Comparison of an Interferon-γ Release Assay with Tuberculin Skin Testing in HIV-infected Individuals

• Published in: American journal of respiratory and critical care medicine Vol. 175; no. 7; pp. 737 - 742
• Main Authors: Luetkemeyer, Annie F., Charlebois, Edwin D., Flores, Laura L., Bangsberg, David R., Deeks, Steven G., Martin, Jeffrey N., Havlir, Diane V.
• Format: Journal Article
• Language: English
• Published: New York, NY American Lung Association 01.04.2007; American Thoracic Society
• Subjects: Adult; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Carrier State; Enzyme-Linked Immunosorbent Assay; Female; H. Tuberculosis; Hematology; HIV Infections - blood; HIV Infections - complications; Human viral diseases; Humans; Infectious diseases; Intensive care medicine; Interferon-gamma - blood; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Predictive Value of Tests; Reproducibility of Results; Tuberculin Test; Tuberculosis - blood; Tuberculosis - complications; Tuberculosis - diagnosis; Urban Health; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids; Immunopathology; Intensive care; Cytokine; Retroviridae; AIDS; Tuberculin; Immune deficiency; Lentivirus; tuberculin skin test; Infection; Virus; Viral disease; latent tuberculosis infection; interferon-γ assay; Interferon; Human immunodeficiency virus; QuantiFERON; Comparative study; Resuscitation; Skin test
• ISSN: 1073-449X; 1535-4970
• DOI: 10.1164/rccm.200608-1088OC

Although interferon (IFN)-gamma release assays are approved for the diagnosis of latent tuberculosis infection (LTBI), limited data exist regarding their performance in HIV infection. To compare tuberculin skin test (TST) results to the commercial IFN-gamma release assay QuantiFERON-TB Gold In-Tube (QFT) for the diagnosis of LTBI in HIV-infected adults. A total of 294 HIV-infected subjects sampled from two San Francisco cohorts underwent TST, using 5 TU of purified protein derivative, and QFT, measuring IFN-gamma response to Mycobacterium tuberculosis-specific RD-1 antigens. Of 294 participants, 205 (70%) returned for an evaluable TST. Concordance between QFT and TST was 89.3% (kappa=0.37, p=0.007). However, in subjects with positive test results by either TST or QFT, only 28% (8/29) had positive test results by both modalities. TST-positive/QFT-negative discordant results were found in 5.1% of subjects and TST-negative/QFT-positive discordance in 5.6%. Indeterminate QFT results occurred in 5.1%, all due to a failure to respond to the phytohemagglutinin-positive control. Subjects with a CD4(+) count of less than 100 cells/mm(3) had a relative risk of an indeterminate result of 4.24 (95% confidence interval, 1.55-11.61; p=0.003) compared with those with a CD4(+) count of 100 or more. Overall concordance between QFT and TST in HIV infection was high, but agreement among subjects with positive tests by either modality was low.