Biomedical subjects

G J Ossenkoppele

Publications and source records attributed to G J Ossenkoppele.

At least 73 records · Page 4Linked to original sources

PubMed1999

Fluconazole versus itraconazole for the prevention of fungal infections in haemato-oncology.

AIMS: To compare the efficacy of and tolerance to oral fluconazole and intraconazole in preventing fungal infection in neutropenic patients with haematological malignancies. PATIENTS: 213 consecutive, afebrile adult patients treated with or without autologous stem cell transplantation for haematological malignancies. METHODS: A randomised, double blind, single centre study. Patients were randomly assigned to receive fluconazole 50 mg or itraconazole 100 mg, both twice daily in identical capsules. An intention to treat analysis was performed on 202 patients, 101 in each group. RESULTS: Microbiologically documented systemic fungal infections occurred in four patients in each group. Clinical fungal infection was thought to be present in seven recipients of fluconazole and four of itraconazole. In all 202 patients, 29 proceeded to intravenous amphotericin (amphotericin B), 16 in the fluconazole group and 13 in the itraconazole group. Superficial fungal infection was seen only in three non-compliant patients in the fluconazole group. All these infections were oral. No major differences were noted in the isolates of fungi in mouth washes and fecal samples. Overall mortality was 8.9% (18 deaths; seven in the fluconazole group, 11 in the itraconazole group). Mortality from microbiologically and clinically documented fungal infection was 4.5% (nine deaths; three in the fluconazole group, six in the itraconazole group). Median time to suspected or proven fungal infection was 16 days in both groups. None of these comparisons reached statistical significance (p < 0.05). No major clinical toxicity was noted and compliance was excellent. CONCLUSIONS: In neutropenic patients treated for haematological malignancies with or without autologous stem cell transplantation, fluconazole and itraconazole in low doses result in a similar low frequency of fungal disease. Fluconazole may be the preferable drug because of the smaller number of capsules and lack of need for timing relative to meals.

Adult↗

PubMed1999

Costs of peripheral blood progenitor cell transplantation using whole blood mobilised by filgrastim as compared with autologous bone marrow transplantation in non-Hodgkin's lymphoma.

OBJECTIVE: The aim of this paper is to compare the costs of autologous bone marrow transplantation (ABMT) and whole blood transplantation in patients with relapsed or poorly responding non-Hodgkin's lymphoma. DESIGN AND SETTING: In a retrospective study, we calculated the treatment costs of 40 patients who received either ABMT or, alternatively, whole blood mobilised by filgrastim (a granulocyte colony-stimulating factor. MAIN OUTCOME MEASURES AND RESULTS: The recovery of granulocytes was markedly accelerated in the whole blood group as compared with the ABMT group. This resulted in a reduction in hospital costs, and costs for diagnostics and medical procedures, antibacterials, nutrition and blood transfusions. The average costs per patient in the whole blood group amounted to approximately $US16,890 as compared with approximately $US20,713 in the ABMT group (1995 values), implying a cost reduction of 18% when changing to whole blood reinfusion. CONCLUSIONS: With the premise that both therapies are equivalent, it seems that whole blood transplantation is more cost effective than ABMT.

Blood Transfusion↗

PubMed1998

Malignant lymphoma of mucosa-associated lymphoid tissue in the larynx.

A 36-year-old woman was referred to the department of Otolaryngology/Head and Neck Surgery, University Hospital Vrije Universiteit, because of complaints of hoarseness. A submucosal swelling of the right ventricular fold was found that was subsequently biopsied. Histopathological examination showed a low-grade B-cell non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue (MALT). Treatment consisted of local radiotherapy (to 2800 cGy). During the 2-year follow-up to date there has been no evidence of recurrent disease. To our knowledge, only four cases of MALT lymphomas in the larynx have been reported. The clinical behavior of MALT lymphoma is clearly quite distinct and requires proper recognition to prevent inadvertent misdiagnosis of overtreatment.

