Epithelial microchimerism: consistent finding in human liver transplants.

BACKGROUND

Eleven liver biopsies from six male patients who received a liver transplant (LT) from female donors were examined in order to determine whether male host-derived hepatic cells were present in female grafts that exhibited minimal or important inflammatory damage.

METHODS

Immunohistochemistry for epithelial cell type differentiation (anticytokeratin monoclonal antibody) and fluorescence in situ hybridization for XY chromosomes identification were performed on each slide.

RESULTS

Host-derived hepatic cells were found in all except one transplant, with a frequency ranging from 2.3 to 25 per thousand of the total hepatocytes in the biopsy specimen. They were usually found as isolated cells scattered throughout the hepatic lobule; in one patient they were grouped into little clusters. Host-derived hepatic cells persisted throughout the histological follow up (up to 535 days after LT). Polyploidy for XY chromosome was observed.

CONCLUSION

Hepatocytes derived from extra-hepatic stem cells are frequently found in small numbers in human liver grafts and persist over time.