Evaluation of mixed chimaerism and origin of bone marrow derived fibroblastoid cells after allogeneic bone marrow transplantation.

We assessed the origin of bone marrow derived fibroblastoid cells (BMF) in long-term cultures of 13 samples obtained from nine patients after allo-BMT by polymerase chain reaction (PCR) amplification of MCT118, one of the variable number of tandem repeats regions (VNTR). BMF showed a complete recipient pattern in nine samples obtained from seven patients; however, a recipient-predominant mixed chimaeric pattern was detected in BMF from four patients. Also, two of the four patients died with bone marrow hypoplasia. These data suggest that mixed chimaeric pattern of BMF may be correlated with bone marrow hypoplasia.