Adult↗

PubMed1998

Pitfalls in grading severity of chemotherapy-induced peripheral neuropathy.

BACKGROUND: Reliable reporting of chemotherapy-induced neurotoxicity is important. The objectives of the current study were to evaluate the differences in the peripheral neurotoxicity sections of several widely used chemotherapy-related toxicity grading systems, and the differences in the way in which observers interpret these scales. PATIENTS AND METHODS: Two neurologists independently rated the severity of chemotherapy-induced peripheral neuropathy, according to WHO, ECOG, Ajani, and NCIC-CTC criteria in 37 patients. RESULTS: The highest percentage grade 1, grade 2 and grade 3 peripheral neurotoxicity was noted when employing the WHO, Ajani and NCIC-CTC scales, respectively. Percentage inter-observer agreement across all grades of severity ranged from 45.9 (NCIC-CTC) to 83.8 (WHO). The degree of agreement varied from 'poor to fair' to 'substantial'. Percentage inter-observer agreement for the dichotomy grade < or = 2 and grade 3 ranged from 81.1 (NCIC-CTC) to 94.6 (Ajani and WHO), however, exact agreement on grade 3 peripheral neurotoxicity ranged from 0 (Ajani and WHO) to 42% (NCIC-CTC). Percentage interscale agreement for the dichotomy grade < or = 2 and grade 3 varied from 67.6 (WHO and NCIC-CTC) to 100 (WHO and ECOG). Interobserver disagreement of severity grading was partly due to different interpretation of scale parameters. CONCLUSIONS: Our results suggest that caution should be used in interpreting results across studies using different scales for neurotoxicity grading in chemotherapy-related peripheral neuropathy. When (multicentre) trials are to be undertaken with potential neurotoxic or neuroprotective agents, consensus should be sought regarding the toxicity rating scale used, and its interpretation by participating physicians.

Adult↗

PubMed1998

Immunoglobulin and T cell receptor gene rearrangement patterns in acute lymphoblastic leukemia are less mature in adults than in children: implications for selection of PCR targets for detection of minimal residual disease.

In order to gain insight into immunoglobulin (Ig) and T cell receptor (TCR) gene rearrangements in adult acute lymphoblastic leukemia (ALL), we studied 48 adult patients: 26 with precursor-B-ALL and 22 with T-ALL. Southern blotting (SB) with multiple DNA probes for the IGH, IGK, TCRB, TCRG, TCRD and TAL1 loci revealed rearrangement patterns largely comparable to pediatric ALL, but several differences were found for precursor-B-ALL patients. Firstly, adult patients showed a lower level of oligoclonality in the IGH gene locus (five out of 26 patients; 19%) despite a comparable incidence of IGH gene rearrangements (24 out of 26 patients; 92%). Secondly, all detected IGK gene deletions (n = 12) concerned rearrangements of the kappa deleting element (Kde) to Vkappa gene segments, which represent two-thirds of the Kde rearrangements in pediatric precursor-B-ALL and only half of the Kde rearrangements in mature B cell leukemias. Thirdly, a striking predominance of immature Ddelta2-Ddelta3 cross-lineage recombinations was observed (seven out of 16 TCRD rearrangements; 44%), whereas more mature Vdelta2-Ddelta3 gene rearrangements occurred less frequently (six out of 16 TCRD rearrangements; 38% vs >70% in pediatric precursor-B-ALL). Together these data suggest that the Ig/TCR genotype of precursor-B-ALL is more immature and more stable in adults than in children. We also evaluated whether heteroduplex analysis of polymerase chain reaction (PCR) products of rearranged Ig and TCR genes can be used for identification of molecular targets for minimal residual disease (MRD) detection. Using five of the major gene targets (IGH, IGK, TCRG, TCRD and TAL1 deletion), we compared the SB data and heteroduplex PCR results. High concordance between the two methods ranging from 96 to 100% was found for IGK, TCRG and TAL1 genes. The concordance was lower for IGH (70%) and TCRD genes (90%), which may be explained by incomplete or 'atypical' rearrangements or by translocations detectable only by SB. Finally, the heteroduplex PCR data indicate, that MRD monitoring is possible in almost 90% of adult precursor-B-ALL and >95% of adult T-ALL patients.

