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Biomedical subjects

M Stockschläder

Publications and source records attributed to M Stockschläder.

At least 37 records · Page 2Linked to original sources

Intensified conditioning regimen in bone marrow transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia.

We investigated an intensified conditioning regimen including fractionated total body irradiation (12 Gy), etoposide (30-45 mg/kg) and cyclophosphamide (120 mg/kg), followed by autologous (n = 5), allo-related (n = 13) or allo-unrelated (n = 6) bone marrow (n = 22) or peripheral stem cell (n = 2) transplantation in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia. One patient received busulfan (16 mg/kg) instead of TBI. Nineteen patients were transplanted in 1CR, two in 2CR, one in 1PR and two in relapse. Major toxicity was mucositis grade II according to the Bearman scale in all patients. The treatment-related mortality was 25%, mainly due to infection or GVHD after allogeneic transplantation. After a median follow-up of 45 months (range 2-93), nine patients (37.5%) remain alive in CR. Nine patients (37.5%) relapsed and eight (33.3%) of these subsequently died. After autologous transplantation, four of five patients (80%) relapsed and died. Late relapse was seen after allogeneic, as well as autologous transplantation, at 33 and 59 months, respectively. The Kaplan-Meier estimate of leukemia-free survival for all patients is 38% at 3 years (95% CI: 18-58%) and 35% at 5 years (95% CI: 15-55%). For allogeneic transplants in first CR (n = 15) the estimate of disease-free survival was 46% at 3 years (95% CI: 19-73%) and 34% at 5 years (95% CI: 17-51%). Patients aged below 30 years had a better estimated overall survival at 3 years (61% vs 11%, P < 0.001). The bcr-abl fusion transcript (p210 vs p190 vs p210/190) did not affect disease-free or overall survival. In our experience, an intensified conditioning regimen seems to improve the results of bone marrow transplantation in patients with Ph+ acute lymphoblastic leukemia. However, the high relapse rate warrants novel approaches to enhance anti-leukemic efficacy.

Adolescent↗

Highly-efficient gene transfer with retroviral vectors into human T lymphocytes on fibronectin.

Genetically modified lymphocytes have been successfully used for correction of ADA deficiency in children and in controlling graft-versus-host disease (GvHD) after allogeneic bone marrow transplantation. Low transduction efficiencies are, however, limiting for gene therapeutic strategies based on lymphocytes. In this study we compared protocols for highly efficient gene transfer into human T cells using retroviral vector-containing supernatant. We showed that infection of both human primary T cells and CD4+ Jurkat cells is most efficient on the matrix component fibronectin. Transduction was carried out with a retroviral vector encoding both the human intracytoplasmatically truncated low-affinity nerve growth factor receptor (deltaLNGFR) as a gene transfer marker and the Herpes simplex virus thymidine kinase for negative selection. Based on LNGFR expression genetically modified cells were enriched to near purity by magnetic cell sorting (MACS). Enriched cells could be shown to be highly sensitive to ganciclovir.

Anti-Allergic Agents↗

Faster engraftment of peripheral blood progenitor cells compared to bone marrow from unrelated donors.

Twenty-six patients received peripheral blood progenitor cells (PBPC) from unrelated donors at five European Centres. Twenty-five donors were HLA-A, -B and -DR identical and one had a one antigen mismatch. PBPC were mobilised by treatment with G-CSF for 4-5 days. Eleven patients receiving PBPC were compared to 11 patients receiving unrelated bone marrow with comparable prognostic factors. The median mononuclear cell count, the CD3+ cells and the CD56+ cells were seven to 10 times higher in PBPC, compared to bone marrow (P < 0.001). The median CD34+ cell content was 6.1 x 10(6)/kg recipient weight with PBPC, compared to 4.3 with bone marrow (NS). Time from transplantation to neutrophils >0.5 x 10(9)/l was a median of 11 (range 6-21) days using PBPC vs 15 (10-22) days after transplantation of bone marrow (P = 0.03). Transfusions and time to discharge did not differ between the two groups. All 26 patients receiving PBPC engrafted. Acute GVHD grades II-IV was seen in 8/26 (31%) and chronic GVHD in 8/18 (44%). Overall, 13/26 (50%) of the patients are alive and well with a median follow-up of 9 (2-35) months.

