Histology & Gene Expression in Bariatric Surgery Patients
The Assessment of Variability in Histology and Gene Expression in Bariatric Surgery Patients
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of abnormal liver tests in the United States. NAFLD is often found in association with obesity and diabetes and it is expected to become increasingly prevalent as the incidence of diabetes and obesity continues to increase.
NAFLD represents a range of disease from simple fatty deposition in the liver to more aggressive inflammation and fibrosis, termed nonalcoholic steatohepatitis (NASH). The distinction of NASH as an entity within NAFLD is an important one, as the natural history of this population is different. Ultimately, NASH may progress to cirrhosis (scarring) in up to 25% of patients, compared to simple steatosis which is thought to be a benign condition. The bariatric surgery population is an ideal cohort to study a large subset of NASH: those with morbid obesity.
The purpose of this study is to examine variability of hepatic histology as well as expression of key metabolic genes in NAFLD/NASH patients undergoing bariatric surgery.
Patients will undergo pre-operative laboratory testing, followed by intra-operative liver and fat biopsies. A 12-month follow up will consist of repeat liver biopsy and laboratory testing. We predict that histologic variability of inflammation and fibrosis in NASH is accompanied by differential gene expression.
Furthermore, if this variability is pronounced, this will temper the reliance on percutaneous liver biopsy in NASH as the gold standard and further emphasize the need for global markers of disease progression.
Standard of care procedures and tests will be billed to the patient's insurance. Specialized tests and procedures will be performed at no cost to the patient.