Adolescent↗

PubMed1998

Differentiation and cell-type-restricted expression of HOXC4, HOXC5 and HOXC6 in myeloid leukemias and normal myeloid cells.

HOX genes have shown a lineage-specific expression in hematopoiesis and are suggested as being involved in the expression of certain adhesion molecules. Recently, we have demonstrated that HOXC4 and HOXC6, but not HOXC5, are expressed during lymphoid differentiation. Reports on the expression of these genes in myeloid leukemias and normal myeloid cells are still scarce. Therefore, we have investigated the expression of HOXC4, HOXC5 and HOXC6 in purified subpopulations of bone marrow in addition to 36 specimens of acute myeloid leukemias (AMLs), eight chronic myeloid leukemias (CMLs), several myeloid cell lines and cutaneous localizations of three myelomonocytic leukemias and one granulocytic sarcoma by RT-PCR and partly by RNA in situ hybridization (RISH). HOXC4 and HOXC6 transcripts were both detected by RT-PCR in 22/36 and 24/36 AMLs, respectively. The distribution of HOXC4 and HOXC6 gene expression over the different types of AML was largely similar and covered all types of AML. In contrast, HOXC5 gene expression was found in only 6/32 AMLs. Expression of HOXC5 was restricted to AMLs of the granulocytic (FAB M1-M3), early monocytic (FAB M4) and early erythroid (FAB M6) lineage. In general, except in one FAB M5b case, no expression of HOXC5 was found in AMLs derived from late stages of monocytic (FAB M5) and megakaryocytic (FAB M7) lineages. As for HOXC4 and HOXC6, expression of HOXC5 was absent in CMLs. Using RISH significant HOXC4, HOXC5 and HOXC6 expression was found in a number of additionally studied AML samples of different FAB classification (M2, M4, M5b and M5b), (M2 and M5b) (M2, M4, M5b), respectively. In tissue localizations of leukemias a different expression pattern of HOXC4, HOXC5 and HOXC6 was found. In contrast to mature leukemic stages of myeloid differentiation, these skin localizations of leukemias expressed HOXC5 and HOXC6. HOXC4 expression was found both in leukemic cells derived from peripheral blood and from cutaneous localizations. Besides HOXC4 expression in monocytes no expression of HOXC4, HOXC5 and HOXC6 was found in granulocytes and monocytes, colonies of growth factor-induced CD34+ bone marrow cells. In earliest CD34+/CD38low and high cell fractions of bone marrow only HOXC4 and in megakaryocytic cells both HOXC4 and HOXC6 were found. Thus, the expression patterns of these HOXC genes found in the limited number of cell fractions of normal bone marrow suggest that the expression patterns found in AMLs and CMLs might reflect the normal situation. Furthermore, the presence of HOXC5 and HOXC6 expression specifically in skin infiltrates of late differentiation stages of myeloid leukemias, suggests an additional role for these genes in the positioning of these myeloid cells in skin tissue.

Acute Disease↗

PubMed1998

Costs of intensive treatment and follow-up of patients with multiple myeloma.

In a retrospective study, we calculated the treatment and follow-up costs of patients with newly diagnosed multiple myeloma. The total treatment programme consisted of eight phases: VAD or VAMP chemotherapy, follow-up I, high-dose melphalan followed by transplantation of whole blood, follow-up II, collection of peripheral blood progenitor cells by leukapheresis, follow-up III, high-dose chemotherapy (busulfan/cyclophosphamide) followed by reinfusion of peripheral stem cells and follow-up IV (until 3 months from hospital discharge after peripheral stem cell transplantation). For each phase the average costs were calculated for all patients who were on treatment/follow-up in each particular phase. The total average cumulative costs of treatment and follow-up of all patients amounted to US$49850. Considering only the patients who completed the total treatment programme as it was scheduled, the average total treatment and follow-up costs were US$44800. The average costs of treatment and follow-up of patients who did not complete the programme as it was scheduled (patients who died, patients who were withdrawn from treatment and patients who received additional treatment) were US$57025.

