Case report. Disseminated infection of Blastoschizomyces capitatus in a patient with acute myelocytic leukaemia

Blastoschizomyces capitatus infection in a 48-year-old man with acute myelocytic leukaemia is reported. A multiorgan involvement and fulminant course of the fungal infection resulted in the patient's death despite fluconazole prophylaxis, therapy with amphotericin B and administration of granulocyte colony-stimulating factor. Predisposing factors to the infection, clinical relevance of surveillance strains and in vitro antifungal susceptibility testing are discussed.     

Appraisal of the MTT assay as a rapid test of chemosensitivity in acute myeloid leukaemia

We describe the application of a simple, rapid, semi-automated assay to the sensitivity testing of cytotoxic drugs in 23 patients with acute myeloid leukaemia (AML). The survival of blast cells from the bone marrow was measured by the MTT assay after 48 h continuous exposure to drugs both singly and in combination. There was a linear relationship between the number of leukaemic cells and the optical density of the formazan produced. The assay demonstrated a variation in drug sensitivity between patients. The technique was reproducible and there was no significant difference in response between blast cells obtained from bone marrow or from peripheral blood. Preliminary results show a correlation between in vitro and in vivo data. The test can be repeated throughout the course of the disease to help identify any change in tumour sensitivity. This technique appears to give useful information to assist in the management of acute myeloid leukaemia.     

Chronic myelocytic leukaemia with unusual (27 years) complete remission terminating in acute undifferentiated leukaemia: a clinical and karyotypic study

A case of clinically typical CML (300 x 10(6)/l leukocytes, 400 x 10(6)/l platelets, splenomegaly) is presented. After complete remission induced by busulphan, no clinical or haematological abnormalities were observed for 27 years until the development of acute leukaemia (type M1), which was rapidly fatal after a brief chemotherapy-induced remission. The cytogenetic findings were also original: no chromosome Ph1 (during remission 3 years after the onset of the disease), no translocation (banding study 5 years later), and no bcr/abl rearrangement (during the terminal phase).     

In vitro chemosensitivity testing in chronic lymphocytic leukaemia patients

Twenty-nine samples from eighteen patients with chronic lymphocytic leukaemia (CLL) were used in a direct comparison of in vitro response to chlorambucil measured in a metabolic (MTT) and dye exclusion (D.Ex) assay. Reduced ability to produce formazan corresponded to a reduced number of dye-excluding viable cells and a significant correlation was found between dose-response measured in the two assays. Initial low absorbance values obtained with untreated control cells in the MTT assay were effectively overcome by increasing both the cell seeding density and MTT exposure time with the consequent increase in assay sensitivity. The MTT assay provided qualitatively similar dose-response data to that obtained in the D.Ex assay. A wide range in in vitro response was seen for both pretreatment and treatment patient groups. In vitro dose-responses were seen to coincide with decreasing or stable white cell counts, taken around the time of sampling, in samples from 4 patients. Less marked dose-responses were observed for 2 patients considered clinically resistant to chlorambucil. The MTT assay would seem, therefore, to be applicable to in vitro assay of cell response in CLL.     

Development and characterisation of a cyclophosphamide resistant variant of the BNML rat model for acute myelocytic leukaemia

A cyclophosphamide resistant subline (BNML/CPR) was developed in vivo in the BN rat acute myelocytic leukaemia (BNML) model. Full resistance was achieved after in vivo exposure of leukaemic animals to cyclophosphamide with, in total, 15 intraperitoneal injections of 100 mg/kg. The CPR line was cross-resistant to ifosfamide, but less so to mafosfamide. Continuous transplantation of the BNML/CPR line without a cyclophosphamide selection pressure resulted in the emergence of a subline (BNML/CPR>S) whose sensitivity to cyclophosphamide was similar to that of the parent BNML/S line. Both in the BNML parent line and in the BNML/CPR>S line, a 2p+ marker chromosome was present, whereas a 2p+q+ marker chromosome was characteristic for the BNML/CPR line. The mechanism of cyclophosphamide resistance can now be investigated in the BNML model at the DNA, at the mRNA and at the protein level.     

Induction of differentiation in chronic myelocytic leukaemia cells by the phorbolester TPA

The mononuclear peripheral blood cells from eight patients with chronic myelocytic leukaemia (CML) were incubated in cell suspension culture in the presence of the phorbolester 12-O-tetradecanoylphorbol 13-acetate (TPA). TPA caused the treated cells to adhere and to acquire morphological and functional features characteristic of macrophage-like cells. Using isoelectric focusing distinct changes in the isoenzyme profiles of carboxylic esterase, acid phosphatase, hexosaminidase and lactate dehydrogenase were detected in the TPA-exposed cells. Besides an increase in the number and staining intensity of isoenzymes of all enzymes, TPA triggered the new expression of a monocyte-specific esterase isoenzyme isoenzyme and of the tartrate-resistant acid phosphatase isoenzyme. The latter two isoenzymes represent further parameters of the monocyte/macrophage complex. The results indicate that immature leukaemic cells arrested along the granulocytic cell axis retain the ability to transform to macrophages.     

In vitro testing of chemotherapeutic drug combinations in acute myelocytic leukaemia using the fluorometric microculture cytotoxicity assay (FMCA).

