Rheumatoid Arthritis: Youinou P

Devauchelle-Pensec V, Pers JO, Youinou P, Saraux A. · No affiliation provided · Rev Med Interne. · Pubmed #18403066 No free full text.

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Youinou P. · No affiliation provided · Joint Bone Spine. · Pubmed #17905630 No free full text.

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Binard A, Devauchelle-Pensec V, Fautrel B, Jousse S, Youinou P, Saraux A. · No affiliation provided · Clin Exp Rheumatol. · Pubmed #17417982 No free full text.

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Youinou P, Daridon C, Saraux A, Devauchelle V, Pers JO. · No affiliation provided · Clin Exp Rheumatol. · Pubmed #17181915 No free full text.

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Youinou P, Pers JO, Saraux A, Pennec YL. · No affiliation provided · Clin Exp Immunol. · Pubmed #15958065 links to  free full text

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Youinou P, Lydyard PM. · No affiliation provided · Lupus. · Pubmed #11530992 No free full text.

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Pers JO, Le Pottier L, Devauchelle V, Saraux A, Youinou P. · Laboratoire d'immunologie, centre hospitalier universitaire de Brest, B.P. 824, 29609 Brest, France. · Rev Med Interne. · Pubmed #18403061 No free full text.

Abstract: INTRODUCTION: Sjögren's syndrome (SS) is an autoimmune epithelitis hallmarked by a disruption of epithelial cells, the subsequent lymphocytic infiltration of lachrymal and salivary glands (SGs), and their ensuing dryness. One may posit that SS is triggered by viruses, and/or modulated by sex steroid hormones, and there is indeed a consensus that its aetiology is multifactorial, with genetic factors interacting with environmental agents. CURRENT KNOWLEDGE AND KEY POINTS: T-cells have long occupied central stage of the debate on the type of lymphocytes involved in the pathogenesis of SS. The relevance of B cells has, however, been emphasized over the past five years and new insights into their functions revealed. Furthermore, increased levels of the B-cell activating factor (BAFF) may be responsible for quantitative and qualitative anomalies of B-cells found in SS such as emergence of self reactive B-cells. This review reports compelling evidence that B-cells are involved in the pathophysiology of SS. PROSPECTS: Since SS may thus be conceived as a model for B-cell-induced autoimmunity, it is no surprise that B-cell ablative-treatment has proven to be relatively effective in SS.

Rochas C, Hillion S, Youinou P, Jamin C, Devauchelle-Pensec V. · Laboratory of Immunology, Brest University Medical School Hospital, BP 824, F 29609 Brest, France. · Autoimmun Rev. · Pubmed #18035327 No free full text.

Abstract: Rheumatoid arthritis (RA) induces major changes in synovial tissue (ST) and cartilage and bone destruction. Still, its pathogenesis is poorly understood. Accumulating evidence points to an important role for B lymphocytes. Rheumatoid-ST is characterized by activation of the synoviocytes and infiltrated by various inflammatory cells such as B and T lymphocytes. The infiltrate is diffuse or organized as germinal centers (GCs). These accommodate the immune response and favor self-tolerance breakdown. Receptor revision in B cells results from re-expression of the recombination activating genes (RAGs) which reinitiate immunoglobulin gene recombination, and modify the B-cell antigen receptor accordingly. In rheumatoid ST, secondary VDJ rearrangements occur and RAG proteins are detected. The mechanism that triggers and controls this revision remains elusive. We favor the hypothesis that such an uncontrolled process leads to autoimmunity.

Youinou P, Devauchelle V, Hutin P, Le Berre R, Saraux A, Pers JO. · Department of Immunopathology, Brest University Medical School, Brest, France. · Clin Rev Allergy Immunol. · Pubmed #17992590 No free full text.

