Intensive combination chemotherapy in treatment of CML

Tumor load reduction has an influence on survival of patients in the chronic phase of chronic myelogenous leukemia (CML). This comprises both reduction of white blood cell (WBC) mass and reduction of the Philadelphia (Ph)-positive clone. Besides drug monotherapy, intensive combination chemotherapy is also very effective in reducing tumor burden in the chronic phase of CML. Therapeutic concepts consisting of combination chemotherapy include intensive chemotherapy alone or in combination with interferon-alpha (IFN-alpha) and preparative regimens before autografting or allografting. All these concepts demonstrate the effectiveness of this treatment form. The high toxicity of combination chemotherapy does not justify its application in unselected patients. However, in suitable patients, possibly in poor interferon-alpha responders (as carried out in the current German CML study) it might be superior with regard to survival.

High prevalence of RET rearrangement in thyroid tumors of children from Belarus after the Chernobyl reactor accident

RET rearrangement was studied in papillary thyroid carcinomas (PTC) of children exposed to radioactive fallout in Belarus after the Chernobyl accident. To detect RET rearrangement in small tissue samples from thyroidectomy specimen (12 PTC of children; 2 PTC and 1 follicular carcinoma of adults; non-tumorous thyroid tissue of 4 children and 4 adults as controls), a RT-multiplex PCR was developed using primers suited to amplify fragments in different quantities depending on the presence or absence of RET rearrangements in the tissues. The type of rearrangement was determined by RT-PCR and direct sequencing using primers for ret/PTC1, 2 and 3. Two-thirds of the papillary thyroid carcinomas of the children revealed a RET rearrangement, with ret/PTC3 being more frequent by a factor of 3 than ret/PTC1. ret/PTC2 was not detected. All RET rearrangement-positive tumors had lymph node metastasis while half of the tumors with wild-type cRET had not. More than half of the cases with ret/PTC3 expressed not only the ELE/RET transcript as expected, but also the RET/ELE transcript. Intrachromosomal rearrangement involving RET and the adjacent H4 or ELE gene on chromosome no. 10 is a very frequent event in thyroid cancer of children of the Chernobyl-contaminated zone of Belarus.

Cytogenetic findings in 179 patients with myelodysplastic syndromes

Cytogenetic analyses were performed on 266 bone marrow and peripheral blood samples from 179 patients with myelodysplastic syndromes (MDS). According to the FAB classification, 42 patients presented with RA, 18 with RARS, 37 with RAEB, 22 with CMML, and 29 with RAEB-T. Nine patients showed a secondary MDS (S MDS). FAB classification was not available for 22 patients. Clonal karyotype anomalies were found in 92 patients (51.4%). Complex chromosome abnormalities occurred in 17 (18.5%) of them. An evolution of the karyotype was detected in 16 cases (17.4%). Cytogenetically independent cells or cell clones were found in eight patients. Nonclonal chromosome abnormalities were uncovered in 29 (16.2%) of the 179 MDS patients. Consecutive studies were performed in 48 patients and revealed a good correlation of initial karyotype and clinical course. The most frequent single anomalies were 5q- in 29 (31.5%), -7 in 22 (23.9%), trisomy 1q in 14 (15.2%), and +8 in 13 (14.1%) of 92 patients respectively. Our cytogenetic findings are presented in detail and discussed in relation to patients' age, morphological classification, clinical course, and prognostic impact. The contribution of cytogenetic findings to the delineation of multistep pathogenesis of MDS with special emphasis to karyotype instability is demonstrated.

