Guidance on preparing an investigational new drug application for fecal microbiota transplantation studies

Fecal microbiota transplantation (FMT) is an effective treatment for Clostridium difficile infections that are refractory to antibiotic therapy. Because of the important roles of the microbiota in the function of the gastrointestinal tract and other aspects of human physiology, there is a growing interest in studying FMT for other clinical indications. The US Food and Drug Administration regulates clinical studies to evaluate the safety and efficacy of FMT. Studies of FMT for recurrent Clostridium difficile infection or other indications could require submission of an investigational new drug application. Most academic physicians and investigators do not have the regulatory experience necessary to undertake this process. We provide guidance to researchers on the preparation and submission of investigational new drug applications to study FMT.

Spectrum of NAFLD and diagnostic implications of the proposed new normal range for serum ALT in obese women

The upper limit of normal for ALT activity has been recommended to be lowered to < or = 30 U/L in men and < or = 19 U/L in women. These changes have been suggested to be diagnostically useful in subjects with nonalcoholic fatty liver disease (NAFLD). Our aim was to investigate the prevalence and spectrum of NAFLD with regard to the new ALT guidelines in 233 women with class II/III obesity. We compared our prior reference range for ALT (ULN < or = 30 U/L in women) with the new standard. Our study demonstrates that only 86 patients (36.9%) would be classified as having normal ALT levels compared with 169 patients (72.5%) by the new and old standards, respectively. In patients with normal ALT activity (new vs. old standard), the prevalence of fatty liver (FL: 39.5% vs 40.2%), portal fibrosis, and steatosis (IPF: 37.2% vs. 33.7%) and nonalcoholic steatohepatitis (NASH: 23.3% vs. 26%) were similar. In comparison, newly defined patients with elevated ALT levels (>19 U/L) demonstrated an increased prevalence of FL (36%) and IPF (11.6%) but a 23.8% decrease in the prevalence of NASH as compared with the old standard. The sensitivity and specificity for NASH were 42% and 80% (ALT > 30 U/L) compared with 74% and 42% (ALT > 19 U/L). In conclusion, a significant increase in the prevalence of FL and IPF is detected in subjects with elevated ALT levels with the application of the new standard. However, the diagnostic utility for ALT to identify NASH or IPF remains poor, and significant healthcare expenditures may be incurred if this standard is adopted.

Portal fibrosis and hepatic steatosis in morbidly obese subjects: A spectrum of nonalcoholic fatty liver disease

Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) that can lead to hepatic fibrosis and cirrhosis. Portal fibrosis in the absence of NASH, called isolated portal fibrosis (IPF), has received less attention and has not been classified as a spectrum of NAFLD. The aims of this study were to determine the prevalence of IPF in subjects undergoing gastric bypass surgery, to identify biochemical variables associated with IPF, and to assess the metabolic syndrome as defined by the AdultTreatment Panel III criteria. We analyzed liver biopsies from 195 morbidly obese subjects after excluding all other causes of liver disease. The prevalence of fatty liver (FL) only, IPF, and NASH was 30.3%, 33.3%, and 36.4%, respectively. Several biochemical parameters significantly trended across the 3 groups, with IPF falling between FL and NASH. Hyperglycemia was the only metabolic parameter associated with NASH (OR, 5.4; 95% CI, 2.4-12; P < .0001) and IPF (OR, 2.8; 95% CI, 1.2-6.5; P = .01). Subjects with diabetes had the greatest risk for NASH (OR, 8; 95% CI, 3.3-19.7; P < .0001) and IPF (OR, 4.3; 95% CI, 1.6-11.6; P = .003). The metabolic syndrome was identified in 78.5% of subjects, and a significant trend for the number of metabolic criteria was observed across the spectrum of FL, IPF, and NASH. In conclusion, a significant subset of morbidly obese individuals has portal fibrosis in the absence of NASH that is associated with glycemic dysregulation. Therefore, IPF should be considered a spectrum of NAFLD that may prelude NASH in morbid obesity.