Background: We analyzed bone marrow changes in heart transplant recipients who develop peripheral cytopenia and underwent bone marrow biopsy (BMB). We correlated the changes in bone marrow with survival, acute and chronic rejection, infections, and malignancy.
Methods: The test group was constituted of 64 heart transplant recipients with peripheral cytopenia, in whom 82 BMBs were performed to assess marrow quantitative (cellularity, erythropoiesis, myelopoiesis, megakaryopoiesis, fibrosis, and blast cells) and qualitative (dyserythropoiesis, dysmyelopoiesis, and dysmegakaryopoiesis) changes. The control series was constituted of 217 matchable transplant recipients without cytopenia. Statistical analysis was aimed at assessing whether: (1) cytopenia is an independent risk factor for survival; (2) acute rejection, chronic rejection, infections, and malignancy predict cytopenia; (3) the degree in BMB change allows further stratification of the risk of death; and (4) characteristics and distribution of BMB lesions vary in patients with and without acute and chronic rejection, infections, and malignancy.
Results: In the test group, BMB specimens showed reduced cellularity in 68% of patients and dysplastic changes of a mild degree affecting all three marrow lines (erythropoietic in 88%, myelopoietic in 43%, and megakaryopoietic in 79%). At statistical analysis, peripheral cytopenia was an independent risk factor for survival, and malignancy proved to be a risk factor for cytopenia. Of BMB specimen changes, only dysmegakaryopoiesis showed a trend as a negative risk factor for survival. Acute rejection was associated with a high score of erythropoiesis, infections with a low score of dysmegakaryopoiesis, and malignancy with a high score of cellularity.
Conclusions: Peripheral cytopenia is an independent risk factor for survival in heart transplant recipients. Different marrow changes correlate with transplantation-related complications, i.e., acute rejection, infection, and malignancy.