SEARCH · PubMed Health

Results for “Tuberculosis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

PubMed2002

Specificities and functions of the recA and pps1 intein genes of Mycobacterium tuberculosis and application for diagnosis of tuberculosis.

The worldwide recrudescence of tuberculosis and the widespread appearance of antibiotic resistance have strengthened the need for rapid and specific diagnostic tools. The prevailing microbiological identification of Mycobacterium tuberculosis, the causative agent of tuberculosis, which implies the use of in vitro cultures and acid-fast staining microscopy, is time-consuming. Detection of M. tuberculosis directly in clinical samples through PCR amplification of mycobacterium-specific genes, designed to shorten diagnostic delay, demonstrated reliability and high sensitivity. However, the quality of the diagnosis depends on the specificity of the target sequence for M. tuberculosis complex strains. In the present study, we demonstrated the specificity of recA and pps1 inteins for this complex and thus the feasibility of using intein-coding sequences as a new target for PCR diagnosis. Indeed, the recA and pps1 genes of 36 clinical isolates of M. tuberculosis and 10 field strains of M. bovis were found to be interrupted by an intein sequence at the RecA-a and Pps1-b sites, respectively, while a large number of nontuberculous mycobacterial species failed to demonstrate these insertions. Besides, the MtuPps1, which was cloned and expressed in Escherichia coli, was shown to possess an endonuclease activity. The intein cleaves the 40-bp sequence spanning the intein insertion site Pps1-b in the inteinless pps1 gene. In addition to the PCR amplification of recA and pps1 intein genes as a tool for diagnosis, the specific endonuclease activity could represent a new molecular approach to identify M. tuberculosis.

Bacterial Proteins↗

PubMed2004

Molecular characteristics of strains of the cameroon family, the major group of Mycobacterium tuberculosis in a country with a high prevalence of tuberculosis.

A preliminary investigation of the genetic biodiversity of Mycobacterium tuberculosis complex strains in Cameroon, a country with a high prevalence of tuberculosis, described a group of closely related M. tuberculosis strains (the Cameroon family) currently responsible for more than 40% of smear-positive pulmonary tuberculosis cases. Here, we used various molecular methods to study the genetic characteristics of this family of strains. Cameroon family M. tuberculosis strains (i) are part of the major genetic group 2 and lack the TbD1 region like other families of epidemic strains, (ii) lack spacers 23, 24, and 25 in their direct repeat (DR) region, (iii) have an identical number of repeats in 8 of 12 variable-number tandem repeats of mycobacterial interspersed repetitive unit (MIRU-VNTR) loci, (iv) have similar IS6110-restriction fragment length polymorphism (RFLP) multiband patterns (10 to 15 copies) with seven common IS6110 bands, (v) do not have an IS6110 element in their DR locus, and (vi) have four IS6110 elements in open reading frames (adenylate cyclase, phospholipase C, moeY, and ATP binding genes). Analysis by spoligotyping, MIRU-VNTR, and IS6110-RFLP typing methods revealed differences not observed in previous studies; polymorphism as assessed by MIRU-VNTR typing was lower than suggested by spoligotyping, and in rare cases, strains with identical IS6110-RFLP patterns had spoligotypes differing by as much as 15 spacers. Our findings confirm the recent expansion of this family in Cameroon and indicate that the interpretation of molecular typing results has to be adapted to the characteristics of the strain population within each setting. The knowledge of this particular genotype, with its large involvement in tuberculosis in Cameroon, allows greater refinement of tuberculosis transmission studies by interpreting data in the context of this geographic area.

Bacterial Proteins↗

PubMed1994

Treatment of tuberculosis and tuberculosis infection in adults and children. American Thoracic Society and The Centers for Disease Control and Prevention.