Abstract: Although the relative contributions of T cells and B cells in Sjögren's syndrome (SS) are far from being settled, recent studies have suggested a crucial role for B cells in its pathophysiology. Early investigations have focused on the ability of B cells to produce autoantibodies, and new studies have enlarged the range of their functions. For example, beyond the paradigm that T lymphocytes maintain strict control over B cells, the latter cells are now acknowledged to solicit their own help from the former cells and release a flurry of cytokines. Further, some of these B cells act as antigen-presenting cells. Increased levels of the B cell activating factor (BAFF) found in SS may be responsible for high numbers of circulating Bm2/Bm2' cells and associated functional abnormalities of B cells, such as a BAFF-induced increased expression of CD19, which decreases the required strength generated by antigen binding for transmitting its signal. This review reports compelling evidence that B cells are involved in the pathophysiology of SS. As this brings novel prospects for the treatment of the disease, it is no surprise that B cell ablative treatment has proven to be relatively efficacious in SS.

Daridon C, Guerrier T, Devauchelle V, Saraux A, Pers JO, Youinou P. · Laboratory of Immunology, Brest University Medical School Hospital, Brest, France. · Autoimmun Rev. · Pubmed #17643928 No free full text.

Abstract: Analysis of salivary glands of patients with primary Sjögren's syndrome has yielded conflicting results with respect to T helper (Th)1/Th2 polarization. This balance might parallel the progress of the local lesions. B-cells are now taking center stage in this disease. They can also be primed to differentiate into two cytokine-production pathways, dubbed B effector (Be) 1 and Be2 cells. This is discussed in the light of our recent finding that Be1 accompany Th1, while Be2 accompany in the tissue lesions.

Youinou P, Jamin C, Saraux A. · Laboratory of Immunology, Brest University Medical School Hospital, Brest, France. · Clin Exp Rheumatol. · Pubmed #17543163 No free full text.

Abstract: The interest for B-cells in rheumatoid arthritis (RA) is currently being revived. They are involved in the development and activation of lymphoid architecture by regulating dentritic cell and T-cell function through cytokine production. Receptor editing an revising are also essential in B-cells and aid in preventing autoimmunity. Abnormalities in the subset distribution and a default in any task assigned to the B-cells may favor autoimmunity. Beneficied responses to B-cell depletion in RA by anti-CD20 monoclonal antibody rituximab illustrate the importance of B-lymphocytes in the pathogenesis of this disease. A new avenue has thus been opened, whereby B-lymphocytes return as a significant contributor to autoimmune disorders.

Bosello S, Pers JO, Rochas C, Devauchelle V, De Santis M, Daridon C, Saraux A, Ferraccioli GF, Youinou P. · Laboratory of Immunology, Medical School, Brest, France. · Int J Immunopathol Pharmacol. · Pubmed #17346422 No free full text.

Abstract: Interest in B-cells has been revived due to the description of new functions. Supporting a role for B-cells in the genesis of autoimmune diseases is the fact that the B-cell activating factor of the TNF ligand family (BAFF) is essential in their physiology. However, in each disease, this is restricted to a subgroup of patients. Based on experiments in mice, and validated in humans, this new cytokine has been highlighted. Excessive production of BAFF alters immune tolerance by rescuing self-binding B-cells. Overexpression in mice leads to autoimmune manifestation, and BAFF levels are elevated in the serum of autoimmune patients. Similar abnormalities occur in chronic lymphocytic leukemia. Recent works suggest that antagonizing the protein (or competing for its receptors) is relevant to the treatment. Advances in our understanding of the BAFF system offers the opportunity to improve our therapeutic approach.

Steinfeld SD, Youinou P. · Erasme University Hospital, Department of Rheumatology, Route de Lennik 808, Brussels 1070, Belgium. · Expert Opin Biol Ther. · Pubmed #16918261 No free full text.

Abstract: B cells play an important role in the pathogenesis of many autoimmune diseases. Different approaches targeting the B cell compartment are under investigation. Selective modulation of B cells has been recently achieved using a humanised monoclonal antibody against the B cell surface marker CD22. This antibody (epratuzumab) was originally developed for the treatment of non-Hodgkin's lymphoma and was found to be effective, with a very good safety profile. Recent studies have demonstrated the efficacy and safety of epratuzumab in several autoimmune diseases, including systemic lupus erythematosus and primary Sjögren's syndrome.