The fluorometric microculture cytotoxicity assay (FMCA) was employed for analysing the effect of different chemotherapeutic drug combinations and their single constituents in 44 cases of acute myelocytic leukaemia (AML). A large heterogeneity with respect to cell kill was observed for all combinations tested, the interactions ranging from antagonistic to synergistic in terms of the multiplicative concept for drug interactions. However, an ''additive'' model provided a significantly better fit of the data compared to the effect of the most active single agent of the combination (Dmax) for several common antileukaemic drug combinations. When the two interaction models were related to treatment outcome 38% of the non-responders showed preference for the additive model whereas the corresponding figure for responders was 80%. Overall, in 248 of 290 (85%) tests performed with drug combinations, there was an agreement between the effect of the combination and that of the most active single component. Direct comparison of Dmax and the combination for correlation with clinical outcome demonstrated only minor differences in the ability to predict drug resistance. The results show that FMCA appear to report drug interactions in samples from patients with AML in accordance with clinical experience. Furthermore, testing single agents as a substitute for drug combinations may be adequate for detection of clinical drug resistance to combination therapy in AML.     

An assessment of a short-term tumour chemosensitivity assay in chronic lymphocytic leukaemia

A 4-day tumour sensitivity assay of potential use in predicting tumour response to cytotoxic drugs has been investigated in patients with chronic lymphocytic leukaemia. The method comprised isolation of white cells from peripheral blood, drug exposure and incubation for 4 days. Drug-induced tumour cell kill was assessed by differential staining of dead and live cells such that the latter could be morphologically identified, with subsequent calculation of tumour cell viability. Concentrations of drug for use in the assay were chosen for chlorambucil (2 micrograms ml-1), 4-hydroperoxy-cyclophosphamide (2 micrograms ml-1)--which was used in vitro in place of cyclophosphamide--prednisolone (0.5 microgram ml-1) and vincristine (0.1 microgram ml-1), to give a scatter of values which was in good agreement with clinical expectations. In 21 cases where the in vitro result could be compared with the in vivo response, there were 4 true positive comparisons (sensitive in vitro, sensitive in vivo), 15 true negative comparisons (resistant both in vitro and in vivo) and 2 false positive comparisons (sensitive in vitro, resistant in vivo). A result was obtained in 86% (65/76) of samples received. The assay appears to show considerable promise as a tumour chemosensitivity test and warrants wider investigation, including prospective in vivo/in vitro correlations that could be based on the results presented here.     

Adult acute leukaemia

Seventy-eight adult patients with acute leukaemia were classified cytologically into 3 categories: acute lymphoblastic leukaemia (ALL), acute myelogenous leukaemia (AML) or acute undifferentiated leukaemia (AUL). The periodic acid-Schiff stain was of little value in differentiating the 3 groups. The treatment response in each group was different: 94% of patients with ALL (16/17) achieved complete remission with prednisone, vincristine and other drugs in standard use in childhood ALL; 59% of patients with AML (27/46) achieved complete remission with cytosine arabinoside and daunorubicin (22 patients), or 6-thioguanine and cyclophosphamide (2 patients), 6-thioguanine, cyclophosphamide and Adriamycin (1 patient), and cytosine and Adriamycin (1 patient); only 2 out of 14 patients (14%) with acute undifferentiated leukaemia achieved complete remission using cytosine and daunorubicin after an initial trial of prednisone and vincristine had failed. Prednisone and vincristine would seem to be of no value in acute undifferentiated leukaemia. It would seem also that no benefit is obtained by classifying all patients with acute leukaemia over 20 years of age as “adult acute leukaemia” and treating them with the same polypharmaceutical regimen. The problems posed by each disease are different and such a policy serves only to obscure them.     

Human histocompatibility antigens and survival in acute myelocytic leukemia

Several previous reports have suggested an association between human histocompatibility antigens (HLA) and survival in acute myelocytic leukemia (AML). The authors have retrospectively analyzed the records of 104 consecutive newly diagnosed patients with AML treated on the Leukemia Service of the Johns Hopkins Oncology Center from March 1978 through May 1982 who had HLA typing performed to further evaluate this point. The authors have been unable to demonstrate a statistically significant association of HLA phenotype with the ability to achieve a complete response (CR), length of CR, survival of the total group of treated patients, or survival of only those patients achieving a CR (P less than 0.05). The available evidence does not strongly support a significant influence of HLA on survival in AML.     

Isoferritins in acute leukaemia.

Leucocytes containing a high proportion of blast cells were obtained from 11 patients with acute myeloid leukaemia, and leucocytes were also obtained from 2 normal subjects. Ferritin was partially purified from leucocyte extracts and subjected to anion-exchange chromatography and isoelectric focusing. The Fe content of leucocyte ferritin was low, and in all but one case the preparations contained isoferritins corresponding to those found in normal tissues or serum. Only some of the preparations contained the relatively acidic isoferritins which have been described as "carcinofoetal", but which are also present in normal heart and kidney. Ferritin from one patient contained isoferritins of lower isoelectric point than heart ferritin. These results show that there does not appear to be any specific isoelectric focusing pattern for leukaemic cells, and that assays for acidic isoferritins are unlikely to be of use in the diagnosis of leukaemia and in monitoring treatment. However, the very acidic protein found in one preparation suggests that the search for abnormal subunits of ferritin may be fruitful in acute leukaemia.     

Cure of acute myelocytic leukemia in adults: a reality

Adult acute myelocytic leukemia (AML) is a curable disease in responsive patients with aggressive treatment in remission. Over the past decade at the Johns Hopkins Oncology Center, AML has been treated with either allogeneic bone marrow transplantation or with intensive timed sequential treatment using high dose cytarabine in remission. With either treatment modality comparable cure rates were obtained. The role, if any, of randomized trials to adequately determine the preferred treatment for appropriate patients has yet to be defined.