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E Thiel

Publications and source records attributed to E Thiel.

At least 145 records · Page 8Linked to original sources
PubMed1996

Prognostic significance of additional chromosome abnormalities in adult patients with Philadelphia chromosome positive acute lymphoblastic leukaemia.

The clinical and biological significance of additional chromosome aberrations was investigated in a large series of 66 adult patients with Philadelphia (Ph) chromosome positive acute lymphoblastic leukaemia (ALL). Additional chromosome changes were observed in 71% of the cases. 9p abnormalities were identified in 26%, and monosomy 7 as well as hyperdiploid karyotypes 50 were both found in 17% of cases. 9p anomalies were characterized by a low complete remission (CR) rate (58%) and an extremely short median remission duration (MRD: 100 d). In patients with monosomy 7, the poor treatment outcome was confirmed (CR rate 55%: MRD 113 d). In contrast, all patients with hyperdiploid karyotypes 50 achieved CR, and the overall survival was superior to all other Ph-positive ALL patients except those without additional chromosome aberrations. Exclusive rearrangement of the minor breakpoint cluster region of the BCR gene and lack of coexpression of myeloid-associated antigens in cases with 9p anomalies as well as a high frequency of rearrangements of the major breakpoint cluster region of the BCR gene in patients with monosomy 7 (89%) further substantiated that additional chromosome aberrations may characterize distinct subgroups of Ph-positive ALL. Moreover, the necessity of the complementing use of chromosome banding analyses, polymerase chain reaction (PCR) assays, and fluorescence in situ hybridizations in the accurate identification of Ph-positive patients has become evident due to variant Ph translocations in 3%, and negative PCR assays in 4% of the cases.

Adolescent↗
PubMed1996

Acute myeloid leukemia with translocation (8;21). Cytomorphology, dysplasia and prognostic factors in 41 cases. AML Cooperative Group and ECOG.

The translocation t(8;21) is one of the most common structural aberrations in acute myeloid leukemia (AML). Excellent response rates and a better relapse-free survival have been described. We analyzed specific morphologic and cytochemical features including dysplasia and other prognostic factors in 41 patients with AML and t(8;21) who underwent aggressive chemotherapy in two national cooperative group studies. Five patients were classified as AML M1 and 36 as AML M2 according to the FAB criteria. Auer rods were detected in 28 patients (68%), however in only 16 patients were they "thin and elongated" as has been described as typical for t(8;21). The presence or absence of Auer rods did not appear to be associated with disease-free survival in this sample. Dysgranulopoiesis was detected in 31/41 patients (90%); five of these patients additionally had dyserythropoiesis (12%). In six cases (15%), dysmegakaryopoiesis was seen in combination with dysgranulopoiesis. Only one patient had trilineage dysplasia. Dysplastic features had no influence on prognosis. Additional cytogenetic abnormalities were detected in 24/41 patients. Twelve male (48%) and four female (25%) had a loss of a sex chromosome. This was correlated with a better disease-free survival (p = 0.039). The complete remission rate (CR) to chemotherapy was 90%. The early death rate was 10%. Disease-free survival of the complete responders was 60% at two years with no relapses observed in ten patients with 2-6 years of follow up. This favorable disease-free survival was observed with a variety of post-induction regimens and t(8;21) had been detected as an independent factor for good prognosis. The need for very intensive therapy, such as bone marrow transplantation, is unanswered at this time.

Adult↗
PubMed1996

Peripheral blood progenitor cell mobilization with Dexa-Beam/G-CSF, ether lipid purging, and autologous transplantation after high-dose CBV treatment: a safe and effective regimen in patients with poor risk malignant lymphomas.