Roguedas AM, Youinou P, Lemasson G, Pennec YL, Misery L. · Laboratory of Immunology, Brest University Medical School, 2 avenue Foch, 29609 Brest Cedex, France. · J Eur Acad Dermatol Venereol. · Pubmed #16503880 No free full text.

Abstract: Gougerot-Sjögren syndrome (GSS) is a chronic heterogeneous non-organ-specific autoimmune disease, encompassing a wide spectrum of clinical manifestations. It is characterized by a lymphocytic infiltration of the exocrine glands, also called epitheliitis, resulting in xerostomia and keratoconjunctivitis sicca. The skin can also be involved; for example, xerosis is a consequence of epitheliitis. Dermatological consequences of polyclonal reactivity are vasculitis and manifestations of B-cell proliferation vary from plasma cell infiltrates to B-cell lymphoma.

Renaudineau Y, Jamin C, Saraux A, Youinou P. · Brest University Medical School, Brest, France. · Autoimmunity. · Pubmed #15804700 No free full text.

Abstract: Rheumatoid factors (RF), which are antibodies (Ab) with specificity directed against gamma (?) globulins, are the commonest auto-Ab ever described in man. Some of them are referred to as agglutinating RF, others designated non-agglutinating RF. Not only do these characterize rheumatoid arthritis (RA), but they are also encountered in a variety of disease conditions, as well as a proportion of healthy controls. Although non-specific for RA, the measurement of agglutinating IgM-RF remains the most useful serological test for the diagnosis of this disease. Demonstration of abnormal amount of serum RF by any method for which the result has been positive in less than 5% of normal subjects has indeed become one of the seven revised criteria, listed by the American College of Rheumatology (Arnett, FC, Edworthy, SM, Bloch, DA, McShane, DJ, Fries, JF, Cooper, NS, et al. The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis. Arthritis Rheum, 1988: 31: 315-24), for the classification of RA. Over the course of years, the relative importance of genetic (Carson, DA, Chen, PP, Kipps, TJ, Radoux, V, Jirik, FR, Goldfien, RD, et al. Idiotypic and genetic studies of human rheumatoid factors. Arthritis Rheum, 1987: 30: 1321-1325) and environmental (Nemazee, DA, Sato, VL. Enhancing antibody, a novel component of the immune response. Proc Natl Acad Sci USA, 1982: 79: 3828-3832) factors in the production of such intriguing auto-Ab has been delineated.

Roguedas AM, Misery L, Sassolas B, Le Masson G, Pennec YL, Youinou P. · Laboratory of Immunology, Brest University Medical School, Brest, France. · Clin Exp Rheumatol. · Pubmed #15485020 No free full text.

Abstract: The association of kerato-conjunctivitis sicca and xerostomia has been termed Sjogren's syndrome (SS). Although this disease is referred to as a non-organ-specific autoimmune condition, the vast majority of the deleterious effects of primary SS are restricted to the exocrine glands. Among them, the lacrymal and salivary glands are at the foreground, owing to the severity of the objective consequences and the importance of the subjective manifestations. As a result, cutaneous manifestations are minimized, albeit relatively common. We have carefully analyzed the literature to draw up an inventory of the possible skin complications of this syndrome. In addition to xerosis and epidermal IgG deposits, they include vasculitis and cutaneous B cell lymphoma. Alopecia, vitiligo and papular lesions have also been reported to be associated with primary SS.

Youinou P, Mariette X. · Laboratoire d'immunologie, Institut de synergie des sciences et de la santé CHU BP 824 29609 Brest. · Rev Prat. · Pubmed #11252942 No free full text.