Bone Marrow Transplantation↗

Selective immunoaffinity-based enrichment of CD34+ cells transduced with retroviral vectors containing an intracytoplasmatically truncated version of the human low-affinity nerve growth factor receptor (deltaLNGFR) gene.

Human hematopoietic stem cells remain one of the most promising target cells for gene therapeutic approaches to treat malignant and nonmalignant diseases. To rapidly characterize transduced cells and to isolate these from residual nontransduced, but biologically equivalent, cells, we have used a Moloney murine leukemia virus (Mo-MuLV)-based retroviral vector containing the intracytoplasmatically truncated human low-affinity nerve growth factor receptor (deltaLNGFR) cDNA as a marker gene. Supernatant transduction of CD34+ cells (mean purity 97%) in fibronectin-coated tissue culture flasks resulted in 5.5-45% (mean 26%) transduced cells expressing deltaLNGFR (LNGFR+ cells). After transduction, more than 65% of the transduced cells remained CD34+. Compared with control (mock- and nontransduced) CD34+ cells, transduction did not decrease the cloning efficiency of CD34+ cells. Immunomagnetic selection of the transduced cells with a monoclonal anti-LNGFR antibody resulted in >90% LNGFR+ cells. Further phenotypic characterization of these highly enriched LNGFR+ cells indicated that the majority co-expressed the CD34 and CD38 antigens. These results show that transduced cells expressing an ectopic cell-surface protein can be rapidly and conveniently quantitated and characterized by fluorescence-activated cell sorting (FACS) analysis and fast and efficiently enriched by immunoadhesion using magnetic beads. The use of cell-surface reporters should facilitate optimization of methods of gene transfer into more primitive hematopoietic progenitors.

Animals↗

Amphotropic murine leukemia viruses induce spongiform encephalomyelopathy.

Recombinants of amphotropic murine leukemia virus (A-MuLV) have found widespread use in retroviral vector systems due to their ability to efficiently and stably infect cells of several different species, including human. Previous work has shown that replication-competent recombinants containing the amphotropic env gene, encoding the major SU envelope glycoprotein that determines host tropism, induce lymphomas in vivo. We show here that these viruses also induce a spongiform encephalomyelopathy in mice inoculated perinatally. This fatal central nervous system disease is characterized by noninflammatory spongiform lesions of nerve and glial cells and their processes, and is associated with moderate astro- and microgliosis. The first clinical symptoms are ataxia, tremor, and spasticity, progressing to complete tetraparesis and incontinence, and finally death of the animal. Sequences within the amphotropic env gene are necessary for disease induction. Coinfection of A-MuLV recombinants with nonneuropathogenic ecotropic or polytropic MuLV drastically increases the incidence, degree, and distribution of the neurodegenerative disorder. The consequence of these results in view of the use of A-MuLV recombinants in the clinic is discussed.

Animals↗

Vascular endothelial growth factor, a possible paracrine growth factor in human acute myeloid leukemia.

Vascular endothelial growth factor (VEGF) is a multifunctional cytokine involved in angiogenesis, inflammation, and wound healing. It is secreted by a variety of tumor cell lines, including hematopoietic lines. Therefore, we investigated expression of VEGF and its receptors on fresh leukemic blasts. VEGF-specific transcripts were detected by polymerase chain reaction (PCR) in 20 of 28 patients with de novo acute myeloid leukemia (AML) and in 3 of 5 patients with secondary AML. Using immunocytochemistry, we found VEGF protein in 2 leukemic cell lines and in 8 AML patients, in concordance with PCR results. Supernatants of fresh leukemic cells from 24 AML patients contained significantly more VEGF than supernatants from bone marrow cells of 9 normal donors or of CD34-enriched cells from 3 normal volunteer donors as determined by an enzyme-linked immunosorbent assay. VEGF possesses two high-affinity receptors, KDR and FLT1. Using a sensitive nested PCR assay, we detected expression of FLT1 in 10 of 20 patients with de novo AML and 3 of 5 patients with secondary AML. KDR was expressed in 4 of 22 patients with de novo AML and 1 of 4 with secondary AML. To study possible paracrine growth stimulation of AML blasts, endothelial cells from human umbilical cords were incubated with increasing concentrations of VEGF. A dose-dependent increase of granulocyte-macrophage colony-stimulating factor secretion from endothelial cells was identified.

