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Biomedical subjects

L Prin

Publications and source records attributed to L Prin.

At least 19 recordsLinked to original sources
PubMed2003

Hypereosinophilia with abnormal T cells, trisomy 7 and elevated TARC serum level.

The idiopathic hypereosinophilic syndrome (HES) is a rare heterogeneous disorder, characterized by persistent blood eosinophilia with possible organ involvement. We describe here the case of a 20-year-old atopic male presenting chronic hypereosinophilia and eczema since childhood. Biological findings included hypereosinophilia (9.5 x 10(9)/L), hyperlymphocytosis (10.9 x 10(9)/L), polyclonal hypergammaglobulinemia and elevated IgE serum level. Flow cytometric analysis of blood lymphoid cells showed a population of CD2+CD3-CD4+TCRab-TCRgd- lymphocytes. These cells displayed a Th0/Th2 cytokine profile, and a clonal TCR rearrangement pattern. A high serum TARC level was observed. Karyotype studies on blood stimulated culture or lymph nodes revealed a cellular hyperdiploïd clone 47, XY, +7. To our knowledge, this chromosomal aberration has never been reported in such case.

Adult↗
PubMed2002

Interferon beta in multiple sclerosis: relationship between sustained serum IgG levels and clinical outcome.

We investigated the effects of interferon beta-1a (IFN beta-1a) on specific response towards two immunodominant MBP peptides and on global production of IgG. We evaluated 54 sera from multiple sclerosis (MS) patients at baseline and 1 year after treatment. We did not observe any modification of immune response to the MBP peptides but we noted a significant decrease in mean IgG concentrations in patients with progression of the disease but not in stable patients. These results suggest that IFN beta1a restores or maintains a beneficial immune response.

Adult↗
PubMed2002

[Relevance of anti-nucleosome antibodies detected by enzyme-based immunoassays in lupus diagnosis. Comparative analysis of four commercial kits].

Among the biological assays used for the diagnosis of systemic lupus erythematosus (SLE), the detection of anti-double strand DNA antibodies (dsDNA Ab) is regarded as highly specific. However this biological parameter is negative among 20 to 40% of patients. Recent studies have revealed potential interest of the anti-nucleosome antibodies in the diagnosis of the lupus, in particular when any anti-dsDNA antibody activity could be detected. We selected 80 sera in order to evaluate four commercial anti-nucleosome enzyme-based immunoassays (EIA) kits. Their sensitivity and specificity values were compared with those obtained by the detection of anti-dsDNA Ab, carried out with both a Farr assay and two EIA kits. No anti-nucleosome EIA kits reached performances of the Farr assay for the diagnosis of lupus. On the other hand, our results show an higher diagnostic value for some anti-nucleosome EIA kits compared with 2 anti-dsDNA EIA kits. Apart from SLE, anti-nucleosome antibodies can be observed in others auto-immune diseases, in particular Sjögren's syndromes, the primary antiphospholipid syndrome, the systemic sclerosis and the mixed connective tissue disease. Compared results of the four anti-nucleosome EIA kits highlight many discordances. These variations, testifying to the absence of standardization for this new parameter, must encourage with a careful interpretation of results, according to the clinical context.

Adolescent↗
PubMed2002

Expression of a human endogenous retrovirus, HERV-K, in the blood cells of leukemia patients.

Human endogenous retroviral sequences (HERVs) are believed to be possible pathogenic agents in carcinogenesis. HERV-K is the most biologically active form, since members of this family have intact open reading frames for the gag, pol or env genes. Antibody response against HERV-K peptides has been reported in leukemia patients, suggesting a possible overexpression of this sequence in leukemic cells. Using real-time quantitative RT-PCR (TaqMan), we found that in six of the eight leukemia samples we collected, transcriptional activity of HERV-K10-like gag gene was 5- to 10-fold higher than in normal peripheral blood mononuclear cells (PBMCs) or mononuclear cells from cord blood. The overexpression was marked enough to be detected by Northern blot. In addition, there was no significant variation of HERV-K expression in normal PBMCs after exposure to different factors (PHA, gamma irradiation, 5-azacytidine) that potentially modulate HERV expression. This suggests that HERV-K relative overexpression in leukemia samples might be specifically associated with tumor development. The origin of these transcriptional variations is therefore worth being investigated further.

