Background: In histocompatibility mismatched experimental animals, a combination of T-cell-depleted autologous and allogeneic marrow may induce mixed chimerism and tolerance. Patients with large primary liver tumors have a poor outcome. We investigated whether it were possible to induce mixed chimerism and obtain an antitumor effect in a patient with a large primary liver cancer after combined liver and bone marrow transplantation (BMT).
Methods: A 46-year-old female with a primary non resectable liver cancer received a liver transplant from a cadaveric donor. Subsequently, she was conditioned with 4x2 Gy of total lymphoid irradiation, 120 mg/kg cyclophosphamide, and 7.5 Gy total body irradiation. Twelve days after liver transplantation, she received T-cell-depleted autologous:cadaveric 5/6 antigen HLA-mismatched marrow in a proportion of CD34+ cells of 0.5:3.0x10(6)/kg. Chimerism status was determined with polymerase chain reaction amplification of variable number tandem repeats from DNA obtained from CD3+, CD19+, and CD45+ magnetic-bead-separated cells.
Results: The early posttransplant period was uneventful; liver function was normal and the hematopoietic engraftment of donor and recipient origin was prompt. Alpha-fetoprotein levels dropped from 440 to 35 microg/l. One month after marrow transplantation, donor T-cells decreased markedly. Monoclonal antibody OKT-3 and 10(5)/kg donor T-cells were given. One month later, the patient developed diarrhea and abdominal pain. A colonoscopy showed moderate gastrointestinal acute graft-versus-host disease and a Cryptosporidium infection. Three months after BMT, she became a complete donor chimera. Chimera cells showed little, if any, reactivity in mixed lymphocyte cultures to recipient and donor cells, but reacted to third party. Five months after BMT, she developed progressive Aspergillus fumigatus pneumonia and died. No tumor was found at the autopsy.
Conclusion: We obtained mixed donor-recipient hematopoietic chimerism without severe acute graft-versus-host-disease, after combined T-cell depleted autologous and allogeneic BMT and a transplantation of a liver from an HLA-mismatched cadaveric donor. Additional donor T-cells enhanced donor bone marrow engraftment, but rejected the autograft. On the basis of this first attempt, further clinical studies are warranted.