Frequency of FOXP3+ Regulatory T-cells in the Blood of Chronic Hepatitis C Patients with Immune Mediated Skin Manifestations; Relationship to Hepatic Condition and Viral Load.

Background: Chronic hepatitis C (CHC) infection causes a wide range of immune mediated hepatic and extrahepatic manifestations. Cutaneous manifestations constitute a major portion of the latter group. Host immune response to the virus - particularly regulatory T lymphocytes - is important in determining the outcome of the infection and the possibility of extrahepatic manifestations. The present study aims to investigate the relationship between immune-mediated cutaneous manifestations of CHC infection and the frequency of CD4+CD25 high FOXP3+ T regulatory lymphocytes. We also investigated the relationships to viral load and hepatic conditions.

Methods: A total of 58 CHC patients (30 had cutaneous manifestations and 28 did not) and 30 healthy HCV free subjects were enrolled in this study. The frequency of CD4+CD25 high FOXP3+ Treg cells was measured in the peripheral blood of all participants. Additionally, serum ALT, RNA viral load, and hepatic ultrasonographic studies were performed for all patients.

Results: Skin manifestations were dominated by small vessel vasculitis and to a lesser extent lichen planus. Treg cell frequency was significantly lower in CHC patients with skin manifestations compared to those without. Chronic hepatic insult was significantly more common among patients with skin manifestations, although serum ALT levels were significantly lower in this group. Treg frequencies did not correlate to either ALT level or viral load.

Conclusions: HCV-associated skin lesions are associated with low frequency of Treg cells. They are not related to liver enzymes or viral load; however, they are associated with a more advanced gross liver insult.