Acute Disease↗
PubMed2001

IgG reactivity against citrullinated myelin basic protein in multiple sclerosis.

An increased level of citrullinated myelin basic protein (MBP-C8) has been reported in the brains of multiple sclerosis (MS) patients. However, the involvement of the immune response to post-translational modified MBP in the pathophysiology of MS remains speculative. The aim of this study was to compare the levels of immunoglobulin G antibodies to several MBP epitopes, before and after citrullination, in the cerebrospinal fluid (CSF) and sera of MS patients using enzyme-linked immunosorbent assay (ELISA). We analyzed antibody reactivity against various MBP-peptides in the CSF and sera of 60 MS patients, and 30 patients with other neurological diseases (OND) as controls. The peptides tested were: MBP(75-98) (peptide 1), native (peptide 2) and citrullinated (peptide 3) MBP(108-126) (ARG(122)-->Cit(122)), and native (peptide 4) and citrullinated (peptide 5) MBP(151-170) (ARG(159, 170)-->Cit(159, 170)). All selected peptides could support an immune reactivity in CSF and sera of MS and OND patients. A higher reactivity against peptide 4 was found in the CSF of MS patients compared with OND patients (P<0.0001), but not against citrullinated peptides (peptides 3 and 5). However, we observed that the citrullination state of peptide 2 modified the patterns of immune reactivity more markedly in MS patients (P<0.0001) than in OND patients (P<0.02). Although some MBP epitopes could be a potential target in MS, our data did not demonstrate any difference of antibody response to MBP peptides in their citrullinated forms.

Adolescent↗
PubMed2001

Molecular analysis of endogenous retrovirus HRES-1: identification of frameshift mutations in region encoding putative 28-kDa autoantigen.

A possible involvement of HTLV-1-related endogenous sequence 1 (HRES-1) in autoimmune diseases has been recently reported. In primate cells, PCRs and RT-PCRs using specific primers reveal the presence and the transcription of gag-related sequences. However antisera generated against selected HRES-1 peptides failed to detect a 28-kDa protein deduced from the translated gag ORF and described previously. Such discordant results led us to perform DNA cloning and sequencing of LTR- and gag-related nucleotidic fragments. Repeated sequence analyses on distinct samples revealed frameshift mutations in the gag and LTR ORFs. Our sequence analyses detected a stop codon in the gag-related ORF, which is inconsistent with the expression of a 28-kDa protein. Instead of the two ORFs previously found, our gag-related region contained three ORFs. One of them demonstrated higher nucleotidic and peptidic homologies with the p19 gag of HTLV-I. However, the molecular analyses of our new sequence did not show evidence of potent translation capacities.

Amino Acid Sequence↗
PubMed2001

Eotaxin expression and eosinophil infiltrate in the liver of patients with drug-induced liver disease.

BACKGROUND: Drug-induced liver disease is due to intrinsic or idiosyncratic hepatotoxins. Liver parenchyma is then infiltrated by immunocompetent cells. Eosinophils are primarily tissue leukocytes which are attracted into tissues by various chemoattractants, including chemokines. The aim of this study was to study eosinophils in the livers of patients with drug-induced liver disease. METHODS: Immunohistochemical studies with antibodies against eosinophil cationic proteins (major basic protein, eosinophil-derived neurotoxin and eosinophil cationic protein), cytokines (interleukin 5 (IL-5), interleukin 3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF)) and chemokines (eotaxin and RANTES (Regulated upon Activation Normal T cell Expressed and Secreted)) were performed to assess the in situ activation of the liver-infiltrating eosinophils of 14 patients with drug-induced liver disease and 19 controls. RESULTS: Eosinophils were only observed in patients with drug-induced liver disease. Eosinophils were morphologically normal when hepatitis was due to paracetamol whereas eosinophils had granular changes when hepatitis was due to an idiosyncratic hepatotoxin. Eotaxin was detected in all patients with drug-induced liver disease, whereas RANTES was detected in three of them. IL-5, IL-3 or GM-CSF were not detected. CONCLUSIONS: In patients with drug-induced liver disease, the recruitment of eosinophils in the liver may depend on eotaxin expression. Eosinophil changes may vary according to the type of drug.