Acute Disease↗

Factors influencing haematological recovery after allogeneic bone marrow transplantation in leukaemia patients treated with methotrexate-containing GVHD prophylaxis. A single-centre experience.

In the present single institution study of 66 leukaemia patients (28 AML, 23 ALL, 15 CML), the factors influencing haematological recovery after allogeneic bone marrow transplantation (alloBMT) were analysed retrospectively to identify the optimal conditions required for rapid haematological recovery after alloBMT. All patients received GVHD prophylaxis with cyclosporine A plus methotrexate. The mean number of days required to achieve a neutrophil count > or = 0.5 x 10(9)/l after alloBMT was 17 (range 9-27), 19 patients (28.8%) had rapid neutrophil recovery within 15 days after alloBMT. Haematological recovery was more rapid in the 38 patients without GVHD or with only grade I GVHD. Also, 50% and 40% of patients receiving 10 (n = 18) or 5 (n = 20) micrograms/kg G-CSF per day, respectively, had rapid neutrophil recovery within 15 days after alloBMT, as against only 7.1% of patients not receiving G-CSF after the transplant (n = 28); P < 0.001. The neutrophil recovery was similar in patients receiving either fresh or cryopreserved allografts and either a TBI-containing or a busulfan-containing conditioning regimen. A significant correlation was found between the neutrophil recovery and either the MNCs or CFU-GM contents of the allografts. The mean number of days required for neutrophil recovery was only 16 (range 9-24) in patients receiving allografts containing > 1 x 10(5) CFU-GM/kg (n = 28), as against 19 (range 13-27) in patients receiving allografts containing < or = 1 x 10(5) CFU-GM/kg (n = 35). Three patients receiving allografts containing < 0.5 x 10(5) CFU-GM/kg had primary neutrophil engraftment failure. The mean number of days required to achieve a platelet count > or = 20 x 10(9)/l was 21 (range 11-50), and 30 patients (46.9%) had platelet recovery within 20 days after alloBMT. The platelet recovery after alloBMT was not affected by the type of leukaemia, conditioning regimen, or G-CSF administration. The mean number of days required for platelet recovery after alloBMT was 20 in patients receiving allografts containing > 1.0 x 10(5) BFU-E/kg (n = 35), as against 23 days in patients receiving allografts containing < or = 1.0 x 10(5) BFU-E/kg (n = 24). Seven patients receiving allografts containing < 0.5 x 10(5) BFU-E/kg had primary platelet engraftment failure. The present study has identified the high number of progenitor cells in the allografts infused and the daily administration of G-CSF posttransplant as the optimal combination for rapid neutrophil recovery after alloBMT. More significantly, the number of BFU-E in allografts was the most significant determining factor in platelet recovery after alloBMT. The development of GVHD of grade II or more during the first weeks after alloBMT was associated with slower haematological recovery, a longer period of fever during neutropenia and longer hospitalization.

Adolescent↗

Nontransferrin-bound iron in serum of patients receiving bone marrow transplants.

Nontransferrin-bound iron (NTBI) and other parameters of iron status were measured in 40 patients undergoing bone marrow transplantation (BMT) prior to conditioning therapy (between day -10 and -7), at the time of BMT (day 0), and 2 weeks later (day + 14). Serum iron and transferrin saturation values were normal before conditioning therapy. At day 0 serum iron values were high and median transferrin saturation was 98% (changes in the values of both serum iron and transferrin saturation, p < .0001). Transferrin saturation values were still elevated 2 weeks posttransplant (day +14 vs. baseline values, p = .0001). Starting at low NTBI levels pretransplant (median 0.4 micromol/l, range 0-4.2 micromol/l, controls: < or = 0.4 micromol/l), all patients revealed high levels on day 0 (median 4.0 micromol/l, range 1.9-6.9 micromol/l, p < .0001) and 2 weeks posttransplant (median 2.7 micromol/l, range 0-6.2 micromol/l, p < .0001). These observations indicate that the plasma iron pool in patients undergoing BMT increases to a level at which the normal ability to sequestrate iron becomes exhausted and considerable amounts of NTBI appear in serum. This "free" form of iron can mediate the production of reactive oxygen species and may cause organ toxicity in the early posttransplantation period.

