-10 levels were the same between the asthma and tuberculosis groups. Atopy was unrelated to the tuberculin response. The IFN-gamma level was correlated with the IL-10 level, and the level of IL-4 was unrelated to the IL-10 or TGF-beta1 level. The level of IL-10 was higher in the negative tuberculin reactors than in the positive tuberculin reactors among patients with asthma, and TGF-beta1 was higher in the positive tuberculin reactors than in the negative tuberculin reactors among patients with tuberculosis. These results demonstrate that the regulatory effects of circulating TGF-beta and IL-10 on T cell cytokines may be different between Th2-type asthma and Th1 tuberculosis.

Enfermedades micobacterianas diseminadas en pacientes con VIH/SIDA. Evaluación de los hemocultivos por método rápido / Disseminated mycobacterial infections in patients with HIV/AIDS. Evaluation of blood cultures

Mil cuarenta hemocultivos correspondientes a 451 enfermos uruguayos con SIDA y diagnóstico clínico de micobacteriosis diseminada fueron evaluados entre 1999 y 2003. Las muestras fueron procesadas en el Centro de Referencia Nacional para Micobacterias (Montevideo, Uruguay), utilizando el sistema de hemocultivos automatizado para micobacterias MB - BacT (BioMérieux). Se detectaron 45 muestras positivas (4,3%) correspondientes a 26 enfermos (promedio 2,3 muestras por paciente). En 10/26 casos se identificó M. avium complex (MAC) y en 13/26 el germen aislado fue M. tuberculosis. El tiempo medio de incubación fue de 12,4 días (intervalo 6-19 días) para MAC y de 22,6 días (intervalo 7-35 días) para M. tuberculosis. El hemocultivo ha demostrado ser la mejor muestra para la confirmación bacteriológica de las enfermedades micobacterianas diseminadas cuando se estudian por lo menos 2 muestras por paciente. La frecuencia de aislamientos de M. tuberculosis y MAC aislados en pacientes con SIDA en Uruguay, corresponde a la de un país con una moderada prevalencia de tuberculosis.

One thousand-forty blood cultures corresponding to 451 Uruguayan patients with AIDS and clinic diagnosis of disseminated mycobacterial infection were evaluated between 1999 and 2003. Samples were processed in the NationalReferenceCenter for Mycobacteria (Montevideo, Uruguay), using the automated blood culture system for mycobacteria MB -BacT (BioMérieux). Forty-five positive samples were detected (4.3%) corresponding to 26 patients with AIDS (average 2.3 samples per patient). In 10/26 patients M. avium complex (MAC) was identified and in 13/26 the isolated germ was M. tuberculosis. The average time of incubation was of 12.4 days (range 6-19 days) for MAC and of 22.6 days (range 7-35 days) for M. tuberculosis. Blood culture has demonstrated to be the best sample for the bacteriological confirmation of the disseminated mycobacterial infections when at least 2 samples by patient are studied. The frequency of isolates of M. tuberculosis and MAC in AIDS patients is according with a moderate prevalence of tuberculosis in Uruguay.

Serodiagnosis of childhood tuberculosis by ELISA.

OBJECTIVE: Diagnosis of childhood tuberculosis remains an enigma despite many recent technological developments. The present study has been taken up with the aim to assess the diagnostic potential of mycobacterium tuberculosis excretory-secretory ES-31 antigen and affinity purified anti ES-31 antibodies in the serodiagnosis of different spectrum of childhood tuberculosis. METHODS: Mycobacterium tuberculosis H37Ra excretory-secretory antigen (ES-31) and affinity purified goat anti ES-31 antibodies were used in stick penicillinase ELISA for IgG antibody detection and stick Sandwich penicillinase ELISA for detection of circulating free and immune complexed antigen in the sera of 230 children. RESULTS: Analysis of tubercular antibody, circulating free and immune complexed antigen (CIC-Ag) was done in both pulmonary and extrapulmonary form of childhood tuberculosis and overall sensitivity of 81.4% with a specificity of 93% was achieved for detection of antitubercular IgG antibodies. Of the five cases of pulmonary tuberculosis showing absence of IgG antibody, 3 showed the presence of CIC-Ag and one was found positive for both free and CIC-Ag. Similarly out of 8 cases of extrapulmonary childhood tuberculosis missed by IgG detection 5 were found to be positive for CIC-Ag and 1 showed the positive reaction for both free and immune complexed antigens. CONCLUSION: IgG antibody to excretory-secretory antigen ES-31 is found to be having good specificity with acceptable sensitivity in detecting different forms of childhood tuberculosis. Further detection of circulating free and/or immunecomplexed antigen can be used as an adjunct tool in the diagnosis of childhood tuberculosis.