Publications by authors named "Plonquet A"

Phenotyping intramuscular immune cells is essential for the characterization of dysimmune/inflammatory myopathies (DIM). Flow cytometry (FC) is the most reliable technique for analyzing leukocyte subpopulations and evaluating their activation levels. We developed a purely mechanical protocol for extracting cells from muscle tissue allowing us to preserve cell surface epitopes and determined its applicability to experimental pathology in mice and myopathological diagnosis in human.

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We aimed to determine whether serum leptin levels are predictive of the occurrence of healthcare-associated infections (HAIs) in hospitalized older patients. In a prospective cohort, 232 patients had available data for leptin and were monitored for HAIs for 3 months. Admission data included comorbidities, invasive procedures, the Mini Nutritional Assessment (MNA), BMI, leptin, albumin and C-reactive protein levels, and CD4 and CD8 T-cell counts.

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Background: Biomarkers of disease severity might help individualizing the management of patients with the acute respiratory distress syndrome (ARDS). Whether the alveolar compartmentalization of biomarkers has a clinical significance in patients with pneumonia-related ARDS is unknown. This study aimed at assessing the interrelation of ARDS/sepsis biomarkers in the alveolar and blood compartments and explored their association with clinical outcomes.

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Background: We hypothesized that low-grade inflammation was driven by microbial translocation and associated with an increased risk of health care-associated infections (HAIs).

Methods: We included 121 patients aged 75 years or over in this prospective cohort study. High-sensitivity C-reactive protein (hs-CRP), I-FABP, and sCD14-as markers for low-grade inflammation, intestinal epithelial barrier integrity, and monocyte activation, respectively-were measured at admission.

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Nodal follicular helper T-cell-derived lymphoproliferations (specifically the less common peripheral T-cell lymphomas of follicular type) exhibit a spectrum of histologic features that may mimic reactive hyperplasia or Hodgkin lymphoma. Even though angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma of follicular type share a common biologic origin from follicular helper T-cells and their morphology has been well characterized, flow cytometry of peripheral T-cell lymphomas of follicular type has not been widely discussed as a tool for identifying this reactive hyperplasia/Hodgkin lymphoma mimic. We identified 10 peripheral T-cell lymphomas of follicular type with available flow cytometry data from five different institutions, including two cases with peripheral blood evaluation.

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Background & Aims: Healthcare-associated infections [HAI] are common in elderly individuals and may be related to both nutritional deficiencies and immunosenescence. Here, we assessed whether overall malnutrition and/or specific nutrient deficiencies were associated with HAI via alterations in immune parameters.

Methods: Prospective observational cohort study in patients aged ≥ 70 years admitted to the geriatric rehabilitation unit of a teaching hospital in France between July 2006 and November 2008.

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Background: Skin lesions are frequent in monoclonal cryoglobulinaemia and may be the first sign of B-cell lymphoma, especially multiple myeloma, Waldenström's macroglobulinaemia and B-cell chronic lymphocytic leukaemia.

Patients And Methods: A 74-year-old woman with no prior medical history presented with necrotic leg ulcer. Skin biopsy showed dermal angiomatosis with numerous PAS+ thromboses, associated with monoclonal intravascular deposits of IgM kappa, indicating monoclonal cryoglobulin, which was confirmed by laboratory tests.

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Epstein-Barr virus (EBV)-infected B cells with Reed-Sternberg-like cell (RS) features may occur in peripheral T-cell lymphomas (PTCLs), especially in angioimmunoblastic T-cell lymphoma. Here, we report 5 patients presenting with lymphadenopathy whose first biopsies demonstrated nodular lymphoid proliferations containing scattered CD30+, CD15+, EBV+ Hodgkin and Reed-Sternberg-like cells, which led to an initial diagnosis of lymphocyte-rich classical Hodgkin lymphoma. However, the uncommon clinical features and/or the occurrence of relapse as PTCL prompted review of the biopsies with expanded immunohistologic and molecular studies and revision of the diagnoses to follicular variant of PTCL (F-PTCL).

