János Földi

Remarkably Reduced Transplant-Related Complications by Dibromomannitol Non-Myeloablative Conditioning before Allogeneic Bone Marrow Transplantation in Chronic Myeloid Leukemia

A non-myeloablative conditioning protocol containing dibromomannitol (DBM/cytosine arabinoside/cyclophosphamide) has been applied to 36 chronic myeloid leukemia (CML) patients followed by bone marrow transplantation (BMT) from sibling donors. Risk factors include: accelerated phase (10 patients), older age (17 patients over >40 years) and long interval between diagnosis and BMT (27 months on average). Severe mucositis did not occur. Venoocclusive liver disease was absent. Infectious complications were rare. Although grade II–IV acute graft-versus-host disease (GVHD) was present in 9 (25%) cases, there were only 2 serious (III–IV) ones. Chronic GVHD occurred in 25 (69%) cases, preceded by acute GVHD in 9 of the 25 affected patients. Early hematological relapse, 7–29 weeks after BMT, developed in 6 patients (17.6%). No relapse was noted in the completely chimeric patients, however molecular genetic residual disease was observed in 6 patients, in most of them after transient short-term mixed chimeric state. Overall actual survival rate is 83.3% for the 36 cases, and leukemia-free survival is 72.2% for the 34 engrafted patients.

Immunological and molecular biological identification of a true case of T-hairy cell leukaemia.

A hairy cell leukaemia (HCL) patient is presented in whom the peripheral blood mononuclear cells (PBMCs) carried suppressor T‐cell markers (CD3 +, CD2 +, CD8 + /CD4‐, CD38 +). Analysis of genomic DNA of PBMNC showed the presence of a monoclonal population of T cells, the T‐cell receptor (TCR) beta‐chain gene being rearranged on both alleles (DR/DR), while the immunoglobulin (Ig) heavy chain‐genes were in germline configuration. The neoplastic cells were found to react with the monoclonal antibody RAB‐1 — originally described as belonging to the B lineage‐restricted monoclonal antibodies — and to carry RAB‐1/CD‐8 in a double marker assay. Natural killer activity of PBMNCs against K562 target cells was severely reduced, while the cells were found to exert strong antibody‐dependent cellular cytotoxicity.

Immunological importance of chimerism in transplantation: new conditioning protocol in BMT and the development of chimeric state

Chimerism is an exceptional immunogenetic state, characterized by the survival and collaboration of cell populations originated from two different individuals. The prerequisits to induce chimerism are immuno-suppression, myeloablation, or severe immunodeficiency of the recipients on the one side and donor originated immuno-hematopoietic cells in the graft on the other. The pathologic or special immunogenetic conditions to establish chimerism are combined with bone marrow transplantation, transfusion, and various kinds of solid organ grafting. Different types of chimerism are known including complete, mixed and mosaic, or split chimerism. There are various methods used to detect the type of chimera state, depending on the immunogenetic differences between the donor and recipient. The induction of complete or mixed chimerism is first determinated by the effect of myeloablative therapy. The chimera state seems to be one of the leading factors to influence the course of the post-transplant period, the frequency and severity of GVHD, and the rate of relapse. However, the most important contribution of the chimeric state is in development of graft versus leukemia effect. A new conditioning protocol (DBM/Ara-C/Cy) for allogeneic BMT in CML patients and its consequence on chimera state and GVL effect is demonstrated.

EXPERIENCES WITH THE DETERMINATION OF CHIMAERA bcr-abl MESSAGES IN BONE MARROW AND PERIPHERAL BLOOD SAMPLES IN CHRONIC MYELOID LEUKAEMIA

W.H.O. Expert Committee on Biological Standardization (1977) Twenty-eighth Report. Technical Report Series 610, p. 5 1. World Health Organization, Geneva. W.H.O. Expert Committee on Biological Standardization (1979) Thirtieth Report. Technical Report Series 638, p. 23. World Health Organization, Geneva. W.H.O. Expert Committee on Biological Standardization (1983) Thirty-third Report. Technical Report Series 687. pp. 83 . 89. World Health Organization, Geneva. W.H.O. Expert Committee on Biological Standardization (1 984) Thirty-fourth Report. Technical Report Series 700, pp. 18, 19. World Health Organization, Geneva. torogy, 88, 223-224.

Single-tube multiplex PCR and capillary electrophoresis for the detection of bcl2-IgH chimeras.

The molecular background of follicular lymphoma is the formation of chimera(s) by the bcl2 gene and one of the immunoglobulin genes, mainly the heavy chain gene. While the diagnosis of follicular lymphoma is based on histological study, the histology cannot be recommended for the follow-up of efficiency of treatment(s). Sensitive detection of the chimera genes in blood or bone marrow samples can serve as informative data without invasive sampling. In this study, a single-tube multiplex reaction was developed for the simultaneous detection of different chimeras of the bcl2 and immunoglobulin heavy chain genes, molecular hallmarks of follicular lymphoma. The method was optimized for the highest yield of reaction and for reproducing the ratio of components in artificial mixtures of two different chimeras. The method is suitable for fast and accurate molecular characterization of follicular lymphomas and for follow-up of residual disease.

Autologous hematopoietic stem cell transplantation in chronic myeloid leukemia with different clinical stages

Seven patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) were treated with an ICE-based regimen plus G-CSF with the aim of mobilizing and collecting Ph-negative peripheral stem cells in the setting of an autologous transplant program. Five patients had CML in the first chronic phase and 2 in the accelerated phase. All patients had been previously treated with interferon-α. Median value and ranges for harvested mononuclear cells, CD34+ cells and CFU-GM, respectively: 5.65 × 108/kg (2.61–11.38); 1.48 × 106/kg (0.216–3.5), and 3.43 × 104/kg (0.243–11.6). FISH was the only useful method for detection of minimal residual disease on apheresis product showing <5% t(9;22) positive cells in 2 cases and <10% positive cells in 4 other cases. Four of seven autologous grafts have been transplanted to date. Busulfan conditioning was used in 1 case and TBI/Cy conditioning in 3 other cases. All patients are alive and well following transplantation and are on interferon-α therapy.