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Biomedical subjects

C Gattringer

Publications and source records attributed to C Gattringer.

At least 19 recordsLinked to original sources
PubMed1999

Recombinant human granulocyte-macrophage colony-stimulating factor applied locally in low doses enhances healing and prevents recurrence of chronic venous ulcers.

BACKGROUND: Chronic venous leg ulcers have a major medical and economic impact on the elderly worldwide. Healing of the large ulcers (>10 cm2) occurs only in two-thirds of the patients and reulceration of healed ulcers recurs in one-third within 1 year. Because both healing and relapse rate influence greatly a patient's quality of life and the overall cost of treatment, every effort should be made to improve these two parameters. OBJECTIVE: To determine the safety and efficacy of topical low-dose recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) for the treatment of venous ulcers, and to document any improvement in healing rates. METHODS: Thirty-eight patients (29 women, 9 men; median age, 74 years) with chronic venous insufficiency were treated with topical rhu GM-CSF (5 microg/mL 0.9% sodium chloride solution), followed by application of a compression dressing. All subjects were treated as outpatients. RESULTS: Complete healing was observed in 47 of the 52 ulcers (90.4%). The average healing time was 19 weeks. No systemic or local side-effects from the therapy were observed. Nine chronic ulcers, previously refractory to conventional treatment (pretreatment for more than 46 weeks), showed the same response rate (9/8, or 88.9%) and healing time (mean, 19 weeks). After 40 months, no reulceration of the healed ulcers was observed, but two patients developed new ulcers on the same leg. Healing remained stable, with excellent cosmetic results. CONCLUSIONS: In this first study, topically applied low-dose rhu GM-CSF was a safe treatment for chronic venous leg ulcers. Healing rates were significantly increased and relapse rates were minimal.

Administration, Cutaneous↗
PubMed1996

CD4 monoclonal antibody VIT4 in human alloimmune response in vitro and in vivo.

In the present report the immunosuppressive effects of the murine anti-human CD4 monoclonal antibody (mAb) VIT4 on human alloimmune response in vitro were analyzed. Moreover, the antibody was tested for its activity to prolong allograft survival in seven patients with steroid-refractory allograft rejection. VIT4 inhibited the proliferative response to alloantigens in the mixed lymphocyte reaction (MLR) in a dose-dependent manner. At concentrations of 1 and 10 micrograms/ml VIT4 blocked MLR by 55 +/- 11% and 77 +/- 1%, respectively. Also alloantigen-specific proliferation of in vitro- generated memory T cells was dose-dependently reduced to 23 +/- 1% at a VIT4 concentration of 100 micrograms/ml. Furthermore, at the same dose level VIT4 blocked proliferation of antigen-specific short-term alloreactive CD4+ cell lines and significantly inhibited the in vitro generation of cytotoxic T lymphocytes (CTL). In a pilot study VIT4 (5 mg/d i.v.) was administered to 7 patients with steroid-refractory allograft rejection for 14 days. In 4 of 7 patients graft function transiently improved and graft survival in all patients was prolonged to a mean of 694 days (range 128-2163) from the beginning of the VIT4 treatment. In the light of our in vitro results and the preliminary clinical data, further clinical trials using higher antibody doses are greatly warranted to assess the efficacy of anti-CD4 mAb VIT4 in the treatment of allograft rejection.

Animals↗
PubMed1996

An unusual case of a splenic gamma/delta T-cell lymphoma with angiocentric tendency and haemophagocytic syndrome.

We report here an unusual post-thymic T-cell neoplasia of the spleen associated with a rapidly progressive haemophagocytic syndrome. The lymphoma was classified as a medium- to large sized pleomorphic T-cell lymphoma with angiocentric tendency (CD3+, CD43+, CD45RO+ CD45+). Clonality was confirmed by PCR and revealed rearrangement of the T-cell receptor gamma chain. Serological tests excluded a recent EBV infection and in situ hybridization with the EBER probe was negative. Haemophagocytic syndrome was the initial finding in an otherwise symptomless patient and this deteriorated with progression of the T-cell malignancy. Both, the T-cell lymphoma and the haemophagocytic syndrome remained unaffected by chemotherapy. Splenic gamma/delta T-cell lymphoma associated with haemophagocytosis is an uncommon entity which has until now not been widely recognized.

Aged↗
PubMed1993

Flow cytometric detection of cytoplasmic antigens in acute leukemias: implications for lineage assignment.

