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Biomedical subjects

G Kvalheim

Publications and source records attributed to G Kvalheim.

At least 37 records · Page 2Linked to original sources
PubMed1999

Minimal residual disease in breast cancer.

The incidence of breast cancer is increasing dramatically in the developed countries. Although attention is being paid to diagnose breast cancer early through screening programs, still a significant number of patients classified to have a localised disease at diagnosis, later experience a systemic recurrence. Therefore, more sensitive and reliable methods to detect the early spread of the disease, permitting the early use of additional systemic therapy, seem justified. New treatment strategies, such as immunotherapy employing monoclonal antibodies against breast cancer cells, is promising. Since such a treatment is most efficient on patients with limited disease, sensitive methods to monitor the therapeutic effect are needed. Immunocytochemistry using tumour associated monoclonal antibodies and reverse transcription polymerase chain reaction assays (RT-PCR), that screen for carcinoma-specific expression of mRNA in bone marrow and blood, have been developed. Many standardisation problems with the detection methods currently in use are unsolved. Despite this, we discuss here recent data showing that the presence of occult tumour cells in the bone marrow is a prognostic factor in patients with breast cancer.

Bone Marrow Neoplasms↗
PubMed1999

High-dose therapy supported with immunomagnetic purged autologous bone marrow in high-grade B cell non-Hodgkin's lymphoma.

From August 1987 to March 1995, 25 patients with high-grade B cell non-Hodgkin's lymphoma (NHL) were treated with high-dose therapy (HDT) followed by bone marrow purged with immunomagnetic beads. At the time of transplantation, 20 patients were in sensitive relapse and five in first complete or partial remission. Ten patients had secondary high-grade NHL transformed from low-grade NHL. The HDT consisted of TBI followed by high-dose cyclophosphamide. All patients engrafted, except for two patients with early treatment-related death. Eleven patients relapsed, of whom nine died of lymphoma, and two are alive in new CR. The estimated event-free and overall survivals at 5 years were 40% and 48%, respectively, with a median follow-up of 48 months (range 1-123). Eight of the tumours contained the translocation t(14;18) at the major breakpoint region (MBR) of BCL-2. In these patients the presence of tumour cells in the bone marrow graft before and after purging were assessed by PCR. Four of five patients infused with non-detectable minimal residual disease in their autografts are in complete remission, while two of three patients reinfused with t(14;18) positive cells after purging, experienced a fast and aggressive relapse. As found by others, our data suggest that reinfusion of tumour-free autografts obtained by efficient in vivo purging using chemotherapy before harvesting, and/or by in vitropurging of the stem cell products, influence the patients remission status after HDT.

Adolescent↗
PubMed1999

Persistent changes in the immune system 4-10 years after ABMT.

The aim of the present study was to investigate whether the early changes in the immune system observed after ABMT would persist over years. Eighty-five patients with malignant lymphoma were treated with ABMT in Norway from 1987 until 1993. Of the 46 patients in CR by 1997, 36 were enrolled in our study. Median time from ABMT was 5 years (4-10 years). Immunophenotyping showed an increase in the median number of B cells (0.35 x 109/l in patients vs 0.28 x 109/l in controls), and a decrease in T cells (1.08 vs 1.35 x 109/l). Furthermore, a lower median count of CD4+ T cells (0.54 x 109/l in patients vs0.87 x 109/l in controls) resulted in reduced CD4/CD8 ratios (0.8 in patients vs 1.6 in controls). The subgroup of CD4+ T cells expressing the 'naive' phenotype CD45RA was 19.5% in patients vs 38% in controls. In contrast, the fraction expressing the 'memory' phenotype CD45RO was higher in the ABMT group (76% vs 54%). When stimulated, larger fractions of CD3+CD4+ cells in patients produced IFN-gamma (32% vs 16%) or IL-4 (7% vs 1%) compared to controls; thus a differentiation into the functionally separate subgroups Th1 and Th2, with a dominant Th2 response. Our data further suggest that the decrease in CD4+ T cell counts and the imbalance between CD45RA+ and CD45RO+ subsets persists 4-10 years after ABMT.

Adolescent↗
PubMed1999

FEC mobilized stem cells for high-dose therapy in breast cancer patients. SB6 9401 Study Group.