Adolescent↗

Expression of FLT4 and its ligand VEGF-C in acute myeloid leukemia.

FLT4 represents a recently cloned member of class III receptor tyrosine kinases which include receptors for the angiogenic growth factor VEGF, namely FLT1 and KDR. The ligand of FLT4 has been identified as VEGF-C which shares sequence homology with VEGF and P1GF. In the adult FLT4 shows a restricted expression pattern that is limited to lymphatic endothelia and endothelia of some high endothelial venules (HEV). FLT4 has also been detected in some tumor cell lines including the hematopoietic line HEL. We therefore investigated expression of FLT4 and its ligand VEGF-C in fresh samples from patients with AML. Using a sensitive PCR method we detected FLT4 m-RNA in 15 of 41 patients with de novo AML at diagnosis or relapse and in three of 12 patients with secondary AML. FLT4 expression was confirmed by immunocytochemistry in a subgroup of the studied patient population. FLT4 was also found in leukemic cell line U937, but not TF-1 and KG1a. VEGF-C expression was found in leukemic samples of four of seven FLT4-positive and four of six FLT4-negative patients. U937 cells also produced VEGF-C m-RNA. Interestingly, FLT4 expression was not detected in bone marrow samples of 15 normal volunteer donors or in CD34-positive cells from three additional donors. Possible autocrine and paracrine growth stimulation of leukemic blasts by VEGF-C is currently being investigated in our laboratory.

Acute Disease↗

Long-term follow-up of leukaemia patients after related cryopreserved allogeneic bone marrow transplantation.

We have previously shown that allogeneic bone marrow transplantation (BMT) with cryopreserved donor marrow cells can be used without prolonging the engraftment time or interfering with the reconstitution of haemopoiesis. In this report we extend our initial observations of the first 40 patients who underwent allogeneic bone marrow transplantation from related donors with cryopreserved donor bone marrow for haematological malignancies, including the long-term follow-up data of the previously reported patients. The outcome of these patients was compared with that of 40 related BMT recipients receiving fresh donor bone marrow (historic control group). Time until engraftment of all patients receiving cryopreserved bone marrow was not different from the control group (ANC > 0.5 x 10(9)/l 17d (range 11-24 d) versus 17.5 d (range 10-28 d): platelets > 20 x 10(9)/l 21 d (range 11-85 d) versus 22 d (range 13-69 d), respectively). There was the same incidence of acute and chronic GvHD in patients receiving either cryopreserved bone marrow or fresh bone marrow (acute GvHD > or = II 61% v 60% and chronic GvHD 56% v 52%, respectively). Chimaerism studies showed no difference between the patient groups. Furthermore, the two groups did not differ in day 100 survival (82% v 72%). With a median follow-up of 520 d (range 47-1365 d) and 1289 d (range 48-1849 d), 60% of the patients receiving cryopreserved and 53% of the patients receiving fresh allogeneic donor bone marrow, respectively, are alive. We conclude that cryopreservation of allogeneic related donor bone marrow does not adversely affect engraftment, does not decrease the incidence of severe acute GvHD, and does not seem to affect the day 100 survival or long-term haemopoiesis.

Adolescent↗

Allogeneic transplantation with CD34+-selected cells.

