Expanded circulating peripheral helper T cells in primary biliary cholangitis: Tph cells in PBC

Area of Science:

• Immunology
• Autoimmune Diseases
• Cell Biology

Background:

• Peripheral helper T (TPH) cells are a subset of T helper cells that support B cell differentiation and antibody production in inflammatory conditions.
• Primary biliary cholangitis (PBC) is a well-established organ-specific autoimmune disease.

Purpose of the Study:

• To investigate the association between circulating TPH cells and primary biliary cholangitis (PBC).
• To determine if TPH cell levels correlate with disease activity and plasma cell counts in PBC patients.

Main Methods:

• Flow cytometry was used to analyze circulating TPH cell subsets in 20 PBC patients and 20 healthy controls (HCs).
• Associations between TPH cells, disease activity markers (AMA-M2, IgM), and plasma cells were assessed.
• Functional TPH and B cell coculture experiments were conducted.

Main Results:

• PBC patients exhibited increased frequencies of circulating TPH cells, including ICOS+ and CD28+ subsets, compared to HCs.
• Elevated ICOS+ TPH cell levels in PBC patients, which decreased post-treatment, correlated positively with AMA-M2, IgM, and plasma cell levels.
• TPH cells from PBC patients demonstrated an enhanced capacity to induce B cell differentiation in coculture studies.

Conclusions:

• Increased TPH cell numbers and their activation status are implicated in PBC pathogenesis and disease severity.
• TPH cells represent a potential biomarker for PBC progression and a future therapeutic target.