Objective Chronic liver diseases, including cirrhosis, may develop in obese patients. Steatosis and non-alcoholic steatohepatitis (NASH) are risk factors for progression to fibrosis. To date, diagnosis of steatosis and NASH relies on liver biopsy. The aim of the study was to identify serum markers of steatosis and NASH in obese patients using SELDI-TOF ProteinChip®.
Patients Eighty obese non-alcoholic patient candidates for bariatric surgery and devoid of hepatitis B and C infection were selected. Serum samples were collected before surgery and at 6 months after surgery for 33 of them. Wedge liver biopsy was performed at the time of bariatric surgery. Twenty-four sera of healthy blood donors served as controls. The protein profiles of each serum were assessed using SELDI-TOF ProteinChip technology and were compared according to liver histological lesions.
Results Twenty-four obese patients (30%) had non significant liver lesion, 32 (40%) significant steatosis and 24 (30%) NASH. Comparison of serum protein profiles according to liver lesions identified 3 peaks (CM10-7558.4, CM10-7924.2 and Q10-7926.9) the intensity of which significantly increased according to severity of liver lesions (steatosis and NASH) and returned to normal after bariatric surgery. None was correlated with either liver function tests or metabolic parameters. Identification using immunoSELDI assay characterized these peaks as the double charged ions of α\- and β]-hemoglobin subunits.
Conclusion Differential Proteomic method demonstrated changes in serum protein profiles in obese patients according to severity of liver lesions. Free hemoglobin subunits may serve as a serum biomarker of severity of liver damages.