Adult↗

PubMed1998

New strategies in hematopoietic stem cell transplantation: G-CSF-mobilized unprocessed whole blood.

Transplantation of mobilized peripheral blood stem cells (PBSC) for rescue of bone marrow function after high-dose chemo-/radiotherapy is widely used in hematologic malignancies and solid tumors. Mobilization of stem cells to the peripheral blood can be achieved by cytokine treatment of the patients. The main advantage of autologous PBSC transplantation over bone marrow transplantation is the faster recovery of neutrophil and platelet counts. The threshold number of PBSC required for adequate rescue of bone marrow is thought to be about 2 x 10(6) CD34+ cells/kg, if the stem cells are collected by leukapheresis and subsequently cryopreserved. We show that this critical number could be further reduced to as few as 0.2 x 10(6) cells/kg. In 30 patients with multiple myeloma and 25 patients with bad risk lymphoma 1 liter of granulocyte colony-stimulating factor (G-CSF)-mobilized unprocessed whole blood (stored at 4 degrees C for 1-3 days) was used for transplantation. Compared to a historical control group, a significant reduction in the duration of neutropenia, thrombocytopenia and the length of hospital stay was documented. Furthermore, the effect of stem cell support was reflected by a lower need for platelet and red cell transfusions and a reduced antibiotic use. Considering the data as a whole, a cost saving of about 50% was achieved. To date, this easy to perform method of transplantation is only feasible following high-dose therapies that are completed within 72 h, since longer storage of unprocessed blood is accompanied by a substantial loss of progenitor cell function. Ongoing investigations include attempts to prolong storage times for whole blood.

Blood↗

PubMed1998

Low p53 and high bcl-2 expression in Reed-Sternberg cells predicts poor clinical outcome for Hodgkin's disease: involvement of apoptosis resistance?

A high number of activated cytotoxic T lymphocytes (CTL) in Hodgkin's disease (HD) biopsy specimens is related to an unfavorable clinical outcome, suggesting that resistance of the Hodgkin and Reed-Sternberg (H-RS) cells to CTL-mediated killing is an important pathogenic factor in HD. bcl-2 and defective p53 are known to inhibit apoptosis induced either by CTLs or by therapy. The purpose of this study was to use immunohistochemical techniques to analyze whether differences in expression of these proteins in H-RS cells in primary biopsy specimens from 78 patients with HD were related to clinical outcome and to assess the number of CTLs in those cells. Cases with H-RS cells mostly staining positive for bcl-2 but negative for p53 had a poor prognosis (55% 5-yr survival). In the group of patients whose H-RS cells had low positivity for both p53 and bcl-2, the 5-year survival was 90%. p53 expression in a high percentage of H-RS cells was invariably related to a 100% 5-year survival, irrespective of bcl-2 expression. Biopsy specimens from patients with a fatal clinical outcome, in which few H-RS cells expressed p53 and many H-RS cells expressed bcl-2, contained relatively many activated CTLs. These data demonstrate that the combination of expression of the apoptosis-regulating proteins p53 and bcl-2 in the H-RS cells can be used as a prognostic marker for HD, and they indicate that resistance to apoptosis of H-RS cells is an important pathogenic mechanism. Our data also support the hypothesis that in patients with a poor prognosis, apoptosis-resistant H-RS cells might be selected for by the presence of many activated CTLs.

Adolescent↗

PubMed1997

Activated cytotoxic T cells as prognostic marker in Hodgkin's disease.

