Possibilities for the treatment of varicella-herpes zoster infections in juvenile leukemia]

Chicken pox and herpes zoster represent afraid complications in patients with malignant diseases which may take a noxious course. During the sequence of two chicken pox epidemias in 1973 in children with acute lymphoblastic leukaemias, the prevention and therapeutic possibilities were checked again. Chicken pox or herpes zoster convalescent sera being compatible for blood groups and zoster-immunoglobulin were not available. At the time of the epidemia the first reports on the effect of cytarabine (Alexan) were published. Moreover, we received an information on the therapeutic application of small pox vaccine inactivated with formaldehyde (vaccinia antigen) in adults with herpes zoster and herpes labialis. From 10 children with leukaemias, who were affected with chicken pox or herpes zoster, 7 received up to 1.0 ml of inactivated small pox vaccine intramuscularly on the first day of manifestation. In 6 of the patients there were no new efflorescences on the third day. A third child died. First of all it seems probable that this influence may be due to an induction of interferon formation. Further studies will have to elucidate to what extent this mechanism will also be efficient in severe cases of immunosuppression.     

Hybrid leukemia among acute childhood leukemias]

Four children with the acute leukemia are presented. Their blasts shown the presence of 2 cellular lines markers. Coexistence of markers in the blasts was detected with the technique of double staining the blasts from the bone marrow with: alkaline phosphatase-anti-alkaline phosphatase, and peroxidase with the use of monoclonal antibodies series. Analysis of blasts phenotype with monoclonal antibodies confirm the occurrence of leukemias different from the normally programmed cellular line. Deviations of leukemic cells phenotype may be explained with the fact that leukemogenesis is not an absolute block of cells differentiation but combines maturation disorders and proliferation enabling expression normally absent antigens. It confirms the concept of line preservation and presentation of "earlier frozen" phenotype, and explains the occurrence of leukemias in which blasts present phenotype of one line which does not comply with cell differentiation pattern. Further genotypic studies are necessary to clarify pathogenesis and origin of such blasts. Consequently examination of the larger group of patients with hybrid leukemias will enable conclusions concerning prognostic value of such findings and necessity of introduction of the special therapies.     

Disturbances in iron utilization in acute leukemia and preleukemia]

With Prussian blue reaction nonhaemoglobin iron in the erythroblasts is demonstrable. Three pathological sideroblast types are recorded separately: abnormal intermediate type I and II sideroblasts and ring sideroblasts, representing increasing levels of sideroachrestic disturbance. This permits the classification of sideroachrestic disturbances into four degrees of seriousness. The frequency of a sideroachrestic disturbance in 47 untreated patients with acute myeloid leukaemia was 87%. Among 11 patients with preleukaemic condition, 8 had a disturbance of iron utilisation. In both preleukaemia and leukaemia mainly intermediate sideroblasts were present. All patients with preleukaemia developed leukaemia within 1-20 months. In the course of preleukaemic condition a slight increase of iron misutilisation was obvious when terminating in overt leukaemia. This could be of prognostic importance. After treatment, pathological sideroblasts disappeared only in 2 out of 15 patients with complete remission. There was no correlation between effect of therapy and course of iron misutilisation.     

Clinical and cytological differences in adult acute lymphatic and acute undifferentiated leukemia]

The usefulness for clinical purposes of the distinction of acute undifferentiated (AUL) and acute lymphocytic leukemia (ALL) is suggested by the following observations: 1. Maturation from AUL to ALL has not been observed. Transformation of ALL to AUL has been reported i.e. less of cytoplasmic polysaccharides; however this seems rather to be the effect of cytotoxic therapy and not a real change of the cytological type. 2. Significant differences among ALL and AUL can be noted as far as the therapeutic response is concerned: All of the 9 patients with ALL but only 2 out of 9 patients with AUL went into remission. The mean survival of the cases with ALL amounts to 34, that of AUL only to 4 months. Out of the patients with ALL 4 patients are still alive in persistant first remission after 77, 57, 36 and 28 months. 3. ALL occurs most frequently in young adults (mean age of 21 patients: 31.7 years): AUL is more frequent in elderly patients (Mean age of 18 patients: 57.6 years). 4. In our material ALL did never occur consequent to a typical preluekemic stage, which was followed either by myeloblastic, monocytic, erythroleukemic or undifferentiated leukemias.     

