Predictive value of interferon-gamma release assays for postpartum active tuberculosis in HIV-1-infected women

• Published in: The international journal of tuberculosis and lung disease Vol. 17; no. 12; pp. 1552 - 1557
• Main Authors: Jonnalagadda, S. R., Brown, E., Lohman-Payne, B., Wamalwa, D., Farquhar, C., John-Stewart, G. C.
• Format: Journal Article
• Language: English
• Published: Paris, France International Union Against Tuberculosis and Lung Disease 01.12.2013; International Union against Tuberculosis and Lung Disease
• Subjects: Area Under Curve; Bacterial diseases; Biological and medical sciences; Biomarkers - metabolism; CD4 Lymphocyte Count; Coinfection; Female; HIV Infections - diagnosis; HIV Infections - epidemiology; HIV Infections - immunology; HIV Infections - virology; HIV-1 - isolation & purification; HIV-infected women; Human bacterial diseases; Human immunodeficiency virus 1; Human viral diseases; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunopathology; Incidence; Infectious diseases; Interferon-gamma - metabolism; Interferon-gamma Release Tests; Kaplan-Meier Estimate; Kenya - epidemiology; Medical sciences; Mycobacterium; Mycobacterium tuberculosis - immunology; Pneumology; Postpartum Period; Predictive Value; Predictive Value of Tests; Pregnancy; ROC Curve; Sensitivity; Specificity; TB IGRA; Time Factors; Tuberculosis - diagnosis; Tuberculosis - epidemiology; Tuberculosis - immunology; Tuberculosis - microbiology; Tuberculosis and atypical mycobacterial infections; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids; Kenya; Human; Immunopathology; Respiratory disease; AIDS; Mycobacterial infection; Puerperium; Immune deficiency; Immunological method; TB IGRA; Infection; Sensitivity; Specificity; Tuberculosis; Viral disease; HIV-infected women; Bacteriosis; Predictive value; Female; Woman; Release
• ISSN: 1027-3719; 1815-7920
• DOI: 10.5588/ijtld.13.0239

BACKGROUND: Data on the prognostic utility of interferon-gamma release assays (IGRAs) for active tuberculosis (TB) among human immunodeficiency virus 1 (HIV-1) infected individuals are limited.METHODS: Samples from a perinatal cohort of HIV-1-infected women in Kenya, obtained during pregnancy, were tested using T-SPOT®.TB IGRAs to detect Mycobacterium tuberculosis-specific interferon-gamma (IFN-γ) responses. IFN-γ (cut-off values of >0, ≥6 and ≥10 spot-forming cells [SFC]/well) and CD4 cell count (cut-off values of <250 and <350 cells/l) were evaluated to determine sensitivity and specificity using a time-dependent receiver operating characteristic curve and positive predictive value (PPV) using the Kaplan Meier method for future TB within 1 year postpartum.RESULTS: Of 327 women, 9 developed TB within 1 year postpartum (incidence rate 3.5/100 person-years of follow-up, 95%CI 1.66.7). IFN-γ ≥ 6 SFC/well was associated with an optimal trade-off between sensitivity (78%) and specificity (55%) and a PPV of 5.9%. In women with CD4 cell count of <250 cells/μl, the sensitivity and specificity of IFN- 6 SFC/well were respectively 89% and 63%, and the PPV was 19.2%.CONCLUSION: Among HIV-1 infected women, IFN-γ response (≥6 SFC/well) during pregnancy lacked a high PPV for postpartum TB, but had higher sensitivity and PPV among immunosuppressed women (CD4 cell count of <250 cells/μl).