RESUMO
The effect of the human immunodeficiency virus (HIV) on mycobacterial antibody production was investigated. Using an enzyme-linked immunosorbent assay (ELISA) for detecting IgG against Mycobacterium tuberculosis PPD, it was observed that individuals at risk of HIV infection show a pattern of humoral response to the tubercle bacillus similar to that previously found in the immunocompetent population not exposed to risk factors: 6 of 12 (50.0%) tuberculosis cases had elevated levels of antibodies to PPD and 27 of 30 (90.0%) asymptomatic individuals had antibody levels within the normal range. In an HIV-seropositive group without AIDS indicator diseases, 8 of 22 (36.4%) tuberculous patients had detectable mycobacterial antibodies whereas 156 of 164 (95.1%) non-tuberculous subjects did not. Among AIDS cases, only 1 of 20 (5.0%) patients with tuberculosis and none of 53 non-tuberculous subjects showed a positive result. The study evidenced an increasing humoral unresponsiveness to PPD in the progression of HIV infection to AIDS. Thus, a serodiagnostic method for detecting tuberculosis such as the ELISA here employed noticeably decreases its utility in the latency stage of the HIV infection, and it is practically useless in clinical AIDS.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/complicações , Anticorpos Antibacterianos/biossíntese , Infecções por HIV/complicações , Mycobacterium tuberculosis/imunologia , Tuberculose/complicações , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Síndrome da Imunodeficiência Adquirida/imunologia , Adulto , Infecções por HIV/imunologia , Soropositividade para HIV/imunologia , Humanos , Imunoglobulina G/biossíntese , Tuberculina/imunologia , Tuberculose/diagnóstico , Tuberculose/imunologiaRESUMO
The ELISA has been extensively evaluated as a serodiagnostic method for tuberculosis. However, there is scarce information about its application to cases that cannot be diagnosed by microscopic examination: those with closed lesions or undergoing early stages of the disease. Since a reliable serological test might substantially contribute to their prompt detection, the objective of the present study was to determine the diagnostic value of an ELISA applied to adult smear-negative cases of tuberculosis. Sera from 235 patients with active tuberculosis--176 pulmonary and 59 extrapulmonary cases--and 181 control subjects were tested for IgG antibodies to PPD by ELISA. Eleven cases of non tuberculous mycobacterial (MOTT) disease and 33 cases of mycosis were also included in this group. With the adopted cut-off value, 73.9% (105/142) of smear positive and 52.7% (49/93) of smear negative tuberculosis cases, were correctly classified. Particularly in the latter, the test was positive in 55.2% (32/58) of patients with positive cultures for Mycobacterium tuberculosis and in 48.6% (17/35) of patients diagnosed by clinical, radiological and or histopathological findings. No antibody activity was demonstrated in 92.7% of sera from the control population which included 92 healthy volunteers, 32 non tuberculous diseased subjects and 13 household contacts of smear-positive cases. Among those control subjects who were skin tested, ELISA results were not related to the tuberculin reactivity: 93.7% (30/32) of tuberculin negative and 95.2% (40/42) of tuberculin positive healthy individuals had no detectable antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Técnicas Imunoenzimáticas , Tuberculose/diagnóstico , Adulto , Estudos de Avaliação como Assunto , Humanos , Imunoglobulina G/análise , Mycobacterium tuberculosis/imunologia , Testes SorológicosRESUMO