We report the outcome of eight patients with different hematological malignancies who were transplanted with allogeneic CD34-selected mononuclear cells following myeloablative therapy. Four patients received G-CSF mobilized CD34-enriched peripheral blood progenitor cells (PBPC) together with CD34-enriched bone marrow (BM), two patients were transplanted with allogeneic G-CSF mobilized CD34-enriched PBPC alone, and two patients received only allogeneic CD34-enriched BM cells. On average, patients received 2.66 x 10(6) CD34+-cells/kg BW (range: 0.53-8.40 x 10(6) CD34+-cells/kg body weight) and 0.57 x 10(6) CD3+-cells/kg BW (range: 0.20-1.10 x 10(6) CD3+-cells/kg BW), respectively. Seven of the eight patients engrafted (ANC > 0.5 x 10(9)/L median: day +19 (range: 16-23 days); platelets > 20 x 10(9)/L median: day +34 (range: 21-47 days); one patient died on day +16 after transplantation and was not evaluable for engraftment. Three of seven patients evaluable for acute graft-versus-host disease (GvHD) developed acute GvHD grade II which resolved upon steroid treatment. Five of the eight patients are still alive and in remission with a median follow-up of 215 days (range: 80-420 days). Causes of death included fungal infection, cerebral bleeding and sepsis. These preliminary data suggest that CD34-enriched cells can be successfully given during for allogenic transplantation following myeloablative therapy in hematological malignancies. The impact of T-cell depletion by enrichment for CD34+-cells in an attempt to reducing the incidence and/or severity of acute and/or chronic GvHD still remains to be determined.

Adult↗

Antimycotic therapy with liposomal amphotericin-B for patients undergoing bone marrow or peripheral blood stem cell transplantation.

Suspected deep or systemic mycosis in patients undergoing high-dose therapy and autologous or allogeneic bone marrow transplantation (BMT) requires an immediate systemic antimycotic therapy. Intravenous therapy with the standard drug conventional amphotericin-B is associated with severe adverse effects like nephrotoxicity and chills. Furthermore, BMT patients often receive other potential nephrotoxic drugs such as CsA or virustatics. In this study, we report 74 BMT-patients treated with liposomal amphotericin-B for culture-documented aspergillosis (n = 5) or candidiasis (n = 6), or for serologically (n = 35) or clinically suspected mycosis or as prophylaxis (n = 2). Therapy was initiated with a median dose of 2.8 (0.64-5.09) mg/kg body-weight and continued for 13 (1-55) days. The drug was excellently tolerated and only in one was therapy stopped due to severe chills and fever. Severe organ impairment was not observed under therapy with liposomal amphotericin-B. Creatinine decreased in five patients after an increase under preceding therapy with the conventional formulation. Influence of liposomal amphotericin-B on bilirubin and transaminases was difficult to evaluate due to therapy-related toxicity, veno-occlusive disease (VOD), and graft-versus-host disease (GvHD). 10/11 culture-positive patients died from aspergillosis (5/5) or candidiasis (5/6), but in 9/11 of these subjects the immunity was additionally compromised by GvHD, steroid therapy, and VOD. Liposomal amphotericin-B was effective in preventing relapse of systemic mycosis in 10/12 patients with a history of aspergillosis (n = 11) or candidiasis (n = 1). We conclude, that favourable toxicity of liposomal amphotericin-B should encourage dose escalation studies of liposomal amphotericin-B randomised against the conventional formulation and that the comparison of patients undergoing BMT with patients under standard chemotherapy might be difficult because of additional risk factors of the BMT-patients.

Adolescent↗

High-dose multidrug resistance in primary human hematopoietic progenitor cells transduced with optimized retroviral vectors.

Retroviral transfer of the multidrug-resistance 1 (mdr1) cDNA into primary human hematopoietic progenitor cells (HPC) of cancer patients undergoing high-dose chemotherapy has been proposed to protect the bone marrow from the dose-limiting cytotoxicity of cytostatic agents. Preclinical studies performed with vectors derived from the Moloney murine leukemia virus (MoMuLV) or the related Harvey murine sarcoma virus have established that chemoprotection of HPC is feasible. The efficacy of vector-mediated multidrug-resistance under high doses of cytostatic agents, however, remained unclear. We report here that this goal can only be achieved with improved vector design. Novel vectors termed SF-MDR and MP-MDR, which are based on the spleen focus-forming virus or the myeloproliferative sarcoma virus for the enhancer and the murine embryonic stem cell virus for the leader, significantly elevate survival of transduced primary human HPC under moderate doses of colchicine and paclitaxel in vitro when compared with a conventional MoMuLV-based vector. Importantly, SF-MDR and also MP-MDR confer an absolute advantage at high doses of paclitaxel in vitro corresponding to peak plasma levels achieved in patients during chemotherapy. This observation has important consequences for a variety of ongoing and planned gene therapy trials.

