rHGH and Intestinal Permeability in Intestinal Failure

This is an open-label pilot study in which a convenience sample of 20 subjects will participate for up to 26 months. At the baseline visit, subjects will sign a consent form after all questions they have are answered. An inpatient appointment will be made at the General Clinical Research Center (GCRC). Subjects will be given instructions to fill out a 7-day food diary the week prior to their inpatient appointment. In this diary, subjects will be asked to record the types and amounts of food they ingest over a 7-day period. This will allow researchers to review subjects' food intake prior to sugar permeability testing. Although each subject serves as his/her own control, this information may be useful upon review of variations in permeability between subjects. To evaluate the potential hepato-protective effects of improving intestinal barrier function, blood tests evaluating liver injury and function (i.e. ALT, AST, total bilirubin, ALP, GGT) will be obtained. These labs are part of the subject's standard of care follow-up, therefore study staff will abstract these data from the subject's medical record. The sugar permeability testing requires an 8-hour overnight fast, followed by the ingestion of 4 capsules of sucralose (250mg per capsule), 2.0 grams of mannitol, 7.5 grams of lactulose, and 40 grams of sucrose in 150 mL of water. Over the next 5 hours, urine is collected. Intestinal permeability is quantified as the urine ratio of lactulose, mannitol and sucralose. After urine collection is complete, subjects will begin their 28 days of Zorbtive® administration. All evaluations (subject food diary, bloodwork, and sugar permeability testing) will be repeated 28 days later, within 72 hours of receiving the final dose of Zorbtive®. The bloodwork drawn is part of the subject's standard of care follow-up, therefore study staff will abstract these data from the subject's medical record. Following completion of study visits at the GCRC, study staff will obtain results of liver injury/ function tests \[(ALT), (AST), bilirubin, alkaline phosphatase (ALK or ALP), (GGT)\] from the medical record from each routine clinical exam from Month 3 through Month 24, following the 28-day treatment with Zorbtive® therapy. These labs are part of the subject's standard of care follow-up, therefore study staff will abstract these data from the subject's medical record. Subjects will not be asked to return for separate study visits. Since the intestinal epithelium is completely reconstituted approximately every 7 days, it is anticipated that the potential influences of rHGH on barrier function and related liver injury will be realized by the end of the 28 day study period. The long term durability of any changes observed after 28 days will be observed, but will likely require further study.