Diagnostic performance of interferon-γ release assay for lymph node tuberculosis.

Area of Science:

• Infectious Diseases
• Immunology
• Diagnostics

Background:

• Lymph node tuberculosis (TB) diagnosis can be challenging.
• Interferon-γ release assays (IGRAs) offer a potential diagnostic tool.

Purpose of the Study:

• To evaluate the diagnostic performance of the T-SPOT.TB interferon-γ release assay (IGRA) for suspected lymph node TB.
• To assess the sensitivity and specificity of T-SPOT.TB in this patient population.

Main Methods:

• The study included 405 patients with suspected lymph node TB.
• T-SPOT.TB testing was performed on peripheral blood mononuclear cells (PBMCs).
• IFN-γ response to Mycobacterium tuberculosis antigens was measured.

Main Results:

• The T-SPOT.TB assay demonstrated an overall sensitivity of 90.4% and specificity of 70.5%.
• Significantly higher spot-forming cells were observed in confirmed lymph node TB cases compared to non-TB cases (P<0.001).
• 83 patients (20.5%) had confirmed lymph node TB; 282 (69.6%) did not have active TB.

Conclusions:

• The T-SPOT.TB IGRA is a potentially valuable aid for diagnosing lymph node tuberculosis.
• The assay shows promising performance in identifying patients with lymph node TB.