Taxa de resultados indeterminados de ensaio de liberação de interferon-gama entre pessoas infectadas pelo HIV
Taxa de resultados indeterminados de ensaio de liberação de interferon-gama entre pessoas infectadas pelo HIV
Data
2017
Autores
Oliveira, Sandra Maria do Valle Leone de
Trajman, Anete
Paniago, Anamaria Mello Miranda
Motta-Castro, Ana Rita Coimbra
Ruffino-Netto, Antonio
Maciel, Ethel Leonor Noia
Croda, Julio
Bonecini-Almeida, MG
Journal Title
Journal ISSN
Volume Title
Publisher
Jornal Brasileiro de Pneumologia
Resumo
Objetivo: Avaliar a frequência de resultados indeterminados de um interferon-gamma
release assay (IGRA, ensaio de liberação de interferon-gama) e os fatores relacionados
com esses resultados em pessoas vivendo com HIV/AIDS (PVHA). Métodos: Foram
avaliadas 81 PVHA na região Centro-Oeste do Brasil, por meio do teste tuberculínico e
de um IGRA. Informações a respeito de variáveis sociodemográficas e clínicas foram
obtidas por meio de questionários e prontuários médicos. A relação entre essas variáveis
e os resultados indeterminados foi avaliada por meio do cálculo da OR ajustada em um
modelo de regressão logística multivariada. A concordância foi avaliada por meio do
coeficiente kappa. Resultados: Os resultados do teste tuberculínico e do IGRA foram
positivos em 18 (22,2%) e 10 (12,3%), respectivamente, dos 81 pacientes avaliados (κ =
0,62). O resultado do IGRA foi indeterminado em 22 (27,1%) dos pacientes (IC95%: 17,8-
38,1%). A chance de resultados indeterminados foi significativamente maior em fumantes
(OR ajustada = 6,0; IC95%: 1,4-26,7) e em amostras armazenadas durante menos
de 35 dias (OR ajustada = 14,0; IC95%: 3,1-64,2). Pacientes com imunossupressão
avançada (contagem de células T CD4+ < 200 células/mm3) apresentaram maior risco
de resultados indeterminados (OR ajustada para tabagismo e tempo inadequado de
armazenamento das amostras = 4,7; IC95%: 0,91-24,0), embora a diferença não tenha
sido significativa. Conclusões: A alta prevalência de resultados indeterminados pode ser
um grande obstáculo ao uso rotineiro de IGRAs em PVHA. A necessidade de repetir o
teste aumenta seu custo e deve ser levada em conta em estudos da relação entre custo
e eficácia. O processamento das amostras pode alterar significativamente os resultados.
Objective: To evaluate the frequency of and factors associated with indeterminate interferon-gamma release assay (IGRA) results in people living with HIV/AIDS (PLWHA). Methods: We tested 81 PLWHA in the central-west region of Brazil, using the tuberculin skin test and an IGRA. Information on sociodemographic and clinical variables was gathered through the use of questionnaires and from medical records. The association of those variables with indeterminate results was analyzed by calculating the adjusted ORs in a multivariate logistic regression model. Concordance was evaluated by determining the kappa statistic. Results: Among the 81 patients evaluated, the tuberculin skin test results were positive in 18 (22.2%) of the patients, and the IGRA results were positive in 10 (12.3%), with a kappa of 0.62. The IGRA results were indeterminate in 22 (27.1%) of the patients (95% CI: 17.8-38.1%). The odds of obtaining indeterminate results were significantly higher in smokers (adjusted OR = 6.0; 95% CI: 1.4-26.7) and in samples stored for less than 35 days (adjusted OR = 14.0; 95% CI: 3.1-64.2). Patients with advanced immunosuppression (CD4+ T-cell count < 200 cells/mm3) were at a higher risk for indeterminate results (OR adjusted for smoking and inadequate duration of sample storage = 4.7; 95% CI: 0.91-24.0), although the difference was not significant. Conclusions: The high prevalence of indeterminate results can be a major limitation for the routine use of IGRAs in PLWHA. The need to repeat the test increases its costs and should be taken into account in cost-effectiveness studies. The processing of samples can significantly alter the results.
Objective: To evaluate the frequency of and factors associated with indeterminate interferon-gamma release assay (IGRA) results in people living with HIV/AIDS (PLWHA). Methods: We tested 81 PLWHA in the central-west region of Brazil, using the tuberculin skin test and an IGRA. Information on sociodemographic and clinical variables was gathered through the use of questionnaires and from medical records. The association of those variables with indeterminate results was analyzed by calculating the adjusted ORs in a multivariate logistic regression model. Concordance was evaluated by determining the kappa statistic. Results: Among the 81 patients evaluated, the tuberculin skin test results were positive in 18 (22.2%) of the patients, and the IGRA results were positive in 10 (12.3%), with a kappa of 0.62. The IGRA results were indeterminate in 22 (27.1%) of the patients (95% CI: 17.8-38.1%). The odds of obtaining indeterminate results were significantly higher in smokers (adjusted OR = 6.0; 95% CI: 1.4-26.7) and in samples stored for less than 35 days (adjusted OR = 14.0; 95% CI: 3.1-64.2). Patients with advanced immunosuppression (CD4+ T-cell count < 200 cells/mm3) were at a higher risk for indeterminate results (OR adjusted for smoking and inadequate duration of sample storage = 4.7; 95% CI: 0.91-24.0), although the difference was not significant. Conclusions: The high prevalence of indeterminate results can be a major limitation for the routine use of IGRAs in PLWHA. The need to repeat the test increases its costs and should be taken into account in cost-effectiveness studies. The processing of samples can significantly alter the results.
Description
Palavras-chave
Testes de liberação de interferon-gama, Interferon gama, Tuberculose, HIV, Tuberculose latente, Teste tuberculínico, Interferon-gamma release tests, Interferon-gamma, Tuberculosis, HIV, Latent tuberculosis, Tuberculin test.
Citação
Oliveira SMVL, Trajman A, Paniago AMM, Motta-Castro ARC, Ruffino-Netto A, Maciel ELN, Croda J, Bonecini-Almeida MG. Taxa de resultados indeterminados de ensaio de liberação de interferon-gama entre pessoas infectadas pelo HIV [Frequency of indeterminate results from an interferon-gamma release assay among HIV-infected individuals]. J. bras. pneumol. 2017 maio-jun;43(3)215-218. doi: 10.1590/S1806-37562016000000125.