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R Handgretinger

Publications and source records attributed to R Handgretinger.

At least 55 records · Page 3Linked to original sources
PubMed2000

Unrelated peripheral blood stem cell transplantation with 'megadoses' of purified CD34+ cells in three children with refractory severe aplastic anemia.

Three children with refractory severe aplastic anemia were transfused with high numbers of unrelated matched (n = 2) or C-locus haploidentical mismatched (n = 1) CD34-selected peripheral blood stem cells in the absence of an HLA-identical family donor. Two leukaphereses of the donors yielded a median number of 10.1 x 10(10) nucleated cells (range 9.7-15.4) with a median number of 9.89 x 10(8) CD34+ cells (range 7.46-26.1) and a median percentage of CD34+cells of 0.98% (range 0.77-1.7). After positive selection by magnetic cell sorting the patients received a median of 14.3 x 10(6) CD34+ cells/kg (range 11.7-24.3) and of 1.3 x 10(4) CD3+ cells/kg (range 0.57-5.8). Median time to ANC >/=0.5 x 10(9)/l was 7 days (range 7-12) and to platelets >/=20 x 10(9)/l 13 days (range 13-27). Chimerism analysis of peripheral blood after transplantation revealed permanent 100% donor hematopoiesis in all patients. The patient with the C-locus haploidentical mismatch presented with acute GVHD (grade III-IV) of the skin, liver and lower gastrointestinal tract (onset day +40) and died despite intensive immunosuppressive treatment on day +238. The two survivors developed lymphopoietic recovery of B and T lymphocytes within 3 months after transplantation. To our knowledge this experience represents the first report of transplantation with unrelated CD34+ enriched peripheral blood stem cell in children with refractory severe aplastic anemia. Bone Marrow Transplantation (2000) 25, 513-517.

Adolescent↗
PubMed2000

Unrelated partially matched peripheral blood stem cell transplantation with highly purified CD34+ cells in a child with Wiskott-Aldrich syndrome.

Stem cell transplantation is the only curative approach to the treatment of Wiskott-Aldrich syndrome. However, using grafts from partially matched unrelated donors is associated with increased risk of graft rejection and graft-versus-host disease. In an attempt to prevent these problems, a 6-year-old boy with Wiskott-Aldrich syndrome lacking a suitable family donor, was transplanted with large numbers of unrelated highly purified CD34+ peripheral blood stem cells mismatched at one C locus. Conditioning consisted of busulfan 16 mg/kg body weight, cyclophosphamide 200 mg/kg body weight and antithymocyte globulin 20 mg/kg body weight x 3 days. The boy had a rapid hematopoietic engraftment and showed immunologic reconstitution by day +92. Although he did not receive prophylactic immunosuppression he did not develop any graft-versus-host disease and is well and alive up to now, 25 months after transplantation.

Antigens, CD34↗
PubMed2000

Characterization of lineage-specific chimaerism in patients with acute leukaemia and myelodysplastic syndrome after allogeneic stem cell transplantation before and after relapse.

Recently, we have shown that patients with acute leukaemias and myelodysplastic syndromes (MDS), who showed increasing mixed chimaerism (MC) upon serial PCR analysis after transplant, have a significantly increased risk of relapse. To determine whether the increasing MC in these patients is caused by the reappearance of normal recipient haematopoiesis or by the reoccurrence of malignant cells, we purified different leucocyte subpopulations and analysed these subfractions with regard to their donor-recipient ratio by a PCR-based method for the analysis of minisatellite DNA regions. In 14 patients [eight acute lymphoblastic leukaemia (ALL), three acute myelogenous leukaemia (AML) and three MDS] subfractions were analysed when increasing MC was first noted upon serial analysis of the peripheral blood. In seven of these 14 patients (four ALL, two AML and one MDS), subfractions were characterized at the time of frank haematological relapse. In all 14 patients investigated with increasing MC, recipient cells were detected in different mononuclear cell subpopulations. In patients characterized during frank relapse, two distinct distribution patterns were found. Patients who relapsed before day +300 (one ALL, two AML and one MDS) showed recipient-derived (normal) cells in addition to blast populations in different mononuclear subsets as well as granulocytes. In patients with acute leukaemias who relapsed after day +300 (two ALL and one AML), only leukaemic cells were found that were of recipient origin, whereas all other haematopoietic cell lines were donor derived. These data show that persistent MC in the early post-transplant period is caused predominantly by normal recipient haematopoietic cells. This finding further supports the hypothesis that a state of mixed haematopoietic chimaerism may reduce the clinical graft-versus-leukaemia (GVL) effect of alloreactive donor-derived effector cells in patients with acute leukaemias and MDS, and thus facilitate the proliferation of residual malignant cells that may have survived the preparative regimen.

