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G C Faure

Publications and source records attributed to G C Faure.

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

Impact of immunophenotyping on management of acute leukemias.

BACKGROUND AND OBJECTIVE: The diagnosis of acute leukemias (AL) requires a multiparametric approach in order to apply risk-adapted therapeutic protocols and appreciate the potential outcome of any given patient. Blast cells immunophenotyping is a key test in this issue, yet the information provided by immunophenotyping has become staggering, and it may be difficult to identify relevant characteristics clearly. This manuscript provides a critical review of the literature regarding the importance of immunophenotyping in acute leukemia diagnosis and management. DATA SOURCES AND METHODS The information given here is based on the experience of the authors, on their literature files and on additional material retrieved through articles and reviews covered by the Institute for Scientific Information (ISI) and the Medline database. Studies with proper definition of the patients and sufficient information regarding follow-up were considered. RESULTS: Immunophenotyping allows an early confirmation of AL diagnosis and establishes lineage assignment. Adequate and comprehensive panels of monoclonal antibodies also allow detection of aberrant immunophenotypic profiles of prognostic value or of use in detecting minimal residual disease. A number of unusual immunophenotypic features are also associated with prognosis. The development of new antibodies, new insights in the functional properties of differentiation antigens, and the quantimetric approach of immunophenotyping will keep this field changing. Moreover, as therapeutic protocols evolve, some earlier results need to be reconsidered. INTERPRETATION AND CONCLUSIONS: Immunophenotyping, together with cytologic, karyotypic and molecular approaches, retains a crucial place in the diagnosis and management of acute leukemias. It remains a rather specialized approach and should be interpreted in a multidisciplinary perspective, considering for each patient the idiosyncrasies possibly relevant to prognosis.

Acute Disease↗
PubMed1998

The use of skin testing in the investigation of cutaneous adverse drug reactions.

Skin testing with the suspected compound has been reported to be helpful in determining the cause of cutaneous adverse drug reactions (ADRs), but the value and specificity of these tests need to be determined. In this study, 72 patients with presumed drug eruptions (27 maculopapular, 18 urticarial, seven erythrodermic, nine eczematous, four photosensitivity, three fixed drug eruptions, three with pruritus and one with acute generalized exanthematous pustulosis) were assessed. All had drug patch tests; 46 also had prick tests and 30 had intradermal tests (performed on hospitalized patients using a sterile solution of the suspected drug, diluted sequentially) with immediate and delayed readings. Among these patients, 52 (72%) had a positive skin test reaction, 43%, 24% and 67% in patch, prick and intradermal skin tests, respectively. The results of skin tests varied with the drug tested and with the clinical type of cutaneous ADR, as a significantly higher number of positive patch tests was observed in maculopapular rashes than in urticarial reactions (P = 0.001). This study supports the value of careful sequential drug skin testing in establishing the cause of cutaneous ADR. Guidelines are proposed for performing these tests, and these include the use of appropriate negative control patients to avoid false-positive results.

Adult↗
PubMed1998

Automated cell count in flow cytometry: a valuable tool to assess CD4 absolute levels in peripheral blood.

The enumeration of lymphocyte subsets in absolute counts has long relied on different methods applied separately to whole blood cell count, lymphocyte differential appreciation, and flow cytometric evaluation of lymphocyte subsets percentages. The development of multicolor labeling methods inflow cytometry now allows a more homogeneous appreciation of several cell subsets among gated lymphocytes. The use of internal calibrators, such as microbead suspensions, also permits a direct appreciation of subsets in absolute counts in a single-platform method. These methods were compared with a traditional multiplatform method of assessing absolute counts of lymphocyte subsets in a pilot study in which all manipulations were performed by 1 person and in a full-scale larger study performed in the normal working conditions of a hospital laboratory. Microspheres seem to be a reliable tool to perform absolute count enumeration inflow cytometry, but several precautions in the sample preparation and flow cytometric analysis are required.

Antibodies, Monoclonal↗
PubMed1998

High levels of soluble intercellular adhesion molecule-1 (ICAM-1) in crevicular fluid of periodontitis patients with plaque.

The intercellular adhesion molecule-1 (ICAM-1) is a membrane-bound molecule involved in cell-cell adhesive interactions which is upregulated on inflammatory epithelial cells. The levels of soluble ICAM-1 (sICAM-1) shed into the gingival crevicular fluid (GCF) were studied in healthy patients and patients with gingivitis, adult periodontitis or rapidly progressive periodontitis, using an ELISA technique. Clinical parameters including plaque index, gingival index, probing depth, and bleeding on probing were recorded following careful sampling of GCF with standardised filter strips. In GCF, sICAM-1 levels were higher for patients with plaque (p=0.04) and for patients with inflammation (p=0.02), but did not correlate with disease classifications. These results suggest that elevated GCF sICAM-1 levels may represent increased shedding of this molecule in the interstitial fluid as a result of membrane-bound ICAM-1 upregulation on ICAM-1 gingival-bearing cells in relation with plaque accumulation and inflammation.

