Association between tuberculosis recurrence and interferon-γ response during treatment.

Area of Science:

• Immunology
• Infectious Diseases
• Tuberculosis Research

Background:

• Tuberculosis (TB) recurrence remains a significant global health challenge.
• Understanding host immune responses during TB treatment is crucial for predicting outcomes.
• Interferon-gamma (IFN-γ) release assays (IGRAs) are used to assess TB infection.

Purpose of the Study:

• To investigate the association between Mycobacterium tuberculosis antigen-stimulated IFN-γ responses and TB recurrence during and after treatment.
• To analyze longitudinal patterns of IFN-γ levels in patients undergoing TB treatment.

Main Methods:

• Plasma IFN-γ levels were measured using QuantiFERON-TB Gold In-Tube™ (QFT-IT) in 407 active pulmonary TB patients at 0, 2, and 7 months of an 8-month treatment regimen.
• Patients were followed for 16 months post-treatment to assess recurrence.
• Statistical analyses included log-rank tests, Cox proportional hazard models, and random coefficient models.

Main Results:

• QFT-IT positivity remained high throughout treatment (95.6% at 0 months, 86.2% at 2 months, 83.5% at 7 months).
• Significant variations in IFN-γ responses were observed during treatment (P < 0.0001).
• A positive-to-negative QFT-IT conversion between 0 and 2 months was strongly associated with earlier TB recurrence (aHR = 5.57; 95% CI, 2.28-13.57).
• Longitudinal IFN-γ patterns differed significantly between patients who recurred and those who did not (P < 0.0001).

Conclusions:

• While IGRA responses are variable, early changes during TB treatment offer insights into host immune mechanisms.
• Monitoring IFN-γ dynamics during treatment may help identify patients at higher risk of tuberculosis recurrence.