Adolescent↗
PubMed2000

OKT-3-based reconditioning regimen for early graft failure in HLA-non-identical stem cell transplants.

Primary non-engraftment or early rejection after transplantation of haematopoietic stem cells represent life-threatening complications of allogeneic stem cell transplantation. Management of early graft failure has been problematic, as the risk of fatal infectious complications increases with the time of pancytopenia and as a second transplant preceded by a conventional myeloablative conditioning regimen has been associated with high rates of cumulative organ toxicity. For paediatric patients with early graft failure following the transplantation of highly purified major histocompatibility complex (MHC)-disparate haematopoietic stem cells, we have evaluated an immunosuppressive OKT-3/methylprednisolone-based reconditioning regimen with low toxicity in preparation for a secondary transplant of purified haematopoietic stem cells from the same donor. This report presents the results from a 4-year pilot study including six patients with early graft failure. The results demonstrate that this antibody-based regimen can be used effectively to prepare patients for secondary transplantation. Successful engraftment after a second transplant procedure was achieved in five of these six high-risk patients. The median interval between first and second transplant was 27 d (range 22-51 d), and the median time for engraftment was 10 d (range 9-13 d). Chimaerism analysis of microsatellite regions by polymerase chain reaction (PCR) demonstrated complete donor chimaerism in four of these patients within the first month after secondary transplant and revealed mixed chimaerism in one patient who converted to complete chimaerism after T-cell add-back.

Adolescent↗
PubMed1999

Transplantation of megadoses of purified haploidentical stem cells.

Peripheral mobilized parental CD34+ progenitors were isolated and used for the hematopoietic reconstitution after a myeloablative therapy in 23 pediatric patients with various diseases. Fourteen donors were human leukocyte antigen (HLA) three-loci mismatches, 6 donors were two-loci and 3 donors were one-locus mismatches. For depletion of T-lymphocytes, a positive selection of the mobilized peripheral CD34+ progenitors using the method of magnetic-activated cell sorting (MACS) was used. The purity of the CD34+ cells after MACS-sorting was 98-99%, the average number of transplanted CD34+ cells was 14.2 x 10(6)/kg (range 5.4-3.9 x 10(6)/kg) and the average number of infused T-lymphocytes was 1.4 x 10(4)/kg. Due to this low T cell number, only a short-term or no prophylaxis of graft-versus-host disease (GVHD) was necessary and no GVHD was seen. A significant GVHD was only seen in patients after add-back of donor T-lymphocytes, which was performed in some patients for prevention of relapse or in patients who showed a transient mixed chimerism. Since the B lymphocyte contamination of the isolated CD34+ cells was low in the range of 0.2%, no Epstein-Barr virus (EBV)-associated lymphoproliferative syndrome was observed. A primary engraftment was seen in 18 patients. Nonengraftment and rejection occurred in three and two patients, respectively. In four of these 5 patients, a second transplant using purified CD34+ cells from the same donor after an immunological reconditioning regimen resulted in a complete and sustained hematopoietic reconstitution. The speed of the immunological recovery was dependent on the number of transplanted CD34+ cells and was more rapid if this number was > 20 x 10(6)/kg. Eleven of the 23 patients are alive and disease free with a median follow-up of 12 months (range 2-30). The main cause of death was relapse (7 patients), and only one fatal infection was seen. Our data suggest that the transplantation of megadoses of haploidentical CD34+ cells is a realistic therapeutic option for patients who otherwise have no suitable donor, and an alternative to the use of unrelated cord blood.

Adolescent↗
PubMed1999

A subset of CD56+ large granular lymphocytes in first-trimester human decidua are proliferating cells.

OBJECTIVE: To determine whether the unusually high number of CD56+ large granular lymphocytes (LGL) in the decidua of early human pregnancy arises from selective migration or in situ proliferation. DESIGN: Controlled clinical study. SETTING: Academic research environment. PATIENT(S): Thirty healthy women undergoing therapeutic abortion of an intact pregnancy at 5-11 weeks' gestation. INTERVENTION(S): Decidua was obtained by suction curettage; tissue and isolated cells were subjected to immunohistochemical and flow cytometric investigation. MAIN OUTCOME MEASURE(S): Proliferation rate of LGL. RESULT(S): The proportion of CD56+ cells positive for the proliferation-associated Ki-67 antigen was found to be 7%-23.5% by three different methods of investigation. These findings are consistent with those of flow cytometric analysis of the nuclear phase, which revealed 6%-22% of the LGL nuclei to be in the phases S+G2+M. CONCLUSION(S): The various methods of investigation revealed marked proliferative activity in the LGL of early pregnancy decidua. This finding suggests that in situ proliferation may be responsible for the high density of these cells in the decidua.

Adult↗
PubMed1999

Clinical scale isolation of highly purified peripheral CD34+progenitors for autologous and allogeneic transplantation in children.