Treatment of Tuberculosis. 1. A 6-mo regimen consisting of isoniazid, rifampin, and pyrazinamide given for 2 mo followed by isoniazid and rifampin for 4 mo is the preferred treatment for patients with fully susceptible organisms who adhere to treatment. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) should be included in the initial regimen until the results of drug susceptibility studies are available, unless there is little possibility of drug resistance (i.e., there is less than 4% primary resistance to isoniazid in the community, and the patient has had no previous treatment with antituberculosis medications, is not from a country with a high prevalence of drug resistance, and has no known exposure to a drug-resistant case). This four-drug, 6-mo regimen is effective even when the infecting organism is resistant to INH. This recommendation applies to both HIV-infected and uninfected persons. However, in the presence of HIV infection it is critically important to assess the clinical and bacteriologic response. If there is evidence of a slow or suboptimal response, therapy should be prolonged as judged on a case by case basis. 2. Alternatively, a 9-mo regimen of isoniazid and rifampin is acceptable for persons who cannot or should not take pyrazinamide. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) should also be included until the results of drug susceptibility studies are available, unless there is little possibility of drug resistance (see Section 1 above). If INH resistance is demonstrated, rifampin and ethambutol should be continued for a minimum of 12 mo. 3. Consideration should be given to treating all patients with directly observed therapy (DOT). 4. Multiple-drug-resistant tuberculosis (i.e., resistance to at least isoniazid and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies. In such cases, consultation with an expert in tuberculosis is recommended. 5. Children should be managed in essentially the same ways as adults using appropriately adjusted doses of the drugs. This document addresses specific important differences between the management of adults and children. 6. Extrapulmonary tuberculosis should be managed according to the principles and with the drug regimens outlined for pulmonary tuberculosis, except for children who have miliary tuberculosis, bone/joint tuberculosis, or tuberculous meningitis who should receive a minimum of 12 mo of therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1993

Clinical evaluation of rapid serodiagnosis of pulmonary tuberculosis by ELISA with cord factor (trehalose-6,6'-dimycolate) as antigen purified from Mycobacterium tuberculosis.

Immunoglobulin G (IgG) antibodies against purified cord factor (trehalose-6,6'-dimycolate) prepared from Mycobacterium tuberculosis H37Rv were determined by enzyme-linked immunosorbent assay (ELISA), and its diagnostic usefulness was evaluated. Serum specimens from 65 patients with active pulmonary tuberculosis, 58 patients with inactive pulmonary tuberculosis, 36 patients with diseases other than tuberculosis, and 66 healthy adults were examined. Patients with active pulmonary tuberculosis showed significantly higher titers of IgG antibodies against cord factor than did other groups (p < 0.001). The antibody titer greater than 0.29 in absorption difference (492 to 630 nm) of 160-times diluted serum was set as positive in ELISA. For patients with active and untreated pulmonary tuberculosis, the ELISA had a sensitivity of 81% and a specificity of 96%. From these results, it was concluded that the detection of IgG antibodies against cord factor is useful for serodiagnosis of active pulmonary tuberculosis. It was also indicated that the anticord factor antibody titers decline to the normal level as a result of antituberculosis chemotherapy.

Adult↗

PubMed2003

CD44 is a macrophage binding site for Mycobacterium tuberculosis that mediates macrophage recruitment and protective immunity against tuberculosis.

Cell migration and phagocytosis are both important for controlling Mycobacterium tuberculosis infection and are critically dependent on the reorganization of the cytoskeleton. Since CD44 is an adhesion molecule involved in inflammatory responses and is connected to the actin cytoskeleton, we investigated the role of CD44 in both these processes. Macrophage (Mphi) recruitment into M. tuberculosis-infected lungs and delayed-type hypersensitivity sites was impaired in CD44-deficient (CD44(-/-)) mice. In addition, the number of T lymphocytes and the concentration of the protective key cytokine IFN-gamma were reduced in the lungs of infected CD44(-/-) mice. The production of IFN-gamma by splenocytes of CD44(-/-) mice was profoundly increased upon antigen-specific stimulation. Flow cytometry analysis revealed that soluble CD44 can directly bind to virulent M. tuberculosis. Mycobacteria also interacted with Mphi-associated CD44, as reflected by reduced binding and internalization of bacilli by CD44(-/-) Mphis. This suggests that CD44 is a receptor on Mphis for binding of M. tuberculosis. CD44(-/-) mice displayed a decreased survival and an enhanced mycobacterial outgrowth in lungs and liver during pulmonary tuberculosis. In summary, we have identified CD44 as a new Mphi binding site for M. tuberculosis that mediates mycobacterial phagocytosis, Mphi recruitment, and protective immunity against pulmonary tuberculosis.