The feasibility of mobilizing peripheral blood stem cells (PBSC) using anthracycline containing polychemotherapy and G-CSF on the first 50 patients randomized to the high-dose arm in the adjuvant SBG 9401 is investigated. The patients were treated with standard FEC (5-fluorouracil 600 mg/m2, epirubicin 60 mg/m2, cyclophosphamide 600 mg/m2) for two courses followed by a modified third FEC course with a C dose of 1200 mg/m2 supported with subcutaneous G-CSF (filgrastim) at 5 mg/kg followed by harvest around day 11. The mean yield of CD34+ cells per patient was 10.6x10(6)/kg (range 2.6-29.1). The side effects after the third course were low and only one patient developed an uncomplicated granulopenic fever. Our data indicated a correlation between number of transfused CD34+ cells and days to neutrophil and platelet recovery. In conclusion, the modified FEC regimen followed by G-CSF is a feasible method for PBSC mobilization in the adjuvant setting.

Antigens, CD34↗
PubMed1998

Increased sensitivity for detection of micrometastases in bone-marrow/peripheral-blood stem-cell products from breast-cancer patients by negative immunomagnetic separation.

Immunocytochemical detection (ICC) of isolated tumor cells in bone marrow (BM) is currently the most established method for monitoring early dissemination in epithelial cancer. However, the low sample size that can practically be analyzed restricts the sensitivity and reliability of the ICC method. To be able to analyze larger samples, a negative immunomagnetic separation (IMS) technique, utilising anti-CD45-conjugated Dynabeads, has been developed. Tumor-cell enrichment by depletion of CD45-expressing mononuclear cells (MNC) is followed by ICC for detection of the cytokeratin (CK)-positive (+) epithelial cells. In this study, bone-marrow samples (n = 165) and peripheral-blood-progenitor-cell (PBPC) apheresis products (n = 22) from breast-cancer patients were analyzed. The negative IMS analysis of 1 to 2 x 10(7) MNC was compared with ICC analysis of 2 x 10(6) unseparated MNC. Negative IMS resulted in 85% mean depletion of MNC. The results showed that 11.7% of the samples were positive by ICC analysis of unseparated MNC, as compared with 23.5% after negative IMS. In samples presenting > 10 CK+ cells, a 4-fold higher number of positive cells was detected by the negative IMS technique. Moreover, there was no evidence for general enrichment of false-positive cells. Altogether our results show that negative IMS is an efficient enrichment method for sensitive detection of CK+ cells in BM/PBPC products from breast-cancer patients. This opens the possibility for further characterization of micrometastatic tumor cells.

Bone Marrow Cells↗
PubMed1998

Immunocytochemical detection of isolated epithelial cells in bone marrow: non-specific staining and contribution by plasma cells directly reactive to alkaline phosphatase.

Detection of isolated tumour cells (TCs) in bone marrow (BM) from epithelial cancer patients by immunocytochemical (ICC) analysis seems to predict future relapse, but the reported percentages of positive BMs among patients with localized cancer show large variations and the number of detected TCs is low. This emphasizes the importance of thoroughly testing the methods in use. This study was performed to clarify to what extent positive staining of haematopoietic cells (HCs) interferes with the ICC detection of epithelial cells in BM. BM mononuclear cells (MNCs) from normal donors and stage I-II breast cancer patients were stained with anti-cytokeratin (CK) and isotype control monoclonal antibodies (MAbs) followed by alkaline phosphatase (AP)-based visualization of immunolabelled cells. In the ICC staining of normal donors by the anti-CK MAbs AE1/AE3 or A45-B/B3, rare immunoreactive cells were detected in 7/20 and 8/19 BMs, respectively. Morphological examination recognized all these cells as typical HCs. In the breast cancer patients (n = 257), anti-CK-positive cells were detected in 26.6 per cent, excluding cells with HC morphology. Using the same morphological criteria, isotype control-positive cells were detected in 5.4 per cent of patients. Some of the false-positive events were further analysed and cells with strong reactivity against the AP enzyme alone were detected. Double ICC staining recognized the majority of these AP directly-reactive cells as CD45-negative and human Ig kappa/lambda-positive, in accordance with the phenotype of mature plasma cells. Morphological evaluation and adequate controls are important to ensure the diagnostic specificity of micrometastases in BM. It is recommended that the number of BM MNCs included in negative controls should equal the number of cells in the diagnostic specimens.

Alkaline Phosphatase↗
PubMed1998

Combination chemotherapy with mitoguazon, ifosfamide, MTX, etoposide (MIME) and G-CSF can efficiently mobilize PBPC in patients with Hodgkin's and non-Hodgkin's lymphoma.