We present our experience with three clinical scale isolation methods for positive selection of CD34+ progenitors from peripheral blood for autologous and allogeneic transplantation in children. A combination of the CellPro device and the Magnetic Activated Cell Sorting system (MACS), as well as two different combinations of MACS systems were used (VarioMACS-SuperMACS and SuperMACS-SuperMACS). With the CellPro-MACS combination (16 separations), a median purity of 96.2% and a median recovery of 42% CD34+ cells could be achieved, whereas the two step MACS systems (55 and 29 separations) showed a median purity of 97.6% and 98.0% and a median recovery of 96.5% and 97%, respectively. Depletion of T cells was profound (4-5 log). A total of 34 patients in the autologous and 18 patients in the allogeneic setting have been transplanted with highly enriched CD34+ cells, obtained by these methods. Only one patient failed to engraft, all other patients showed a rapid and sustained hematological engraftment with the longest follow-up of 3 years. In summary, especially the two step MACS systems have proven to be appropriate tools for enrichment of CD34+ cells, yielding both high purity and good recovery, and can thus be used for tumor cell purging in the autologous setting and for effective T cell depletion in the allogeneic setting.

Adolescent↗
PubMed1999

Transplantation of highly purified peripheral blood CD34+ cells from HLA-mismatched parental donors in 14 children: evaluation of early monitoring of engraftment.

HLA-mismatched family members may represent an important cell source for patients that require stem cell transplantation but lack both a matched sibling donor and a closely matched unrelated donor. We report the outcome of 19 transplantations from HLA two- or three- loci mismatched parental donors in which 14 pediatric patients with hematological malignancies or other disorders, received a median of 21.5 x 106 (range, 5.4-58) highly purified CD34+peripheral blood stem cells (PBSC), as well as 4.7 x 104 (range, 0.4-12) donor T cells per kg body weight. T cell depletion was performed using a two-step CD34-positive selection on two different magnetic beads devices. Ten of 14 patients presented with rapid myeloid engraftment. The four patients who presented with graft failure (two non-engraftments, two rejections) received a second stem cell graft and one a third. Graft rejection was detected early by polymerase chain reaction (PCR) analysis of FACS-sorted T cells. Eight of the 14 patients are still alive after a median observation period of 15. 6 months (range, 3-31.3) with full donor chimerism in all hematopoietic cell lineages. No acute organ graft-versus-host disease (GVHD) and no chronic GVHD have occurred. One patient experienced relapse of leukemia. We conclude that transplantation of allogeneic PBSC from haploidentical donors will open new perspectives for pediatric patients for whom an HLA-matched stem cell graft is not available. Close monitoring of recipient and donor hematopoiesis might be of clinical value, to recognize early engraftment or rejection.

Adolescent↗
PubMed1999

Prevention of relapse in pediatric patients with acute leukemias and MDS after allogeneic SCT by early immunotherapy initiated on the basis of increasing mixed chimerism: a single center experience of 12 children.

The success of allogeneic stem cell transplantation (allo-SCT) in children is mainly affected by relapse or graft rejection. We have recently shown in a study of 55 patients with acute leukemias (ALL 21, AML 20 and MDS 14), that patients who demonstrate increase amounts of autologous marrow repopulation (increasing mixed chimerism) have a significantly enhanced risk of relapse (P < 0. 0001). Based on these findings, we asked whether post-transplant relapse can be prevented by withdrawal of immunosuppression and/or by donor lymphocyte infusion (DLI). We describe the results of a pilot study where adoptive immunotherapy was used to treat 12 patients (five ALL, three AML, four MDS) who showed increasing mixed chimerism (MC) post-transplant. A response to immunotherapy, defined as the re-establishment of complete chimerism (CC) and continuous complete remission (CCR), was achieved in four patients (two ALL, two AML) following withdrawal of CsA and in a further six patients (three ALL, three MDS) after additional DLI. One ALL patient, who initially responded to DLI, developed severe GVHD that required further immunosuppression. GVHD was controlled but this patient subsequently relapsed. Another patient with ALL became a CC but developed an isolated relapse in the bone marrow 260 days later. One patient with MDS developed severe GVHD after DLI and died. Two children (one AML and one MDS) did not show any response to interventional treatment and died due to relapse. Of the 12 patients treated, seven remain in CCR at a median follow-up of 747 days (range 351-1109 days). In summary, these results provide evidence that increasing MC can be used to guide adoptive immunotherapy strategies and that these treatment modalities can be used to prevent relapse in children with acute leukemias or MDS after allo-SCT.

Adolescent↗
PubMed1999

Constitutional mutations of the hSNF5/INI1 gene predispose to a variety of cancers.

