The Investigators propose to test the hypothesis that GCSF therapy enhances the clinical outcome of Kasai operated Biliary Atresia (BA) patients. In this study, Investigators will conduct a dose determination for GCSF use in post Kasai subjects to support a future phase 2 efficacy study. The first 3 post Kasai BA subjects with liver biopsy-confirmed BA will be given 5 ug/kg/d of GCSF in 3 daily subcutaneous doses starting on post Kasai day 3. A second group of 3 subjects will be assigned to the 10 ug/Kg/d dose after the 5ug/kg/d dose has been proven to be safe. The levels of circulating hematopoietic stem cells and a 1-month safety profile will be analyzed.

In BA, neonatal fibrous obliteration of the biliary tract obstructs biliary drainage and promotes biliary fibrosis. BA is the leading cause of pediatric chronic end-stage liver disease and pediatric liver transplantation. Relief of cholestasis by the Kasai portoenterostomy is only partly successful with continued progression of fibrosis to hepatic insufficiency and, for long term survival, with eventual need for liver transplantation in the majority of the patients. In animal models of liver injury, GCSF enhances hematopoietic stem cell HSC mobilization and engraftment in the liver with associated improved liver repair response and attenuated hepatic necrosis and fibrosis. Randomized controlled trials of GCSF intervention for chronic liver failure in adult patients with acute hepatic decompensation showed improved short-term survival and hepatic indices such the model for end-stage liver disease (MELD) scores.

The Investigators propose that post Kasai GCSF therapy attenuates biliary fibrosis and progression to cirrhosis. The objectives are meant to demonstrate that Kasai-GCSF sequential therapy improves biliary drainage, and delays the progression of hepatic insufficiency. Toward this goal, Investigators will first evaluate in post Kasai subjects the maximum tolerated dose of GCSF in mobilizing circulating CD34+ hematopoietic stem cells, with the limiting dose based on GCSF-related severe adverse effects. A one-month safety of GCSF will be tested with the 2 standard doses of 5 ug/kg/d and 10 ug/kg/d.

Inclusion Criteria:

1. Completed the preliminary work up for cholestasis with suspected or inconclusive diagnosis of BA
2. Gestational Age > 36wks
3. Weight > 2 Kg
4. Age >-2 weeks-<180 days at diagnosis
5. Serum Direct Bilirubin > 2 mg/dL GGT > 100 U/L
6. Kasai operated patients for Type 3 or 4 anatomy of BA
7. Cholangiogram/porta hepatis findings diagnostic of BA
8. Liver biopsy supporting BA diagnosis

Exclusion Criteria:

1. Having access to liver transplantation for immediate Kasai failure
2. Prior Kasai patients
3. Major cardiac, renal, CNS malformations with poor prognosis
4. Intracranial hemorrhage
5. History of recent TPN use within the last 2 weeks of surgery
6. GI tract obstruction
7. Laparoscopic Kasai repair