Manipulation of Biliary Lipids by Gene Therapy: Potential Consequences for Patients with Progressive Familial Intrahepatic Cholestasis

Partial external biliary diversion in children with progressive familial intrahepatic cholestasis and Alagille disease

BACKGROUND

Partial external biliary diversion (PEBD) is a promising treatment for children with progressive familial intrahepatic cholestasis (PFIC) and Alagille disease. Little is known about long-term outcomes.

PATIENTS AND METHODS

A retrospective chart review of all patients undergoing PEBD in the University Medical Centre of Groningen (UMCG).

RESULTS

Between 2000 and 2005, PEBD was performed on 14 children with severe pruritus (PFIC 11, mean age 5.3 +/- 4.4 years; Alagille 3, mean age 7.4 +/- 4.2 years). Stature was <-2 standard deviation score (SDS) in 50%. Median preoperative serum bile salt concentration was 318 micromol/L (range 23-527 micromol/L). Twenty-nine percent had severe liver fibrosis and 71% had mild or moderate fibrosis. Median follow-up was 3.1 years (range 2.0-5.7 years). One patient (7%) underwent a liver transplantation at 3.2 years post-PEBD. Two years postoperatively, 50% were without pruritus and 21% had mild pruritus. In 29%, pruritus had not diminished; 3 of them had severe fibrosis preoperatively. In patients with mild or moderate fibrosis, PEBD decreased serum bile salts (105 micromol/L [range 8-269 micromol/L] 2 years postoperatively). Bile salts did not decrease in the patients with severe fibrosis. Two years after PEBD, 27% had a stature below -2 SDS.

CONCLUSIONS

At median follow-up of 3.1 years after PEBD, pruritus has been relieved in 75%. Bile salts level and growth are improved in most patients. Longer follow-up is needed to determine whether PEBD can postpone or avoid the demand for liver transplantation.

Allograft steatohepatitis in progressive familial intrahepatic cholestasis type 1 after living donor liver transplantation

We studied histological features and long-term outcomes in patients with progressive familial intrahepatic cholestasis type 1 (PFIC1) after liver transplantation (LT). Histological findings were correlated with the post-LT course and treatment in 11 recipients with PFIC1. Ages at LT varied from 1 to 18 years (median, 4 years). Macrovesicular steatosis was observed in 8 patients at a median of 60 days post-LT (range, 21-191 days). Severe steatosis progressed to steatohepatitis in 7 patients at a median of 161 days (range, 116-932 days). The patients were followed up for a median of 7.3 years (range, 2.3-16.1 years). Six showed bridging fibrosis, with 2 progressing to cirrhosis. One patient with cirrhosis died because of the rupture of a splenic artery aneurysm 13.6 years post-LT. Post-LT refractory diarrhea was present in all 8 having steatosis. Three without post-LT diarrhea showed no allograft steatosis. Bile adsorptive resin therapy reduced the diarrhea and steatosis. Patients with posttransplant steatosis typically had more severe mutations of the ATPase class I type 8B member 1 (ATP8B1) gene and were more likely to have systemic complications such as pancreatitis. In conclusion, allograft steatosis was present in patients with PFIC1, progressing to steatohepatitis and cirrhosis. Because expression of the familial intrahepatic cholestasis 1 gene occurs in several organs, including the small intestine, pancreas, and liver, and it is involved in enterohepatic bile acid circulation, post-LT steatosis may be due to a malfunction of the ATP8B1 product.

Liver transplantation in children with progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis (PFIC) is caused by mutations of the bile salt export pump or the multidrug resistance P-glycoprotein, resulting in chronic hepatic failure. Partial external diversion of bile or ileal bypass is effective in some cases and, in others, liver transplantation (OLT) is necessary. Forty-two children were included in this study. Twenty-six children suffered from PFIC type 2 and 16 from PFIC type 3. Symptoms included pruritus, cholestasis, liver cirrhosis, and growth retardation. Seventeen patients received external biliary diversion. Ten had to undergo OLT in the following course. As of this report, three of the remaining patients were on the wait list for OLT. Twenty-three children received a liver graft primarily with excellent outcome. Our data show that OLT is the option of choice in symptomatic PFIC and whenever liver cirrhosis is present. We suggest a very restrictive recommendation of external biliary diversion. However, gene therapy may be a future option for children with PFIC.