A new study has found that kidney transplant surgery alone can improve hematologic conditions in patients simultaneously suffering from severe aplastic anemia and end-stage renal disease, two intractable diseases.
Seoul St. Mary's Hospital announced Wednesday that it applied a strategy of performing kidney transplantation first, followed by hematopoietic stem cell transplantation if necessary, on patients diagnosed with both severe aplastic anemia and end-stage renal disease. All four patients showed stable renal function and meaningful hematologic improvement.
Patients with long-standing intractable blood disorders can develop deteriorating kidney function as a complication, progressing to a state requiring kidney transplantation. Severe aplastic anemia, in which bone marrow dysfunction causes decreases in red blood cells, white blood cells and platelets, is a prime example. Hematopoietic stem cell transplantation is the curative treatment for severe aplastic anemia. For end-stage renal disease, kidney transplantation is known to be the best treatment in terms of survival rates and quality of life. However, when both conditions coexist, there were no clear guidelines on determining the order of treatment. Performing stem cell transplantation while on dialysis raises infection risks and makes it difficult to adjust doses of anticancer and immunosuppressive drugs. Conversely, performing kidney transplantation in a state of severe thrombocytopenia can increase the risk of bleeding and rejection.
A joint research team led by Professor Park Soon-chul of the Department of Vascular and Transplant Surgery, Professor Chung Byung-ha of the Department of Nephrology, and Professor Park Silvia of the Department of Hematology chose a strategy of prioritizing kidney transplantation, followed by stem cell transplantation if needed, considering these limitations. All four patients had transfusion-dependent pancytopenia, but renal graft function recovered immediately after kidney transplantation. They showed stable clinical courses within one year after surgery without acute rejection or significant complications.
Two of the patients underwent additional hematopoietic stem cell transplantation from the same donor approximately three months after kidney transplantation. The two patients maintained stable courses even after discontinuing immunosuppressive drugs at seven months and 17 months, respectively. The research team explained, "This suggests that immunological remission was induced by donor chimerism, a state in which cells different from the patient's own cells coexist within the patient's body." This means that donor-specific immunological aggression was eliminated, enabling long-term maintenance of the transplanted kidney without immunosuppressive drugs.
The remaining two patients showed gradual improvement in anemia and thrombocytopenia without stem cell transplantation, becoming free from transfusion dependence. Bone marrow function also showed signs of recovery. The research team interpreted that reduction of uremic toxins following kidney transplantation likely alleviated systemic inflammation, and the immunosuppressive drugs used after transplantation likely had a positive effect on aplastic anemia. Professor Chung said, "The finding that hematologic recovery is possible with kidney transplantation alone in some patients is a clinically very meaningful result," adding, "Systematic prospective studies are needed in the future to establish criteria for selecting appropriate patient groups."
The clinical findings were published in a recent issue of the American Journal of Transplantation, the official journal of the American Society of Transplantation.