Animals↗

PubMed2005

Identification of moaA3 gene in patient isolates of Mycobacterium tuberculosis in Kerala, which is absent in M. tuberculosis H37Rv and H37Ra.

BACKGROUND: Tuberculosis is endemic to developing countries like India. Though the whole genome sequences of the type strain M. tuberculosis H37Rv and the clinical strain M. tuberculosis CDC1551 are available, the clinical isolates from India have not been studied extensively at the genome level. This study was carried out in order to have a better understanding of isolates from Kerala, a state in southern India. RESULTS: A PCR based strategy was followed making use of the deletion region primers to understand the genome level differences between the type strain H37Rv and the clinical isolates of M. tuberculosis from Kerala. PCR analysis of patient isolates using RD1 region primers revealed the amplification of a 386 bp region, in addition to the expected 652 bp amplicon. Southern hybridization of genomic DNA with the 386 bp amplicon confirmed the presence of this new region in a majority of the patient isolates from Kerala. Sequence comparison of this amplicon showed close homology with the moaA3 gene of M. bovis. In M. bovis this gene is present in the RvD5 region, an IS6110 mediated deletion that is absent in M. tuberculosis H37Rv. CONCLUSION: This study demonstrates the presence of moaA3 gene, that is absent in M. tuberculosis H37Rv and H37Ra, in a large number of local isolates. Whether the moaA3 gene provides any specific advantage to the field isolates of the pathogen is unclear. Field strains from Kerala have fewer IS6110 sequences and therefore are likely to have fewer IS6110 dependent rearrangements. But as deletions and insertions account for much of the genomic diversity of M. tuberculosis, the mechanisms of formation of sequence polymorphisms in the local isolates should be further examined. These results suggest that studies should focus on strains from endemic areas to understand the complexities of this pathogen.

Base Sequence↗

PubMed1998

Rapid diagnosis of tuberculosis in various biopsy and body fluid specimens by the AMPLICOR Mycobacterium tuberculosis polymerase chain reaction test.

STUDY OBJECTIVES: This study was undertaken to determine the usefulness of the AMPLICOR Mycobacterium tuberculosis (MTB) polymerase chain reaction (PCR) test (Roche Diagnostic Systems, Inc; Branchburg, NJ) in diagnosing TB in tissue and body fluid specimens other than respiratory secretions. DESIGN AND SETTING: Prospective analysis of clinical and laboratory data in patients with suspected TB at the four divisional hospitals of Catholic Medical Center, located in New York. PATIENTS AND MEASUREMENTS: A total of 1,090 tissue and body fluid specimens from 1,032 patients with suspected TB were subjected to acid-fast bacillus (AFB) smear, culture, and the AMPLICOR MTB PCR test. RESULTS: Of the 1,090 specimens, 32 grew M tuberculosis complex and 8 specimens grew isolates belonging to the Mycobacterium avium complex (MAC). The AMPLICOR MTB PCR test was positive for 24 of the 32 specimens that grew M tuberculosis. It was also positive for four additional specimens that were culture-negative for M tuberculosis or MAC. Two of these specimens were from patients with a previously recorded positive sputum culture for M tuberculosis. The AMPLICOR test was negative for all eight specimens that yielded MAC only. When AMPLICOR MTB PCR test results were compared with the confirmed clinical diagnosis of TB, the sensitivity, specificity, positive predictive value, and negative predictive value for the AMPLICOR MTB PCR test were 76.4%, 99.8%, 92.8%, and 99.2%, respectively. PCR results were available within 6.5 hours, compared with an average of 3 weeks for culture of M tuberculosis. CONCLUSIONS: These data establish the utility of the AMPLICOR MTB PCR test for the rapid detection of M tuberculosis in tissue and body fluid specimens other than respiratory secretions.

