Repeated tuberculin testing in patients with active pulmonary tuberculosis

Area of Science:

• Immunology
• Infectious Diseases
• Mycobacteriology

Background:

• Tuberculin reactivity correlates with mycobacterial exposure and BCG immunization.
• Understanding tuberculin response stability is crucial for genetic studies of mycobacterial infections.
• Maximal mycobacterial exposure in tuberculosis provides a unique model to study host responses.

Purpose of the Study:

• To determine mean tuberculin reactivity in recent-onset pulmonary tuberculosis patients.
• To assess the stability of tuberculin reactions during and after tuberculosis treatment.
• To investigate factors influencing tuberculin reaction size and stability.

Main Methods:

• Serial tuberculin testing in 58 newly diagnosed pulmonary tuberculosis patients over 2 years.
• Repeated testing at 2 weeks for patients with initial reactions < 15 mm.
• Additional tests at 3-month intervals for 42 patients over 1 year.

Main Results:

• Tuberculin reactions showed unimodal distribution at diagnosis (mean 14.8-16.5 mm).
• A moderate increase in reaction size was observed after 2 weeks in some patients.
• Reaction sizes remained stable over 1 year of follow-up and treatment.
• BCG status and initial reaction size influenced reactivity variations.

Conclusions:

• Tuberculin reactivity is relatively constant in tuberculosis patients without anergy.
• Reaction size and stability depend on individual factors like baseline reactivity and BCG status.
• Findings are relevant for understanding host-mycobacterial interactions and immune responses.