Hepatocytes of Donor Origin in Recipients Liver, after Hematopoietic Stem Cell Transplantation in BetaThalassemia Major.

Background Bone marrow and circulating stem cells contains stem cells with the potential to differentiate into mature cells of various organs. We determined whether stem cells transformed to hepathcytes.

Methods Biopsy specimens from the liver were obtained from 11 patients who had undergone transplantation of hematopoietic stem cells from peripheral blood (8 patients) or bone marrow (3 patients). Four female patients had received transplants from a male donor and seven male patients had received transplants from a female donor.All patients had beta thalassemia major and fibrosis in biopsy specimens from the liver before hematopoietic stem-cell transplantation. Hematopoietic stem-cell engraftment was verified by short tandem repeat analysis. The biopsies were studied for the presence of donor-derived hepatocytes with the use of fluorescence in situ hybridization of interphase nuclei and immunohistochemical staining for CD45 (leukocyte common antigen), and a hepatocyte-specific antigen.

Results All 11 recipients of sex-mismatched transplants showed evidence of complete hematopoietic donor chimerism. XY-positive hepatocytes accounted for 4 to 6.7 percent of the cells in histologic sections of the biopsy specimens of female patients. These cells were detected in liver tissue as early as 1 year and as late as 8.5 year after the hematopoietic stem cell transplantation.

Conclusions Bone marrow and circulating stem cells can differentiate into mature hepatocytes in beta thalassemia major patients who undergone hematopoietic stem cell transplantation.