Interleukin-2 bolus infusion as late consolidation therapy in 2nd remission of acute myeloblastic leukemia

The activation of autologous cytotoxic cells by interleukin-2 (IL-2) may be a promising tool for elimination of minimal residual blast populations in patients with acute myelocytic leukemia (AML) to prolong disease-free survival. Here, we report the results of a phase II study using IL-2 for consolidation therapy in patients with second remission of de novo AML. All patients in 1st relapse of AML received a uniform induction therapy consisting of intermediate high-dose AraC (iHDAraC) 2 x 600 mg/m2 d1-4 and VP-16 100 mg/m2 d1-7. Patients achieving 2nd remission were treated with 4 cycles recombinant IL-2 (rIL-2) 9 x 10(6) IU/m2 administered on d1-5 and 8-12/cycle as 1h infusion every six weeks. In 37/66 (56%) evaluable patients, complete remission (CR) was achieved. So far, 21/37 patients (4 after additional autologous bone marrow transplantation (ABMT) received rIL-2 consolidation. Three patients are too early for evaluation, 4 received allogeneic BMT, 6 relapsed before IL-2 was scheduled and 4 refused treatment with rIL-2. The median disease-free survival (DFS) was 11 (4-49+) months. Up to now, in 5/21 (24%) patients the duration of 2nd remission exceeded that of 1st remission 7/21 (33%) are in ongoing 2nd remission (7+ to 49+ months). The side effects of rIL-2 were generally moderate and manageable. Only in two patients, previously treated with ABMT, severe side effects occurred; septicaemia and pneumonia in one patient and desquamative erythrodermia in the second one. In accordance with other studies rebound lymphocytosis with a marked increase of CD56(+)-cells and release of secondary cytokines such as TNF-alpha, IFN-gamma and IL-6 was observed. The schedule is feasible and the data suggest a possible benefit for DFS, which, however has to be confirmed by randomized trials.

Effect of activated oxygen species in human lymphocytes

The cytogenetic effectiveness of activated oxygen species (AOS) generated by the superoxide forming xanthine-xanthine oxidase (X/XO) system was studied in human lymphocyte cultures. The observed chromosome damage was exclusively of the chromatid type. In the experiments a clear dependence of aberration induction on XO concentration and exposure time could be demonstrated. While using anti-AOS agents, the H2O2 antagonist catalase and the hydroxyl radical scavenger formate reduced X/XO induced chromosome damage whereas superoxide dismutase (SOD) did not. In the presence of SOD, aberration frequency was even enhanced. The results indicate that the chromosome damage is caused indirectly via H2O2 formation from spontaneous dismutation of superoxide, whereas H2O2 might be reduced intracellularly giving rise to the highly reactive hydroxyl radical. This effect might be enhanced by SOD, possibly by raising the intracellular amount of easily membrane passing H2O2. Thus, referring to chromosome aberrations, SOD, which is generally reported to protect from AOS, is capable of increasing oxygen mediated biological damage. This observation might be explained by the involvement of DNA associated transition metal, like iron or copper ions, in reducing H2O2. DNA bound copper ions, thought to be necessary for maintenance of DNA quaternary structure, might represent a generator complex for the hydroxyl radical by reduction of X/XO derived hydrogen peroxide. This might cause 'site specific damage' to the DNA which is subsequently converted into chromatid-type aberration by S-dependent misreplication and/or misrepair. This is different to the formation of radiation induced chromosome aberrations which arise by an S-phase independent mechanism.

[Complete remission in acute promyelocytic leukemia. The advantages of all-trans-retinoic acid compared to conventional chemotherapy]

In all of seven patients (six men, one woman; mean age 43 [24-55] years) with newly diagnosed acute promyelocytic leukaemia, treated between 1989 and 1993, complete remission was achieved. In three of these patients, treated between 1989 and 1991, remission was induced with conventional chemotherapy (cytarabine and anthracycline), after this in four patients with all-trans retinoic acid (tretinoin). The seventh patient who had a very rapid increase in leucocytes during tretinoin administration, was as a precaution also given conventional chemotherapy. All seven patients received consolidating chemotherapy with an intensive treatment cycle. Retrospective analysis indicated that induction with tretinoin had marked advantages: quicker regression of the clotting abnormalities (mean of 9 vs 25 days), shorter period of leukopenia (mean of 3.5 vs 30 days), shorter time until complete remission (mean of 38 vs 48 days). There were no specific side effects ascribable to tretinoin. Toxicity after chemotherapy corresponded to WHO grades 2-4. The results indicate that tretinoin markedly reduces the two main risks in the treatment of acute promyelocytic leukaemia: bleeding and infection.