This study aimed at optimizing the conditions for flow cytometric detection of myeloperoxidase (MPO), cytoplasmic CD3 (cCD3), and cytoplasmic CD22 (cCD22), which seem to be more reliable lineage-associated markers in acute leukemia than surface antigens. Fixation methods employing saponin as detergent resulted in accurate detection of MPO and cCD3, whereas cCD22 was detectable only after buffered-formaldehyde-acetone fixation. MPO was detected in 16/17 AML, but only in 1/6 ALL, the MPO positive ALL being also CD13 positive. MPO was detectable in 3/4 AML with T-lymphoid features; a case of myeloid antigen-positive T-ALL, however, was MPO-negative. cCD3 was expressed only in T-ALL, and five cases of lymphoid antigen-positive AML were cCD3-negative. We suggest that these flow cytometric assays are useful for the lineage assignment of poorly differentiated leukemias and contribute to the identification of truly biphenotypic acute leukemias.

Acute Disease↗
PubMed1993

Long-term follow-up of patients with hairy cell leukaemia treated with pentostatin: lymphocyte subpopulations and residual bone marrow infiltration.

Peripheral blood lymphocyte (PBL) subsets and bone marrow biopsies were analysed in six patients with hairy cell leukaemia (HCL) treated with 2'-deoxycoformycin (pentostatin, DCF) according to a phase II trial of the EORTC Leukemia Cooperative Group. All patients responded to DCF with four complete and two partial remissions according to conventional criteria. Within the PBL subsets, major changes concerned the CD4+ T cells, which during DCF therapy were distinctly suppressed to nadir values of 0.038-0.18 (median 0.126) x 10(9)/l. In five patients these cells returned to normal 3.0-49.5 (median 14.5) months after the last DCF injection. CD8+ cells were decreased to a lesser extent, and NK cell numbers improved during treatment. Bone marrow immunohistology applying the MoAb B-ly7 demonstrated residual hairy cells (HCs) in all of the six patients following DCF treatment with nadir HC numbers of 0.2-3.0% of bone marrow cells. Immunoglobulin gene rearrangement analysis of DNA obtained from these biopsies showed only germline bands, whereas rearranged bands had been present on the pretreatment specimens. Within the observation period of 15.5-54.0 (median 47.0) months after discontinuation of DCF therapy, immunohistology demonstrated a continuous increase in HC numbers in five of the six patients with clonal rearrangement detectable in bone marrow specimens from three of these patients at last follow-up date. Although established on the basis of a small number of patients, these data suggest that DCF treatment as currently employed in HCL is unable to eradicate the malignant B cell clone.

Adult↗
PubMed1992

Subpopulations of normal peripheral blood and bone marrow cells express a functional multidrug resistant phenotype.

The multidrug-resistance gene, MDR1 is expressed in many normal tissues, but little is known about its expression in normal hematopoietic cells. Using the monoclonal antibody C219 and flow cytometric analysis, P-glycoprotein (P-gp) was found to be expressed in all peripheral blood (PB) subpopulations (CD4, CD8, CD14, CD19, CD56) except granulocytes. To specifically determine MDR1 gene expression, these PB subpopulations were isolated by fluorescence-activated cell sorting (FACS) and analyzed for MDR1 mRNA by polymerase chain reaction (PCR). All subsets were positive by PCR, but only minimal MDR1 mRNA was detected in monocytes and granulocytes. Significant efflux of Rhodamine-123 (Rh-123), a measure of P-gp function, was detected in CD4+, CD8+, CD14+, CD19+, and CD56+ cells but not in granulocytes. Next, PCR-analysis was performed on FACS-sorted bone marrow (BM) cells to assess MDR1 expression in different maturational stages. Precursors (CD34+), early and late myeloid cells (CD33+/CD34+, CD33+/CD34-) as well as lymphocytes of the B-cell lineage (CD19+/CD10+, CD19+/CD10-) expressed the MDR1 gene. BM monocytic cells (CD33++/CD34-) were negative, and a very weak signal was detected in erythroid cells (glycophorin A+). Significant Rh-123 efflux was found in CD34+, CD10+, CD33+, and CD33++ BM cells, but not in glycophorin A+ cells. We conclude that PB and BM lymphocytes, PB monocytes, BM progenitors, and immature myeloid cells, but not late BM monocytes, erythroid cells, and PB granulocytes, express MDR1 mRNA and a functional P-gp. These results have to be taken into account when MDR1 expression is determined in tumor samples containing normal blood cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Flow cytometric determination of atypical antigen expression in acute leukemia for the study of minimal residual disease.