Biallelic, truncating mutations of the hSNF5/INI1 gene have recently been documented in malignant rhabdoid tumor (MRT), one of the most aggressive human cancers. This finding suggests that hSNF5/INI1 is a new tumor-suppressor gene for which germline mutations might predispose to cancer. We now report the presence of loss-of-function mutations of this gene in the constitutional DNA from affected members but not from healthy relatives in cancer-prone families. Furthermore, a constitutional mutation is documented in a patient with two successive primary cancers. In agreement with the two-hit model, the wild-type hSNF5/INI1 allele is deleted in the tumor DNA from mutation carriers. In all tested cases, DNA from parents demonstrated normal hSNF5/INI1 sequences, therefore indicating the de novo occurrence of the mutation, which was shown to involve the maternal allele in one case and the paternal allele in two other cases. These data indicate that constitutional mutation of the hSNF5/INI1 gene defines a new hereditary syndrome predisposing to renal or extrarenal MRT and to a variety of tumors of the CNS, including choroid plexus carcinoma, medulloblastoma, and central primitive neuroectodermal tumor. This condition, which we propose to term "rhabdoid predisposition syndrome," may account for previous observations of familial and multifocal cases of the aforementioned tumor types. It could also provide the molecular basis for cases of Li-Fraumeni syndrome without p53 germline mutations.

Chromosomal Proteins, Non-Histone↗
PubMed1999

Comprehensive restriction analysis of the UL97 region allows early detection of ganciclovir-resistant human cytomegalovirus in an immunocompromised child.

Children with innate immunodeficiencies may be at high risk for early development of ganciclovir-resistant human cytomegalovirus (HCMV) infection after bone marrow transplantation (BMT). For early and frequent monitoring of the occurrence of ganciclovir resistance-associated mutations in codons of the UL97 gene, a panel of previously described restriction assays was expanded for use on codons 591, 592, and 603. This technique enabled detection of suddenly emerging ganciclovir-resistant HCMV after BMT in a 7-year-old child with a T cell defect. Resistance emerged among the isolation of a ganciclovir-sensitive HCMV strain 32 days after transplantation, the first detection of genotypical resistance at day 44, and the isolation of resistant HCMV (ID50>12 microM) at day 54. Simple and yet comprehensive methods for therapy surveillance may be important in this patient group, in which the restriction assays proved useful.

Antiviral Agents↗
PubMed1999

Isolation of highly purified autologous and allogeneic peripheral CD34+ cells using the CliniMACS device.

The CliniMACS CD34+ selection device was used for positive selection of apheresis products for autologous transplantation from 10 patients with malignant diseases and for allogeneic transplantation from 26 healthy donors. A total of 71 separations were performed. In 1 allogeneic donor, CD34+ progenitors were also isolated from bone marrow. Between 0.27 and 8.9 x 10(10) nucleated cells (median 4.9 x 10(10)) containing 0.09%-10.8% (median 0.67%) CD34+ progenitor cells were separated. After separation, a median number of 227 x 10(6) mononuclear cells (MNC) (51-524) were recovered, with a median viability of 99% (22%-100%) and a median purity of 97.0% (68.3%-99.7%) CD34+ cells. Depletion of T cells was extensive, with a median of 0.04% residual CD3+ cells (range <0.01%-0.92%). Residual CD19+ cells were between <0.01% and 17%, including CD34+CD19+ cells. Recovery of CD34+ cells was calculated according to the ISHAGE guidelines and ranged from 24% to 105% (median 71%). We conclude that with the CliniMACS device CD34+ cells with high purity and recovery can be isolated with concomitant effective T cell depletion in the allogeneic setting and with a high purging efficacy in the autologous setting.

Antigens, CD34↗
PubMed1999

Detection of circulating melanoma cells by immunomagnetic cell sorting.

We developed a cellular approach to the identification of circulating melanoma cells in peripheral blood using immunomagnetic cell sorting. One hundred seventy-eight blood samples from 129 melanoma patients and 30 samples from healthy persons and nonmelanoma patients were examined. After density gradient centrifugation the interphase was incubated with the mAb 9.2.27. Positive cells were labeled with magnetic microbeads and enriched by immunomagnetic cell sorting. Cells were stained using an alkaline phosphatase-antialkaline phosphatase assay and examined by light microscopy. In spiking experiments, melanoma cells seeded at a concentration of one melanoma cell per ml whole blood could be detected reliably with the assay. Circulating melanoma cells were not found in 30 controls examined, nor were 9.2.27-positive cells found in 41 patients with primary malignant melanoma. In patients with regional lymph node metastases and in patients with disseminated disease, circulating 9.2.27-positive cells could be detected in 3 out of 22 patients (13.6%) and 10 out of 66 patients (15.2%) examined. We present a sensitive and specific immunocytological approach to detect circulating melanoma cells in peripheral blood. The method is not suitable for early detection of metastases but is a valuable tool for further investigating biological characteristics of circulating melanoma cells.

Antibodies↗