Biopsy↗

PubMed2003

IS6110 restriction fragment length polymorphism of Mycobacterium tuberculosis isolated from patients with pulmonary tuberculosis in Campinas, Brazil: evidence of intercontinental distribution of strains.

Tuberculosis (TB) is a major concern in developing countries. In Brazil, few genotyping studies have been conducted to verify the number of IS6110 copies present in local prevalent strains of Mycobacterium tuberculosis, the distribution and clustering of strains. IS6110 DNA fingerprinting was performed on a sample of M. tuberculosis isolates from patients with AFB smear-positive pulmonary TB, at a hospital in Brazil. The IS6110 profiles were analyzed and compared to a M. tuberculosis database of the Houston Tuberculosis Initiative, Houston, US. Seventy-six fingerprints were obtained from 98 patients. All M. tuberculosis strains had an IS6110 copy number between 5-21 allowing for differentiation of the isolates. Human immunodeficiency virus infection was confirmed in nearly half the patients of whom data was available. Fifty-eight strains had unique patterns, while 17 strains were grouped in 7 clusters (2 to 6 strains). When compared to the HTI database, 6 strains matched isolates from El Paso, Ciudad de Juarez, Houston, and New York. Recently acquired infections were documented in 19% of cases. The community transmission of infection is intense, since some clustered strains were recovered during the four-year study period. The intercontinental dissemination of M. tuberculosis strains is suspected by demonstration of identical fingerprints in a distant country.

Bacterial Typing Techniques↗

PubMed2004

Mycobacterium tuberculosis resides in nonacidified vacuoles in endocytically competent alveolar macrophages from patients with tuberculosis and HIV infection.

Alveolar macrophages (AM) are the first professional phagocytes encountered by aerosols containing infections in the lungs, and their phagocytic capacity may be affected by these infections or environmental particles. The aim of this study was to evaluate the innate endocytic and phagocytic properties of human AM obtained from patients with pulmonary tuberculosis and to characterize the vacuoles in which Mycobacterium tuberculosis bacilli reside in vivo. AM were obtained by bronchoalveolar lavage from patients with suspected tuberculosis and from asymptomatic volunteers (controls). Clinical case definitions were based on mycobacterial culture of respiratory specimens and HIV serology. To assess phagocytosis, endocytosis, and acidification of the endosomal system, AM were cultured with IgG-coated polystyrene beads, dextran, and a pH-sensitive reporter (3-(2,4-dinitroanilino)-3-amino-N-methyldipropylamine) and were evaluated by light and immunoelectron microscopy. Cells from 89 patients and 10 controls were studied. We found no significant difference between the two groups in the ability of AM either to ingest beads and dextran or to deliver them to acidified lysosomes. In AM from patients with tuberculosis, the bacilli were located in vacuoles that failed to accumulate endocytosed material and were not acidified. We concluded that AM from patients with tuberculosis and HIV infections were competent to endocytose and phagocytose material and to deliver the material to functional, acidified lysosomes. M. tuberculosis residing in these AM arrests the progression of their phagosomes, which fail to fuse with acidified lysosomes. This confirms, for the first time in humans with tuberculosis and HIV, the conclusions from previous animal and in vitro studies.

Adult↗

PubMed2000

The first occurrence of a multi-drug resistant tuberculosis epidemic in the Czech Republic caused by genetically closely related Mycobacterium tuberculosis strains.

