Histological NASH Score (NAS) Correlates with M30 Immune Expression in Obese Patients undergoing Bariatric Surgery

Aims: Bariatric surgery (i.e. gastric banding; gastric bypass) is an effective therapeutic approach in morbidly obese patients (BMI >40). Apoptosis is believed to play a crucial role in the pathogenesis of non-alcoholic steatohepatitis (NASH). The extent of apoptosis could be measured by assessing M30 immune expression. NAS scoring system is a newly established method to assess the extent of steatosis including scores for ballooning, inflammation and steatosis (NAS 2–3: suspicious of NASH; NAS 5–8: NASH). Methods: 30 morbidly obese patients (BMI: 54.8±8.5; age: 39±8.6; 12 males, 18 females), who underwent bariatric surgery were included, and liver biopsy was assessed during the procedure. Biopsies were evaluated for fibrosis and the NAS scoring system. Also, M30 essays were performed on patientsrsquor; peripheral-blood samples and correlated with the histological findings. Results: M30 immune expression was significantly (p<0.05) higher in patients (265±53.6 U/l) compared to controls (64±7.2 U/l). Twenty-eight patients revealed NAS scores above 5, indicating NASH in the majority of patients. M30 immune expression levels positively correlated with the assessed NAS scores while the other histological markers did not correlate with M30 immunoexpression (fibrosis staging: 1: n=12; 2: n=14; 3: n=1; 4: n=1; Malloryrsquor;s hyaline was found in one patient). Conclusion: These results support a key role of apoptosis in the pathogenesis of NASH while, in this group of patients, the extent of fibrosis did not correlate with the degree of apoptosis. Further studies with higher numbers of patients will have to prove M30 immune expression as a validated peripheral marker for the extent of non-alcoholic fatty liver disease.

Apoptosis - Bariatric surgery - M30 - NASH Score