The aim of this study was to investigate to which extent acute leukemias could be monitored for residual disease by using atypical antigen combinations as leukemia-related markers. Atypical antigenic features were determined by double color flow cytometry and included coexpression of lymphoid and myeloid related antigens, unphysiological coexpression of immature and mature antigens, and lack of an antigen that is normally expressed during maturation. Atypical immunophenotypes were detected in 35 of 68 patients with AML (51.5%) and 15 of 24 patients with ALL (62.5%). When 12 patients with leukemia-associated markers were again analyzed at relapse, the relevant antigen combinations were retained in 11 of them. The sensitivity of this two color flow cytometric assay as determined in dilution experiments was 1 in 10(3) to 10(4) cells. Follow-up studies of bone marrow samples revealed that, after induction chemotherapy cells with leukemia-associated markers were detectable in several patients at a frequency of 0.5 to 4%, but only patients in whom the cells with atypical antigens never disappeared suffered from relapse. In contrast, patients who became negative for the atypical cells remained in complete remission (median remission duration after the first negative bone marrow assessment by flow cytometry 52 weeks, range 20-102). We conclude that atypical antigen combinations, which are present in a meaningful number of acute leukemias, are a valuable means of monitoring acute leukemia patients during follow-up. This flow cytometric approach can complement other strategies to get a more accurate definition of remission in acute leukemia.

Acute Disease↗
PubMed1992

Surface immunoglobulin density in the differential diagnosis of B-cell chronic lymphocytic leukemia and leukemic immunocytoma.

Using flow cytometry peripheral blood samples of 37 consecutive patients with B-cell chronic lymphocytic leukemia (B-CLL) and 17 consecutive patients with leukemic immunocytoma (IC) were studied in order to determine quantitative differences in the surface immunoglobulin (slg) density. In 8/37 (21.6%) cases of B-CLL and 1/17 (5.9%) cases of IC slg staining remained in the control level. Analysis of slg-positive cases demonstrated a close association between the amount of slg and diagnosis: per case the mean calculated fluorescence intensity for IC lymphocytes was 209.7 arbitrary linear intensity units (IU) (median: 156.4, standard error of the mean (SEM): 53.7) and for B-CLL lymphocytes 10.8 IU (median: 7.3, SEM: 1.1; p less than 0.0001). Altogether, 94.6% of all B-CLL patients and 76.5% of all IC patients were correctly classified when a cut-off point was fixed at a mean fluorescence intensity value of 20.0 IU. The percentage of leukemic cells as characterized by CD19 and HLA-DR reactivity was significantly lower in cases of IC (p less than 0.03 and p less than 0.01, respectively). In both entities disease progression occurred more frequently in advanced stages (II-IV) according to the Rai classification (p less than 0.01). In progressive disease rather than in stable disease circulating T lymphocytes were shown to express decreased amounts of surface CD3 antigen (p less than 0.02). We conclude that the quantitative assessment of surface antigens in addition to their qualitative characterization provides accurate information. In particular, the diagnostic discrimination between B-CLL and IC may be improved by determining the lymphocytes' slg amount.

Antigens, CD↗
PubMed1992

Direct demonstration of binding of aggregated mouse IgG1 to the 40-kDa Fc receptor for IgG (Fc gamma RII) in both high and low responders.

Several directly fluorochrome-conjugated murine monoclonal antibodies (mAb) of the IgG1 subclass and directed against B or T cell antigens were found to bind to monocytes via the 40-kDa Fc receptor for IgG (Fc gamma RII). As expected from the established polymorphism of Fc gamma RII, strong staining was observed in about 75% of individuals. In the remaining 25% staining was clearly weaker, but could be definitely demonstrated with a mAb against the B cell-specific CD19 differentiation antigen. Specificity of binding to Fc gamma RII was confirmed by the ability to block the binding of the CD19 mAb by pre-incubation with aggregated IgG1 or with mAb against Fc gamma RII. The extent of T cell proliferation induced with a CD3 mAb of the IgG1 isotype (a-Leu 4), which is dependent on the interaction of monocyte Fc gamma RII with the Fc portion of the CD3 mAb, exactly correlated with the amount of binding to Fc gamma RII in all individuals. Proliferation was dose-dependent for both high and low responders; cells of low responders did not proliferate at concentrations below 16 ng/ml of mAb, whereas there was a small but unequivocal proliferation at higher concentrations. These results confirm that monocytes from previously characterized "non-responders" are able to bind aggregated murine IgG1 via Fc gamma RII. They also demonstrate that directly labeled mAb can cause extensive nonspecific staining which may not be excluded by the use of control antibodies of the same isotype.