DNA fingerprinting based on the detection of the insertion sequence IS6110 in Pvull restriction fragments was applied to M. tuberculosis isolates originating in the first microepidemic of multidrug resistant tuberculosis recorded in the Czech Republic. Their disseminators were 21 individuals living in--or roaming between three distant areas. The age of 17 males ranged from 36 to 64 years (average 45 years) and of 4 females aged from 38 to 52 years. The index person was most probably a former male prisoner, aged 49 years, who disseminated multidrug resistant M. tuberculosis over a period of 28 months. In ten of the patients the following risk factors for tuberculosis were found: imprisonment, homelessness, immigration and previous stay in asylum--or in a psychiatric ward. In six cases, M. kansasii infection preceded tuberculosis. Four out of the 21 patients died. The RFLP analysis separated the patients into two distinct groups: group A comprising 14 members of which M. tuberculosis strains were isolated with six IS6110 copies, whereas the isolates of seven individuals of the group B, the RFLP profile displayed highly similar RFLP patterns compared to the isolates of group A, but with two additional IS6110 copies. In one patient, both A and B patterns were found: the first one in a M. tuberculosis strain isolated in 1993 and the second one in the isolate isolated two years later. Both the appearance of pattern B among the isolates of a part of patients and the switch from A to B pattern in one of patients can be plausibly explained by the unstability of DNA genotypes caused by transposition of IS6110 elements.

Adult↗

PubMed1998

[Detection of Mycobacterium tuberculosis DNA in peripheral blood mononuclear cells from patients with pulmonary tuberculosis by polymerase chain reaction technique].

OBJECTIVE: To evaluate the clinical value of detection of Mycobacterium tuberculosis DNA (MTB-DNA) in peripheral blood mononuclear cells (PBMC) for diagnosis of pulmonary tuberculosis. METHOD: Polymerase chain reaction (PCR) technique was used to amplify gene of 240 bp DNA fragment prepared by Triton X-100 method, and some factors affecting PCR result were also analysed. RESULT: In blood samples of 89 patients with pulmonary tuberculosis and in sputum samples of 84 patients with pulmonary tuberculosis, the positive rates of PCR were 73% and 57% respectively, and the total positive rate of combinative detection of blood and sputum samples was 87% in 84 pulmonary tuberculosis patients. In 30 non-tuberculosis patients, 3 showed MTB-DNA positive. CONCLUSION: PCR technique prepared by Triton X-100 method is rapid, simple, specific, and sensitive for detection of MTB-DNA in PBMC, and its sensitivity and accuracy could be increased in combination with sputum MTB examination. Detection of MTB-DNA in PMBC is of value in diagnosis of pulmonary tuberculosis.

DNA, Bacterial↗

PubMed1998

[Culture of mycobacterium tuberculosis of gastric juice collected through different ways in diagnosis of pulmonary tuberculosis in children].

OBJECTIVE: To explore the value of culture of Mycobacterium tuberculosis through gastric juice specimens in diagnosis of patients with pulmonary tuberculosis in children. METHOD: Sputum, early morning vomited gastric juice (MVG), the other time vomited gastric juice (OVG) and early morning gastric lavage (MGL) were collected from 46 children with suspected pulmonary tuberculosis. All the specimens were processed to culture for Mycobacterium tuberculosis using pyruvate media, and the results were compared. RESULT: Of the 46 cases, Mycobacterium tuberculosis was found in 4 sputum samples (9%), 15 MGL samples (33%), 12 MVG samples (26%) and 2 OVG samples (4%). CONCLUSION: Collecting gastric juice through different methods for culture of Mycobacterium tuberculosis is specific for diagnosis of paediatric pulmonary tuberculosis.

Adolescent↗

PubMed1999

[Nested polymerase chain reaction in detecting Mycobacterium tuberculosis DNA in bioptic tissue from patients with endobronchial tuberculosis].

