Impact of HIV and CD4 Count on TB Test Performance
Author Information
Author(s): Aabye Martine G., Ravn Pernille, PrayGod George, Jeremiah Kidola, Mugomela Apolinary, Jepsen Maria, Faurholt Daniel, Range Nyagosya, Friis Henrik, Changalucha John, Andersen Aase B.
Primary Institution: University of Copenhagen
Hypothesis
How does HIV infection and CD4 cell count affect the sensitivity of the QuantiFERON TB-Gold In-Tube test in patients with pulmonary tuberculosis?
Conclusion
The QFT-IT test is reasonably sensitive for diagnosing active TB in HIV-negative patients, but its performance is limited in HIV-positive patients, especially those with low CD4 counts.
Supporting Evidence
- The QFT-IT was positive in 74% of patients with culture-confirmed PTB.
- Sensitivity was higher in HIV-negative patients (81%) compared to HIV-positive patients (65%).
- Sensitivity increased with higher CD4 cell counts in HIV-positive patients.
Takeaway
This study looked at how well a specific TB test works in people with and without HIV. It found that the test works better in people without HIV.
Methodology
161 patients with culture-confirmed pulmonary tuberculosis were tested for HIV and underwent the QFT-IT test along with CD4 cell count measurement.
Potential Biases
Potential biases may arise from the study's reliance on a single test for TB diagnosis and the exclusion of patients without valid HIV results.
Limitations
The study's findings may not be generalizable to populations outside of the TB- and HIV-endemic settings.
Participant Demographics
The study included 161 patients, with 68 (42%) being HIV-positive; more men participated than women (104 vs. 57).
Statistical Information
P-Value
0.02
Confidence Interval
95% CI: 67–81%
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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