RESUMO
In this work we characterize the Mycobacterium bovis bacillus Calmette-Guerin (BCG) -induced pleurisy and investigate the role of chemical mediators and cytokines in BCG-induced granulocyte accumulation at 24 h. Intrathoracic injection of BCG in C57B1/6 mice induces a biphasic inflammatory reaction with intense leukocyte accumulation at 24 h and 15 days. Neutrophils were observed in the pleural cavity at 4-24 h, mononuclear cells and eosinophils after 24 h. A new wave of mononuclear cells and neutrophils were observed after 15 days. Pretreatments with dexamethasone, BW 755C, BW A4C, WEB 2170, L-NAME, and monoclonal antibody (mAb) anti-interleukin-5 (IL-5; TRFK-5) had inhibited the eosinophil accumulation. On the other hand, only the pretreatments with dexamethasone, L-NAME, or mAb anti-tumor necrosis factor alpha (TNF-alpha; MP6-XT3) had inhibited the neutrophil influx. These results suggest the involvement of leukotrienes, platelet-activating factor, nitric oxide, and IL-5 in the eosinophil accumulation, and a role for nitric oxide and TNF-alpha in the neutrophil influx induced by BCG.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Movimento Celular/imunologia , Citocinas/farmacologia , Eosinófilos/imunologia , Mycobacterium bovis , Neutrófilos/imunologia , Pleurisia/imunologia , Animais , Movimento Celular/efeitos dos fármacos , Eosinófilos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/patologia , Pleurisia/microbiologia , Pleurisia/patologiaRESUMO
BACKGROUND: Bacillemia is a key event in the pathogenesis of tuberculosis. Although current evidence indicates that Mycobacterium tuberculosis bacteremia is rare in patients seronegative for the human immunodeficiency virus, it has been increasingly reported in patients with the acquired immunodeficiency syndrome (AIDS). OBJECTIVE: To determine clinical and laboratory characteristics of patients with AIDS and tuberculosis with and without bacillemia. METHODS: Fifty patients with AIDS with clinical suspicion of disseminated mycobacterial disease were prospectively selected. Three consecutive blood samples were collected for culture using a standardized protocol. RESULTS: Mycobacterium was isolated from any body site in 42 patients (84%). Bacillemia was detected in 30 (71.4%) of these 42 patients: 11 (28.2%) caused by Mycobacterium avium-intracellulare complex and 19 (71.8%) caused by M tuberculosis. Blood culture was the only method used to confirm the diagnosis in 5 (15%) of the 33 tuberculosis cases. Tuberculosis in patients with AIDS developed with nonspecific insidious symptoms, a remarkable elevated alkaline phosphatase level, and without the classic miliary radiological pattern. We could demonstrate 2 previously unrevealed clinical characteristics of bacteremic tuberculosis in patients with AIDS: a shift to the left in the white blood cell count and abdominal lymph node enlargement. In patients with tuberculosis, the in-hospital mortality rate was higher among patients with bacillemia, although the posttreatment survival rate was comparable. CONCLUSIONS: Blood culture is a valuable tool to confirm the clinical diagnosis of disseminated tuberculosis in patients with AIDS and can distinguish patients with characteristic clinical findings and outcome. Abdominal ultrasonography may be an additional helpful tool to identify these patients.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Bacteriemia/microbiologia , Complexo Mycobacterium avium , Mycobacterium tuberculosis , Adulto , Feminino , Humanos , Masculino , Complexo Mycobacterium avium/isolamento & purificação , Infecção por Mycobacterium avium-intracellulare/diagnóstico por imagem , Infecção por Mycobacterium avium-intracellulare/microbiologia , Mycobacterium tuberculosis/isolamento & purificação , Estudos Prospectivos , Radiografia , Tuberculose Pulmonar/diagnóstico por imagem , Tuberculose Pulmonar/microbiologiaRESUMO