Se evaluó un enzimoinmunoensayo (EIE) para la detección de anticuerpos IgG circulantes anti-PPD en el diagnóstico de la tuberculosis paucibacilar del adulto. El 73,9% de 142 pacientes bacilíferos y el 52,7% de 93 casos con baciloscopia negativa resultaron seropositivos por EIE. Particularmente en este último grupo la prueba fue positiva en el 55,25 de 58 pacientes diagnosticados por cultivo y en el 48,6% de 35 pacientes con diagnóstico clínico-radiológico de tuberculosis. El 92,7% de 137 sueros de la población control carecia de anticuerpos detectables. En los sujetos sanos que fueron tuberculinizados los resultados del EIE no se realacionaron con la respuesta tuberculínica: el 93.7% (30/32) de los tuberuclino negativos y el 95,2% (40/42) de los reactores a la tuberculina fueron negativos por EIE. Trece de 33 casos de PPD. Ciertamente el EIE tuvo máxima sensibilidad en la detección de casos bacilíferos, no obstante permitió identificar también a más de la mitad de los pacientes con baciloscopia negativa. Por lo tanto, puede ser considerado um método útil para el diagnóstico presuntivo rápido de la tuberculosis paucibacilar, excepto en los casos en los que se plantee el diagnóstico diferencial con micosis o con otras micobacterosis
Assuntos
Humanos , Adulto , Técnicas Imunoenzimáticas , Tuberculose/diagnóstico , Estudo de Avaliação , Imunoglobulina G/análise , Mycobacterium tuberculosis/imunologiaRESUMO
Se evaluó un enzimoinmunoensayo (EIE) para la detección de anticuerpos IgG circulantes anti-PPD en el diagnóstico de la tuberculosis paucibacilar del adulto. El 73,9% de 142 pacientes bacilíferos y el 52,7% de 93 casos con baciloscopia negativa resultaron seropositivos por EIE. Particularmente en este último grupo la prueba fue positiva en el 55,25 de 58 pacientes diagnosticados por cultivo y en el 48,6% de 35 pacientes con diagnóstico clínico-radiológico de tuberculosis. El 92,7% de 137 sueros de la población control carecia de anticuerpos detectables. En los sujetos sanos que fueron tuberculinizados los resultados del EIE no se realacionaron con la respuesta tuberculínica: el 93.7% (30/32) de los tuberuclino negativos y el 95,2% (40/42) de los reactores a la tuberculina fueron negativos por EIE. Trece de 33 casos de PPD. Ciertamente el EIE tuvo máxima sensibilidad en la detección de casos bacilíferos, no obstante permitió identificar también a más de la mitad de los pacientes con baciloscopia negativa. Por lo tanto, puede ser considerado um método útil para el diagnóstico presuntivo rápido de la tuberculosis paucibacilar, excepto en los casos en los que se plantee el diagnóstico diferencial con micosis o con otras micobacterosis (AU)
Assuntos
Humanos , Adulto , Tuberculose/diagnóstico , Técnicas Imunoenzimáticas , Imunoglobulina G/análise , Estudo de Avaliação , Mycobacterium tuberculosis/imunologiaRESUMO
The ELISA has been extensively evaluated as a serodiagnostic method for tuberculosis. However, there is scarce information about its application to cases that cannot be diagnosed by microscopic examination: those with closed lesions or undergoing early stages of the disease. Since a reliable serological test might substantially contribute to their prompt detection, the objective of the present study was to determine the diagnostic value of an ELISA applied to adult smear-negative cases of tuberculosis. Sera from 235 patients with active tuberculosis--176 pulmonary and 59 extrapulmonary cases--and 181 control subjects were tested for IgG antibodies to PPD by ELISA. Eleven cases of non tuberculous mycobacterial (MOTT) disease and 33 cases of mycosis were also included in this group. With the adopted cut-off value, 73.9
(105/142) of smear positive and 52.7
(49/93) of smear negative tuberculosis cases, were correctly classified. Particularly in the latter, the test was positive in 55.2
(32/58) of patients with positive cultures for Mycobacterium tuberculosis and in 48.6
(17/35) of patients diagnosed by clinical, radiological and or histopathological findings. No antibody activity was demonstrated in 92.7
of sera from the control population which included 92 healthy volunteers, 32 non tuberculous diseased subjects and 13 household contacts of smear-positive cases. Among those control subjects who were skin tested, ELISA results were not related to the tuberculin reactivity: 93.7
(30/32) of tuberculin negative and 95.2
(40/42) of tuberculin positive healthy individuals had no detectable antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)