Adolescent↗
PubMed1998

Maturation of B cells in the lamina propria of human gut and bronchi in the first months of human life.

Little is known of the maturation of the mucosae-associated lymphoid tissue (MALT) in man, because, for ethical reasons, tissues from newborns are not easy to obtain. We used the opportunity provided by autopsies systematically performed in infants who died of Sudden Infant Death Syndrome (SIDS) to study the maturation of the MALT after birth. Gut and bronchus samples of 90 infants from postpartum to 90 months and who died from SIDS were collected and studied by histological and immunofluorescence examination. Plasma cells, absent at birth, appeared within a few hours after birth and initially were of the IgM isotype. IgA plasma cells appeared at 12 days. These cells were first observed in gut and later in bronchi, indicating that maturation of the gut precedes that of bronchi. The number of plasma cells increased rapidly over time and IgA plasma cells became predominant after 3 weeks in the gut and 6 weeks in bronchi. At birth, only small IgM bearing B-cell foci were seen and organized germinal centers appeared to develop over a few days, first in the gut and only later in bronchi. These results confirm that, in man, the MALT organization at birth is still in its fetal form and that maturation depends on intestinal challenges and evolves over several weeks before IgA becomes the predominant isotype secreted.

B-Lymphocytes↗
PubMed1998

Activation of epithelial cells in gastritis.

BACKGROUND: Helicobacter pylori is now recognised to be the major cause of antral gastritis and a risk factor for further development of gastric cancer. This infection results in local inflammation and a modification of gastric mucosal epithelial cell characteristics. Systematic investigation for the expression of the secretory component by gastric epithelium in a personal historical series of biopsy specimens showed the expression of this activation marker in 38% of the cases, 19% also showing clear signs of H. pylori infection. AIMS: To further appreciate the activation of epithelial cells in the chronic gastric inflammation associated with H. pylori infection and other types of gastritis without consideration of the grade of gastritis. METHODS: Punch gastric biopsies from 36 patients (10 patients with confirmed H. pylori gastritis, 16 patients with non-H. pylori gastritis and 10 controls) were tested for the expression of ICAM-1/CD54, HLA-DP, -DQ, -DR, secretory component and bcl-2 by immunofluorescence. RESULTS: Up-regulation of most markers was observed both in H. pylori and non-H. pylori gastritis, although secretory component, CD54 and DP expression was more closely associated with H. pylori gastritis. CONCLUSION: H. pylori infection appears to activate gastric epithelial cells more strongly than other types of gastritis. This suggests an active relationship between this bacterium and epithelial cells. Investigation of the up-regulationship between this bacterium and epithelial cells. Investigation of the up-regulation of secretory component, ICAM-1/CD54 or DP in gastric biopsies may serve as extensive markers in search of H. pylori gastric infections.

Adult↗
PubMed1998

PreB1 (CD10-) acute lymphoblastic leukemia: immunophenotypic and genomic characteristics, clinical features and outcome in 38 adults and 26 children. The Groupe dEtude Immunologique des Leucémies.

The less differentiated stage (CD10-) of B-lineage acute lymphoblastic leukaemia (ALL) described as preB1-ALL in the GEIL nomenclature, accounts for less than 10% of ALL. It is classically considered to be associated with translocation (4;11)(q21;q23), and to have a poor prognosis. We report an extensive immunophenotypic, genomic and clinical study of a series of 64 preB-1 ALL patients, representing 6.3% of a cohort of consecutive ALLs. The engagement of preB1-ALL cells in the B-lineage was confirmed by their B-lineage score, equal to or higher than 2. In addition, more than 90% of the cases tested showed rearranged IGH genes. Translocation (4;11) was the most frequent karyotypic anomaly seen, but only accounted for 24% of the preB1-ALL cases tested. Expression of the myeloid associated antigen CD15 was also found with high incidence in this subset. Clinical and biological features at presentation showed more significant differences between preB1- and T-ALL than between preB1- and preB2-ALL (CD10+). However, outcome characteristics of the 22 children with preB1-ALL confirmed the worse prognosis of this entity.

Adolescent↗
PubMed1998

Evaluation of human sperm acrosome reaction and viability by flow cytometry.