We studied 567 patients with active pulmonary tuberculosis (APT) in Rio de Janeiro, Brazil, by using a standardized questionnaire and by testing blood for HIV antibodies. The rate of HIV infection was 3.9% in 1987, 4.8% in 1988, and 5.2% in 1989, and did not differ by sex. It was highest (7.4%) in the 15- to 39-year age group. There was no difference between patients infected and not infected by HIV with regard to education, income, housing, or employment. Among all patients with definite HIV risk behavior, the HIV infection rate was 23.3%, rising to 31.2% among homo/bisexual men and 36.4% among intravenous drug users, and the rate was 6.5% for blood-transfusion recipients. Among patients who denied risk behavior, the rate was 1.2%. Generalized lymphadenopathy and oral candidiasis occurred with greater frequency among HIV-infected patients (p < 0.0001). Applying the World Health Organization 1985 clinical criteria and revised case definition for AIDS, we found, respectively, sensitivities of 34% and 76.9% and specificities of 31% and 26.3%; in the Rio de Janeiro environment, these clinical criteria without HIV serology should not be adopted for tuberculosis patients. For chest radiographs, a significant association was found between HIV infection and the occurrence of atypical images (p = 0.0001), and hilar and/or mediastinal adenopathy (p = 0.0002) and absence of cavities (p = 0.0003). A PPD (purified protein derivative) skin test induration of < 5 mm was identified in 53% of the HIV-positive cases and in 31.3% of the HIV-negative cases. Only 11.5% of HIV-infected APT patients met the Centers for Disease Control 1987 AIDS criteria.
Assuntos
Infecções por HIV/epidemiologia , Tuberculose Pulmonar/complicações , Adolescente , Adulto , Fatores Etários , Idoso , Transfusão de Sangue , Brasil/epidemiologia , Candidíase Bucal/complicações , Feminino , Anticorpos Anti-HIV/sangue , Infecções por HIV/complicações , Comportamentos Relacionados com a Saúde , Homossexualidade , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Prevalência , Radiografia , Fatores de Risco , Sensibilidade e Especificidade , Abuso de Substâncias por Via Intravenosa/complicações , Inquéritos e Questionários , Teste Tuberculínico , Tuberculose Pulmonar/diagnóstico por imagemRESUMO
STUDY OBJECTIVE: Risk factors associated with treatment failure and multidrug-resistant tuberculosis (MDR-TB) were examined among HIV-seronegative patients who were previously treated for tuberculosis (TB). DESIGN: Prospective, cohort study of patients referred to the study hospital for retreatment of TB between March 1986 and March 1990. PATIENTS: The patients belonged to three groups, according to outcomes following their previous treatment: 37 patients who abandoned treatment or suffered relapse after completion of therapy (group A), 91 patients who failed to respond to the first-line drug regimen (group B), and 78 patients who failed to respond to the second-line drug regimen (group C). RESULTS: Patients with Mycobacterium tuberculosis strains resistant to rifampin and isoniazid were found in 2 (6%) in group A, 29 (33%) in group B, and 49 (65%) in group C. Cure was achieved in 77% in group A, 54% in group B, and 36% in group C. Death occurred in none of the patients in group A, 8% in group B, and 24% in group C. In a multivariate logistic regression analysis, unfavorable response (failure to sterilize sputum culture, death, and abandonment) was significantly associated with infection with a multidrug-resistant M tuberculosis strain (p = 0.0002), cavitary disease (p = 0.0029), or irregular use of medications (p < 0.0001). CONCLUSIONS: These observations show that a previous treatment outcome and current clinical and epidemiologic histories can be used to predict the development of MDR-TB and adverse outcomes in patients undergoing retreatment for TB. Such information may be useful for identifying appropriate patient candidates for programs such as directly observed therapy.
