[Which tuberculin skin test hyperreactive child should be treated with -our experience]

Area of Science:

• Immunology
• Infectious Diseases
• Pediatrics

Background:

• Latent tuberculosis infection (LTBI) is a significant reservoir for active tuberculosis (TB) disease.
• Accurate diagnosis and treatment of LTBI are crucial for TB control and eradication efforts.
• Diagnosing LTBI in BCG-vaccinated children presents challenges due to potential cross-reactivity with tuberculin skin tests (TST).

Purpose of the Study:

• To evaluate the diagnostic utility of interferon-gamma release assays (IGRAs) in BCG-vaccinated school children with hyperreactive TST reactions.
• To assess the role of QFT-GIT in differentiating LTBI in this population.
• To determine if IGRA results can guide decisions on preventive therapy.

Main Methods:

• A study involving 120 BCG-vaccinated school children with hyperreactive TST results.
• Performance of the QuantiFERON-TB Gold In-Tube test (QFT-GIT) on all participants.
• Analysis of QFT-GIT results in comparison to TST reactions and interferon-gamma (IFN-γ) levels.

Main Results:

• 12.5% of children tested positive on QFT-GIT, while 87.5% tested negative.
• No significant difference in TST reaction size was observed between QFT-GIT positive and negative groups.
• Children with positive QFT-GIT exhibited statistically higher levels of IFN-γ compared to the negative group.

Conclusions:

• Interferon-gamma determination via QFT-GIT can be a key factor in diagnosing LTBI in BCG-vaccinated children.
• QFT-GIT may aid in clinical decision-making regarding the initiation of preventive therapy.
• Further investigation into IFN-γ levels, basic and stimulated, did not reveal significant differences between groups.