Correlation of cytogenetic findings with clinical features in 18 patients with inv(3)(q21q26) or t(3;3)(q21;q26)

An inversion in the long arm of chromosome 3--inv(3)(q21q26)--or a translocation between both homologous chromosomes 3--t(3;3)(q21;q26)--is found specifically in myeloid neoplasias characterized by disturbances of thrombopoiesis and megakaryocyte development. Cytogenetic findings were correlated with clinical and hematological data in altogether 18 patients with acute nonlymphocytic leukemia (ANLL) and with inv(3) (13 patients) or t(3;3) (five patients), six of whom were male and 12 who were female. Chromosomal changes in addition to the 3q anomalies were demonstrated in 14 out of 18 patients, predominantly numerical and structural aberrations of chromosome 7 (12 cases) and/or abnormalities of 5q (five cases). Complex karyotype abnormalities were observed in six of 13 patients with inv(3), but in only one of five patients with t(3;3). In ten out of our 18 patients a preceding myelodysplastic syndrome (MDS) and/or exposure to mutagenic/carcinogenic agents had been established. In eight patients the morphology of ANLL blasts was immature (FAB subtype M1); in three patients ANLL-M4, and in two patients each ANLL-M5, M6, and M7 was diagnosed; in one patient with antecedent MDS the leukemic blasts were not classifiable according to the FAB criteria. A disturbed megakaryocyte development, characterized by an excess of micromegakaryocytes was observed in 14 patients, seven of them showed normal or elevated platelet counts as an unusual feature in patients with ANLL. The clinical course and outcome was extremely poor: 15 of 18 patients died within 10 months after the diagnosis of ANLL. Because of their missing response to conventional chemotherapy, patients with inv(3) or t(3;3) have to be estimated as at high risk. The characterization of genes affected by inv(3) or t(3;3) could help to elucidate molecular changes leading to impaired proliferation and differentiation of hematopoietic cells, also of the megakaryocytic lineage. Based on molecular genetic findings new therapeutical approaches could be designed.

Induction of oxidative stress and protection against hydrogen peroxide-mediated cytotoxicity by the superoxide dismutase-mimetic complex copper-putrescine-pyridine

The low molecular weight Cu2Zn2-superoxide dismutase (SOD) active centre analogue copper-putrescine-pyridine (Cu-PuPy, N,N'-bis(2-pyridylmethylene)1,4-butanediamine(N,N',N",N")-Cu (II)- -diperchlorate) has been shown to dismutate superoxide with high efficiency. In the presence of glutathione it sustains the production of H2O2 via redox cycling. We investigated the influence of Cu-PuPy on the glutathione status and the clonogenic survival of Chinese hamster ovary (CHO) cells. At 0.05 mM Cu-PuPY was not toxic and exerted only a minor effect on cellular glutathione. At Cu-PuPy concentrations of 0.1-0.5 mM glutathione became increasingly oxidized and was depleted during treatment while toxicity dramatically increased. The time course of toxicity was unusual: after passing a minimum at 50 or 100 min (0.5 mM or 0.2 mM Cu-PuPy, respectively), clonogenic survival increased by two orders of magnitude in the following 50 min. On the other hand, Cu-PuPy protected cells effectively against toxic doses of hydrogen peroxide. We conclude that Cu-PuPy combines a prooxidant and an antioxidant mode of action that sequentially modify the survival response of CHO cells: initial production of hydrogen peroxide by Cu-PuPy-catalysed glutathione oxidation leads to the intracellular accumulation of potentially toxic radical intermediates that may be inactivated via superoxide dismutation upon further treatment with Cu-PuPy.