Assuntos
Antituberculosos/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico , Adulto , Idoso , Antituberculosos/administração & dosagem , Causas de Morte , Protocolos Clínicos , Estudos de Coortes , Feminino , Previsões , Soronegatividade para HIV , Humanos , Isoniazida/uso terapêutico , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mycobacterium tuberculosis/efeitos dos fármacos , Cooperação do Paciente , Estudos Prospectivos , Recidiva , Indução de Remissão , Retratamento , Rifampina/uso terapêutico , Fatores de Risco , Escarro/microbiologia , Resultado do Tratamento , Recusa do Paciente ao TratamentoRESUMO
Experimental inoculation of tubercle bacilli does not correspond to natural contagion. The classic and unique study published in the literature, performed by Max Lurie with inbred rabbit families to evaluate resistance and susceptibility to tuberculosis, closely simulated the natural mode of infection, reproducing the varying types of the disease as it occurs in man. Lurie observed that resistant families developed cavitary tuberculosis and susceptible families developed disseminated tuberculosis. The conclusions were based only on resistance to the progress of tuberculous infection due to cellular-mediated immunity. In this report we have made an additional analysis of this experiment, looking for the resistance to infection itself.
Assuntos
Predisposição Genética para Doença , Tuberculose Pulmonar/imunologia , Animais , Imunidade Inata/genética , Coelhos , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/patologiaRESUMO
As the leading infectious killer of youths and adults, tuberculosis (TB) kills more women than all other causes of maternal mortality combined. The aim of this study is to investigate gender differences in the reported cases in Rio de Janeiro from January 1995 to December 1999. There were 18,428 females and 36,830 males, with a female:male ratio of 0.5; 30.8% (5676) of the female cases reported had had previous close contact with a tuberculosis case compared to 23.1% (8510) of the males. Extra-pulmonary tuberculosis occurred in 3966 (21.5%) and 6521 (17.7%) women and men, respectively. Genitourinary tuberculosis had the highest female:male ratio.
Assuntos
Tuberculose/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Brasil/epidemiologia , Notificação de Doenças , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição por Sexo , Fatores de TempoRESUMO
OBJECTIVE: To evaluate the association between an early humoral response to Mycobacterium tuberculosis antigens and the later development of tuberculosis (TB) disease in human immunodeficiency virus (HIV)-infected individuals. METHODS: Using an ELISA test, IgG antibodies against 4 M. tuberculosis antigens--purified protein derivative (PPD); 2,3 diacyl trehalose (DAT); a lipooligosaccharide (LOS) and a trehalose dicarboxylic acid bis N,N-dioctadecylamide (BDA.TDA)--were measured in sera from 25 HIV-infected tuberculous patients and 52 HIV-infected persons without TB. RESULTS: With the DAT and LOS antigens, a positive result in sera obtained in the 12 months preceding the onset of TB was significantly associated with later development of TB. Using the BDA.TDA antigen, the same association was observed in sera collected during the 6 months before the diagnosis of TB. No significant association was found with the PPD antigen. CONCLUSIONS: These results suggest that specific antibody markers may be useful to evaluate the risk of active TB in HIV-infected individuals, and a helpful indicator for preventive treatment.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/imunologia , Anticorpos Antibacterianos/análise , Mycobacterium tuberculosis/imunologia , Tuberculina/análise , Tuberculose/imunologia , Infecções Oportunistas Relacionadas com a AIDS/sangue , Adulto , Formação de Anticorpos , Estudos de Casos e Controles , Intervalos de Confiança , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Sensibilidade e Especificidade , Tuberculose/sangue , Tuberculose/diagnósticoRESUMO
Mycobacteria as intracellular pathogens have evolved mechanisms to survive within macrophages. Our previous data showed that M. leprae (ML), unlike M. bovis BCG, did not induce an inflammatory response in the mice subcutaneous tissue. Further, ML inhibited BCG-induced foot pad oedema and seemed to transform macrophages in epithelioid cells. Since these mycobacteria share common antigens, here we seeked to compare the acute and chronic cellular response evoked by ML and BCG in pleurisy of a mycobacteria-susceptible mice (BALB/c). The total leukocytes, the cell type that migrated to the pleural cavity and macrophage activation assayed by nitric oxide release were determined. Live or dead BCG Moreau recruited the same extent of cells, essentially monocytes and neutrophils, dose-dependently, in both acute and chronic pleurisy. BCG-induced eosinophilia was observed only in the acute response (after 24 h of injection). A significant nitric oxide release by pleural macrophages was triggered by BCG Moreau without previous activation. Nevertheless, ML failed to recruit leukocytes to the pleural space or to lead to nitric oxide production despite the number of bacilli used and the time studied (1, 7 or 14 days after injection). Although these mycobacteria have common antigens that cross-react, these data show a distinct ability of ML or BCG to recruit cells to the pleural space and to activate pleural macrophage for nitric oxide production in vivo.
