Analysis of Factors Lowering Sensitivity of Interferon-γ Release Assay for Tuberculosis

2011

Factors Affecting Sensitivity of Tuberculosis Test

Sample size: 543 publication 10 minutes Evidence: moderate

Author Information

Author(s): Hang Nguyen Thi Le, Lien Luu Thi, Kobayashi Nobuyuki, Shimbo Takuro, Sakurada Shinsaku, Thuong Pham Huu, Hong Le Thi, Tam Do Bang, Hijikata Minako, Matsushita Ikumi, Hung Nguyen Van, Higuchi Kazue, Harada Nobuyuki, Keicho Naoto

Primary Institution: NCGM-BMH Medical Collaboration Center, Hanoi, Viet Nam

Hypothesis

What factors contribute to false-negative results in interferon-γ release assays for tuberculosis?

Conclusion

Aging, low body mass index, HIV co-infection, and specific HLA genotypes negatively affect the sensitivity of the IGRA test for tuberculosis.

Supporting Evidence

The overall sensitivity of IGRA was found to be 92.3%.
Factors such as age, low BMI, and HIV co-infection were significantly associated with IGRA negativity.
HLA-DRB1*0701 allele was linked to lower IFN-γ responses.
Patients with BMI <16.0 had a higher odds ratio for negative results.
HIV co-infection was associated with indeterminate results.
Logistic regression models were used to analyze the data.
Only new patients with smear-positive TB were included in the study.
Statistical significance was determined with p-values less than 0.05.

Takeaway

Some people with tuberculosis might get a wrong negative result from a test because of their age, weight, or other health issues.

Methodology

The study involved 543 patients with smear-positive pulmonary tuberculosis, where blood samples were tested using the IGRA and various factors were analyzed using logistic regression.