Many centers use CY and G-CSF to mobilize PBPC. In this study we explored whether a standard chemotherapy regimen consisting of mitoguazon, ifosfamide, MTX and etoposide (MIME) combined with G-CSF was capable of mobilizing PBPC in lymphoma patients. Twelve patients with Hodgkin's disease (HD) and 38 patients with non-Hodgkin's lymphoma (NHL) were mobilized with MIME/G-CSF. Most patients were heavily treated with different chemotherapy regimens receiving a median of 11 cycles (range 3 to 20) of chemotherapy prior to mobilization. It was found that the optimal time of PBPC harvest was at days 12 and 13 after initiating the mobilization regimen. The median number of collected CD34+ cells per kg body weight was 7.1 x 10(6) (range 0.5-26.2). More than 2.0 x 10(6) CD34+ cells/kg were achieved in 69% of the patients after one apheresis. When additional cycles of apheresis were done, only 6% failed to harvest this number of CD34+ cells. There was a statistically significant inverse correlation between the number of prior chemotherapy cycles and CD34+ cell yield (P = 0.003). No such association was found between CD34+ cell yield and prior radiotherapy. When MIME/G-CSF was compared with Dexa-BEAM/G-CSF, it was found that MIME/G-CSF tended to be more efficient in mobilizing PBPC in spite of being less myelotoxic. All patients transplanted with MIME/G-CSF mobilized PBPC had fast and sustained engraftment. These results demonstrate that an ordinary salvage chemotherapy regimen, such as MIME combined with G-CSF can be successfully used to mobilize PBPC.

Adolescent↗
PubMed1998

Diagnosis of minimal residual disease in bone marrow and blood in cancer patients--methods and clinical implications.

For some types of cancer the presence of tumour cells in the bone marrow at diagnosis is an independent prognostic factor. Immunocytochemical staining techniques have led to improvements in the ability to detect occult cancer cells in bone marrow. One major limitation of these methods is that the monoclonal antibodies used are only tumour-associated and not tumour-specific. Therefore, some cross reaction with normal cells can occur. Polymerase chain reaction (PCR) has been applied extensively to measure minimal residual disease in bone marrow and blood of lymphomas carrying the t(14;18) translocation and Philadelphia chromosome (PH)-positive chronic myelogenous leukaemia. One major limitation of the PCR method is that not all tumours of interest carry chromosomal translocation. Reverse transcription PCR assays (RT-PCR) that screen for expression of tissue-specific and tumour-associated genes mRNA in bone marrow and blood have been developed. As in the case of immunocytochemistry, not all RT-PCR assays have the specificity required for them to be used safely in the clinic. Therefore, prior to introducing these methods in the clinic, standardized protocols need to be developed and validated.

Antibodies, Monoclonal↗
PubMed1998

Mycobacterial crossreactivity of M. tuberculosis reactive T cell clones from naturally converted PPD positive healthy subjects.

Mycobacterium tuberculosis reactive CD4+, CD8- T cell clones were established from six naturally converted PPD positive healthy subjects by using whole bacilli as the primary stimulation antigen in vitro. Antigen specificity of the T cell clones was mapped by testing their proliferative response against a panel of pathogenic and environmental mycobacterial species. The crossreactivity patterns obtained showed that the T cell clones distributed along a spectrum from reactivity restricted to the M. tuberculosis complex to broadly crossreactive clones recognizing all mycobacterial species tested. Two of the T cell clones were able to discriminate between M. tuberculosis and M. bovis BCG, and importantly one of these clones was exclusively specific to M. tuberculosis. All of the CD4+ T cell clones tested, displayed MHC class II restricted cytotoxicity against macrophages pulsed with M. tuberculosis. In addition, some of these clones secreted GM-CSF upon antigen stimulation. The T cell clones described here represent relevant tools to identify and characterize target antigens of the immune response against M. tuberculosis with relevance to diagnosis and subunit vaccine design.

Antigens, Bacterial↗
PubMed1997

Immunomagnetic techniques for the enrichment and detection of isolated breast carcinoma cells in bone marrow and peripheral blood.

