Poor graft function - causes and potential solutions

Abstract

Introduction. Poor graft function is one of the most severe complications after allogeneic hematopoietic stem cell transplantation, which manifests as pancytopenia/cytopenia in the blood count, with the presence of complete or incomplete donor chimerism. There are three entities of graft weakness: 1. poor graft function: pancytopenia with complete donor chimerism, 2. graft failure: pancytopenia with incomplete, i.e., mixed donor chimerism and 3. graft rejection: progressive decline of donor chimerism. Definition. Poor graft function is diagnosed as pancytopenia (hemoglobin < 70 g/L, absolute neutrophil count < 0.5 x 109/L, platelets < 20 x 109/L) for 3 consecutive days from D+28, excluding the presence of severe graft versus host disease and relapse, with complete donor chimerism in poor graft function, and incomplete in graft failure. Risk factors and therapeutic principles. The most common risk factors for poor graft function are a small dose of CD34+ hematopoietic stem cells in the transplant, graft versus host disease, cytomegalovirus infection, the presence of donor-specific antibodies, high serum ferritin, i.e., iron overload, as well as splenomegaly. Pathogenetic mechanisms in the development of poor graft function are still not fully elucidated. The role of the microenvironment of the patient?s bone marrow is also important, as well as disorders of the immune system Therapeutic options for overcoming this complication include using selected ?stem cell boost?, mesenchymal stem cells, and newer medical agents (N-acetyl cysteine, atorvastatin, thrombopoietin receptor agonists). Conclusion. The type of poor function of the graft is defined in relation to the percentage of donor chimerism, and is necessary for planning further treatment strategy.