Acetaminophen↗
PubMed2001

[Detection of anti-DNA antibodies for the diagnosis of disseminated lupus erythematosus. Comparative study of immunoenzyme methods and a Farr test].

Among the biological assays used for the diagnosis of systemic lupus erythematosus, the detection of anti-double strand DNA (dsDNA) antibodies is highly specific, especially at a high level. Different methods are using for the detection of this specificity, particularly enzyme-based immunoassay (EIA) kits that become widespread in autoimmunity because of several advantages like standardization, simple use and automation. We selected 80 sera in order to evaluate six commercial anti-dsDNA EIA kits and a Farr assay. The results were compared with clinical data, to appreciate both the sensitivity and the specificity of each method. EIA assays are highly sensitive, but are less specific than the Farr assay. These EIA methods should remain organized in an integrative biological step, following an evocative clinical examination. Moreover, the EIA results require confirmations with a more specific assay.

Antibodies, Antinuclear↗
PubMed2001

Dexamethasone inhibits apoptosis of eosinophils isolated from hypereosinophilic patients.

Glucocorticoids reduce in vivo the number of eosinophils and are effective in treatment of blood and tissue hypereosinophilia. Dexamethasone is a synthetic glucocorticoid known to induce in vitro apoptosis of eosinophils of healthy donors, and apoptosis may be a mechanism induced by glucocorticoids to reduce eosinophilia. Here we confirm that dexamethasone exerts a pro-apoptotic effect on eosinophils isolated from healthy subjects but that dexamethasone is not always a pro-apoptotic agent towards eosinophils from hypereosinophilic patients. Implications of these results in the resistance of some patients to a treatment by glucocorticoids are discussed.

Anti-Inflammatory Agents↗
PubMed1998

Increased interleukin-6 production during the acute phase of the syndrome of episodic angioedema and hypereosinophilia.

BACKGROUND: The Gleich syndrome is rare and associates recurrent angioedema, urticaria, fever, weight gain and blood hypereosinophilia, underlying systemic and local inflammation. The pathogenesis of those symptoms remains unclear. OBJECTIVE: We wanted to address the possible implication of Interleukin-6 (IL-6) in the development of those clinical features, and to identify the cells involved in its production. METHODS: A 26-year-old man suffering of this disease was referred in hospital. During an acute attack with weight gain, fever and a diffuse oedema, a marked increase in eosinophils count (42700/mm3 was observed. Serum ECP was elevated at 47 microg/L (normal less than 16). Corticosteroid therapy administrated on the 7th day was followed by a rapid remission. Blood samples were collected (before, during the attack and under corticosteroid therapy) for measurements of serum IL-6 (ELISA, Immunotech, Marseille, France) and plasma histamine (RIA, Immunotech, Marseille, France). Blood monocytes and eosinophils were isolated and a skin biopsy was performed during the attack. RESULTS: The plasma histamine level was within normal range. The level of IL-6 in sera peaked to 74 pg/mL, concomitant with the peak of eosinophilia at the acute phase phase of the attack. Under corticosteroids, we observed a drop in the IL-6 serum level to 29 pg/mL, concomitant with the clinical remission. During the attack, an increase in IL-6 production was observed in 24 h blood monocyte supernatants (11.10(3) pg/mL compared with 2.4+/-0.8.10(3) pg/mL for BM from controls) as well as in skin endothelial cells but not in the blood and skin eosinophils. In vitro, when endothelial cells were incubated in eosinophils supernatants of the patient, liberation of IL-6 was observed (3.3 10(3) pg/mL compared with controls: 2.1 10(3) pg/mL) CONCLUSION: Serum IL-6 elevation may be related to an increased production by blood monocytes and endothelial cells, possibly stimulated by eosinophil mediator during the acute phase of the disease, and might participate in the inflammatory reaction of this syndrome.

Acute-Phase Reaction↗
PubMed1998

[Eosinophils: receptors, mediators, functions].

