Th1/Th17-Treg Imbalance in Asian Atrial Fibrillation: Subtype and Demographic Heterogeneity

Area of Science:

• Immunology
• Cardiology
• Genetics and Genomics

Background:

• Atrial fibrillation (AF) is linked to adaptive immune system imbalance, particularly involving T-cell subsets.
• Existing research on immune profiles in Asian AF cohorts is limited, necessitating further investigation.

Purpose of the Study:

• To characterize peripheral adaptive immune dysregulation in Asian patients diagnosed with AF.
• To investigate potential heterogeneity in immune alterations across different AF subtypes and demographic groups.

Main Methods:

• A case-control study involving 173 AF patients and 87 controls from a hospital setting.
• Quantification of T-cell subsets via flow cytometry and serum cytokines using ELISA.
• Multivariable logistic regression models adjusted for clinical factors (left atrial diameter, LVEF, NLR) to assess immune index associations with AF.

Main Results:

• AF patients exhibited increased T helper 1 (Th1) and T helper 17 (Th17) cell counts and percentages, with unchanged T regulatory cells (Tregs).
• Elevated Th1/Treg and Th17/Treg ratios, along with systemic inflammatory markers (hs-CRP, IL-6) and effector cytokines (IFN-γ, IL-17A), were observed in AF.
• Higher Th17 counts and Th1/Treg ratios were significantly associated with AF. Immune alterations were more pronounced in paroxysmal AF than persistent AF.

Conclusions:

• The study identified an adaptive immune shift towards Th1/Th17 cells relative to Tregs in an Asian AF cohort.
• Distinct immune patterns were observed between paroxysmal and persistent AF subtypes.
• Findings are hypothesis-generating, highlighting the need for prospective, tissue-level studies to elucidate mechanisms and clinical relevance.