We report in this work a quantitative procedure developed to evaluate the acrosomal reaction and vitality of human spermatozoa, with three color staining simultaneously. Twenty normal human sperm were labeled with GB24 monoclonal antibody, a fluorescein isothiocyanate conjugated lectin and propidium iodide (supravital stain). Four conjugated lectins were investigated: WGA, Con-A, PNA and UEA-1. Acrosome reaction was induced with calcium ionophore A-23187. Analyses were made by flow cytometry and electron microscopy. A high percentage of spermatozoa that stained with propidium iodide was found. The results of four lectins show an interaction between GB24 and lectin binding. Significant differences of fluorescence index were obtained between the samples with calcium ionophore A-23187 and the samples without it. The WGA-GB24 association shows an independent behavior and this may depend on the fact that WGA binds to the cytoplasmic membrane of human spermatozoa and GB24 antibody bind inner acrosome membrane. Using Con-A, PNA and UEA-I a crowded staining is likely to occur because these lectins and GB24 antibody mainly bind to acrosome membranes, and our results then show a close relation.

Acrosome Reaction↗
PubMed1997

Ultrastructural and immunohistological evidence for dendritic-like cells within human choroid plexus epithelium.

Ultrasonic examination of human choroid plexus (CP) disclosed the presence of a possibly new type of CP cells displaying many of the features of dendritic cells and apparently expressing HLA Class II antigens. These cells bear long processes, devoid of tight junctions, inserted between CP epithelial cells, and have close contacts with CP basement membrane. They could, therefore, play a key role in immunosurveillance in the central nervous system.

Aged↗
PubMed1997

Enhanced expression of CD31 and CD54 on tonsillar high endothelial venules in IgA nephropathy.

Abnormalities in the partition of IgA- and IgG-producing cells in the tonsils of patients with IgA nephropathy have been suggested to result from a dysregulation of cell trafficking and homing through high endothelial venules in this lymphoid tissue. In order to document such adhesion anomalies, we used the 36 monoclonal antibodies of the cell adhesion molecules subpanel of the Fifth International Workshop on Leukocyte Differentiation Antigens on frozen sections of tonsils from 10 patients and 15 controls. This allowed us to describe the partition of cell adhesion molecules in human tonsils and to demonstrate a significant enhancement of CD31 and CD54 expression on high endothelial venules of tonsils from patients with IgA nephropathy. These observations are in keeping with the hypothesis of an increased lymphocyte recruitment in tonsils in this disease.

Adolescent↗
PubMed1997

Coexpression of CD40 and class II antigen HLA-DR in Graves' disease thyroid epithelial cells.

In Graves' disease, thyroid epithelial cells abnormally express HLA-DR Class II molecules in the vicinity of lymphocyte infiltrates, suggesting that lymphocyte proliferation is sustained by the appropriate presentation of antigenic material. The ability of thyroid epithelial cells to provide the necessary second signals has however not been documented. The expression of HLA-DR, CD40, CD40L, CD80, and CD28 was investigated on thyroid samples from 30 patients (Graves' disease, n = 16; benign toxic adenoma, n = 8; multinodular goiter, n = 6). Apoptotic cells were searched for using the TUNEL method. CD40 appeared to be coexpressed with HLA-DR in Graves' disease patients samples and in two control samples also containing lymphoid infiltrates. Almost no apoptotic cells were found. These data suggest that thyroid epithelial cells from Graves' disease patients have the ability to successfully present autoantigens. The near absence of apoptotic cells in surrounding lymphoid infiltrates is in keeping with this efficient provision of a rescue second signal.

Adolescent↗
PubMed1997

Kinetics of specific salivary IgA responses in man after oral challenge by ribosomal immunostimulant.

The kinetics of specific IgA mucosal responses was assessed in 12 healthy volunteers over 3 weeks of treatment by oral administration of an immunostimulant, Ribomunyl, composed of ribosomes from the four bacteria Streptococcus pyogenes, Streptococcus pneumoniae, Klebsiella pneumoniae and Haemophilus influenzae. The levels of IgA specific for these four bacteria increased after each immunization and, after the third week of treatment, were significantly higher than baseline day 0 values. This study demonstrates that oral ribosomal immunostimulation results in the production of specific salivary antibodies liable to recognize whole bacteria antigens, and therefore likely to confer protection. The kinetic analysis performed also demonstrates the rapidity of specific mucosal immune responses after oral stimulation in man, a feature still seldom explored.

Adjuvants, Immunologic↗
PubMed1997

Low levels of spontaneously activated peripheral IgA-secreting cells in nontransplanted IgA nephropathy patients.

