Increased Th17/Treg ratio in chronic liver GVHD

Area of Science:

• Immunology
• Graft-versus-Host Disease Research

Background:

• The role of T helper 17 (Th17) cells in chronic graft-versus-host disease (cGVHD) is established in mouse models.
• Their specific contribution to human liver cGVHD remains largely undetermined.

Purpose of the Study:

• To investigate the presence and significance of Th17 cells in liver biopsies from patients with human liver cGVHD.
• To compare Th17 cell levels with Th1 and regulatory T cells (Tregs) and assess relevant cell ratios.

Main Methods:

• Analysis of liver biopsies from 17 patients diagnosed with liver cGVHD.
• Quantification of Th17 cells (CCR6+, CD161+, RORγt+), Th1 cells, and Treg cells using flow cytometry or immunohistochemistry.
• Calculation of Th17/Th1 and Th17/Treg cell ratios.

Main Results:

• A significant increase in Th17 cells (CCR6+, CD161+, RORγt+) was observed in the liver of cGVHD patients.
• Numbers of Th1 and Treg cells were low and did not differ significantly between groups.
• Significantly elevated Th17/Th1 and Th17/Treg ratios were found in patients with liver cGVHD.

Conclusions:

• This study provides evidence of Th17 cell infiltration in the human liver affected by cGVHD.
• The increased Th17/Treg ratio suggests a potential imbalance involving impaired Treg regulation or overactivated effector Th17 cells, or both, in human liver cGVHD pathogenesis.