Assuntos
Vacinas Bacterianas/administração & dosagem , Mycobacterium bovis/imunologia , Mycobacterium leprae/imunologia , Óxido Nítrico/metabolismo , Pleura/efeitos dos fármacos , Vacinação , Animais , Movimento Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Cinética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pleura/citologia , Pleura/metabolismo , Pleurisia/metabolismo , Pleurisia/prevenção & controleRESUMO
We studied the kinetics of in vivo nitrite production in the inflammatory reaction induced by M. bovis BCG into the pleural space. Pleural macrophages harvested from C57Bl/6 mice after acute BCG infection produced high levels of nitric oxide (NO). Enhanced production was obtained upon stimulation with LPS plus IFN-gamma. In sharp contrast, macrophages from DBA-2 mice produced low levels of NO, as nitrite, at the same time interval (24 h after BCG infection), being completely refractory to further stimulation. After the third day, NO production was similar in both strains. There was a close relationship between nitrite levels in the pleural exudate in vivo and those produced by harvested macrophages in vitro. In this in vivo system, the pattern of NO production by pleural macrophages one day after BCG infection was discrepant and unexpected in the response of C57Bl/6 and DBA-2 mice. However, this early response did not affect the late progressive NO production in both mice strains, that may be responsible to the late control of the mycobacteria growth.
Assuntos
Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Pleura/metabolismo , Animais , Inflamação/metabolismo , Interferon gama/farmacologia , Cinética , Leucócitos/metabolismo , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Mycobacterium bovis , Nitritos/metabolismo , Ornitina/análogos & derivados , Ornitina/farmacologia , Pleurisia/metabolismo , Zimosan/farmacologiaRESUMO
Limited data are available on the cellular and immunocytological characteristics of bronchoalveolar lavage (BAL) fluid in individuals infected with the human immunodeficiency virus (HIV) and pulmonary tuberculosis (TB). The immune host response against tuberculosis in early HIV-infection may differ from that in later stages of HIV disease, as is strongly suggested by different clinical and radiographic patterns. We studied the cellular elements in the lungs of 15 HIV-infected patients with advanced immunosuppression and pulmonary tuberculosis (TB/AIDS). The findings were compared with data from four other groups: 1) 15 HIV-seronegative patients with pulmonary TB; 2) 12 HIV-seropositive TB patients without previous AIDS-defining illnesses and with CD4+ >200 cells mm(-3); 3) five AIDS patients without pulmonary lesions; and 4) five healthy controls. BAL fluid and differential cell counts, as well as lymphocyte subsets, were determined. Despite a low CD4/CD8 ratio, the TB/AIDS group had a higher absolute number of CD8+ lymphocytes in the BAL fluid than the other groups. Alveolar macrophages and neutrophils were significantly increased in TB/AIDS patients compared to control groups. The number of eosinophils was increased in TB/HIV--patients but not in TB/AIDS patients. We conclude that tuberculosis in late stage HIV-infected patients has a distinct inflammatory cell profile, suggesting an enhanced compensatory mechanism that amplifies the unspecific inflammatory reaction.
Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , Fagócitos/imunologia , Tuberculose Pulmonar/imunologia , Adulto , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Feminino , Humanos , Contagem de Leucócitos , Linfócitos/imunologia , MasculinoRESUMO
Isolates of Mycobacterium tuberculosis derived from patients with AIDS from a single hospital in Rio de Janeiro were typed using a standardized RFLP technique detecting IS6110 polymorphism. Nineteen isolates were obtained from 15 different patients. Eleven distinct IS6110 patterns were found, with 4 banding patterns shared by 2 patients. The clustering value of 53% was much higher in comparison with clustering of M. tuberculosis strains from TB patients without clinical signs for HIV infection from randomly selected health centers. We present these results as preliminary data on M. tuberculosis strain polymorphism in Brazil and on the higher risk for recent transmission amongst patients with AIDS.
