Pro12Ala polymorphism of the peroxisome proliferator-activated receptor γ2 in patients with fatty liver diseases

AIM: To test the occurrence of the Pro12Ala mutation of the peroxisome proliferator-activated receptor-gamma (PPAR gamma)2-gene in patients with non-alcoholic fatty liver disease (NAFLD) or alcoholic fatty liver disease (AFLD). METHODS: DNA from a total of 622 specimens including 259 blood samples of healthy blood donors and 363 histologically categorized liver biopsies of patients with NAFLD (n = 263) and AFLD (n = 100) were analyzed by Real-time polymerase chain reaction using allele-specific probes. RESULTS: In the NAFLD and the AFLD collective, 3% of the patients showed homozygous occurrence of the Ala12 PPAR gamma 2-allele, differing from only 1.5% cases in the healthy population. In NAFLD patients, a high incidence of the Ala12 mutant was not associated with the progression of fatty liver disease. However, we observed a significantly higher risk (odds ratio = 2.50, CI: 1.05-5.90, P = 0.028) in AFLD patients carrying the mutated Ala12 allele to develop inflammatory alterations. The linkage of the malfunctioning Ala12-positive PPAR gamma 2 isoform to an increased risk in patients with AFLD to develop severe steatohepatitis and fibrosis indicates a more prominent anti-inflammatory impact of PPAR gamma 2 in progression of AFLD than of NAFLD. CONCLUSION: In AFLD patients, the Pro12Ala single nuclear polymorphism should be studied more extensively in order to serve as a novel candidate in biomarker screening for improved prognosis. (C) 2010 Baishideng. All rights reserved.