Abstract: Sjögren's syndrome presents as an autoimmune exocrinopathy, and the term autoimmune epitheliitis has recently been coined. The major lesion is a lymphocyte infiltrate affecting the salivary glands and consisting predominantly of activated CD4+ T cells. The remaining 20% B lymphocytes, first polyclonal, turn out to be monoclonal. Epithelial cells are endowed with a key-part in the play, inasmuch as they gather together most of the Sjögren's syndrome-specific target autoantigens within apoptotic bodies, and possess all the characteristics of antigen presenting cells. There appears to be every likelihood that the sequence is triggered off by a thus far unknown virus.

Durand V, Lamour A, Devauchelle V, Youinou P, Jamin C. · Laboratory of Immunology, Institut de Synergie des Sciences et de la Santé, Brest, France. · Clin Rev Allergy Immunol. · Pubmed #10907104 No free full text.

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Mamoune A, Durand V, Le Goff P, Pennec YL, Youinou P, Le Corre R. · Laboratory of Immunology, Brest University Medical School, France. · Histol Histopathol. · Pubmed #10809380 No free full text.

Abstract: CD45RO+ T cells are referred to as memory or helper-inducer while CD45RA+ T cells are regarded as naive or suppressor-inducer T cells. The former population predominates in the peripheral blood and even more in the synovial fluid of patients with rheumatoid arthritis, to the expense of the latter population. Within the CD45RB+ compartment, there appears to be more of the fully-differentiated than of the early-differentiated CD4+ T cells. In spite of the fact that these lymphocytes are close to undergoing apoptosis, this programmed cell death is inhibited in the rheumatoid synovium.

Pers JO, Jamin C, Predine-Hug F, Lydyard P, Youinou P. · Division of Dentistry, Brest University Medical School Hospital, Brest, France. · Int J Mol Med. · Pubmed #10028047 No free full text.

Abstract: The CD5(+) B cell population is prominent in early life and produce low avidity and, thereby, polyreactive antibodies. CD5(+) B cells are receptive to cytokines and interleukin-10 seems to be influential in the regulation of some of these CD5(+) B cells. The question of whether CD5 is a marker of activation or a molecule specific for a B cell lineage remains unresolved because evidence in support or against a separate lineage are still a matter for debate. However, we suggest the possibility of different kind of CD5(+) B cells. Indeed, activated CD5(+) B cells do proliferate, following CD5 engagement, while resting CD5(+) B cells do not. Moreover, three ligands for CD5 have, thus far, been identified but their functional effects are yet unknown. CD5(+) B cells probably play a role in setting up the idiotype network, antigen presentation and tolerance induction. B cells of most of the chronic lymphoid leukemias express CD5 molecules and, surprisingly, these cells may be expanded in non-organ-specific autoimmune diseases, such as rheumatoid arthritis or primary Sjögren's syndrome. CD5(+) B cells seems to be involved in the autoantibody production (this does not necessarily imply that pathogenic autoantibodies are produced by CD5(+) B cells) in autoimmune disease and particularly susceptible to transformation in lymphoproliferative disorders. Thus, this B cell population appears to play a key role at the crossroad of the non-organ-specific autoimmune diseases and B lymphoproliferative disorders.

Devauchelle-Pensec V, Pennec Y, Morvan J, Pers JO, Daridon C, Jousse-Joulin S, Roudaut A, Jamin C, Renaudineau Y, Roué IQ, Cochener B, Youinou P, Saraux A. · Hôpital de la Cavale Blanche, CHU Brest, France. · Arthritis Rheum. · Pubmed #17330280 links to  free full text

