Immunophenotypic and ultrastructural study in peripheral blood neutrophil granulocytes following bone marrow transplantation.

Neutrophil studies after bone marrow transplantation (BMT) describe chemotactic and phagocytotic alterations and dyshaemopoiesis. Neutrophil granulocytes (NG) in peripheral blood after BMT were analysed in 28 patients. 14 patients (six receiving GM-CSF) underwent autologous BMT and 14 underwent allogeneic BMT. Immunophenotypic and electron microscopic studies were performed during post-BMT granulopoietic regeneration. Results were compared with NG from 15 healthy bone marrow donors (control group A) and from six patients receiving intensive chemotherapy before autologous BMT (control group B). A significant increase in CD15 and a decrease in 8C7 antigen expression was observed in peripheral blood NG from BMT patients compared with controls A. MPO-7 in NG after BMT did not differ from control group A. Autologous BMT patients showed a lower percentage of NG expressing 13F6, 31D8 and CD16 (Leu 11a) than allogeneic BMT patients, and a significant decrease in 8C7 antigen expression compared with patients receiving intensive chemotherapy. Ultrastructurally, a marked decrease of azurophilic granules was observed in NG from BMT patients compared with control groups A and B. These data indicate that repopulation after BMT was made by phenotypically less mature NG with dysgranulopoietic features. Differences between autologous and allogeneic BMT patients may be partly related to GM-CSF usage. In conclusion, NG present immunophenotypic and ultrastructural changes after BMT which may be involved in abnormal NG response against bacterial infections, although further investigation is needed.