In the current study, we followed 839 household contacts (HHCs) of tuberculosis (TB) patients for 2 years and identified the factors that enhanced the development of TB. Fourteen of the 17 HHCs who progressed to TB were in the 15- to 30-year-old age group. At baseline (the “0“ time point, when all the individuals were healthy), the concentration of the thyroid hormone thyroxine (T4) was lower, and there were increased numbers of Tregs in PBMCs of TB progressors. At baseline, PBMCs from TB progressors stimulated with early secretory antigenic target 6 (ESAT-6) and 10 kDa culture filtrate antigen (CFP-10) produced less IL-1α. Thyroid hormones inhibited Mycobacterium tuberculosis (Mtb) growth in macrophages in an IL-1α–dependent manner. Mtb-infected Thra1PV/+ (mutant thyroid hormone receptor) mice had increased mortality and reduced IL-1α production. Our findings suggest that young HHCs who exhibit decreased production of thyroid hormones are at high risk of developing active TB disease.
Kamakshi Prudhula Devalraju, Deepak Tripathi, Venkata Sanjeev Kumar Neela, Padmaja Paidipally, Rajesh Kumar Radhakrishnan, Karan P. Singh, Mohammad Soheb Ansari, Martin Jaeger, Romana T. Netea-Maier, Mihai G. Netea, Sunmi Park, Sheue-yann Cheng, Vijaya Lakshmi Valluri, Ramakrishna Vankayalapati
Immune cell distribution in the PBMCs of household contacts of TB patients.