Although the results of treatment of Hodgkin's disease (HD) have improved considerably in the last decades, the disease remains fatal in a minority of patients. We have recently shown that numbers of activated cytotoxic T cells (CTLs), present in tumor biopsy specimens, differ considerably among individual HD patients. Because CTLs are the major effector cells in elimination of neoplastic cells, we investigated whether the number of activated CTLs is related to the clinical outcome of the individual patient with HD. Activated CTLs present in tumor biopsy specimens of patients with nodular sclerosis or mixed cellularity HD were identified by immunohistochemistry using an antibody directed against granzyme B (GrB), a major constituent of the cytotoxic granules of activated CTLs and natural killer cells, and an antibody directed against CD8. The presence of a high percentage of GrB+ lymphocytes was found to be an unfavorable prognostic marker. The large majority of GrB+ cells were also CD8+, indicating that these cells are activated CTLs. Prognosis was found to decrease with increasing percentages of GrB+ lymphocytes. Optimal discrimination between patients with good and poor prognosis was obtained when the threshold was set at 15% GrB+ cells; 6 of 10 patients with > or = 15% GrB+ lymphocytes died as a result of the disease, as compared with 6 of 70 patients with less than 15% GrB+ lymphocytes (P < .0001). In stage-2 patients, the percentage of GrB+ lymphocytes retained its predictive value in a multivariate analysis including histology, sex, age, erythrocyte sedimentation rate, and the presence of B symptoms as covariables. In addition, patients with > or = 15% GrB+ lymphocytes had a shortened progression-free survival time (P = .002). We conclude that a high percentage of activated CTLs present in biopsy material of HD patients is a strong indicator for an unfavorable clinical outcome.

Adolescent↗

PubMed1997

Mobilization of hematopoietic progenitors in patients with chronic myeloid leukemia.

Although the mobilization and harvesting of Philadelphia chromosome-negative progenitors has been proven feasible by a number of groups, it is not clear which techniques should be used with regard to the monitoring of purging and evaluation of stem cell yield. Therefore, we isolated CD34-positive cells from leukapheresis samples of seven CML patients after induction therapy. These cells were analyzed using the colony-forming unit granulocyte-macrophage (CFU-GM) and long-term culture-initiating cell (LTCIC) assays. In addition, we analyzed frequency and clonogenicity of single stem cells using the LTCIC assay at limiting dilution. Individual colonies derived from these assays were subsequently analyzed for the presence of the bcr-abl gene with interphase fluorescence in situ hybridization (FISH) and for the presence of bcr-abl mRNA with RT-PCR. We compared these results with the cytogenetic analysis of the leukapheresis material. Molecular analysis of individual colonies correlated well with the results of cytogenetic analysis. However, in nine out of 18 samples, cytogenetic analysis exclusively demonstrated the presence of either Philadelphia chromosome-positive or -negative cells whereas with the molecular analysis of individual colonies tumor contamination or the presence of residual normal cells could be substantiated. We concluded that molecular analysis of individual colonies should be employed to further optimize induction protocols. With regard to stem cell mobilization we demonstrated that about 67 CFU-GM colonies and clusters were generated by one single LTCIC both for the CML samples and the samples obtained from patients with non-hematologic malignancy. This number is important since until now most centres use a number of four colonies and clusters generated by one LTCIC. Dividing the CFU-GM output in the LTCIC assay by four to determine LTCIC frequency could thus lead to an almost 20-fold overestimation of the LTCIC frequency. It is concluded that stem cell frequency analysis is an important tool with regard to the interpretation of mobilization protocols.

Adult↗

PubMed1997

Molecular analysis of hematopoietic colonies derived from chronic myeloid leukemia patients: interphase fluorescence in situ hybridization compared with RT-PCR.

