[Expression of COX-2 and PPARg in the livers of patients with acute on chronic HBV-related liver failure and their relationship with clinic parameters].

Objective To study the expressions of cyclooxygenase-2 (COX-2) and Peroxisome proliferator-activated receptor gamma (PPAR γ) in liver of patients with hepatitis B virus (HBV) related acute-on-chronic liver failure (ACLF) and their correlation with clinical parameters. Methods 35 patients with ACLF, 35 patients with HBV related chronic liver failure (CLF), 27 patients with chronic hepatitis B (CHB) and 15 normal control were enrolled to study the expressions of COX-2 and PPAR γ in the liver tissues by immunohistochemical staining, and to analyze the correlation of the COX-2 and PPAR γ levels in liver tissues with clinical parameters. Results COX-2 was distinctly expressed in the cytoplasm of the hepatocytes, but PPAR γ was mostly expressed in the nuclei of the hepatocytes and also could be seen in the cytoplasm. The expressions of COX-2 in the liver of ACLF, CLF and CHB groups increased significantly as compared with NC group (z = -5.18, -4.50, -5.32, P < 0.01). The levels of COX-2 in ACLF livers also increased evidently as compared with CLF groups (z = -1.98, P < 0.05). The expression levels of PPAR γ in ACLF liver tissues were much higher than the other three groups, and statistical significances existed between ACLF group and the other two groups (CLF, NC groups) (z = -2.62, -4.28, P < 0.01). In ACLF group, the expression of COX-2 correlated with MELD score (r = 0.337, P < 0.05) and the expression of PPAR γ correlated with HBV DNA load (r = 0.348, P < 0.05). Clinical data showed that the levels of AST, TBil, CHOL, PT, INR, FIB and MELD score in ACLF group were significantly different from that in CLF, CHB and NC groups. Conclusions COX-2 expressed in liver may be a marker to reflect the degree of inflammation and injury of liver tissue. The PPAR γ expression of liver could be increased during chronic HBV infection and may be a protective mechanism against liver injury.. Key words: Hepatitis B virus;  Liver failure;  Cyclooxygenase-2;  Peroxisome proliferator-activated receptor gamma