Eosinophils have been studied using various models. Resulting data indicate that these polynuclear cells may have good and bad effects on the host. Eosinophils have been shown to destroy parasites in vitro but also to contribute to inflammation especially in association with bronchial asthma. These findings illustrate the functional versatility of a cell with the ability to interpret messages from its environment including chemokines, cytokines, growth factors, lipid mediators, and neuropeptides. In succession, these signals can stimulate eosinophils to express a range of regulated (homeostasis) or unregulated (pathogenesis) activity. Some signals cause selective migration into target tissues, especially submucosa in contact with the environment. Other signals determine local function. Understanding these mechanisms will be crucial to development of effective management of persistent hypereosinophilia syndromes.

Chemokines↗
PubMed1997

Capture-ELISA: a new assay for the detection of immunoglobulin M isotype antibodies using Chlamydia trachomatis antigen.

We present here a new method of IgM antibody-capture enzyme-linked immunosorbent assay (IgM-Capture-ELISA) for the diagnosis of recently acquired infections with Chlamydia trachomatis. For this analysis, plates were coated with goat IgG anti-human Fc mu. The capture of serum IgM antibodies was revealed indirectly by the sequential addition of biotinylated chlamydial proteins and peroxidase-conjugated streptavidin. In chlamydial extracts, cysteine-rich proteins are preferential antigenic targets for the humoral response. 3-(N-maleimidopropionyl)-biocytin (MPB), which binds biotinylated moieties to sulfhydryl groups, was used for the labeling procedure. The preservation of the antigenic specificity of labeled proteins was controlled by a blotting of these proteins, which were, respectively, probed either with specific IgM antibodies or with streptavidin. This analysis revealed that, after labeling, recognized epitopes are more particularly present on the major outer membrane protein (MOMP) of Chlamydia trachomatis. The validation of IgM-Capture-ELISA was assessed by using 170 selected sera from patients suspected of being infected by Chlamydia. Results were respectively compared to conventional indirect immunofluorescence assays (MIF-IgM assays) and to Western blotting. Sixteen sera were found to possess IgM antibodies against Chlamydia trachomatis with IgM-Capture-ELISA. Among these 16 sera, 14 and 15 were, respectively, positive with MIF-IgM assays and in Western blotting. Data obtained with IgM-Capture-ELISA reveal the absence of false-positive results in sera containing rheumatoid factor, which has been shown to interfere in the two other methods. IgM-Capture-ELISA value was then confirmed using sera from patients consulting for genital or pulmonary diseases, from patients with confirmed chlamydial infections, and from patients with other pathologies. IgM-Capture-ELISA appears as an alternative simple semi-quantitative assay for the detection of early chlamydial infection.

Animals↗
PubMed1997

Low bone mineral density and peripheral blood monocyte activation profile in calcium stone formers with idiopathic hypercalciuria.

Calcium stone formers (CaSF) with idiopathic hypercalciuria (IH) have been shown to have decreased bone mineral density (BMD). The mechanism of their bone loss remains obscure. Monokines like interleukin-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), and granulocyte macrophage stimulating factor (GM-CSF) are involved in bone remodeling, but only IL-1 excess has been incriminated in the bone loss of CaSF with IH. Therefore, to more precisely delineate the role of monocyte activation in the pathogenesis of bone loss in these patients, we studied the production of IL-1 beta, IL-6, TNF-alpha, and GM-CSF by unstimulated or lipopolysaccharide (LPS)-stimulated cultured peripheral blood monocytes in 15 CaSF with IH, in 10 CaSF with dietary calcium-dependent hypercalciuria (DH), and in 10 healthy controls (C). Cytokines were measured in the culture medium by sensitive enzyme-linked immunosorbent assay and vertebral BMD by single energy computed tomography. The decrease of vertebral BMD in IH compared with DH, was confirmed (Z score: -1.2 +/- 0.2 vs. -0.5 +/- 0.2; P = 0.04; Mann-Whitney). In the supernatant of unstimulated peripheral blood monocytes, IL-1 beta and TNF-alpha levels were higher in IH than in C (respectively, 40 +/- 21 vs. 7 +/- 1 pg/mL, P = 0.008 and 236 +/- 136 vs. 39 +/- 23 pg/mL, P = 0.03); those of GM-CSF were greater in IH than in DH and C (respectively, 52 +/- 27 vs. 6 +/- 2, P = 0.04 and 6 +/- 2 pg/mL, P = 0.01) and those of IL-6 were not significantly different among the groups. After in vitro stimulation by LPS (10 micrograms/mL), the levels of the various monokines were not significantly different. In IH patients, the post-LPS levels of IL-6 were negatively correlated to vertebral BMD (n = 15, Z = -1.97, P = 0.04; Spearman), whereas those of GM-CSF were positively related to vertebral BMD (n = 15, Z = 2.01, P = 0.04). In this study, calcium stone formers with IH have bone mineral decrease and a particular profile of peripheral blood monocytes activation. This latter is characterized by a spontaneously increased synthesis of IL-1 beta, TNF-alpha, and GM-CSF. Furthermore, post-LPS levels of IL-6 and GM-CSF are correlated with vertebral BMD. These results suggest that monocyte activation may be involved in the bone loss of calcium stone formers with IH.