In this study we compared interphase fluorescence in situ hybridization (I-FISH) with reverse transcription polymerase chain reaction (RT-PCR) for the molecular analysis of hematopoietic colonies derived from patients with chronic myeloid leukemia (CML). Molecular analysis of individual colonies is often performed to monitor purging efficacy in CML. We harvested individual colony-forming unit granulocyte-macrophage (CFU-GM) colonies. One half was analyzed with I-FISH, for the presence of bcr-abl fusion gene. The other half was analyzed with RT-PCR for the presence of the bcr-abl mRNA. We wanted to address the following questions: (1) is the bcr-abl gene always expressed in CFU-GM colonies and (2) which technique has to be preferred to analyze individual CFU-GM colonies? In total, 133 colonies, derived from six CML patients, could be analyzed both with I-FISH and RT-PCR. We found a positive correlation in 89% of the cases: 118 colonies showed the same results with both techniques. However, 15 of the 106 I-FISH-positive colonies were negative in the RT-PCR. Serial analysis of the cDNA derived from 22 colonies showed in each round of amplification 21-29% RT-PCR-negative but I-FISH-positive colonies. However, all I-FISH-positive colonies showed at least one positive RT-PCR, either in the first, second or third round of amplification. These results indicate that the bcr-abl gene is probably always transcriptionally active in CFU-GM colonies. Reliable analysis with RT-PCR is possible but likely to generate false negative results. We conclude that: (1) I-FISH offers a reliable alternative to RT-PCR for analyzing individual hematopoietic colonies and (2) results obtained with RT-PCR should only be interpreted with caution.

Adult↗

PubMed1997

Theoretical and practical considerations for the measurement of P-glycoprotein function in acute myeloid leukemia.

This paper summarizes experimental data and theoretical considerations, that are important for the measurement of P-glycoprotein (Pgp) function in acute myeloid leukemia (AML). The data are presented in subdivisions based on the techniques used, which will facilitate finding specific information. Based on our extensive experience with Pgp analysis, which includes radioactive assays, flow cytometry and fluorescence microscopy, we recommend a flow cytometry-based assay, that measures the effect of 2 microM PSC 833 on rhodamine 123 (R123) accumulation as the most practical and sensitive functional Pgp test. In combination with the flow cytometric measurement of Pgp using an antibody against an extracellular epitope (eg MRK16), this offers a sensitive and reproducible method for Pgp detection in AML, which is also rapid and practical. Furthermore, an R123 accumulation assay is specific for Pgp, because R123 is transported much less efficiently by the multidrug resistance protein (MRP) than by Pgp. Another probe of similar sensitivity and specificity is 3,3'-diethyloxacarbocyanine iodide. Alternatively, especially for the analysis of small numbers of cells (for example sorted subpopulations of leukemic cells), convenient and sensitive procedures are being developed by using DNA-binding Pgp substrates which remain fixed in the nuclei of the cells upon formaldehyde exposure for quantitative fluorescence laser scanning microscopy with image analysis. Less experimental data have been published to establish the optimal conditions for dual parameter flow cytometry (Pgp function, in eg Pgp+ or CD34+ cells). However, laboratories with flow cytometry experience will be able to implement this useful option to analyze subpopulations of cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Hypersensitivity of bcr-abl-positive progenitors to hyperthermia in patients with chronic myeloid leukemia.

In this study, we evaluated the effect of hyperthermia on hematopoietic progenitors from six chronic myeloid leukemia (CML) bone marrow (BM) samples at diagnosis and four peripheral blood stem cell (PBSC) samples from CML patients after stem cell mobilisation. CD34-positive cells, isolated from these samples, were incubated for 2 h at 37, 42 or 43 degrees C and were plated in the colony-forming unit granulocyte-macrophage (CFU-GM) and the long-term culture initiating cell (LTCIC) assay. To evaluate purging, individual colonies from these assays were analyzed for the presence of the bcr-abl gene with interphase fluorescence in situ hybridization (FISH) and/or RT-PCR. BM samples showed a significant higher sensitivity both at the CFU-GM and LTCIC level, after treatment at 42 degrees C, as compared to the control BM samples obtained from healthy volunteers. The four BM samples of CML patients with a low leukocyte number at diagnosis harbored a mixture of bcr-abl-negative and positive colonies and an increase in the percentage of bcr-abl-negative colonies was observed in all cases. CML patients with a high leukocyte count at diagnosis, however, showed only bcr-abl-positive progenitors even after hyperthermia. PBSCs showed a significant higher sensitivity at the LTCIC level but not at the CFU-GM level, after treatment at 42 degrees C, as compared to the control PBSC samples obtained from nonhematologic cancer patients. Molecular analysis of individual colonies demonstrated an increase of bcr-abl-negative progenitors after thermic treatment in two out of three samples. When comparing both stem cell sources, PBSCs showed a decreased thermic sensitivity as compared to the BM samples at the CFU-GM level, whereas at the LTCIC level an increased thermic sensitivity was observed, both for the controls and the CML samples. In conclusion, both for BM and PBSCs samples, CML progenitors are more sensitive to hyperthermia than control cells, especially at the LTCIC level. In agreement with these results, an increase of bcr-abl-negative progenitors in six out of seven samples could be demonstrated either at the CFU-GM level, LTCIC level or both. Hyperthermia should be explored further as a possible purging modality in CML.