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Background: In angioimmunoblastic T-cell lymphoma, symptoms linked to B-lymphocyte activation are common, and variable numbers of CD20(+) large B-blasts, often infected by Epstein-Barr virus, are found in tumor tissues. We postulated that the disruption of putative B-T interactions and/or depletion of the Epstein-Barr virus reservoir by an anti-CD20 monoclonal antibody (rituximab) could improve the clinical outcome produced by conventional chemotherapy.

Design And Methods: Twenty-five newly diagnosed patients were treated, in a phase II study, with eight cycles of rituximab + chemotherapy (R-CHOP21).

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Background: Central nervous system (CNS) relapse is an uncommon but dramatic complication of diffuse large B-cell lymphoma (DLBCL). Several studies have demonstrated the superiority of cerebrospinal fluid (CSF) flow cytometry (FCM), as compared with conventional cytology (CC), in detecting occult leptomeningeal disease. The clinical relevance of a positive FCM still has to be clarified.

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Background: Nosocomial infections are extremely common in the elderly and may be related to ageing of the immune system. The Immune Risk Phenotype (IRP), which predicts shorter survival in elderly patients, has not been evaluated as a possible risk factor for nosocomial infection. Our aim was to assess the prevalence of nosocomial infections in elderly in-patients and to investigate potential relationships between nosocomial infections and the immunophenotype, including IRP parameters.

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Background: Belatacept is thought to disrupt the interaction between CD80/86 and CD28, thus preventing T-cell activation by blocking the co-stimulatory second signal. However, the consequences on the T-cell profile in human renal transplant cases have not been determined.

Methods: In this study, we analysed intra-graft levels of the mRNAs for Treg (FOXP3), cytotoxic CD8 T cells (Granzyme B), Th1 (INFγ, Tbet), Th2 (GATA3) and Th17 (RORγt and IL-17) in protocol biopsies obtained 12 months after renal transplantation in recipients treated with Belatacept or calcineurin inhibitor (CNI).

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Background: T follicular helper (T(FH)) cells reside in the light zone of germinal centers and are considered the cell of origin of angioimmunoblastic T-cell lymphoma. Recently, CXCL13, PD-1 and SAP were described as useful markers for T(FH) cells and angioimmunoblastic T-cell lymphoma but also reported in some peripheral T-cell lymphomas, not otherwise specified.

Design And Methods: In the present study the expression pattern of ICOS protein was investigated by immunohistochemistry-based techniques in routine sections of normal lymphoid tissues and 633 human lymphomas.

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Objective: Skeletal muscle may be the site of a variety of poorly understood immune reactions, particularly after myofiber injury, which is typically observed in inflammatory myopathies. This study was undertaken to explore both the cell dynamics and functions of resident macrophages and dendritic cells (DCs) in damaged muscle, using a mouse model of notexin-induced myoinjury to study innate immune cell reactions.

Methods: The myeloid cell reaction to notexin-induced myoinjury was analyzed by microscopy and flow cytometry.

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The prognostic impact of minimal residual disease (MRD) was analyzed in 259 patients with mantle cell lymphoma (MCL) treated within 2 randomized trials of the European MCL Network (MCL Younger and MCL Elderly trial). After rituximab-based induction treatment, 106 of 190 evaluable patients (56%) achieved a molecular remission (MR) based on blood and/or bone marrow (BM) analysis. MR resulted in a significantly improved response duration (RD; 87% vs 61% patients in remission at 2 years, P = .

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Leptomeningeal disease is an important adverse complication occurring in patients with B and T cell lymphomas and acute leukemias of lymphoid and myeloid origin. Recent reports suggest that multiparameter flow cytometry immunophenotypic assessment of spinal fluid samples could improve the efficiency of detection of CNS involvement, due to its high specificity and greater sensitivity. However, spinal fluid samples are frequently paucicellular with a rapidly decreasing cell viability.