[Fatal subileus caused by intestinal amyloidosis in light chain plasmacytoma]

This report concerns a patient with systemic amyloidosis due to a plasmocytoma, in whom massive amyloid depositions in the small bowel caused severe diarrhoea and malabsorption. The excessive amyloid depositions in the lamina muscularis propria of the bowel finally resulted in therapy-resistant motility disturbance and adynamic subileus with fatal outcome.

A pulse radiolytic study on the reaction of hydroxyl and superoxide radicals with yeast Cu(I)-thionein

In a pulse radiolytic study employing aqueous intact yeast copper(I)-thionein at pH 7 it was shown that both superoxide and hydroxyl radicals efficiently react with this Cu(I)- and thiolate-rich protein. The reaction constant of hydroxyl radicals with Cu(I)-thionein was determined by competition kinetics and was 2.2 x 10(11) M-1 s-1 at a rate close to a diffusion-controlled limit. The reaction of Cu(I)-thionein with superoxide was also successful and proceeded at a rate of 7.5 x 10(6) M-1 s-1. According to chiroptical and luminescence emission measurements minor oxidation of the copper(I)-thiolate oligonuclear binding centres was observed, leading to the release of some Cu(II). It is important to realise the dual reactivity of this yeast Cu(I)-thiolate protein in controlling copper transport and storage as well as its distinct role in the scavenging of free radicals.

[Detection of HIV-1 antigen--determination using 3 different test systems]

51 human sera containing antibodies to human immunodeficiency virus 1 (= HIV-1) were examined for HIV-1-antigen by three different enzyme immunoassay procedures (= EIA) of Abbott, Organon and Dupont. Sensibilities, handling as well as the correlation with the clinical stages of HIV-infection were compared. The EIA's diagnosed in accordance 6 sera which contained HIV-1-antigen and 42 sera to be HIV-1-antigen negative. 3 sera showed differences: according to the EIA of Organon none of these sera contained HIV-1-antigen, the EIA of Abbott (but not of Dupont) analysed HIV-1-antigen in one of these sera, in the other two sera only the EIA of Dupont showed HIV-1-Antigen. It is concluded that the differences in these 3 serum samples may originate not only in the different types of EIA used (indirect/direct procedure) but also in the different capture antibodies provided (antibodies against p-24 antigen or polyvalent antibodies).

[Hypercalcemias in chronic lymphatic leukemias and other non-Hodgkin's lymphomas]

Three years after diagnosis of chronic lymphocytic leukaemia in a 57 year old man developed a hypercalcaemia with multiple bone fractures, concomitant an increase of activity of the leukaemia. There was no hyperparathyroidism, nor in serum, nor inside the lymphocytes. The osteopenia was caused by leukaemic infiltrations. An additional activation of osteoclasts was caused by an osteoclasts activating factor (OAF), produced by the leukaemic cells. 2 (= 2.25%) of 89 Non-Hodgkin-Lymphomas except chronic lymphatic leukaemia had a moderate hypercalcaemia with concomitant activation of the underlying disease. 9 (= 7.7%) of 116 chronic lymphocytic leukaemias had hypercalcaemia, 2 thereof with increased activity of the leukaemia. Hypercalcaemia is thus very rarely found in other Non-Hodgkin-Lymphomas, in chronic lymphocytic leukaemia some what more often, and only here a concomitant increase in the activity of the underlying disease could be observed in some cases.