Adult↗

PubMed1997

A functional study on the migration of human monocytes to human leukemic cell lines and the role of monocyte chemoattractant protein-1.

In the present study the migration of human monocytes towards the supernatants of five different human myeloid leukemic cell lines, four different human lymphatic leukemic cell lines and blasts derived from three different patients with acute myeloid leukemia (AML) was studied and the role of monocyte chemoattractant protein (MCP)-1 was established with an ELISA assay. Large differences in migration of monocytes towards the leukemic cell supernatants were shown (variation of approximately 10 to 150% compared to positive control), but high amounts of monocyte migration was always restricted to myeloid leukemic cells (cell lines or patient blasts). MCP-1 turned out to play a major role in the migration, firstly since there was a direct correlation between the amount of migration and the concentration of MCP-1 in the supernatants, and secondly since the addition of anti-hMCP-1 was able to inhibit migration to background level in all cases. Cytotoxicity experiments with a MTT test using MCP-1-stimulated monocytes against two human myeloid leukemic cell lines showed no increase in cell death compared to unstimulated monocytes. It is concluded that monocyte migration towards leukemic cells is restricted to the myeloid lineage and is regulated by MCP-1, which is produced in different amounts by the leukemic cells. Besides, MCP-1 does not increase the direct toxic effects of monocytes on leukemic cells.

Cell Culture Techniques↗

PubMed1997

Value of different modalities of granulocyte-macrophage colony-stimulating factor applied during or after induction therapy of acute myeloid leukemia.

PURPOSE: The hematopoietic growth factors (HGFs) introduced into induction chemotherapy (CT) of acute myeloid leukemia (AML) might be of benefit to treatment outcome by at least two mechanisms. HGFs given on days simultaneously with CT might sensitize the leukemic cells and enhance their susceptibility to CT. HGFs applied after CT might hasten hematopoietic recovery and reduce morbidity or mortality. MATERIALS AND METHODS: We set out to evaluate the use of granulocyte-macrophage colony-stimulating factor (GM-CSF; 5 microg/kg) in a prospective randomized study of factorial design (yes or no GM-CSF during CT, and yes or no GM-CSF after CT) in patients aged 15 to 60 years (mean, 42) with newly diagnosed AML. GM-CSF was applied as follows: during CT only (+/-, n = 64 assessable patients), GM-CSF during and following CT (+/+, n = 66), no GM-CSF (-/-, n = 63), or GM-CSF after CT only (-/+, n = 60). RESULTS: The complete response (CR) rate was 77%. At a median follow-up time of 42 months, probabilities of overall survival (OS) and disease-free survival (DFS) at 3 years were 38% and 37% in all patients. CR rates, OS, and DFS did not differ between the treatment groups (intention-to-treat analysis). Neutrophil recovery (1.0 x 10(9)/L) and monocyte recovery were significantly faster in patients who received GM-CSF after CT (26 days v 30 days; neutrophils, P < .001; monocytes, P < .005). Platelet regeneration, transfusion requirements, use of antibiotics, frequency of infections, and duration of hospitalization did not vary as a function of any of the therapeutic GM-CSF modalities. More frequent side effects (eg, fever and fluid retention) were noted in GM-CSF-treated patients predominantly related to the use of GM-CSF during CT. CONCLUSION: Priming of AML cells to the cytotoxic effects of CT by the use of GM-CSF during CT or accelerating myeloid recovery by the use of GM-CSF after CT does not significantly improve treatment outcome of young and middle-aged adults with newly diagnosed AML.