OBJECTIVE: To evaluate the nested polymerase chain reaction (NPCR) technique in diagnosing endobronchial tuberculosis. METHODS: NPCR method was used to detect Mycobacterium tuberculosis DNA in bioptic tissue from 67 patients with endobronchial tuberculosis, and the results were compared with pathologic examination, brushing smear, sputum smear and culture for Mycobacterium tuberculosis after bronchoscopy. The controls were 43 patients with lung cancer. RESULTS: The positive rates of detecting Mycobacterium tuberculosis were 13%, 19%, 22%, 15% and 76% respectively by pathologic examination, brushing smear, sputum smear, culture after bronchoscopy and NPCR methods. Significant differences were found between NPCR and the other 4 methods (all Ps < 0.01). No positive result for Mycobacterium tuberculosis was found in 43 controls by NPCR. CONCLUSIONS: NPCR is a useful method for diagnosing patients with endobronchial tuberculosis, especially for those with normal demonstration in X-ray chest film, negative sputum and nonspecific pathologic changes in endobronchial biopsy.

Biopsy↗

PubMed2003

Mycobacterium tuberculosis complex is not detected by DNA amplification assay in sputum specimens of patients with lung scars due to past pulmonary tuberculosis.

OBJECTIVE: To evaluate detection of false-positive sputum amplification assay results in former tuberculosis patients with residual pulmonary scars. DESIGN: A total of 268 sputum specimens from 25 war veterans with tuberculosis during 1940-1959, without adequate chemotherapy, and 19 subjects effectively treated for cavitary tuberculosis during 1980-1993 were tested by smear, culture and DNA amplification, as were 34 controls with no history of tuberculosis or pulmonary scars. RESULTS: No active tuberculosis cases were identified. All specimens were negative on DNA amplification and smear. Eight specimens from six subjects were positive on culture, revealing atypical mycobacteria. CONCLUSION: No genetic Mycobacterium tuberculosis material in sputum specimens of subjects with residual lesions of pulmonary tuberculosis and no false-positive amplification results were detected.

Adult↗

PubMed2003

[Long-term results of surgical treatment of pulmonary tuberculosis wtih respect to the extent of bacterial isolation and to drug resistance of Mycobacterium tuberculosis].

The remote postoperative results were followed up for as long as up to 10 years. It was established in case of abacillary patients that the frequency rate of relapses was minimal ranging from 3.6% in the group of patients operated for tuberculosis and caseous-necrotic tuberculosis to 11.5% in fibrous-cavernous tuberculosis. Patients with bacterial discharge, primarily of the extensive nature, had more often relapses (19.4% in operated patients for caseous-necrotic tuberculosis and 31.7% in patients operate for fibrous-cavernous tuberculosis). Drug resistance (DR) of Mycobacterium tuberculosis (MBT) to three and more anti-TB preparations essentially increase a possibility of relapses in all clinical forms of tuberculosis with maximum threat being in patients with fibrous-cavernous lesions (36%). As for the repeatedly operated patients for postoperative relapses involving DR MBT to isoniazid and rifampicin, only slightly above 50% of them survived 5 years after surgery; the index of the 5-year survival was 33% among the patients with DR to 4 and more drugs.

Antitubercular Agents↗

PubMed2004

[Usefulness of a novel diagnostic method of tuberculosis infection, QuantiFERON TB-2G, in an outbreak of tuberculosis].

