Regeneration of graft livers and limited contribution of extrahepatic cells after partial liver transplantation in humans.
BACKGROUND
Liver regeneration is still not fully understood. Partial liver transplantation (LT) can provide the opportunity to investigate the mechanisms of liver regeneration, including the contribution of extrahepatic cells to liver regeneration.


METHODS
Of 61 patients transplanted with partial liver graft between August 1997 and October 2006, 56 patients were studied, including 49 adults and 7 children. Sequential computed tomography volumetric analysis was performed for volume measurement, while proliferating cell nuclear antigen (PCNA) labeling index was investigated for liver cell proliferation in nonprotocol liver biopsy specimens. In addition, 15 male recipients who had female liver grafts were investigated in order to detect Y chromosomes as extrahepatic cells in nonprotocol liver biopsy specimens.


RESULTS
Graft volume per standard liver volume was markedly increased after adult-to-adult living-donor (LD) LT. In pediatric transplants, there was no volume increase over time. PCNA labeling index was vigorous in adult-to-adult LDLT in the early period after LDLT. No Y chromosome was evident in hepatocytes from female-donor male-recipient grafts during or after liver regeneration. However, in the cases of failing grafts of this type, many Y-chromosome-positive cells were observed in the graft liver. The character of those cells was CD34(-), CK9(-), hepatocyte-specific antigen(-), and CD68(+/-).


CONCLUSIONS
In adult-to-adult LDLT, vigorous liver regeneration occurs in the graft liver, demonstrated by not only volumetric but cell kinetic analysis. Involvement of extrahepatic cells in normal liver regeneration seems limited.
Eguchi
Susumu
S
Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan. sueguchi@net.nagasaki-u.ac.jp
Takatsuki
Mitsuhisa
M
Yamanouchi
Kosho
K
Kamohara
Yukio
Y
Tajima
Yoshitsugu
Y
Kanematsu
Takashi
T
D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D041322:Chromosomes, Human, Y; D004247:DNA / Q000096:biosynthesis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008099:Liver / Q000033:anatomy & histology / Q000166:cytology / Q000000981:diagnostic imaging; D008115:Liver Regeneration / Q000502:physiology*; D016031:Liver Transplantation / Q000379:methods*; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D014057:Tomography, X-Ray Computed
D018809:Proliferating Cell Nuclear Antigen; D004247:DNA