Assuntos
Impressões Digitais de DNA , Infecções por HIV/complicações , Mycobacterium tuberculosis/genética , Tuberculose/complicações , Brasil/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/microbiologia , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/epidemiologia , Tuberculose/microbiologiaRESUMO
The effect of the human immunodeficiency virus (HIV) infection on IgG production against purified protein derivative (PPD) and 2,3-diacil-trehalose (SL-IV) was investigated by an enzyme-linked immunosorbent assay (ELISA) test. Comparison between the antigens showed that immunocompetent patients produce preferentially antibodies to SL-IV than to PPD (73.3% versus 63.3%). Combination of these results showed an increase of the sensitivity to 80%, which decreased over the spectrum of immunodepression caused by HIV. In the tuberculous HIV seropositive group the sensitivities of SL-IV and PPD were 36.4% versus 40% and 0% versus 22.2% in the tuberculosis/acquired immunodeficiency syndrome (TB/AIDS) group. Combination of these results gave respectively 54.5% and 20%, showing that serological tests have limited value for diagnosis of tuberculosis in HIV infected patients. High antibody levels were observed in HIV seropositive asymptomatic group, but only two individuals were positive for both antigens. In the follow up, one of them developed tuberculous lymphadenitis, indicating that further work is needed to access the value of serological tests in predicting tuberculosis in HIV infected individuals.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Tuberculose/complicações , Ensaio de Imunoadsorção Enzimática , Humanos , Sensibilidade e Especificidade , Trealose , Tuberculose/diagnósticoRESUMO
With the development of the acquired immunodeficiency syndrome (AIDS) epidemic, the isolation of mycobacteria from blood has become a common problem for clinical laboratories. In this study two methods were used for the recovery of mycobacteria from blood specimens obtained from AIDS patients: (1) direct inoculation of a biphasic medium, and (2) a non-commercial lysis-centrifugation method. A total of 3 consecutive blood samples were taken at 15-minute intervals from each of 50 AIDS patients with clinical suspicion of disseminated mycobacterial disease. Mycobacterium growth was noted in 70/138 blood specimens from 30 (60%) patients. These cultures yielded Mycobacterium tuberculosis in 19 (63%) and Mycobacterium avium complex organisms in 11 (37%) patients. Cultures using the lysis-centrifugation method were positive in 54% of the patients while cultures using biphasic medium were positive in 44% (P > 0.05). The positivity for M. avium complex was higher with lysis-centrifugation (91%) than with biphasic medium (45.4%) (P < 0.05). However, the positivities for M. tuberculosis with the lysis-centrifugation method (89.5%) and direct inoculation in biphasic medium (100%) were similar (P > 0.05). The use of a non-commercial lysis-centrifugation technique is inexpensive, reliable, and can be an alternative method for the diagnosis of mycobacteraemia in developing countries.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Bacteriemia/diagnóstico , Infecções por Mycobacterium/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Bacteriemia/microbiologia , Técnicas Bacteriológicas , Sangue/microbiologia , Países em Desenvolvimento , Humanos , Infecções por Mycobacterium/microbiologia , Complexo Mycobacterium avium/isolamento & purificação , Infecção por Mycobacterium avium-intracellulare/diagnóstico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Tuberculose/microbiologiaRESUMO
OBJECTIVE AND DESIGN: The host response to Mycobacteria focuses on the development of cell-mediated immunity and granuloma formation. Here, we investigated the onset of cellular responses to mycobacteria in murine pleurisy. MATERIAL: Distinct mouse strains previously described as Bcg susceptible or resistant were inoculated intrathoracically with different doses of live M. bovis BCG. METHODS: At various time intervals, cells harvested from the inflammatory site were identified and ultra-structurally analysed. RESULTS: BCG-induced pleurisy had two peaks of cellular influx at 1 and 15 days after infection. At the first half hour, macrophages were found to be heavily infected. Neutrophil arrival started after 2 h of infection and peaked at 4 h. At this time, neutrophils were found ingesting mycobacteria exclusively with a high infecting dose. BCG was potently more eosinophilotactic in Bcg susceptible mice than in the resistant ones and to other well known eosinophilia inducers: IL-5, PAF-acether or LPS. CONCLUSIONS: Mycobacterial load and mouse susceptibility seem to determine the early granulocyte dynamics in the lesion.