Phage display-based generation of novel internalizing antibody fragments for immunotoxin-based treatment of acute myeloid leukemia

The current standard treatment for acute myeloid leukemia (AML) is chemotherapy based on cytarabine and daunorubicine (7 + 3), but it discriminates poorly between malignant and benign cells. Dose-limiting off?target effects and intrinsic drug resistance result in the inefficient eradication of leukemic blast cells and their survival beyond remission. This minimal residual disease is the major cause of relapse and is responsible for a 5-year survival rate of only 24%. More specific and efficient approaches are therefore required to eradicate malignant cells while leaving healthy cells unaffected. In this study, we generated scFv antibodies that bind specifically to the surface of AML blast cells and AML bone marrow biopsy specimens. We isolated the antibodies by phage display, using subtractive whole-cell panning with AML M2?derived Kasumi?1 cells. By selecting for internalizing scFv antibody fragments, we focused on potentially novel agents for intracellular drug delivery and tumor modulation. Two independent methods showed that 4 binders were internalized by Kasumi-1 cells. Furthermore, we observed the AML?selective inhibition of cell proliferation and the induction of apoptosis by a recombinant immunotoxin comprising one scFv fused to a truncated form of Pseudomonas exotoxin A (ETA'). This method may therefore be useful for the selection of novel disease-specific internalizing antibody fragments, providing a novel immunotherapeutic strategy for the treatment of AML patients.     

Phage display-based generation of novel internalizing antibody fragments for immunotoxin-based treatment of acute myeloid leukemia

The current standard treatment for acute myeloid leukemia (AML) is chemotherapy based on cytarabine and daunorubicine (7 + 3), but it discriminates poorly between malignant and benign cells. Dose-limiting off‑target effects and intrinsic drug resistance result in the inefficient eradication of leukemic blast cells and their survival beyond remission. This minimal residual disease is the major cause of relapse and is responsible for a 5-year survival rate of only 24%. More specific and efficient approaches are therefore required to eradicate malignant cells while leaving healthy cells unaffected. In this study, we generated scFv antibodies that bind specifically to the surface of AML blast cells and AML bone marrow biopsy specimens. We isolated the antibodies by phage display, using subtractive whole-cell panning with AML M2‑derived Kasumi‑1 cells. By selecting for internalizing scFv antibody fragments, we focused on potentially novel agents for intracellular drug delivery and tumor modulation. Two independent methods showed that 4 binders were internalized by Kasumi-1 cells. Furthermore, we observed the AML‑selective inhibition of cell proliferation and the induction of apoptosis by a recombinant immunotoxin comprising one scFv fused to a truncated form of Pseudomonas exotoxin A (ETA''). This method may therefore be useful for the selection of novel disease-specific internalizing antibody fragments, providing a novel immunotherapeutic strategy for the treatment of AML patients.     

The cytogenetics of acute leukemia

Methodological prerequisites for the culture of leukaemic blasts and the fluorescence banding of spread metaphases are represented in detail. By using an improved method the percentage of aneuploid karyotype findings increased in AML from 49% to 68% and ALL from 65% to 81% of all evaluable patients. Specific aberrations known up to the present day are discussed. They could be diagnosed in 46% of aneuploid AML-clones and in 59% of ALL-clones. The fluorescence banding according to the three-colour technique is demonstrated by three examples of "non-specific" aberrations: a) Tandem translocation of 1q and 7 q (64a, male, FAB:M5B), b) Karyotype instability with variability of chromosome numbers arising from trisomy, tetrasomy and polyploidisation of single normal as well as marker chromosomes (57a, female, FAB:M6), c) Identification of a marker chromosome as a derivative chromosome 16 (33a, female, FAB:L2, c-ALL).     