Abstract: OBJECTIVE: There is evidence to support a dominant role for B cells in the pathophysiology of primary Sjögren's syndrome (SS). Therefore, we evaluated the safety and efficacy of anti-CD20 monoclonal antibody. METHODS: Sixteen patients who met the new American-European Consensus Group criteria for primary SS and scored >50 on at least 2 of 4 visual analog scales (VAS; 100 mm) evaluating global disease, pain, fatigue, and global dryness received infusions of low-dose rituximab (375 mg/m(2)) at weeks 0 and 1 without steroid premedication. RESULTS: Slow rituximab infusions (100 mg/hour) were well tolerated, with only 1 patient experiencing serum sickness-like disease. There was a dramatic reduction in B cells of the blood and salivary gland (SG). At week 12, VAS scores with respect to fatigue and dryness (P < 0.05), tender point count (P < 0.035), and quality of life as evaluated by the Short Form 36 questionnaire (SF-36; P < 0.001) were significantly improved. At week 36, significant improvements were noted in the 4 VAS scores (P < 0.05), tender joint count (P = 0.017), tender point count (P = 0.027), and SF-36 (P < 0.03). Pulmonary manifestations were ameliorated in 1 patient. Patients with improvements on at least 3 of the 4 VAS scores at any visit (n = 11) had a shorter disease duration than the other patients (n = 5; mean +/- SD duration 3.8 +/- 5.4 versus 30.1 +/- 29.5 years; P = 0.02). CONCLUSION: Low-dose rituximab infusions were well tolerated without the benefit of steroids. Infusions induced a rapid depletion of B cells in the blood and SG and could improve primary SS. Controlled studies are needed.

Devauchelle Pensec V, Saraux A, Berthelot JM, Alapetite S, Jousse S, Chales G, Thorel JB, Hoang S, Nouy-Trolle I, Martin A, Chiocchia G, Youinou P, Le Goff P. · Unit of Rheumatology and the Laboratory of Immunology, Hôpital de la Cavale Blanche, CHU Brest, Brest, France. · J Rheumatol. · Pubmed #14705220 No free full text.

Abstract: OBJECTIVE: In a cohort of patients with early arthritis, to evaluate how well foot radiographs at study inclusion predicted a diagnosis of rheumatoid arthritis (RA) 2 years later. METHODS: A cohort of patients with arthritis of less than one year duration was evaluated in a multicenter study and followed for 30 +/- 11 months. An observer blinded to patient data read all 149 hand and foot radiographs done at study inclusion, using item 7 of the 1987 American College of Rheumatology (ACR) criteria for RA and Sharp's method to score erosions and joint space narrowing. RESULTS: The kappa coefficient for the 1987 ACR item 7 was 0.52 for bony decalcification and 0.87 for erosions. Intra and interobserver correlation coefficients for Sharp's scores ranged from 0.90 to 0.98. Erosions at the feet were significantly associated with RA. The item 7 erosion component at the feet was more specific than the full item 7 (97.5% vs 94%; p = 0.01). Sharp's erosion score at the feet was not better than the erosion component of item 7 (sensitivity 18%; specificity 97.5%). Combined use of radiographs of the hands and feet improved the diagnostic performance of the item 7 erosion component; (sensitivity and specificity of item 7 erosions at the hands combined with the feet were 32.5% and 94.5%, respectively). CONCLUSION: The "erosion" criterion at the feet had the best diagnostic performance and was significantly associated with a diagnosis of RA. Combining hand and foot radiographs improved diagnostic performance.

Rochas C, Hillion S, Saraux A, Mageed RA, Youinou P, Jamin C, Devauchelle V. · Université Européenne de Bretagne, Université de Brest, IFR 148 ScInBioS, and Laboratory of Immunology, Centre Hospitalier Universitaire, Brest Hôpital Morvan and Cavale Blanche, Brest, France. · Arthritis Rheum. · Pubmed #19404965 No free full text.

