Normalization of serum lactic dehydrogenase in beta-thalassemia patients following bone marrow transplantation.

Serum lactic dehydrogenase (LDH) levels are mildly elevated in beta-thalassemia major due to ineffective erythropoiesis. We reviewed the charts of 15 consecutive thalassemic children who underwent allogeneic, T-cell-depleted bone marrow transplantation (BMT) in our department during the last 3 years. Eleven patients had successful engraftment and are alive and well without evidence of disease, according to physical examinations, blood counts, and polymerase chain reaction (PCR) tests, with a median follow-up of 2 years. Two patients died due to transplantation-related complications, and two rejected the graft and received their backup autologous marrow. The LDH levels in the transplanted patients gradually decreased from an average of 952 +/- 155 IU/L 10 days pre-transplant (N = 300-620) to 426 +/- 56 IU/L at the day of transplantation, and stayed at approximately the same level post-transplant (489 +/- 55 IU/L). By contrast, the LDH levels reverted to the pre-transplant value in those patients who rejected their marrow. The significance of this clinical observation for the pathophysiologic mechanism of intramedullary hemolysis and ineffective erythropoiesis in beta-thalassemia major is discussed.