Adult↗
PubMed1997

Activated Stat related transcription factors in acute leukemia.

Cell proliferation and differentiation are under the control of cytokines and growth factors. Different signaling pathways are involved in the transmission of a specific signal through successive phosphorylation and dephosphorylation of proteins leading to gene transcription necessary for growth and differentiation. The cytokines and growth factors activate the Stat family of transcription factors. The Jak-Stat pathway is essential for cytokine signal transduction. Dysregulation of this cascade might lead to uncontrolled hematopoiesis. Studies have been carried out to examine the functionality of this pathway in cells from patients with acute leukemia. Members of the Stat protein family (Stat1, Stat3 and Stat5) are constitutively activated in cells collected from some acute leukemias suggesting dysregulation of the Jak-Stat pathway. Evidence of the existence of constitutively activated spliced variants of Stat3 and Stat5 proteins are described. The mechanisms of such activation remain to be clarified.

Acute Disease↗
PubMed1996

Synthesis of type 1 (IFN gamma) and type 2 (IL-4, IL-5, and IL-10) cytokines by human eosinophils.

Eosinophils are not only the source of cytotoxic and proinflammatory mediators but they can also generate cytokines and growth factors, including their own factors of differentiation, namely IL-3, GM-CSF, and IL-5. Synthesis of IL-5 by eosinophils was demonstrated by in situ hybridization and immunostaining in a variety of diseases, such as coeliac disease, asthma, hypereosinophilic syndrome, or skin diseases. However, IL-5 synthesis by eosinophils was not shown in Crohn's disease, whereas in other diseases, it was restricted to a subpopulation of eosinophils, suggesting some heterogeneity in cytokine-producing eosinophils. Here, we report that human eosinophils, in addition to the synthesis of IL-5, and Th2 cytokine, can synthesize IFN gamma, a Th1 cytokine, as well as IL-10 and IL-4, known to be mainly produced by Th2 cells. Double immunostaining procedures reveal the coexpression of IL-5, IL-4, and IL-10 by the same eosinophil populations, different from IFN gamma-producing eosinophils. We propose that distinct subpopulations of human eosinophils express Th2 or Th1 cytokines. These results point to the importance of cytokines derived from non T cells in the regulation of the immune response.

Eosinophils↗
PubMed1996

Study of human cord blood lymphocytes by immobilized metal ion affinity partitioning.

The potential of immobilized metal ion affinity partitioning (IMAP) using dextran-PEG+PEG-IDA-M(II) systems to separate mononuclear cells from cord blood has been evaluated. The distribution of B cells, T cells, monocytes and hematopoietic stem cells between PEG and dextran phases was determined by flow cytometry with fluorochrome-labelled specific antibodies. Comparing these values with the post-Ficoll repartition resulted in the determination of enrichment factors, for each subpopulation, in the different phases. We were able to distinguish the partition pattern of B cells, T cells, monocytes and stem cells in different IMAP systems. Their partition was affected by the nature and the concentration of the metal used, but no specificity in distribution for the subpopulations was found.

Cell Separation↗