High-dose chemotherapy followed by autologous peripheral blood progenitor cell transplantation (PBPCT) is increasingly applied in patients with relapsed, poor risk malignant lymphomas. Different strategies for progenitor cell mobilization using cytoreductive chemotherapy, hematopoietic growth factors, or both have been described. We studied the safety and efficacy of a modified DexaBEAM regimen (dexamethasone, BCNU [carmustine], etoposide, ara-C, melphalan) followed by granulocyte-colony stimulating factor (G-CSF) that was administered in order to minimize any residual disease and to obtain a sufficient amount of progenitor cells in the autografts. Until now, 16 patients at poor risk (8 with Hodgkin's disease, 8 with non-Hodgkin's lymphoma) entered the study. All the 12 patients with measurable disease at study entry responded to DexaBEAM. Median time of subsequent leukopenia (leukocytes < 1.000/microL) was 6 days (range 5-8 days). Peak numbers of CD34+ hematopoietic progenitor cells appeared in the peripheral blood after a median of 20 days (range 18-22 days) after onset of therapy. At that time, peripheral mononuclear cells were collected for autografting. Thereafter, the leukapheresis products were frozen until the day of transplantation, either unpurged in the case of Hodgkin's disease or purged with the ether lipid edelfosine in cases of non-Hodgkin's lymphoma. After high-dose chemotherapy with the CBV regimen (cyclophosphamide, BCNU, etoposide) the patients received their autografts, followed again by G-CSF treatment. A stable hematopoietic recovery was reached with granulocytes > 2.000/muL within 11 days (range 8-17 days), and platelets > 50.000/microL within 15 days (range 10-31 days), respectively, without significant differences between the purged and unpurged transplants. After a median follow-up of 28 months (range 1-40 months) 7 patients are alive without signs of recurrent disease, while 1 patient has died due to acute treatment related toxicity. Three patients had refractory disease, and 5 have relapsed of whom 4 have died. In summary, the DexaBEAM/G-CSF/CBV strategy appears to be safe and effective for salvage treatment in patients with poor risk malignant lymphomas.

Adolescent↗
PubMed1996

BCR rearrangement without juxtaposition of ABL in pre-T acute lymphoblastic leukaemia.

The incidence and clinical relevance of the Philadelphia (Ph) translocation t(9:22) (q34:q11) in T-lineage acute lymphoblastic leukaemia (ALL) are unknown. We describe a patient with pre-T-ALL and a clonal 22q-aberration detected by conventional cytogenetics, suggestive of a Ph translocation. However, fluorescence in situ hybridization (FISH) using BCR and ABL probes revealed a translocation with one breakpoint within the BCR gene on chromosome 22 without juxtaposition of ABL on chromosome 9. We discuss the diagnostic and possible pathogenetic implications of this Ph-like chromosomal aberration.

Chromosomes, Human, Pair 22↗
PubMed1996

Chemopurging of peripheral blood-derived progenitor cells by alkyl-lysophospholipid and its effect on haematopoietic rescue after high-dose therapy.

One reason for relapse after high-dose tumor therapy with subsequent autologous stem cell transplantation is tumor cell contamination of the graft. Removal of tumor cells from bone marrow grafts by chemopurging with the ether lipid edelfosine has been established as an effective and simple method. When compared with bone marrow derived grafts, progenitor cells from peripheral blood have considerably reduced the haematological recovery times. However, this advantage is put at risk by the nonspecific haematotoxic activity of the purging agent. We therefore compared the in vitro recovery of peripheral blood derived progenitor cells (PBPC) from either non-purged (n = 41) or purged (75 micrograms/ml of ether lipid for 4 h at 37 degrees C, n = 48) leukapheresis products. The recovery of CFU-GM after cryopreservation was 63 +/- 4% without and 48 +/- 3% with purging (P = 0.007). After high-dose therapy, patients (n = 37) received similar amounts of either non-purged (n = 17) or purged (n = 20) autologous PBPC. The median haematological recovery times (non-purged vs purged) to > 500 WBC/microlitres were 9.0 vs 8.5 days after transplantation, to > 2000 PMN/microlitres 10.5 vs 10.0 days, and to > 50,000 PLT/microlitres 15.5 vs 14.0 days. All differences were statistically not significant. We conclude that ether lipid purging of PBPC leads to a significant, however tolerable loss of progenitor cells in vitro, and that haematological recovery times after high-dose therapy are identically short, provided similar amounts of PBPC are reinfused.

Adult↗
PubMed1995

Long-term follow-up of adults with acute lymphoblastic leukemia in first remission treated with chemotherapy or bone marrow transplantation. The Acute Lymphoblastic Leukemia Working Committee.

