The serum level of the immunomodulatory peptide cathelicidin LL37 and T helper cell type 1 inflammatory response in viral hepatitis B, C, and D

Abstract

Cathelicidin LL37 is an innate immunity antimicrobial peptide involved in the immune modulation of IFN-γ, the key cytokine of T helper cell type 1 (Th1) response. The role of LL37 in viral hepatitis inflammation is unknown. We assessed the serum variations of LL37 and the Th1 response in hepatitis C virus (HCV), hepatitis B virus (HBV) and hepatitis D virus (HDV) infections. The LL37 level (Elisa detection) and Th1 response (defined by IFN-γ level, CD4+ and CD8+ T cell count) were analyzed in 87 patients: 65 hepatitis patients (34 HCV, 18 HBV, 13 HDV) and 22 healthy controls. The subjects, 33 males/ 54 women aged 20-64 years, were selected at Matei Bals Institute, Bucharest, Romania. Hepatitis patients were classified according to viral etiology and viral replication as active cases (detectable viremia) versus negative cases (undetectable viremia). Student T test and Mann Whitney analysis were applied. High levels of LL37 (138.09±88.45ng/ml, p=0.045) and IFN-γ (69.82 pg/ml, p=0.005) were detected in the whole group of hepatitis. Active HCV hepatitis presented a significant increase in LL37 level (155.15±78.84ng/ml, p=0.014) and Th1 response by comparison with inactive HCV hepatitis. Conversely active HBV patients displayed low LL37 levels (76.75ng/ml, p=0.009) and no Th1 dominant response by comparison with inactive B hepatitis. High levels of LL37 up to 171.01±72.08 ng/ml and a moderate Th1 response defined HDV patients. Our results highlights increased levels of the cathelicidin LL37 in all viral hepatitis correlated with a strong and concordant immune response in active HCV hepatitis.