[Importance of the detection of minimal residual disease in the management of acute leukemia]. / Minimális reziduális leukaemia vizsgálatának jelentösége az akut leukaemiás betegek kezelésében.

Between 1984-1988, 57 adult acute leukemic patients were treated with intensive combined chemotherapy in the National Institute of Haematology and Blood Transfusion. For the evaluation of response to therapy, 4 investigations were performed in parallel: bone marrow aspirate, bone marrow biopsy, cytogenetic analysis and bone marrow culture. Nonparametric test for samples taken for the evaluation of remission status showed that bone marrow biopsy was significantly the most sensitive method for the detection of residual disease. The bone marrow culture was also on the borderline of significance, but the low CFU-GM level did not always correlate with the further clinical course. Occasionally, karyotypic abnormality was the only sign of the residual disease. It would be of great importance to quantitate the minimal residual disease in order to evaluate and compare the various intensive postinduction therapeutic strategies.

[Cytochemical, immunologic and gene rearrangement studies in adult acute leukemia]. / Cytochemiai, immunológiai és génátrendezödés vizsgálatok felnöttkori akut leukaemiákban.

Results of morphological, cytochemical and immunological studies performed in adult acute leukaemias have been compared. Thirty one cases proved to be acute myeloid leukaemia, while 25 cases were shown to be acute lymphoid leukaemia. Based on our results we conclude that immunophenotyping with monoclonal antibodies does not help in distinguishing the subtypes of AML. For purposes of clinical diagnosis cytochemical methods are valuable. On the other hand the monoclonal antibodies are essential in distinguishing the very immature myeloid and lymphoid leukaemias and this is of great importance from the clinical point of view, in determining therapy. Moreover, the diagnosis of acute lymphoid leukaemias is not possible without the specific monoclonal antibodies. Their application is first of all in haematological centers caring for leukaemia patients nowadays already obligatory. Gene rearrangement studies make the diagnosis more accurate and help in the diagnosis of leukaemias of unknown immunological origin.

Clinical value of cytomorphologic, immunologic and cytogenetic investigations of acute leukaemias.

The valuability of immunophenotyping of acute myeloid and lymphoid leukaemias in comparison to morphological and cytochemical classification were approached in 56 cases. In the case of acute myeloid leukaemias the immunophenotyping by monoclonal antibodies CD14, CD13, CD33 was less informative concerning the subtypes of the disease. The clinical diagnosis can be achieved on the basis of cytochemical investigation alone. In contrast, the diagnosis of lymphoid leukaemias requires all information obtained by immunophenotyping by a series of monoclonal antibodies CD3, CD2, CD4, CD8, CD1, CD19, CD20, CD21 and CD10. On the other hand, the monoclonal antibodies are essential in differentiation of the very immature myeloid and lymphoid leukaemias. This is of great importance from the clinical point of view for determining the therapy. Molecular genetic studies based on the characterisation of the state of gene rearrangement of immunoglobulin and T-cell receptor beta chains have basic importance in the confirmation of the result of immunophenotyping and in the determination of leukaemias of unknown origin.

Human fetal liver as a valuable source of haemopoietic stem cells for allogeneic bone marrow transplantation.

The CFU-GM and T cell contents of human fetal livers were studied at various times between 6-14 weeks of gestation. The number of CFU-GM increased parallel to gestational age, especially after week 10. Cells bearing mature T cell markers, however, were found only in one case out of 35 fetal liver samples. Cryopreservation of fetal liver cells hardly affected the viability and proliferative capacity of CFU-GM in the sample. According to these findings fetal liver is, at least up to the 14th gestational week, practically free of mature T cells but it does contain a considerable amount of CFU-GM (an accepted indicator of pluripotent stem cell content), consequently fetal liver can be considered as a valuable source of haemopoietic stem cells for allogeneic bone marrow transplantation for children.

Plasmapheresis in patients with leukaemia, multiple myeloma and immune complex diseases.

Therapeutical partial plasma exchange was performed on 9 patients with acute leukaemia, 14 patients with monoclonal and polyclonal gammopathies and 3 with primarily immune complex disease. The procedure was effective in 21 out of the 27 courses performed on patients with gammopathies and in all cases of the primarily immune complex diseases. In acute leukaemic patients the course of the disease was favourably influenced by plasmapheresis. The results show that partial plasma exchange is an effective adjunct therapy in the treatment of patients with haematological diseases.

Intracellular "labyrinths" in acute leukaemia. Do they indicate the maturational ability of leukaemic cells?

The occurrence and ultrastructure of the so-called "labyrinths" were investigated in the bone marrow cells from 13 patients with preleukaemia and acute leukaemia. Except for one patient, labyrinths were found in the myeloid cells from patients with preleukaemia and acute myelogenous leukaemia. Labyrinths could not be detected in lymphoblasts from patients suffering from acute lymphoblastic leukaemia or in plasma cells from a patient with plasma cell leukaemia. In patients with preleukaemia and smoldering leukaemia, labyrinths could be detected in all differentiation forms, from myeloblasts to mature polymorphonuclear granulocytes. Since it is improbable that labyrinths develop in consequence of exogenous effects, their presence in the mature granulocytes points to the in vivo maturational ability of leukaemic precursors in certain cases of acute myelogenous leukaemia and preleukaemia.

T acute lymphoblastic leukaemia with breast tumor. A brief report.

Acute lymphoblastic leukaemia of L-2 type was diagnosed in an 18-year-old female with breast tumour. Her peripheral leukaemic cells reacted with anti-human peripheral T cell serum and part of the cells expressed SRBC receptor indicating the T origin of her leukaemia. She had a tumoral mass in her breast consisting of the same leukaemic cells. Combination chemotherapy was applied and she went into complete haematological remission with simultaneous disappearance of the breast tumour.