TNF-alpha antagonist therapy modify the tuberculin skin test response

Area of Science:

• Immunology
• Rheumatology
• Infectious Diseases

Background:

• Tumour necrosis factor-alpha (TNF-α) antagonists are used for rheumatic disorders.
• TNF-α antagonists are associated with an increased risk of tuberculosis (TB).
• Tuberculin Skin Test (TST) is crucial for identifying latent TB infection.

Purpose of the Study:

• To prospectively analyze the effect of TNF-α antagonists on TST responses.
• To evaluate changes in TST reactivity during TNF-α antagonist therapy.

Main Methods:

• A prospective study involving 182 patients receiving TNF-α antagonists for rheumatic disorders.
• Patients underwent TST at baseline and 12-month follow-up.
• TST was repeated for patients with <5 mm induration to assess booster effect.

Main Results:

• Initially, 48% of patients had negative TST (0-4 mm) and 52% had positive TST (≥ 5 mm).
• TST responses significantly increased after one year of TNF-α antagonist treatment (9.15 ± 0.55 mm vs. 6.60 ± 0.51 mm, P < 0.001).
• TST conversion from negative to positive occurred in 30% of patients within one year.

Conclusions:

• Increased TST responses in patients on TNF-α antagonists may reflect restored immune reactivity against TB antigens.
• The clinical significance of TST conversion and the need for chemoprophylaxis in this population require further investigation.