Detection of isolated tumor cells (TC) in bone marrow (BM) from patients with breast cancer is usually accomplished by immunocytochemical (ICC) analysis of up to 2 X 10(6) mononuclear cells (MNC). However, this method is cumbersome if large numbers of BM cells (i.e. > 1 X 10(7) cells) are to be analyzed. This emphasizes the need for TC enrichment strategies. This report describes immunomagnetic separation (IMS) techniques for enrichment and detection of viable breast carcinoma cells in BM and peripheral blood (PB). The positive IMS technique was performed by incubation of MNC with 2.8 microns magnetic particles (rat antimouse IgG1 M280-Dynabeads) coated with monoclonal antibody (mAb) against epithelial surface antigens. The rosetted tumor cells were then visualized by ICC staining using alkaline phosphatase-conjugated A45-B/B3 anticytokeratin mAb (Fab). The negative IMS technique was performed by incubation of MNC with anti-CD45-coated M450-Dynabeads (4.5 microns), followed by ICC staining of the nonrosetted cells. When 1000, 100, and 10 breast carcinoma cells were mixed with 1 X 10(7) MNC, an average of 748 (n = 9), 70 (n = 10), and 7.8 TC (n = 8), respectively, were detected with the positive IMS technique. With the negative IMS technique, 648 (n = 8), 57.8 (n = 6), and 7.3 TC (n = 6), respectively, were detected. The analysis of 1 X 10(7) MNC with the IMS techniques was compared with the ICC analysis of 2 X 10(6) unseparated MNC. A mean 3.7-fold (range 1.5-6.4) to 4.2-fold (2.5-8.2) (positive IMS) and 3.1-fold (range 2.0-5.0) to 3.8-fold (2.0-6.0) (negative IMS) higher TC detection frequency was achieved after enrichment by IMS in experiments with 100 and 1000 TC/10(7) MNC. The IMS techniques were used for examination of BM samples from locally advanced breast cancer patients. A 5.3-fold mean increase (range 2.1-13.3) in the number of TC detected was obtained when the use of positive and negative IMS together was compared with the direct ICC analysis of unseparated MNC (n = 11). Enrichment of TC by IMS techniques enables us to examine large numbers of MNC from BM or PB, which can result in the detection and characterization of minimal residual disease with increased sensitivity and specificity.

Bone Marrow↗
PubMed1996

[High-dose therapy of cancer with CD34 positive cells as stem cell support].

In this article we report our initial clinical experiences in connection with immunomagnetic isolated CD34-positive cells from peripheral blood progenitor cells. Six patients, five with breast cancer and one with non-Hodgkin's lymphoma, were mobilized by chemotherapy and G-CSF (5ug/kg). CD34-positive cells were isolated by means of immunomagnetic beads (Dynalbeads) and Isolex 300 Cell Separator (Baxter, USA). Mean purity of isolated CD34-positive cells was 97% (94.7-99.7) and mean yield was 54% (35-68). Three patients were treated with high dose therapy followed by reinfusion of CD34-positive cells as stem cell support. Recovery of neutrophils (> 0.5 x 10(9) leucocytes/liter) occurred at day 8, 11 and 13 and of platelets (> 20 x 10(9) platelets/litre) at day 9,14 and 32. It is concluded that immunomagnetic isolated CD34-positive cells give high purity and yield. Although use of CD34-positive cells reduces the content of contaminating tumour cells in the graft, breast cancer cells were still detectable in two out of five CD34-positive cell products.

Antigens, CD34↗
PubMed1996

[High-dose therapy with autologous stem cell support in malignant lymphoma and breast cancer. Experiences with hematopoietic stem cells isolate from blood].

Since 1994, 17 breast cancer patients and 16 lymphoma patients have been treated at the Norwegian Radium Hospital with high-dose therapy supported by autologous peripheral progenitor cells. All the patients were given granulocyte colony stimulating factor in the recovery phase after cytotoxic treatment in order to mobilize and harvest peripheral progenitor cells. Aphareses were successful in all patients and the mean number of CD34 cells reinfused per kilo body weight was 7.05 x 10(6) for the lymphoma patients and 11.1 x 10(6) for the breast cancer patients. The mean time to recover > or = 0.5 x 10(9)/l granulocytes and > or = 20 x 10(9)/l platelets after reinfusion of stem cells was 10 days and 11.7 days respectively for the lymphoma patients, while the breast cancer patients engrafted at day 8.6 and day 9.3. No severe treatment-related complications were observed.

Adult↗
PubMed1996

Purging of tumor cells from leukapheresis products: experimental and clinical aspects.