Abstract: OBJECTIVE: B cells that accumulate in the synovial tissue of rheumatoid arthritis (RA) patients revise their receptors due to coordinate expression of recombination-activating gene 1 (RAG-1) and RAG-2 genes. The aim of this study was to determine the mechanisms that control this re-expression. METHODS: B cells from healthy control subjects were cocultured with fibroblast-like synoviocytes (FLS) from patients with RA and osteoarthritis (OA). Re-expression of RAG messenger RNA (mRNA) and proteins was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and indirect immunofluorescence. Activity of RAG enzymes was evaluated by flow cytometry to measure variations in immunoglobulin kappa and lambda light chain expression and by ligation-mediated-PCR to assess specific DNA breaks. Blocking antibodies, short hairpin RNA, and recombinant cytokine were used to identify the molecules involved in RAG re-expression. RESULTS: RA FLS, but not OA FLS, induced B cells to re-express RAG mRNA and proteins. Enzymes were functional, since the kappa-to-lambda ratios decreased and specific DNA breaks were detectable after coculture with RA FLS. Transmembrane BAFF provided the first signal of RAG re-expression, since its down-regulation in RA FLS prevented RAG gene transcription in B cells. The failure of transmembrane BAFF from OA FLS to induce RAG suggests that a second signal was provided by RA FLS. Interleukin-6 (IL-6) is a candidate, since blockade of its receptors precluded transcription of RAG genes by RA FLS. Unless supplemented with IL-6, OA FLS were unable to induce RAG gene expression in normal B cells. CONCLUSION: Two independent signals are required for the induction of RAG gene expression in B cells that infiltrate the synovium of patients with RA.

Youinou P, Jamin C. · Université Européenne de Bretagne, France. · J Autoimmun. · Pubmed #19307104 No free full text.

Abstract: Interleukin (IL)-6 is a prevailing factor of polyclonal B-cell activation of B cells, and thereby of their tolerance breach. Its receptor (R) complex consists of a transducing unit, and a membrane-bound or soluble protein. Many activities ascribed to this cytokine are generated by the soluble IL-6R. Evidence has however been gleaned in autoimmune diseases that the system is instrumental in rheumatoid arthritis (RA), Sjögren's syndrome and systemic lupus erythematosus (SLE). To gain insight into the understanding of the mechanisms behind these observations, a prime example is the recombination-activating gene (Rag) machinery in B lymphocytes. It is interesting that the expression of Rags is favored by IL-6, and repressed by anti-IL-6R antibody (Ab) in RA and SLE. Not surprisingly, clinical benefits are reported in the treatment of autoimmune disorders with anti-IL-6R Ab, and other perspectives about to be open in biotherapy.

Le Pottier L, Devauchelle V, Fautrel A, Daridon C, Saraux A, Youinou P, Pers JO. · Equipe d'Accueil 2216 and Institut Fédératif de Recherche 418, Science et Ingénierie en Biologie-Santé, Université de Brest, Brest, and Université Européenne de Bretagne, Brest, France. · J Immunol. · Pubmed #19265132 No free full text.

Abstract: This study reports on the characterization of B cells of germinal center (GC)-like structures infiltrating the salivary glands (SGs) of patients with Sjögren's syndrome. Eight two-color combinations were devised to characterize the phenotype of these B cells in 11 SG specimens selected from biopsies obtained from 40 Sjögren's syndrome patients and three normal tonsils. The 9G4 mAb, which recognizes V4.34-encoded autoAbs, enabled us to identify autoreactive B cells. Quantitative RT-PCR was used to determine the level of mRNAs for activation-induced cytidine deaminase (AICDA), repressors and transcription factors. CD20(+)IgD(-)CD38(+)CD21(+)CD24(-) B cells, similar to those identified in tonsil GCs, were seen in the SGs of four patients and, and since they expressed AICDA, they were termed "real GCs". CD20(+)IgD(+)CD38(-)CD21(+)CD24(+) B cells, seen in aggregates from the remaining seven samples, were characteristically type 2 transitional B cells and marginal zone-type B cells. They lacked AICDA mRNAs and were termed "aggregates". Real GCs from SGs contained mRNAs for Pax-5 and Bcl-6, like tonsil GC cells, whereas aggregates contained mRNAs for Notch-2, Blimp-1, IRF-4, and BR3, similar to marginal zone B cells. Further experimental data in support of this dichotomy included the restriction of CXCR5 expression to real GC cells, while sphingosine 1-phosphate receptor 1 was expressed only in aggregates. In contrast, both types of B cell clusters expressed the idiotype recognized by the 9G4 mAb. Our data indicate that, in SGs, a minority of B cell clusters represent genuine GC cells, while the majority manifest features of being type 2 transitional B cells and marginal zone cells. Interestingly, both types of B cell aggregates include autoreactive B cells.