Selective engraftment of the granulocyte compartment after allogeneic bone marrow transplantation in a patient with severe aplastic anemia.
OBJECTIVE
We present a patient with severe aplastic anemia who had partial engraftment with full chimerism after allogeneic bone marrow transplantation from an HLA identical sibling.


METHODS
A 3-year-old girl with severe aplastic anemia (SAA) received a bone marrow transplantation (BMT) from an HLA identical brother 9 months after her diagnosis. Before BMT she was red blood cell tranfusion dependent, had an absolute neutrophil count (ANC) of 1,000-1,500 x 10(9)/1 and a platelet count of 15-19,000 x 10(9)/1. She was conditioned with 800 cGy total body irradiation (TBI) and cyclophosphamide and received 3X10(8) nucleated cells/kg.


RESULTS
She reached an ANC of 1500 x 10(9)/1 on day +35 but her reticulocyte and platelet counts did not recover. A bone marrow aspirate and biopsy post BMT showed hypoplasia with marked decrease in megakaryocyte and red blood cell precursors. The granulocyte compartment showed a left shift with predominance of promyelocytes and myelocytes. The karyotype showed full chimerism (46,XY) with no 46,XX metaphases.


CONCLUSIONS
This case illustrates the possibility of a bone marrow microenvironment defect as the cause of SAA.
Barriga
F J
FJ
Department of Pediatrics and Hematology, Catholic Univesity of Chile, Santiago.
Legues
M E
ME
Bertin
P
P
D000741:Anemia, Aplastic / Q000601:surgery*; D016026:Bone Marrow Transplantation / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D006084:Graft Rejection / Q000276:immunology; D006098:Granulocytes / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D008297:Male; D018183:Transplantation Chimera / Q000276:immunology
D006680:HLA Antigens