Endometrial cells derived from donor stem cells in bone marrow transplant recipients

Abstract

Context: Regeneration of the endometrium in each menstrual cycle is required for reproduction. Endogenous endometrial stem cells reside in the basalis layer and serve as a source of cells that differentiate to form the endometrium. Bone marrow-derived cells have been shown to take on functions outside the hematopoietic system.

Objective: To investigate the possibility that cells of extrauterine origin could repopulate the endometrium.

Design, setting, and patients: Endometrium from 4 HLA-mismatched bone marrow transplant recipients (1998-2002) was evaluated for donor HLA expression. Each recipient had a bone marrow donor with an HLA type that enabled determination of the origin of any cell. Endometrial biopsies also were obtained from 4 healthy control women.

Main outcome measure: HLA type was determined by immunohistochemistry and by reverse transcription-polymerase chain reaction.

Results: Donor-derived endometrial cells were detected in endometrial biopsy samples from all bone marrow recipients and accounted for 0.2% to 48% of epithelial cells and 0.3% to 52% of stromal cells. None of the controls demonstrated HLA mismatch in endometrial samples.

Conclusion: These findings demonstrate that endometrial cells can originate from donor-derived bone marrow cells and suggest that nonuterine stem cells contribute to the regeneration of endometrial tissue.