Disturbances of coagulation and fibrinolysis in patients with acute leukemia]

In 30 patients with acute leukemia--18 with myeloblastic acute leukemia, 1 with promyelocytic acute leukemia, 4 with myelo-monocytic acute leukemia, 4 with chronic myelocytic leukemia exacerbation--coagulation and fibrinolysis tests were performed in different stage of the disease. Most of the disorders were noted in the III period of the disease (significant levels of the factors II, IX decrease, clot contractility weakness and platelets count decrease). I in patients with manifestation of haemorrhagic diathesis and in patients without them disturbances in examined tests were similar, but platelets count in patients with bleeding was always significantly reduced. The main reasons of the bleeding in acute leukemias are thrombocytopenia together with the in coagulation factors.     

Effect of immunotherapy on lymphocyte function in acute lymphatic leukemia]

During the immunotherapy children suffered from acute leukaemias will have a significantly higher transformation rate than at the beginning of the immunotherapy. This may be explained by an increase of the immunological competence as well as by an enhanced mobilization of lymphatic cells. Leukaemic blasts used for immunoinduction-therapy will have no higher transformation rates as antigens than those cells never contacted by children. During the immunotherapy an increase of transformation rates may be observed after administering unspecific antigens and in mixed cultures. In a retrospective manner the indication for immunotherapy may be checked again in children with immunotherapy on the basis of the clinical course and evaluation of the cellular immunoreaction.     

Effect of stromal fibroblasts on antibody formation in cultures deficient in A-cells]

Stromal fibroblasts from the monolayer cultures of the rabbit thymus, spleen, and bone marrow when added to suspension cultures of non-adherent rabbit spleen cells had a significant effect on the response of the plaque-forming cells (PFC). Thymus-derived stromal fibroblasts caused an increase in the number of PFC, and bone marrow stromal fibroblasts suppressed the antibody formation in these cultures. Spleen-derived stromal fibroblasts influenced the PFC response similarly to adherent cells. Thymus-derived stromal fibroblasts irradiated by 5000 R influenced the PFC response in the same way as non-irradiated cells. The action of stromal fibroblasts on the antibody formation in the cultures depended on their attachment to the culture flask surface.     

Mechanism of action of T cell factors regulating antibody formation]

While the induction of antibody synthesis depends on antigen specific T cell factors, its magnitude is under control of non antigen specific T cell factors. In this respect, TRF ("T cell Replacing Factor") amplifies antibody responses while IBF ("Immunoglobulin Binding Factor") acts as a suppressor factor. Using cultures of spleen cells from nude mice, we show that both factors act sequentially, influencing the final differenciation of B cells to antibody producing cells. We have no evidence of direct interaction between TRF and IBF.     

Mechanism of disorders in energy formation in acute hepatic ischemia]

Respiration of hepatic mitochondria of rats after addition of ischemic toxin to the incubation medium was compared with respiration of mitochondria isolated from an ischemic rat liver. Its change could be prevented in both cases by the preliminary administration of dithiotreitol and could be decreased by the subsequent addition of cytochrome C or dithiotreitol into the incubation medium. Similarity of the mechanisms of disturbed energy formation in vivo and in vitro is supposed.     

Monoclonal antibody OKT-9 recognizes the receptor for transferrin on human acute lymphocytic leukemia cells

The monoclonal antibody OKT-9 recognizes a surface protein of human lymphocytes that consists of a disulfide bonded homodimer of m.w. 200,000 intact and 95,000 reduced. A similar protein is precipitated by transferrin-agarose, but not by agarose alone. Peptide mapping by limited proteolysis shows that the proteins precipitated by OKT-9 antibodies and transferrin-agarose are homologous. It is concluded that OKT-9 antibodies recognize the transferrin receptor. Expression of receptors for transferrin may be useful as a marker for activated or dividing cells.