OBJECTIVE: To determine whether the conclusions of a 1991 study, which showed that adults with acute lymphoblastic leukemia in first remission had similar leukemia-free survival rates when treated with chemotherapy or HLA-identical sibling bone marrow transplantation, remain valid after more than 4 years of additional follow-up. DESIGN: Retrospective comparison of two cohorts of patients using left-truncated Cox regression to adjust for differences in baseline characteristics and time to treatment. SETTING AND PATIENTS: Chemotherapy recipients were 484 consecutive patients with acute lymphoblastic leukemia in first remission treated in 44 hospitals in Germany that were participating in two consecutive trials of the German Acute Lymphoblastic Leukemia Therapy Trials Group. Transplant recipients were 234 consecutive recipients of HLA-identical sibling bone marrow transplants for acute lymphoblastic leukemia in first remission in 98 centers, worldwide, reporting data to the International Bone Marrow Transplant Registry. INTERVENTIONS: Intensive combination chemotherapy or HLA-identical sibling bone marrow transplantation preceded by high-dose chemotherapy with or without total body irradiation. MEASUREMENTS: Relapse, treatment-related mortality, and leukemia-free survival rate 9 years after first complete remission. RESULTS: The conclusions of our previous analyses were confirmed. Actuarial relapse probabilities at 9 years were 66% (95% CI, 61% to 70%) for chemotherapy and 30% (CI, 22% to 37%) for transplantation (P < 0.0001). The leukemia-free survival rates at 9 years were 32% (CI, 27% to 37%) for chemotherapy and 34% (CI, 28% to 40%) for transplantation (P > 0.02). CONCLUSIONS: Fewer relapses but more treatment-related deaths were seen with transplantation than with chemotherapy. Thus, leukemia-free survival rates were similar in adults receiving transplantation and adults receiving chemotherapy for acute lymphoblastic leukemia in first remission.

Antineoplastic Agents↗
PubMed1995

Nerve growth factor stimulates clonal growth of human lung cancer cell lines and a human glioblastoma cell line expressing high-affinity nerve growth factor binding sites involving tyrosine kinase signaling.

The growth of a panel of 22 different human tumor, leukemia, and lymphoma cell lines was examined in a human tumor cloning assay in agar or methylcellulose and a tritiated thymidine uptake assay. The cultures were performed in the absence or presence of increasing concentrations (0.5-500 ng/ml) of nerve growth factor (NGF). The growth of 17 of the 22 cell lines was not significantly and reproducibly affected by NGF. There was minor (1.2-fold) but reproducible stimulation of clonal growth in one glioblastoma cell line (86-HG-39) by NGF, but in this cell line NGF induced no growth modulation in a tritiated thymidine uptake assay. However, clonal growth of another glioblastoma cell line (87-HG-31) and all three lung cancer cell lines tested (HTB 119, HTB 120, CCL 185) could be stimulated up to 3-fold by NGF with a dose-response relationship for the growth factor. Growth stimulation by NGF could be completely reversed by neutralizing anti-NGF antibody and by the tyrosine kinase inhibitor genistein. Evaluation of secondary plating efficiency revealed the stimulation of colony formation as representing self-renewal and not terminal differentiation. Reverse transcriptase-PCR experiments in the five responding cell lines showed expression of both low-affinity NGF receptor (glycoprotein 75) and c-trk transcripts on the mRNA level. Of the five responding cell lines, only 86-HG-39, the cell line with the lowest responsiveness, revealed low-affinity NGF receptor on the protein level; the other four cell lines with high responsiveness, including the three lung cancer cell lines, expressed no low-affinity NGF receptor as shown by fluorescence-activated cell sorter analysis and immunoprecipitation using the ME 20.4 antibody. Immunoprecipitation using anti-trk antibodies was negative in all five responding cell lines. However, binding studies with iodinated NGF showed only low-affinity binding on the 86-HG-39 cell line and only high-affinity binding on the high-responder cell lines CCL 185 and 87-HG-31. In summary, our data suggest that NGF can be operative in stimulation of clonal growth of malignant tumor cells. High-affinity but not low-affinity binding sites mediate signal transduction for clonal growth and signaling involves tyrosine kinase activity.

Base Sequence↗
PubMed1995

Recombinant human interleukin 4 has antiproliferative activity on human tumor cell lines derived from epithelial and nonepithelial histologies.

