A case of granulocyte‐colony stimulating factor/plasmapheresis–induced activation of granulocyte‐colony stimulating factor–positive hepatic progenitors in acute‐on‐chronic liver failure
Authors: Anna Chiara Piscaglia, Vincenzo Arena, Stefano Passalacqua, Antonio Gasbarrini
Journal: Hepatology (2015)

Liver regeneration can involve hepatocytes, cholangiocytes, and liver stem cells (LSCs), named "hepatic progenitor cells" (HPCs) in humans. The LSC origin has been highly debated; a portion of them likely derive from bone marrow (BM) cells, even if some studies indicate that this portion may be insignificant.1 Mobilization of liver-committed, BM-derived hematopoietic stem cells (HSCs) into the circulation can be induced by granulocyte-colony stimulating factor (G-CSF).2, 3 In rodents, G-CSF treatment induced LSC proliferation. However, BM-derived hepatocytes were rare, supporting the concept that alternative mechanisms, rather than HSC transdifferentiation, regulate liver recovery.4 Indeed, murine LSCs express G-CSF and its receptor (G-CSFR), and G-CSF exerts a "hepatotrophic effect" in rodents.2 To date, the expression of G-CSFR by HPCs has never been reported. A 40-year-old male patient was admitted to our hospital for acute-on-chronic liver failure. He was an active drinker with alcoholic and hepatitis C virus–related cirrhosis. Abdominal ultrasonography showed a slightly enlarged liver, with a nodular margin and nonhomogeneous structure. Given his status of active drinker, liver transplantation could not be considered. Two days later, due to persistent hyperbilirubinemia, encephalopathy, and severe liver dysfunction, experimental plasmapheresis with plasma-exchange (PA-PE) combined with G-CSF was proposed. The patient underwent 10 sessions of PA-PE (PA with 3 L volume in 4 hours and PE with 8 units of fresh frozen plasma), associated with G-CSF (10 µg/kg/day for 5 days, administered subcutaneously, starting after the first PA-PE session); 2 weeks later, a second cycle of G-CSF/PA-PE was performed (three PA-PE sessions plus 5 days of G-CSF) (Fig. 1A). The patient's clinical and biochemical conditions improved (Fig. 1B), and good HSC mobilization was obtained (Fig. 1C). At day 23, ultrasonography showed an enlarged liver with a more nonhomogeneous structure and hyperechogenic nodules (Fig. 2A). Liver biopsy showed regenerating nodules characterized by a ductular reaction with CK7+ HPCs expressing G-CSFR (Fig. 2B-H). The nodules disappeared 1 week later. The patient was discharged 2 months following the admission, in serious but stable condition (Model for End-Stage Liver Disease 25). A month later, being still abstinent from alcohol, he was enlisted for liver transplantation and successfully transplanted after a 6-month wait. Treatment scheme and laboratory parameters. (A) Scheme depicting the combined treatment administered to the patient starting from the third day after admission (day 1). The patient underwent 10 sessions of plasmapheresis (PA) with plasma exchange, associated with G-CSF (10 µg/kg/day for 5 days, starting immediately after the first PA session); 2 weeks later, a second combined treatment was performed (3 PA sessions associated with 5 days of G-CSF). (B) Serum concentrations of albumin, cholesterol, pseudocholinesterase, total bilirubin, aspartate aminotransferase, and gamma-glutamyl transpeptidase during the course of the combined treatment, from day 1 to day 43. (C) Circulating CD133+/CD45+ HSCs counts during the course of the combined treatment, from day 1 to day 55. Every time PA was scheduled, HSCs were measured twice, before (black bars) and after (white bars) the procedure. At days 2, 4, 6, 38, 40, 42, 44, and 52 HSCs were measured once a day (gray bars). Abbreviations: AST, aspartate aminotransferase; gamma-GT, gamma-glutamyl transpeptidase; p-cholinesterase, pseudocholinesterase. Hepatic progenitor cells positive for G-CSF. (A) Abdominal ultrasonography 23 days after the beginning of the combined treatment showed multiple hyperechogenic nodules. (B) Hematoxylin and eosin staining upon percutaneous ultrasound-guided liver biopsy showed a strong ductular reaction within the nodules. (C,D) Ductular cells expressed CK7 and had morphologic features consistent with HPCs (arrows). (F,G) Many HPCs were G-CSFR+ (arrows). (E,H) Negative controls for CK7 and G-CSFR, respectively. Liver transplantation represents the only curative treatment for end-stage liver disease. The efficacy of BM transplantation and/or G-CSF administration in liver failure has been investigated in small clinical trials, with encouraging results.3, 5 In the case presented here, G-CSF/PA-PE was administered to an acute-on-chronic liver failure patient, based on the theory that removal of the patient's plasma would eliminate circulating toxic factors and that G-CSF would stimulate hepatocyte regeneration. This regimen induced HSC mobilization and a ductular reaction, in which HPCs expressing G-CSFR were observed. Together with abstinence and routine clinical care, G-CSF/PA-PE administration might have contributed to the patient's rapid and long-lasting clinical improvement. We believe that the G-CSFR+ HPCs were mainly endogenous LSCs, activated by the acute-on-chronic liver failure and expanded by the combined treatment. It is possible that PA-PE beneficially modulated the liver microenvironment, due to the removal of potentially toxic factors in the plasma. This may have provided an environment more conducive to G-CSF–mediated amplification of endogenous HPCs that promoted liver regeneration. Also, G-CSF might be directly involved in modifying the HPC niche, given that G-CSFR was expressed by HPCs. Clinical trials are needed to confirm these results. We thank Prof. Thomas Shupe for his critical revision of the final manuscript. We are also grateful to Dr. Carlo Rumi, Dr. Mariachiara Campanale, Dr. Valentina Cesario, and Dr. Pietro M. Ferraro for their contribution in the clinical management of this case. Author names in bold designate shared co-first authorship.