Acute Disease↗

PubMed1997

Treatment of multiple myeloma in elderly patients. New developments.

The median of survival among patients with multiple myeloma (MM) is about 30 months from the onset of treatment. Tumour burden and a range of other parameters, such as C-reactive protein levels, the plasma cell labelling index and beta2-microglobulin levels, can be used to assign patients to favourable and unfavourable prognostic groups. Conventional chemotherapy consists of melphalan and prednisone, and is as effective as moderately intensive cytotoxic drug regimens. Although second-line chemotherapy is initially effective, all patients eventually die. Maintenance therapy will interferon-alpha prolongs the plateau phase of the disease, but its effects on overall survival are minimal. One of the promising developments in the treatment of MM has been the introduction of high dosage chemotherapy, which can now be safely administered when stem cells are used for haematological recovery. Autologous bone marrow transplantation has been shown to produce a significant improvement in survival compared with conventional therapy. Several studies are under way that are examining the effects of multiple courses of high dosage chemotherapy together with peripheral stem cell support. Purging of autologous stem cell harvests will be performed in the near future to minimise contamination with myeloma cells. It is now feasible to use high dosage chemotherapy, with the support of granulocyte colony-stimulating factor-stimulated whole blood, in selected elderly patients. Besides the promising development of intensive therapy, a number of other treatment strategies have emerged, including treatment with monoclonal antibodies against interleukin-6 and multidrug resistance-modulating agents. Better supportive care can be provided for some patients by using epoetin (recombinant human erythropoietin), and the sequelae of lytic bone lesions can be ameliorated through the use of bisphosphonates.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

Quality control of multidrug resistance assays in adult acute leukemia: correlation between assays for P-glycoprotein expression and activity.

We have compared multiple assays for the P-glycoprotein (Pgp/MDR1) phenotype in fresh and thawed adult acute leukemia to validate and quantitate measures for the expression and function of Pgp. The results are related to the Pgp-expressing KB8 and KB8-5 call lines. The most sensitive assay was the measurement of modulation of the rhodamine 123 (R123) fluorescence by 2 micromol/L PSC833, followed by the modulation of the probe calcein-AM. We also found a good intralaboratory and interlaboratory correlation between the values of the R123/PSC833 assay for fresh as well as thawed samples. In addition, the affects of PSC833 on 3H-daunorubicin (DNR) accumulation, DNR fluorescence, and 3H-vincristine accumulation were very similar. The correlation between the DNR/PSC833 and R123/PSC833 test was r = .86 (N = 51). The modulation of drug accumulation by 8 micromol/L verapamil was the some as the PSC833 effect for DNR (117%, N = 21), but was higher for vincristine in every single case (161% v 121%, N = 22; P< .001), indicating additional verapamil effects, not related to Pgp. The correlation of the staining of viable cells for Pgp with the monoclonal antibody MRK16 was r = .77 (N = 52) for the R123/PSC833 functional test and r = .84 (N = 50) for the DNR/PSC833 test. From these results it could be calculated that a maximal increase of the mean DNR accumulation of about 50% can be achieved by blocking Pgp pump activity with PSC833 in leukemic blast samples with the highest mean Pgp expression. Subpopulations of blast calls with higher Pgp activity are likely to be present. Their relevance has to be studied further. The methods outlined here allow the reliable, quantitative monitoring of the Pgp/MDR1 phenotype in leukemias in multicentered, clinical Pgp modulation studies.

ATP Binding Cassette Transporter, Subfamily B, Mem↗