Animals↗

Comparison between bone marrow and G-CSF-mobilized peripheral blood allografts undergoing clinical scale CD34+ cell selection.

Allogeneic transplantation of selected CD34+ cells, rather than conventional transplantation of bone marrow (BM) harvest or peripheral blood (PB) leukapheresis products, has the advantage of reducing volume, facilitating storage and decreasing the amount of dimethylsulfoxide (DMSO) and cell lysis products, as well as reducing the number of T-lymphocytes responsible for graft-versus-host disease (GVHD). Using biotinavidin immunoaffinity columns (Ceprate SC system, CellPro; Bothell, WA), CD34+ cells were selected from each of 20 allografts (12 G-CSF-mobilized PB and 8 BM) collected from 14 HLA-identical normal healthy donors for transplantation. After the clinical-scale selection, the median concentration of CD34+ cells was 44.6% (range, 13% to 91%) in BM and 50.4% (range, 15% to 77%) in PB. Whereas 75% of the PB allografts had a CD34+ cell yield of more than 65%, only 37.5% of the BM allografts achieved such a yield, p < 0.01. The number of T-lymphocytes in the selected CD34+ cell allografts was reduced by two to three logs from a median of 4.2 x 10(9) to 7.8 x 10(5) CD3+ cells. The enrichment in CD34+ cells was 240-fold (range, 24- to 382-fold) in PB versus only 34-fold (range, 14- to 108-fold) in BM. Also, the enrichment in clonogenic cells was significantly more in PB (median value of 38.6-fold) than in BM (median value of 19.2-fold) and more in allografts from younger (< 50 years old) rather than older (> or = 50 years old) adult donors. A correlation was found between the percentage of CD34 or CD3+ cells before and after selection (r = 0.58 or r = 0.60, respectively, p < 0.05). Selective enrichment of the colony forming units-granulocyte-macrophage (CFU-GM) was found in all 20 allografts. The progenitor cell recovery after freezing and thawing was similar in BM and PB allografts, with a mean of about 60% for the CFU-GM and BFU-E. In the same six donors, the CD34+ cell yield was significantly more in the PB after mobilization (median 78.5%, range 50% to 90%) than in the BM before mobilization (median 41.5%, range 25% to 87%), p < 0.01. Ten patients with hematologic malignancies have been allotransplanted with 14 of the 20 selected CD34+ cells either combined BM + PB (n = 4) or single (n = 6) grafts. Seven patients did not develop acute GVHD, and only two patients developed > or = grade II GVHD, one of whom developed only grade II GVHD that resolved after brief treatment with corticosteriods. Only one patient showed chronic GVHD (skin and liver). The low incidence and severity of GVHD seen in the present study (only 30%) could be due to the two- to three-log reduction of T-lymphocytes in the selected CD34+ cell allotransplants. All 10 patients had stable hematological recovery, and seven had full donor hematopoiesis. In conclusion, G-CSF-mobilized PB leukapheresis products undergoing selection of CD34+ cells have a greater yield and enrichment of progenitor cells than BM harvests collected from HLA-identical normal healthy donors for allogeneic transplantation. The low incidence and severity of both acute and chronic GVHD (30%) seen in the present study are very encouraging.

Adult↗

Reverse transcriptase/polymerase chain reaction detection of cytokeratin-19 mRNA in bone marrow and blood of breast cancer patients.

A two-step reverse-transcriptase-based polymerase chain reaction (PCR) with nested primer pairs was developed to amplify sensitive and specific cytokeratin-19 (CK-19) mRNA sequences from human breast cancer cells. No CK-19 pseudogene interference was seen. The larger DNA-derived amplification products could be clearly discriminated from mRNA-derived products. The CK-19 message was not amplified from bone marrow or blood of healthy volunteers and patients with haematological malignancies nor from myeloid and lymphoid cell lines. Breast cancer cells were diluted in buffy coat cells up to 10(-6) and CK-19 mRNA sought by PCR. The CK-19 message was detected in 14 of 26 blood samples and 14 of 24 marrow samples but in neither of two peripheral blood stem cell samples taken from 35 breast cancer patients. By sequence-analysis control of two of these samples and two cell lines, the amplified DNA fragments were confirmed to be homologous with the CK-19 sequence. The CK-19 message was further sought in matched blood/marrow samples taken from 13 untreated women in the same cohort at the time of diagnosis. In 3 of these, CK-19 RNA was detected in blood and marrow and, in 3 others, only in blood, but never in marrow alone. The results show that CK-19 assay by reverse transcriptase/PCR is a sensitive and specific technique for the detection of cancer cells in bone marrow and blood. It could be helpful in diagnosis and monitoring of metastatic breast cancer and detection of micrometastases. This should be evaluated on larger numbers of patients, with different clinical samples and epithelial malignancies.

