Long-term detection of microchimaerism in peripheral blood after pretransplantation blood transfusion.

Renal allograft survival is prolonged after pretransplantation blood transfusion. The aim of this study was to test retrospectively the development and persistence of microchimaerism after pretransplantation blood transfusion and to assess whether the type of blood transfusion (partially matched [= sharing of at least one HLA-B and one HLA-DR antigen between blood donor and recipient] versus mismatched) influences the (continued) presence of donor-type cells. A sensitive nested PCR technique based on HLA-DRB1 allele-specific amplification using sequence-specific primers (detection level: one donor cell among 10(5) recipient cells) for detection of donor cells was implemented in our laboratory.

Optimization of purging of autologous bone marrow grafts for children with precursor B acute lymphoblastic leukemia.

In our laboratory, a two-step procedure is used for purging precursor B ALL from autologous bone marrow grafts of children in second bone marrow remission. An immunorosette depletion method with CD19 and CD22 MAbs is followed by one cycle of complement-mediated cell lysis with CD9 and CD10 MAbs. The aim of the present study was to determine if the efficacy of this procedure could be further enhanced by including CD20 and CD72 MAbs in the current protocol.

PCR-positivity in harvested bone marrow predicts relapse after transplantation with autologous purged bone marrow in children in second remission of precursor B-cell acute leukaemia.

Purging of autologous bone marrow (BM) grafts of children in second remission after a relapse of precursor B acute lymphoblastic leukaemia (ALL) in the BM has been carried out in our laboratory since 1987, initially by complement mediated cell lysis. This protocol was extended by performing an immunorosette depletion before lysis with complement. The aim of the present study was to assess by polymerase chain reaction the presence of residual leukaemic cells in the BM grafts before and after purging.

99mTc-CD19 monoclonal antibody is not useful for imaging of B cell non-Hodgkin's lymphoma.

In this study we investigated the applicability of 99mTc-labeled CD19 monoclonal antibody (mAb) for tumor imaging in patients with B cell non-Hodgkin's lymphoma. A 1-mg sample of murine CD19 mAb was labeled with approximately 550 MBq [99mTc]pertechnetate. The labeled mAb was administered i.

Triple immunofluorescence staining for prediction of relapse in childhood precursor B acute lymphoblastic leukaemia.

In this study we describe a fast and sensitive method using three-colour immunofluorescence for the detection of cells with phenotypes that are rare in normal bone marrow (BM) but occur frequently in children with precursor B acute lymphoblastic leukaemia. We show that, in the first year after initiation of therapy, in 17/18 patients (10 patients were analysed after first diagnosis and nine patients after first BM relapse; one patient was analysed on both occasions) the percentage of CD10+ CD19+ cells and CD20- CD22+ cells in the CD34+ cell population indicated the likelihood of relapse. A suppression of cells expressing these phenotypes after initiation of therapy was followed by an outgrowth of normal precursor B cells after 12 months.