OBJECTIVE: The purpose of this study was to evaluate QuantiFERON TB-2G (QFT), a novel method of detecting tuberculosis infection among contacts of a tuberculosis patient by determining the whole-blood interferongamma response to the specific antigens. SUBJECTS AND METHODS: A teacher of a college who had been coughing for the preceding two months was diagnosed with smear-positive tuberculosis. About 270 students of the college were considered to have been exposed to tuberculosis infection, of whom 73 were in closer contact with the index case because they participated in a one-week group excursion attended by the teacher. Two of the contact students developed active tuberculosis shortly thereafter. Tuberculin tests were conducted to almost all students, and QFT was performed for only those with tuberculin reactions having erythema diameters of 30 mm or larger. RESULTS: Tuberculin tests of students, all of whom had been vaccinated with BCG at least once, revealed that the distribution of the close contact group was slightly shifted to right (larger side) than those with less close contacts. The QFT positive rate for close contacts was 45.5%, while that for less close contacts was only 7.1%, which obviously indicates that QFT is hardly affected by the tuberculin allergy due to past BCG vaccination. The distribution of interferon-gamma measurements (log-transformed) of the close contacts showed typical bimodality, one mode representing the infected, another the non-infected. This was not clear for the less close contacts. The correlation of interferon-gamma measurements (log-transformed) with tuberculin reaction erythema size was weak, if not non-significant. CONCLUSION: It was concluded that QFT was a useful method for diagnosing tuberculosis infection and was unaffected by the BCG-caused tuberculin allergy. In the case of the outbreak mentioned above, QFT greatly reduced the indication of chemoprophylaxis, from 28% of all the contacts solely based on tuberculin test to only 7%. Although there remains some problems to be overcome for QFT to be widely used with high confidence, this technology will provide a high possibility for wider and more accurate indication of chemoprophylaxis and will be one of the essential tools of tuberculosis control of the 21st century in Japan.

Adolescent↗

PubMed2006

[Study on specific cellular immunity of enhance intracellular survival antigen of Mycobacterium tuberculosis in patients with pulmonary tuberculosis].

OBJECTIVE: To investigate the level of specific cellular immunity in patients with active pulmonary tuberculosis and its potential relationship with severity of the disease. METHODS: Thirty active pulmonary tuberculosis patients with positive tubercle bacilli in sputum were enrolled for the study. Immune responses including lymphocytes proliferation enhanced by enhance intracellular survival (EIS) antigen and cytokine production including interferon-gamma (IFN-gamma) and interleukin-10 (IL-10), were assayed. Cell proliferation was determined by methyl thiazolyl tetrazolium (MTT), while cytokine production was quantified by enzyme linked immunoadsorbent assay (ELISA). The results were compared to those of 20 healthy individuals and 16 persons recovered from tuberculosis. RESULTS: Cell proliferation response and IFN-gamma production were significantly higher in patients convalescent from tuberculosis compared to patients with active pulmonary tuberculosis, EIS antigen was found to elicit a dominant Th2 cytokine response. CONCLUSION: Impaired Th1 immune response to EIS is observed in patients with active pulmonary tuberculosis. Induction of imbalance of Th1/Th2 immune response may be the main action of EIS, which may be a factor of pathogenesis of tuberculosis.

Acetyltransferases↗

PubMed1984

Serodiagnosis of pulmonary tuberculosis in Argentina by enzyme-linked immunosorbent assay (ELISA) of IgG antibody to Mycobacterium tuberculosis antigen 5 and tuberculin purified protein derivative.

IgG antibody to Mycobacterium tuberculosis antigen 5 and tuberculin purified protein derivative (PPD) was measured, by enzyme-linked immunosorbent assay (ELISA), in serum samples from 86 patients with active pulmonary tuberculosis and 91 non-tuberculous control subjects from Santa Fé, Argentina. The geometric mean titre for the tuberculosis patients was 74.6 with antigen 5 and 99.5 with PPD. In 91 control subjects the geometric mean titres were 3.6 and 15.6 respectively. Titres were not related to tuberculin reactor status or prior BCG vaccination. At a serum dilution end-point of 1:40, ELISA with antigen 5 had a sensitivity of 81.4% and a specificity of 93.4% for tuberculosis. At 1:40, ELISA with PPD showed a sensitivity of 82.6% and a specificity of 54.9% for tuberculosis. Applied at a serum dilution of 1:40 to a hypothetical model population with a tuberculosis prevalence of 2%, ELISA using antigen 5 would correctly classify 93.2% of persons and ELISA with PPD, 55.5%. At a dilution of 1:80, accuracy is increased to 99.3% with antigen 5 and 83.3% with PPD, but sensitivity decreases to 64.0% with antigen 5 and 72.1% with PPD. Thus, antigen 5 is more accurate than PPD for the diagnosis of tuberculosis using ELISA.

Antigens, Bacterial↗