High-dose cytosine arabinoside in combination with mitoxantrone for the treatment of refractory acute myeloid and lymphoblastic leukemia

In the present study 55 patients with refractory acute myeloid leukemia (AML) (n = 44) and acute lymphoblastic leukemia (ALL) (n = 11) were treated with high-dose cytosine arabinoside (HD-ara-C) and mitoxantrone (HAM) to assess the toxicity and antileukemic activity of the two-drug combination. All patients had received a standardized first-line therapy according to the corresponding multicenter trials of the German AML and ALL cooperative groups and were considered refractory to conventional treatment. Therapy consisted of HD-ara-C 3 g/m2 every 12 hours on days 1 to 4; mitoxantrone was started at 12 mg/m2/d on days 3, 4, and 5 and was escalated to four and five doses of 10 mg/m2/d on days 2 to 5 and 2 to 6. From the 44 patients with AML, 24 (54%) achieved a complete remission, two a partial remission, and five were nonresponders. Thirteen patients died of infections (n = 11), pericardiac effusion, or acute cardiomyopathy. In refractory ALL, seven of 11 patients (64%) went into a complete remission, one patient was resistant, and three patients were early deaths. Nonhematologic side effects consisted predominantly of nausea and vomiting, mucositis, and diarrhea. More severe CNS symptoms were encountered during five treatment courses. The median time to complete remission was 36 days. Excluding five patients who underwent bone marrow transplantations, the median remission duration was 4.5 months in AML and 2.3 months in ALL. The median survival time was three months for all patients and nine months for responders only. These data emphasize a high antileukemic activity of HAM in refractory AML and ALL and support the incorporation of the HAM regimen into first-line treatment.

High-dose cytosine arabinoside and mitoxantrone: a highly effective regimen in refractory acute myeloid leukemia

In a clinical phase I/II study, high-dose cytosine arabinoside and mitoxantrone (HAM) were given in combination to 40 patients with refractory acute myeloid leukemia. All patients had received a 9-day combination of thioguanine, Ara-C, and daunorubicin (TAD-9) as standardized first-line treatment. Refractoriness was defined as (a) nonresponse against two TAD-9 induction cycles, (b) early relapse within the first 6 months on monthly maintenance or after TAD-9 consolidation, (c) relapse after 6 months with nonresponse against one additional TAD-9 cycle, and (d) second and subsequent relapses after successful TAD-9 therapy at the preceding relapse. Therapy consisted of HD-Ara-C 3 g/m2 every 12 hours on days 1 through 4; mitoxantrone was started at 12 mg/m2/day on days 3, 4, and 5 and was escalated to 4 and 5 doses of 10 mg/m2/day on days 2 through 5 and 2 through 6. Of the 40 patients, 21 achieved a complete remission (53%), 1 patient had a partial remission, and 5 patients were nonresponders. Thirteen patients died in aplasia due to infections (n = 11), pericardiac effusion, or acute cardiomyopathy. Nonhematologic side effects consisted predominantly of nausea and vomiting, mucositis, and diarrhea. Central nervous system (CNS) symptoms were observed during six treatment courses. Recovery of blood counts occurred at a median of 27 days from the onset of treatment; the median time to complete remission was 36 days. Two of the 21 responders underwent successful bone marrow transplantations. The median remission duration for the remaining 19 patients is 4.5 months, and the median survival time is 9 months. These data emphasize that HAM has high antileukemic activity in refractory AML and strongly suggest starting the combination at earlier stages in AML therapy.

Hyaluronic acid degradation by ascorbic acid and influence of iron

The effects of ascorbic acid, iron and ADP on hyaluronic acid, a compound present in inflamed joints, were investigated in an in vitro system. Ascorbic acid induces degradation of hyaluronic acid which increased in the presence of FeCl3 and which is additionally stimulated by ADP chelated ferric ions. The hyaluronic acid degrading reactions induced by the Fe-III/ADP/ascorbic acid system were inhibited by catalase and formate to various extents whereas the presence of superoxide dismutase did not exert any inhibitory effect. Desferrioxamine, a specific iron chelator, completely inhibited hyaluronic acid depolymerisation by ascorbic acid as well as in combination with FeCl3 or FeCl3/ADP, respectively. We suggest that the ultimate hyaluronic acid degrading species is OH, generated via the Fe-III/ADP catalysed Haber Weiss reaction. There is also an indication for the involvement of perferryl or/and ferryl species in the degradation process.