Peripheral blood progenitor cell autografts are being used increasingly in conjunction with high-dose therapy of cancer patients, in the belief that these products have a low probability of containing tumor cells. However, recent findings demonstrate that tumor cell involvement is frequent in leukapheresis products. Although the clinical value of purging has not been clinically established by prospective randomized trials, several studies indicate that contaminating tumor cells in autografts contribute to relapse of the disease in the recipients. We describe our experimental and clinical experience in purging tumor cells from leukapheresis products. Based on our work with purging of lymphoma cells from bone marrow by the use of anti-B cell and anti-T cell antibodies and immunobeads, a purging procedure to deplete leukapheresis products of lymphoma cells has been developed. Moreover, we present data showing that breast cancer cells can be efficiently removed from leukapheresis products using antibreast cancer antibodies, either in combination with immunobeads or as immunotoxins. Our experience with enrichment of CD34 cells employing immunobeads in leukaphresis products from patients with breast cancer and lymphomas shows high purity and yield of CD34 cells. In spite of this, contaminating tumor cells can be observed, strongly suggesting that a combination of CD34 cell enrichment and a purging procedure might be warranted.

Antibodies, Monoclonal↗
PubMed1996

Immunomagnetic purging of lymphoma cells from autografts.

This report describes experiences at the Norwegian Radium Hospital in immunomagnetic purging of lymphoma from autologous stem cell grafts by negative and positive selection. Clinical data from 83 patients who received purged marrow grafts and 3 patients who received purged, mobilized leukapheresis products are presented. Early data indicate that immunomagnetic enrichment of CD34+ cells from leukapheresis products does not routinely achieve effective purging, as 1%-2% residual lymphoma cells could still be detected in the selected grafts.

Hematopoietic Stem Cell Transplantation↗
PubMed1996

Leucocyte depletion filter removes cancer cells in human blood.

BACKGROUND: Autologous blood transfusion has been avoided in cancer surgery because of the metastatic potential of reinfused tumour cells. METHODS: This study evaluated the efficacy of a blood transfusion filter in removing tumour cells from blood. Whole human blood was admixed with two different malignant cell lines (breast cancer PM1 and MCF7). The blood was filtered through a RC400TE leucocyte depletion filter. Unfiltered blood was used as a control. Detection of malignant cells was performed with immunomagnetic beads and clonogenic assays. RESULTS: No viable tumour cells were found after filtration with the leucocyte depletion filter. CONCLUSION: These findings suggest that the use of a leucocyte filter after intra-operative blood salvage may make autotransfusion safe even in tumour surgery.

Blood Transfusion, Autologous↗
PubMed1996

Detection of occult tumour cells in bone marrow and blood in breast cancer patients--methods and clinical significance.

Immunocytochemistry using tumour-associated monoclonal antibodies has led to improvements in the ability to detect occult breast cancer cells in bone marrow aspirates and peripheral blood. Nevertheless, the immunocytochemistry method needs to be further developed before it can be used routinely in the clinic. Reverse transcription polymerase chain reaction assays (RT-PCR) that screen for carcinoma-specific expression of mRNA in bone marrow and blood have been developed. However, it is not yet clear whether the most frequently employed RT-PCR assay for cytokeratin 19 has the specificity required to be safely used in the clinic. In spite of many unsolved standardization problems with micrometastatic detection methods, recent data show that the presence of occult tumour cells in the bone marrow at diagnosis and in the reinfused autograft after high-dose therapy appears to increase the rate of recurrence in the patients.

Bone Marrow↗
PubMed1996

Purging of autografts: methods and clinical significance.

High-dose chemoradiotherapy with autologous haematopoietic progenitor cell support is being used with increasing frequency to treat patients with a variety of malignancies. The most common reason for the ultimate failure in patients treated with high-dose therapy with stem cell support is not lack of engraftment, toxicity of therapy, or infection, but rather relapse of disease. There is solid evidence that reinfusion of autografts containing clonogenic tumour cells can contribute to relapse and influence patient outcome after high-dose treatment. In patients undergoing high-dose treatment, tumour cell contamination can be observed in histologically normal bone marrow or peripheral blood by sensitive micrometastatic detection techniques. Consequently, methods for detection of minimal residual disease in the autografts, together with techniques to remove tumour cells from the harvest are considered to be important in patients receiving high-dose therapy with stem cell support.

Antineoplastic Agents↗