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Delayed hemolytic transfusion reaction (DHTR), a life-threatening transfusion complication in sickle cell disease (SCD), is characterized by a marked hemoglobin drop with destruction of both transfused and autologous red blood cells (RBCs) and exacerbation of SCD symptoms. One mechanism of RBCs destruction is auto-antibody production secondary to transfusion. As rituximab specifically targets circulating B cells, we thought that it could be beneficial in preventing this immune-mediated transfusion complication.

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Skin manifestations of angioimmunoblastic T-cell lymphoma (AITL) are frequent, sometimes as first manifestations of the disease. In the absence of a specific marker for neoplastic cells, diagnosis of AITL in skin biopsies is often difficult. CD10 and CXCL13 have been recently recognized as characteristic markers of AITL, but have not been yet investigated in the skin.

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Background: Lymphocytopenia is a prognostic factor in Hodgkin's disease. In diffuse large B-cell lymphoma (DLBCL), data are much less established, in spite of numerous reports on immune system-lymphoma interactions. This study addresses the prognostic value of blood lymphocyte subsets at diagnosis in DLBCL.

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Macrophages (MPs) are important for skeletal muscle regeneration in vivo and may exert beneficial effects on myogenic cell growth through mitogenic and antiapoptotic activities in vitro. However, MPs are highly versatile and may exert various, and even opposite, functions depending on their activation state. We studied monocyte (MO)/MP phenotypes and functions during skeletal muscle repair.

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Angioimmunoblastic T-cell lymphoma (AITL) represents a distinct entity among peripheral T-cell lymphomas (PTCLs). The cellular origin of AITL remains unknown, although a possible derivation from follicular helper T cells (TFH) has been suggested based on the CD4/Bcl-6 phenotype. It has been recently shown that expression of CXCL13, a chemokine critically involved in B-cell migration into germinal centers, is characteristic of TFH cells, as compared with other T helper subsets.

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Whether methicillin-resistant Staphylococcus aureus (MRSA) constitutes per se an independent risk factor for morbidity and mortality after surgery as compared with methicillin-sensitive Staphylococcus aureus (MSSA) remains a subject of debate. The aim of this study was to assess whether innate defenses against MRSA and MSSA strains are similarly impaired after cardiac surgery. Both intracellular (isolated neutrophil functions) and extracellular (plasma) defenses of 12 patients undergoing scheduled cardiac surgery were evaluated preoperatively (day 0) and postoperatively (day 3) against two MSSA strains with a low level of catalase secretion and two MRSA strains with a high level of catalase secretion, inasmuch as SA killing by neutrophils relies on oxygen-dependent mechanisms.

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Anti-Hu syndrome is a paraneoplastic neurologic disease seemingly associated with an efficient antitumoral immune response against HuD protein expressed by both small cell lung cancer (SCLC) and neurons. Since anti-Hu antibodies are not pathogenic, and oligoclonal CD8(+) T cells infiltrate neoplastic and nervous tissues, we examined MHC class I-restricted immunogenicity of human HuD. Among 14 HuD-derived peptides potentially immunogenic in HLA-A*0201 restriction, 10 had actual in vitro binding capacity to the HLA molecule, 8 elicited specific cytotoxic T lymphocytes (CTLs) in a humanized murine model after peptidic vaccination, 2 also elicited specific CTLs in healthy humans, and 1 was naturally processed and presented to the immune system.

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We describe the unreported pattern of inflammatory myopathy with abundant macrophages (IMAM) as a main differential diagnosis of postimmunization aluminum hydroxide-induced macrophagic myofasciitis (MMF). IMAM was mainly detected among patients with a dermatomyositis (DM)-like disease. Among 113 muscle biopsies from DM patients collected from 1974 to 2000, intensity of macrophage infiltration was highly variable: 41.

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