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(PTFS03-01-26) Undernutrition and Nutritional Rehabilitation Are Associated With TB Antigen-Stimulated Th1 Responses Among Adult Household Contacts of People With TB in India

Saturday, July 25, 2026
1:00 PM - 1:04 PM ET
Location: Prince George's Hall B-E (The Hub) - Poster Theater 2 / Poster Board Number: PT2-1
Disclosure(s):
Lindsey M. Locks, ScD MPH: Edesia Nutrition: Grant/Research Support (Ongoing)
Objectives: Undernutrition is the largest modifiable risk factor for tuberculosis (TB) globally, yet immunologic mechanisms remain unclear, limiting development of targeted interventions. We evaluated whether baseline BMI is associated with TB antigen–stimulated immune responses among adult household contacts (HHC) of people with TB, and whether responses change after nutritional rehabilitation.

Methods: TB-LION was a prospective study that provided nutrition support (food basket + multiple micronutrient supplement) for undernourished adult HHCs of TB patients in India. Whole blood from baseline (V1) was stimulated with TB antigens (TB2) and compared with unstimulated controls (NIL) using multiplex cytokine assays. Responses were summarized as geometric mean ratios (GMR=TB2/NIL). Composite immune scores were calculated for cytokine groups: Th1 (IFN-γ, IL-), Th2 (IL-4, IL-5), Th17 (IL-17), regulatory (IL-10), pro-inflammatory (TNF-α, IL-1β, IL-6), chemokine (MCP-1, MIP-1β), and myeloid/growth factors (G-CSF, GM-CSF). Models evaluated effect modification by BMI ( < 18.5 vs ≥18.5 kg/m²) adjusting for age, sex, education, and parasitic infection. Undernourished participants received 6 months of nutrition support and were reassessed at V6.

Results: TB antigen–stimulated Th1 responses among adults with low BMI at baseline (n=53) versus BMI ≥18.5 kg/m² (n=52; GMR 1.54 [1.28–1.85] vs 2.30 [1.80–2.94]; interaction: crude p=0.01, adjusted p=0.02). Participants with low BMI also showed higher regulatory and pro-inflammatory responses, whereas chemokine responses were similar by nutritional status.

After 6 months of nutrition support, participants with undernutrition at baseline showed higher Th1 responsiveness (V1 GMR 1.51 [1.24–1.85]; V6 GMR 2.26 [1.84–2.79]; ratio-of-GMRs 1.49 [1.10–2.04]; crude p=0.01, adjusted p=0.10), while other cytokine groups changed minimally.

Conclusions: Undernutrition among adult HHCs of TB patients was associated with reduced Th1 responses to TB antigens. Improvement following nutrition support suggests partial recovery of antigen-specific immune function and supports efforts to integrate nutrition into TB prevention and care.

Funding Sources: Warren Alpert Foundatio