Conversion or Reversion of Interferon γ Release Assays for Mycobacterium tuberculosis Infection: A Systematic Review...

Area of Science:

• Infectious Diseases
• Immunology
• Public Health

Background:

• Interferon gamma release assays (IGRAs) are crucial for diagnosing latent tuberculosis infection.
• Interpreting IGRA transformations, such as conversion or reversion, poses a significant challenge in clinical practice.
• Understanding the frequency and risk factors of IGRA transformation is essential for accurate diagnosis and management.

Purpose of the Study:

• To determine the pooled frequency of IGRA conversion and reversion across numerous studies.
• To identify key risk factors associated with IGRA test result transformations.
• To evaluate the significance of transient IGRA transformations and indeterminate results.

Main Methods:

• A systematic review and meta-analysis of published studies reporting IGRA transformation frequencies.
• Extraction of study and participant characteristics, IGRA testing details, and results.
• Calculation of pooled frequencies and odds ratios for IGRA conversion and reversion, examining associated risk factors.

Main Results:

• The pooled frequency of IGRA conversion was 7.3% and reversion was 22.8%.
• Transient IGRA conversions and reversions occurred in 46.0% and 19.6% of events, respectively.
• Borderline IGRA results increased conversion/reversion risk; BCG vaccination, smoking, and female sex were associated with decreased transformation risk.

Conclusions:

• IGRA conversion is less frequent than reversion and often transient, necessitating further research on the benefits of preventive treatment for reversion cases.
• Indeterminate IGRA results rarely convert to positive, suggesting retesting is generally not indicated.
• Risk factors like borderline results, BCG vaccination, smoking, and sex influence IGRA transformation, aiding in result interpretation.