The pathognomonic presence of IgA in the glomerular mesangium of patients with IgA nephropathy (IgAN) suggests an abnormal control of IgA metabolism in this disease that could be modified in transplanted IgAN patients. Alterations of IgA production have been demonstrated in both bone marrow samples and mucosae-associated tissues from IgAN patients, but the analysis of IgA production by peripheral B lymphocytes in culture has yielded conflicting results, some investigators showing an enhanced secretion of IgA and others reporting similar data as with control samples. Little is known about the endogenous activation state of B cells in IgAN, which can be approached by analyzing peripheral Ig-producing cells, a number of which are recirculating between lymphoid organs. In the present study, two methods were applied to appreciate the numbers of spontaneously activated peripheral B cells. The ELISPOT method provided information about short-term secretion of Igs. Intracytoplasmic immunofluorescence for IgA allowed to identify IgA-containing cells, either as short-rimmed immunocytes or as brightly stained immunoblasts with an enlarged cytoplasm. These cells were enumerated in IgAN patients (n = 31), transplanted IgAN patients (n = 27), control patients with other biopsy-proven renal diseases (nontransplanted, n = 48; transplanted, n = 38), and in healthy individuals (n = 18). The number of IgA spot-forming cells obtained in the control groups (1,251 +/- 95 cells/10(6) lymphocytes [mean +/- SE]) was consistent with those in similar previously reported studies, but differed significantly (P = 0.01) from those observed in nontransplanted IgAN patients, who had a surprisingly lower number of such cells (699 +/- 97 cells/10(6) lymphocytes); the number of IgA spot-forming cells in the transplanted IgAN patients (1,355 +/- 182 cells/10(6) lymphocytes) did not differ from that in the control groups. The same pattern was seen for IgA-containing immunoblasts. There was no difference in IgG (overall, 214 +/- 13 cells/10(6) lymphocytes) and IgM (overall, 61 +/- 10 cells/10(6) lymphocytes) spot-forming cell numbers between the five groups of individuals tested, suggesting that the anomaly noted in IgAN patients was not related to technical problems and that this could be a new feature of this renal disease. The normal levels of spontaneously activated peripheral IgA-producing cells found in transplanted IgAN patients suggest that immunosuppressive treatments could interfere with the anomalies of IgA metabolism in this disease.

Adult↗
PubMed1997

Serum anti-rabbit and anti-horse IgG, IgA, and IgM in kidney transplant recipients.

BACKGROUND: The therapeutic efficacy of horse antilymphocyte globulins (ALG) or of rabbit antithymocyte globulins (ATG), used for both the prevention and treatment of allograft rejection has been well documented. However, clinical use of these heterologous antibodies can result in the production of antibodies against horse or rabbit proteins and in the development of serum sickness via circulating immune complexes. METHODS: We studied the production of human IgG, and IgM anti-rabbit and anti-horse globulins, in 240 serum samples from 111 kidney transplant recipients, of whom 89 were treated with ALG or ATG (Mérieux-France) as prophylaxis. RESULTS: Up to 8.9% of the patients had anti-ALG and/or -ATG antibodies before the first transplantation. This proportion increased significantly after. Preimmunization did not appear to be predictive of the occurrence of clinical serum sickness, yet sensitization increased, after transplantation, in up to 71% of the subjects who developed this disorder (P = 0.02). In patients receiving a second transplant, pretransplantation antibody levels were not modified by the immunosuppressive therapy applied. No relationship was found between early rejection and antiglobulin antibodies. CONCLUSIONS: Serum anti-rabbit and/or -horse antibodies were demonstrated in a significant proportion of kidney recipients, even before transplantation, possibly due to environmental exposure. A classical pattern of IgM increase was observed when the patients developed an immune response to ALG or ATG, and an IgA response after ALG. These results suggest that patients receiving ALG/ATG should be monitored for the production of anti-ALG/ATG immunoglobulins.

Adult↗
PubMed1997

Sequential assessment of cell cycle S phase in flow cytometry: a non-isotopic method to measure lymphocyte activation in vitro.

Lymphocyte multiplication can be induced in vitro by mitogens or specific antigens, and is usually measured using isotopic methods involving tritiated thymidine. Cellular proliferation can also be analyzed by flow cytometry techniques based on cell cycle analysis through the measurement of DNA content. We applied this method to lymphocytes from 113 individuals, to evaluate lymphocyte proliferation after stimulation in vitro by a mitogen (phytohaemagglutinin, PHA) or a recall antigen (tetanus toxoid), using a kinetic approach with four points sequential measurements of the S and G2 phases over six days of culture. The proportion of cells in S phase after PHA stimulation was significantly higher than in controls overall and as early as on day three of the culture. Activation with a recall antigen significantly induced increasing S phase cell proportions up to day six. These data suggest that flow cytometric assessment of the S phase could be a useful alternative to isotopic methods measuring lymphocyte reactivity in vitro.

Adult↗