Background:
Approximately 95% of individuals infected with Mycobacterium tuberculosis do not progress to active tuberculosis (TB) disease. Identifying the specific determinants of TB progression among close contacts is critical for focusing prevention efforts and prioritizing the delivery of TB preventive therapy (TPT) to those at highest risk. While factors like age, HIV status, and initial infection markers are known, the role of readily available biomarkers like body mass index (BMI) in identifying progressors within high-risk, IGRA-positive populations needs clearer definition.
Abstract:
- Methods: This prospective multi-center cohort study (RePORT-Brazil) followed 1,846 close contacts of pulmonary TB patients for 24 months between 2015 and 2019. Dimension reduction techniques (LASSO regression and empirical review) were used to develop prediction models for all contacts, IGRA-positive contacts, and IGRA-positive contacts who did not receive TPT.
- Results: Among the contacts, 25 (1.4%) progressed to active TB. Not receiving TPT was the strongest risk factor for progression among all contacts (aHR: 16.55). For IGRA-positive contacts who did not receive TPT, BMI was inversely associated with TB risk (aHR: 0.89 per unit increase). A critical BMI threshold was identified; IGRA-positive contacts with a BMI $<25$ kg/m² had a 4.14-fold higher risk of progression compared to those with a BMI $\ge25$ kg/m² (8.4% vs. 2.1% progression rate, respectively).
- Conclusion: A BMI $<25$ kg/m² is a robust and readily available biomarker that identifies IGRA-positive close contacts at high risk of progressing to TB disease. Prioritizing TPT for this specific group could significantly enhance TB prevention and control efforts.
Keywords: close contact; TB progressor; active TB; prediction model; tuberculosis; interferon gamma release assay; body mass index.
Clique aqui
- Data de Publicação: 01/10/2025
- Autores: María B. Arriaga, PhD1,2* , Gustavo Amorim, PhD 3* , Marina C. Figueiredo, MS1 , Cody Staats, MS1 , Afrânio L. Kritski, PhD4 , Marcelo Cordeiro-Santo, PhD5,6,7, Valeria C. Rolla, PhD8 , Peter F. Rebeiro, PhD1,3,9^ , Bruno B. Andrade, PhD 10,11,12,13,14^ , Timothy R. Sterling, MD1^ , for the RePORT-Brazil consortium