Interleukin 4, a T cell-derived 20-kDa glycoprotein, plays an important role in regulating the immune response of B cells, T cells, and macrophages against infections and malignant cells. For this reason recombinant human interleukin 4 (rhIL-4) has entered early clinical trials in cancer patients. In the present study we report that rhIL-4 has an antiproliferative effect on five of nine cell lines derived from human colon tumors, head and neck tumors, and glioblastomas as measured by a decrease of colony formation in human tumor cloning assays. All of the cell lines with in vitro responsiveness express at least 100 high-affinity receptors for human interleukin 4 per cell on their cell surface, whereas the nonresponsive tumor cell lines lack expression of high-affinity receptors for human interleukin 4 on their cell surface. In the next series of experiments we have xenotransplanted some of the responsive cell lines into athymic nude mice. Subsequently, the animals were treated s.c. twice daily with 0.5 mg/m2 rhIL-4 or control vehicle for at least 12 days. There was a clear growth inhibition of these xenotransplanted tumors in the mice treated with rhIL-4. Histology of the tumors in both groups revealed no marked infiltration with murine hematopoietic and lymphocytic cells as evaluated by staining with a rat anti-mouse CD45 antibody. We conclude that rhIL-4 has a direct therapeutic activity on the growth of some human epithelial and nonepithelial tumor cell lines which, along with its regulatory function on hematolymphopoietic cells, makes this cytokine an interesting candidate for experimental tumor therapy.

Animals↗
PubMed1995

Biochemical modulation of cytotoxic drugs by cytokines: molecular mechanisms in experimental oncology.

The combination of cytokines and cytotoxic drugs offers a new approach to increase the therapeutic index in the treatment of neoplastic diseases. There is no consensus on optimal strategies for combining these agents so far. The molecular mechanisms underlying the interaction, however, should be defined in order to design clinical trials based on preclinical rationales. The broad spectrum of cytotoxic drugs whose activity can be enhanced by cytokines argues for multiple levels of drug interaction in vitro: alteration in the cellular drug uptake, modulation of drug target enzymes, and changes in metabolism or disposition of a drug. In vivo interaction between cytokines and cytotoxic agents involves an additional layer of complexity because of the effects of cytokines on the host immune system and on drug-metabolizing enzymes. A major mechanism involved in the synergistic interaction of interferon (IFN) and 5-fluorouracil (5-FU) seems to be the increase of active 5-FU metabolites by IFN. Moreover, IFN can reverse resistance against 5-FU by inhibiting the overexpression of thymidylate synthase. The absence of cytokinetic effects of IFN and FU argues against the recruitment of Gs cells into the cell cycle. Topoisomerase has emerged as a critical intracellular target of cytotoxic drugs. There is convincing evidence that the synergy between tumor necrosis factor (TNF) and topoisomerase-targeted intercalative (Adriamycin, doxorubicin hydrochloride; m-AMSA, amsacrine; mitoxantrone) and nonintercalative (VM-16, etoposide; VM-26, teniposide) drugs is related to a rapid increase in specific activity of topoisomerase I and II, resulting in enhanced DNA strand breaks and cleavage complex. Furthermore, sensitivity to topoisomerase II targeted drugs can be enhanced by granulocyte colony-stimulating factor (G-CSF) through elevated enzyme activity in tumor cell response to G-CSF. The synergistic interaction between cytokines and cytotoxic agents seems to be sequence dependent. It has recently been demonstrated that newly synthesized metal compounds and IFN are synergistic only after preincubation with cytokines. Cytokines can modulate expression of adhesion receptors on tumor cell lines, thereby influencing their metastatic potential. A considerable number of phase II trials with combination of cytokines and cytotoxic drugs based on these mechanisms have demonstrated promising response rates and tolerable toxicity. Phase III trials are currently in progress to identify enhanced activity combining cytokines and cytotoxic drugs in the treatment of malignancies.

Animals↗
PubMed1995

Four generation reproductive toxicity study with 2,3,7,8-tetrachlorodibenzo-P-dioxin (TCDD) in rats. I. Toxicokinetic variations in dams and offspring.

A multigeneration study on the reproductive toxicity of TCDD in rats was conducted. In this paper, the results of extensive pharmacokinetic evaluations are presented. The time course of tissue concentrations within the framework of a multigeneration study was investigated, using radioactive labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a substance with a long elimination half-life. So far, long term exposure to TCDD has generally been conducted by administering the same daily doses via the feed. Since the half-life of TCDD in rats is several weeks, the concentration of the test substance can be predicted to change continuously during such a study. Therefore we intended to expose the animals to a constant tissue concentration by using a loading dose/maintenance dose approach. To achieve this, the animals were treated with initial loading doses of 50, 120 or 250 ng TCDD/kg body wt. Based on the elimination half-life of 3 weeks and a planned dosing interval of 7 days, the weekly maintenance doses were calculated to be 20% of the loading dose. During the postnatal phase of rapid growth, this dosing schedule was insufficient to keep the tissue concentration of TCDD constant. It was necessary to administer a second loading dose and to increase the weekly maintenance dose to 40% of the loading dose. While it was possible to control the tissue concentrations in the F0 generation, a considerably larger variation was observed during the different developmental stages of the F1 generation. The fluctuations could be reduced by using a complex dosing schedule, but even with that it was impossible to achieve completely steady levels in liver and adipose tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1995

