Non-cirrhotic portal hypertension (obliterative portal venopathy) is the predominant form of chronic liver disease in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF)-associated liver disease commonly manifests as portal hypertension and its complications. We investigated the proposal that the pathophysiology is of non-cirrhotic rather than cirrhotic portal hypertension. This distinction may have important implications for treatment. METHODS: We compared liver transplant explants from cystic fibrosis patients with explants from patients with classical cholestatic diseases, primary biliary cholangitis and primary sclerosing cholangitis. Presence of cirrhosis, fibrosis, nodular regenerative hyperplasia, biliary and portal venous pathology were recorded. Quantitation of portal venules in representative section was performed. RESULTS: Nine patients with cystic fibrosis liver disease, 7 primary biliary cholangitis (PBC) and 7 primary sclerosing cholangitis (PSC) were evaluated. Cirrhosis was present in 0/9 of CF patients and 11/14 of the PBC and PSC controls (p < 0.01). Nodular regenerative hyperplasia was present in 8/9 of the CF patients but none of the controls (p < 0.01). Portal venule numbers per 15 mm2 section were significantly lower in the CF patients 52 (20-72) compared to the primary biliary cholangitis 78 (47-110) and primary sclerosing cholangitis patients, 79 (41-134) (p < 0.05). Portal sclerotic nodules were found in all the CF patients but in only one of the controls (9/9 vs 1/14 p < 0.01). CONCLUSIONS: This study demonstrates that non-cirrhotic portal hypertension or obliterative portal venopathy is the predominant hepatic pathophysiology in adult CF patients requiring liver transplantation. It suggests that treatments directed at the hepatic portal venous system may be more effective than current treatment directed at the biliary system in cystic fibrosis.

Lower expression of Nrf2 mRNA in older donor livers: a possible contributor to increased ischemia-reperfusion injury?

BACKGROUND: The cellular mechanisms involved in mediating cytoprotection against ischemia-reperfusion (IR) injury are not well understood. In animal models, NF-E2-related factor-2 (Nrf2) protects against IR injury by transcriptional activation of phase II antioxidants. Here, we investigate how the expression of Nrf2 mRNA in human donor livers in the setting of liver transplantation (LT) correlates with the histological damage associated with IR injury and whether or not this influences the outcome of LT. METHODS: Pairs of biopsies were acquired from 14 donor livers; the first biopsy of each pair was taken at the start of the retrieval operation, prior to the IR phase of LT and the second at the end of transplantation. RNA was extracted from snap frozen tissue and cDNA was prepared. Nrf2 mRNA expression was determined using real-time polymerase chain reaction (PCR). The modified Suzuki scoring system was used for histological grading of IR injury and relevant donor, recipient, and after LT clinical data were compiled. RESULTS: Nrf2 expression was observed in all biopsies, both before and after IR. Some donor organs had greater expression of Nrf2 mRNA before IR injury, and these organs had lower Suzuki scores and better liver functions (ALT) after LT. Donors of livers with greater Nrf2 levels were significantly younger (40.5 yrs, range 28-53 yrs) than those with low Nrf2 levels (55.5 yrs, range 48-61 yrs), P<0.05. CONCLUSION: Livers from older donors have lower levels of Nrf2 perhaps exposing these organs to more IR-related damage.