Assuntos
Adjuvantes Imunológicos , Vacina BCG/toxicidade , Eosinófilos/patologia , Pleura/patologia , Pleurisia/patologia , Animais , Vacina BCG/imunologia , Exsudatos e Transudatos/citologia , Contagem de Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Microscopia Eletrônica , Neutrófilos/imunologia , Pleurisia/induzido quimicamente , Especificidade da Espécie , Fatores de TempoRESUMO
Multidrug-resistant tuberculosis (MDRTB) has emerged as a major public health problem worldwide. To determine the incidence and risk factors associated with tuberculosis among contacts of MDRTB index cases, we studied human immunodeficiency virus-seronegative close contacts of 64 culture-confirmed MDRTB patients in Rio de Janeiro, Brazil. Between March 1988 and July 1992, tuberculosis developed in 17 (7.8%) of 218 previously healthy close contacts of 64 MDRTB index cases (1.6 cases per 1,000-person-months of contact). Among strains of Mycobacterium tuberculosis isolated from 13 contacts of 12 index cases, six (46%) had susceptibility patterns identical to those of their index cases, four (31%) had different patterns of resistance, and three (23%) were susceptible to all drugs. Tuberculosis developed more frequently in male contacts (p < 0.05), persons > or = 15 yr of age (p < 0.05), nonwhites (p < 0.001), and persons not previously vaccinated with bacillus Calmette-Guerin (BCG) (p < 0.05). The association of BCG vaccination with decreased risk of disease was significant even when this variable was controlled (by Cox's regression analysis) for age, sex, race, purified protein derivative (PPD) status, and isoniazid prophylaxis. BCG vaccination appears to offer protection against tuberculosis during prolonged exposures to persons with MDRTB, which identifies a novel and specific indication of BCG use.
Assuntos
Tuberculose Resistente a Múltiplos Medicamentos/transmissão , Tuberculose/transmissão , Adolescente , Adulto , Fatores Etários , Vacina BCG/administração & dosagem , Criança , Pré-Escolar , Interpretação Estatística de Dados , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais , Tuberculose/prevenção & controle , Tuberculose Resistente a Múltiplos Medicamentos/prevenção & controleRESUMO
We compared the peripheral and pulmonary response to assess the phagocytic activity of monocytes/macrophages and neutrophils and the lymphoproliferative response (LPR) against Mycobacterium tuberculosis antigens from 21 AIDS patients, presenting at diagnosis with active pulmonary tuberculosis (TB), other non-TB pulmonary infection, or no pulmonary infection, as well as patients with active pulmonary TB and healthy control subjects. Alveolar lymphocyte analysis demonstrated that AIDS/TB patients had more markedly reduced percentages of CD4(+) lymphocytes than AIDS/TB patients and an increase in the percentage of CD8(+) lymphocytes, probably reflecting the impairment of CD4(+) T lymphocytes in peripheral blood at the lungs. Moreover, alveolar lymphocytes from AIDS/TB patients demonstrated a two- to fourfold decrease in LPR against M. tuberculosis antigens. Interestingly, it was observed an enhanced migration of natural killer cells to the lungs in all patients group. The phagocytic activity in alveolar macrophages and neutrophils showed that AIDS/TB patients had a twofold decreased capacity to ingest inert particles compared with AIDS patients. Comparing the alveolar and peripheral lymphocyte number and functional activity to M. tuberculosis-antigens it was possible to demonstrate that in both sites these cells had similar profile. However, the innate immune response in lungs showed a reduced activation in the presence of HIV infection, regarding the M. tuberculosis coinfection. These findings suggest that the advanced impairment of CD4(+) T lymphocyte in HIV-1 infection may lead to a deactivation of alveolar macrophages, enhancing bacilli burden and HIV replication in the lungs and furthering dissemination.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/imunologia , HIV-1 , Linfócitos/imunologia , Macrófagos Alveolares/imunologia , Alvéolos Pulmonares/imunologia , Tuberculose Pulmonar/imunologia , Infecções Oportunistas Relacionadas com a AIDS/sangue , Adulto , Divisão Celular , Feminino , Humanos , Masculino , Neutrófilos/imunologia , Fagócitos/imunologia , Alvéolos Pulmonares/citologia , Linfócitos T/imunologia , Tuberculina/imunologia , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/complicaçõesRESUMO