Recombinant human stem cell factor does exert minor stimulation of growth in small cell lung cancer and melanoma cell lines.

We have previously reported on the stimulation of clonal growth of a glioblastoma cell line by rhSCF (Berdel et al., Cancer Res 1992, 52, 3498-3502). Within an extensive screening programme of haematopoietic growth factor activity on malignant cells, the effects of rhSCF were further tested on the growth of 29 different human cell lines derived from a wide range of solid tumours, among them six lung cancers and five melanomas. RhSCF (0, 1, 10, 100 ng/ml) was tested in a human tumour cloning assay (HTCA) which reliably detects growth modulation of tumour cells by cytokines. Additionally, a tritiated thymidine uptake test was used. Growth of 27 of the 29 cell lines tested was not affected by rhSCF. However, growth of the small cell lung cancer (SCLC) cell line HTB 120 was slightly stimulated (1.5 fold that of controls), and that of the melanoma cell line MeWo was stimulated up to 1.3-fold. This activity was eliminated dose-dependently by the tyrosine kinase inhibitor, genistein. We further analysed the cell lines for expression of the proto-oncogene C-KIT and its ligand SCF. All melanoma and lung cancer cell lines expressed SCF as assessed at the mRNA level. Northern blotting also revealed clear C-KIT mRNA expression in three melanoma (HAS, MeWo, SK-MEL-28), one NSCLC (HTB 53), and four SCLC cell lines (HTB 119, HTB 120, HTB 171, HTB 175). Furthermore, C-KIT protein expression was detected by flow cytometric analysis on the cell surface of MeWo, HTB 119 and HTB 120 cells. Our data indicate that SCF can be operative in growth modulation of non-haematopoietic malignant cells, especially SCLC and melanoma. However, our extensive screening of SCF/tumour cell interaction shows that this interaction is rare and makes potential hazards, such as tumour stimulation upon clinical use of rhSCF in conjunction with chemotherapy in cancer patients, unlikely for the majority of other tumour histologies.

Base Sequence↗
PubMed1995

Immunomagnetic selection of CD34+ cells from fresh peripheral blood mononuclear cell preparations using two different separation techniques.

Immunomagnetic separation using anti-CD34 monoclonal antibodies and paramagnetic microspheres has been used to enrich hematopoietic stem cells from human bone marrow, whole cord blood, or mobilized peripheral blood mononuclear cell collections. The aim of the present study was to compare the efficacy of two different CD34+ cell selection techniques in enriching CD34+ cells from mobilized fresh peripheral blood mononuclear cells. Using the magnetic cell sorter (MACS), the final product purity was 74.1% CD34+ cells (starting population 2.3% +/- 3.3%) with a 60.3% CD34+ cell yield. Using Dynabeads and subsequent chymopapain incubation for releasing the target cells from the beads (Isolex system), the released cells contained 83.3% CD34+ cells (starting population 1.2% +/- 0.7%) with a 43.4% yield. These results indicate that CD34+ cells can be isolated with high purity from fresh leukapheresis products using both immunomagnetic techniques.

Antigens, CD34↗
PubMed1995

Trisomy 12 in B-cell chronic lymphocytic leukemia: correlation with advanced disease, atypical morphology, high levels of sCD25, and with refractoriness to treatment.