Base Sequence↗

Philadelphia chromosome-positive secondary acute myeloid leukemia following high-dose chemotherapy with peripheral blood progenitor cell support for relapsed low-grade non-Hodgkin's lymphoma.

We report the case of a 47-year-old patient who developed acute myelogenous leukemia (AML) 18 months after receiving high-dose chemotherapy with peripheral blood progenitor cell support (PBPCT) for relapsed low-grade follicular non-Hodgkin's lymphoma (NHL). Cytogenetic analysis of the leukemic cells showed the translocation (9;22)(q34;q11). In three mitoses, an additional Philadelphia chromosome (Ph1) was present. In the literature, Philadelphia chromosome-positive secondary AML has been described only once before in a patient with multiple myeloma.

Acute Disease↗

Comparison of the content and subpopulations of CD3 and CD34 positive cells in bone marrow harvests and G-CSF-mobilized peripheral blood leukapheresis products from healthy adult donors.

Recombinant human granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem/progenitor cells (PBPC) have replaced bone marrow (BM) harvests for autologous transplantation after myeloablative therapy in cancer patients. G-CSF-mobilized PBPC from healthy donors contain one log excess of T lymphocytes representing a potential risk for graft-versus-host disease (GVHD). However, recent pilot clinical studies of G-CSF-mobilized allogeneic PBPC transplantation have shown rapid haematological recovery and no severe acute GVHD except in a very few cases. Therefore, the risk of inducing severe acute GVHD is not as high as was expected during the pioneering period of allogeneic PBPC transplantation. The present study was performed to address the possible reasons for the rapid haematological recovery and the absence of severe acute GVHD observed after allogeneic PBPC transplantation by comparing the contents and subsets of CD3+ and CD34+ G-CSF-mobilized PBPC (n = 31) with those of BM (n = 26) allografts from healthy adult donors. The present results revealed that the phenotypic profiles of CD3+ and CD34+ cells differ between PBPC and BM allografts. The single PBPC leukapheresis product contained 10 times more mononuclear cells, 1.5 times more CD34+ cells, 5.5 times more CD3+ T lymphocytes, 3 times more CD19+ B lymphocytes and 3.8 times more CD14+ monocytes than the single BM harvest. Both CD34+CD33+ myeloid progenitor cells and CD34+HLA-DR-long-term reconstituting haemopoietic stem cells were significantly increased in the CD34+ G-CSF-mobilized PBPC compared with the CD34+ BM cells; median 73.1% and 30.4% vs 60.6% and 5.0%, respectively, P < 0.01. The percentage of CD3+ cells coexpressing CD4 (T helper/inducer) was similar in both PBPC and BM allografts, 47.2% and 45.6%, respectively, whereas the percentage of CD3+ cells coexpressing CD8 (T suppressor/cytotoxic) was significantly decreased in PBPC compared with BM; 37.0% vs 55.9%, p < 0.01. The rapid haematological recovery after allogeneic PBPC transplantation could be due to the increased content of CD34+CD33+ myeloid committed cells and the CD34+HLA-DR-long-term reconstituting haemopoietic stem cells in the PBPC allografts. Also, the absence of an increased risk of severe acute GVHD after allogeneic PBPC transplantation could be due to the increased T lymphocyte ratio of CD4+/CD8+ in the PBPC allografts. In conclusion, rapid haematological recovery without an increased risk of severe acute GVHD can be achieved using G-CSF-mobilized PBPC rather than BM for allogeneic transplantation.

Adult↗