Stem cell mobilization and collection in patients with liver cirrhosis.

BACKGROUND: Bone marrow-derived stem cells (BMSC) and granulocyte colony-stimulating factor (G-CSF) have been proved to contribute to tissue regeneration after liver injury.

AIMS: To test the safety of G-CSF and define the exact dose capable of mobilizing BMSC in the majority of patients with liver cirrhosis; and to assess the feasibility of leukapheresis to collect BMSC from peripheral blood.

METHODS: In this study, we treated 18 patients affected by liver cirrhosis with increasing doses of G-CSF to mobilize CD34(+) and CD133(+) BMSC into the peripheral blood.

RESULTS: The dose-finding phase demonstrated that 15 microg/kg/day of G-CSF is the optimal dose to mobilize both CD34(+) and CD133(+) stem cells. Circulating BMSC were collected by a single step leukapheresis in three patients and the mean number of CD34(+) and CD133(+) cells cryopreserved was 1.3 +/- 0.7 and 1.2 +/- 0.5 x 10(6)/kg, respectively. No severe adverse events were observed during the drug administration and stem cell collection. Noteworthy is, none of the patients showed a significant modification of liver function.

CONCLUSIONS: Our study demonstrates that G-CSF administration and BMSC collection from the peripheral blood is possible and safe in patients with liver cirrhosis. The optimal dose to mobilize BMSC in cirrhotics is 15 microg/kg/day. At this dose, G-CSF does not seem to modify the residual liver function in cirrhotic patients.