Con el desarrollo de la epidemia del síndrome de inmunodeficiencia adquirida (sida), el aislamiento de micobacterias de la sangre se ha convertido en un problema habitual de los laboratorios clínicos. En el presente estudio se evaluaron dos métodos para aislar micobacterias en muestras de sangre de pacientes de sida: 1) la inoculación directa en un medio bifásico y 2) un método no comercializado de lisis por centrifugación. A cada uno de los 50 pacientes de sida con sospecha de enfermedad micobacteriana diseminada se le extrajeron tres muestras de sangre consecutivas a intervalos de 15 minutos. En 70 de 138 muestras de sangre obtenidas de 30 (60%) pacientes se detectó crecimiento de micobacterias. A partir de estos cultivos, en 19 pacientes se aisló Mycobacterium tuberculosis y en 11 (37%), el complejo Mycobacterium avium. Los cultivos en que se utilizó el método de lisis por centrifugación fueron positivos en 54% de los pacientes, mientras que esta cifra se redujo a 44% en los cultivos en que se usó el método bifásico (P > 0,05). El porcentaje de muestras positivas al complejo M. avium fue mayor con el método de centrifugación por lisis (91%) que con el de inoculación directa en medio bifásico (45,4%) (P < 0,05). Sin embargo, los porcentajes de muestras positivas a M. tuberculosis detectadas con el método de lisis por centrifugación (89,5%) y con el de inoculación directa en un medio bifásico (100%) fueron similares (P > 0,05). La técnica no comercializada de centrifugación por lisis es barata, fiable y puede constituir un método alternativo para el diagnóstico de micobacteriemia en países en desarrollo.
With the development of the acquired immunodeficiency syndrome (AIDS) epidemic, the isolation of mycobacteria from blood has become a common problem for clinical laboratories. In this study two methods were used for the recovery of mycobacteria from blood specimens obtained from AIDS patients: (1) direct inoculation in biphasic medium, and (2) a noncommercial lysis-centrifugaton method. A total of three consecutive blood samples were taken at 15-minute intervals from each of 50 AIDS patients with clinical suspicion of disseminated mycobacterial disease. Mycobacterium growth was noted in 70/138 blood specimens from 30 (60%) patients. These cultures yielded Mycobacterium tuberculosis in 19 (63%) and Mycobacterium avium complex organisms in 11 (37%) patients. Cultures using the lysis-centrifugation method were positive in 54% of the patients, while cultures using biphasic medium were positive in 44% (P > 0,05). The positivity for M. avium complex was higher with lysis-centrifugation (91%) than with biphasic medium (45,4%) (P < 0,05). However, the positivities for M. tuberculosis with the lysis-centrifugation method (89,5%) and direct inoculation in biphasic medium (100%) were similar (P > 0,05). The use of a noncommercial lysis-centrifugation technique is inexpensive, reliable, and can be an alternative method for the diagnosis of mycobacteremia in developing countries.
Assuntos
Técnicas Microbiológicas , Países em Desenvolvimento , Interações MicrobianasRESUMO
Isolates of Mycobacterium tuberculosis derived from patients with AIDS from a single hospital in Rio de Janeiro were typed using a standardized RFLP technique detecting IS6110 polymorphism. Nineteen isolates were obtained from 15 different patients. Eleven distinct IS6110 patterns were found, with 4 banding patterns shared by 2 patients. The clustering value of 53 percent was much higher in comparison with clustering of M. tuberculosis strains from TB patients without clinical signs for HIV infection from randomly selected health centers. We present these results as preliminary data on M. tuberculosis strain polymorphism in Brazil and on the higher risk for recent transmission amongst patients with AIDS.