In situ hybridization was performed to study the clinical significance of trisomy 12 in fifty patients with B-cell chronic lymphocytic leukemia at various stages of disease. Trisomy 12 was detected in 12%-65% (median 53%) of the circulating neoplastic cells in seven out of 20 patients with advanced Binet stage C disease. In contrast, 22 patients with Binet stage A and eight patients with Binet stage B disease were found to be negative for trisomy 12. As occurrence of trisomy 12 was associated with the presence of B-symptoms and hepatosplenomegaly, its association with advanced disease was further considered. In addition, atypical morphology was a common finding in trisomic patients who also displayed higher serum levels of soluble CD25 than patients without trisomy at Binet stage C. No significant differences were detected in serum levels of soluble CD8 and of soluble CD23. No correlation with a lymphocyte doubling time of < 12 months, marked lymphadenopathy, or prior treatment was apparent. However, refractoriness to treatment was evident more frequently in trisomic than in non-trisomic patients (p < .05). In conclusion, trisomy 12 in B-cell chronic lymphocytic leukemia appears to occur predominantly in advanced and symptomatic disease with atypical morphology. It could indicate a high risk for treatment failure thus serving as a marker of poor prognosis in this disease.

CD8 Antigens↗
PubMed1995

Antiproliferative effect of human interleukin-4 in human cancer cell lines: studies on the mechanism.

Interleukin-4 (IL-4) plays an important role in activating the immune system against malignant cells. The human interleukin-4 receptor (hIL-4R) is not only expressed by hematopoietic cells but also on a large number of tissue specimens which include colon, breast and lung carcinomas. In this study we report that rhIL-4 has an antiproliferative effect on 2 out of 3 non-small cell lung carcinoma (NSCLC) cell lines in vitro as measured by human tumor cloning assays (HTCA). In comparison, rhIL-4 had no effect on the growth of small cell lung carcinoma cell lines (SCLC) in vitro. The response towards the cytokine is correlated with expression of at least 1500 high affinity receptors/cell for hIL-4 on the responsive cell lines. Xenotransplanting the human lung tumor cell lines into nude mice followed by 12 days of systemic treatment of the mice with rhIL-4 revealed a significant growth retardation of the IL-4R positive NSCLC cell lines when compared with the controls, whereas the growth of the IL-4R negative SCLC cell lines was unaffected also in vivo. Studies of possible mechanisms involved in the antiproliferative effect of rhIL-4 showed that rhIL-4 does not induce apoptosis or modulation of the transcription factor c myc in the responsive NSCLC cell lines. Additionally, the expression of the epidermal growth factor receptor (EGFR), which is discussed as mediating autocrine/paracrine growth stimulation of NSCLC, is unaffected by rhIL-4. However, we have observed that rhIL-4 inhibited G1-S-phase cell cycle progression. We conclude that rhIL-4 has an antiproliferative effect on the growth of some NSCLC in vitro and in vivo. The mechanisms involved remain to be further elucidated.

Animals↗
PubMed1995

Presence of Wilms' tumor gene (wt1) transcripts and the WT1 nuclear protein in the majority of human acute leukemias.

The wt1 gene is located on chromosome 11p13 and encodes a zinc finger motif-containing transcription factor involved in regulation of growth and differentiation. Its expression was shown during embryonic development in various tissues as well as in a few human malignancies including acute leukemias. Using RT-PCR, we found wt1 gene expression in blast cells of the majority of 150 acute leukemia patients. Particularly, the wt1 transcript was detected in 12 of 14 (86%) pre-pre-B-ALL patients, in 33 of 41 (80%) cALL patients, in 23 of 31 (74%) T-ALL patients, and in 53 of 57 (93%) AML patients. Additionally, mononuclear cells from CML patients expressed the wt1 gene only when diagnosed with blast crisis. In contrast to acute human leukemias, mononuclear cells from reactive bone marrow (n = 4), and peripheral blood of healthy volunteers (n = 20), as well as normal peripheral CD34+ hematopoietic progenitors (n = 6) did not express the wt1 gene at detectable levels. Using the anti-WT1 MoAb 6F-H2 in an immunofluorescence assay on single cell level, we found the translated WT1 protein only in nuclei of leukemia blast cells but not in nuclei of normal CD34+ hematopoietic progenitor cells. Blast cells of 12 of 20 leukemia patients (60%) all tested positive for the wt1 gene expression by RT-PCR displayed a strong nuclear immunofluorescence. Its expression in the majority of human acute leukemias but not in normal mononuclear blood cells and normal CD34+ hematopoietic progenitors qualifies the wt1 gene transcript as a 'pan-acute leukemic' marker probably useful in monitoring minimal residual disease after chemotherapy and in detecting leukemic blast cells in purged or unpurged hematopoietic stem cell preparations intended to be used for autologous bone marrow transplantation.

Adult↗