Animals↗
PubMed1992

Detection of activity of P-glycoprotein in human tumour samples using rhodamine 123.

Based on the fluorescent properties of the dye rhodamine 123 (Rh123), which is transported by the membrane efflux pump P-glycoprotein (P-gp), we developed a functional flow cytometric assay for the detection of multidrug-resistant (MDR) cells. Using drug sensitive cell lines (KB-3-1) and MDR mutants (KB-8-5, KB-C1) experimental conditions were established that enabled demonstration of significant differences in Rh123 efflux and accumulation. Subsequently we investigated the applicability of this functional assay for the prediction of MDR in human peripheral blood and bone marrow samples. Using two-colour flow cytometry, the leukaemic blast cells of six patients suffering from acute myeloid leukaemia (AML) were analysed. In three cases the blast cells showed a rapid and marked Rh123 efflux. In the presence of MDR inhibitors these cells retained Rh123. To determine whether the efflux of Rh123 was associated with P-gp expression, the leukaemic cells were stained with the monoclonal antibody MRK-16. In addition extracted RNA was analysed by polymerase chain reaction to evaluate the expression of mdr 1 mRNA. In all three Rh123+ cases mdr 1 mRNA was detectable whereas only one AML case expressed P-gp. In comparing Rh123 with daunorubicin, which also allows the detection of MDR cells, accumulation studies proved Rh123 to be the more sensitive drug for flow cytometric MDR screening. Additionally, two-colour flow cytometry was much easier to perform with Rh123 than with daunorubicin. Our results indicate that flow cytometric measurement of Rh123 accumulation/efflux proves applicable to detect MDR cells in heterogenous clinical samples.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

[Recombinant interferon alpha-2c in Ph-positive chronic myeloid leukemia. Results of a multicenter phase II study].

In a Phase II study, 82 patients with Philadelphia chromosome(Ph)-positive chronic myelogenous leukaemia were treated with 3.5 million I.U./d of recombinant interferon alpha-2c (rIFN). 73 patients have so far been evaluated (42 male, 31 female, mean age 50 [12-87] years). At the start of therapy, 10 were in the accelerated phase (group 1) and 63 in the chronic phase, of whom 19 had received previous treatment with cytotoxics (group 2), while the remainder (group 3, n = 44) had received primary treatment with rIFN. There was short-term stabilization in 7 of the 10 group 1 patients, but none had complete haematological or cytogenetic remission. In contrast, the remission rate (complete or partial haematological remission) was 63% in the previously treated (group 2) and 66% in the previously untreated chronic phase patients (group 3). There was a reduction in the proportion of Ph-positive metaphases in 7 group 2 patients (11%) and in 10 group 3 patients (23%). Complete cytogenetic remission has so far been seen in 2 patients. Cytogenetic improvement occurred after 3 months at the earliest, and in some patients only after 12 to 19 months treatment. Differences in response to treatment were related to stage (prognostic staging system of Kantarjian et al.) in group 3 patients: complete or partial haematological remission was seen in 22 out of 25 patients with stage 1 disease, in 4 out of 7 in stage 2, and in only 3 out of 12 in stages 3 and 4.

Adolescent↗
PubMed1991

Combined flow cytometric assessment of cell surface antigens and nuclear TdT for the detection of minimal residual disease in acute leukaemia.

To define more precisely the immunophenotype of lymphoid blast cells, a new flow cytometric technique for the simultaneous detection of surface antigens and nuclear terminal deoxynucleotidyl transferase (TdT) was established. After staining for the cell surface marker, mononuclear cells were treated with paraformaldehyde (1%) and methanol to permeabilize the cell membrane. Then the cells were stained by indirect immunofluorescence using a rabbit anti-human TdT antibody. Dilution experiments were performed to reveal the sensitivity of the described flow cytometric assay: 0.02% leukaemic cells could reliably be detected above background level among normal peripheral blood lymphocytes. It is concluded that the double-staining procedure described here is a sensitive tool that contributes to the detection of minimal residual disease in a substantial proportion of acute leukaemias.

Antigens, Neoplasm↗