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Resume Objectif Decrire la signification clinique des anticorps anti-SG2NA egalement appeles anti-pseudo-PCNA de type 1 ( proliferating cell nuclear antigen auto-antibodies ) qui sont des anticorps antinucleaires (ANA) rares detectes par immunofluorescence indirecte (IFI) sur cellules proliferatives HEp-2 en phase S/G2. Par analogie avec les anticorps anti-PCNA, ils sont associes au lupus erythemateux systemique (LES), aux cancers ou aux pathologies virales. Methodes Entre mai 2006 et fevrier 2013, 16 827 patients ont eu une recherche d’ANA positive au laboratoire d’immunologie de Strasbourg (France). Nous avons analyse de facon retrospective les donnees cliniques et biologiques des 126 patients ayant un aspect de fluorescence de type anti-pseudo-PCNA de type 1. Resultats La prevalence des anticorps anti-pseudo-PCNA de type 1 etait de 0,75 % parmi les patients ayant une recherche d’ANA positive. L’âge median etait de 56,9 ans (deviation standard [DS] 13,4 ans), avec un sex-ratio de 1,9 en faveur des femmes. En comparaison avec les patients porteurs d’anticorps antinucleaires, significativement plus de patients etaient hospitalises dans le service d’oncologie et hematologie de l’hopital (23 % vs 6,3 %, p + ( p −6 ). Finalement, la presence de l’anticorps anti-pseudo-PCNA de type 1 etait associee dans 30 cas sur 126 avec d’autres auto-anticorps (en particulier diriges contre les proteines du cycle cellulaire), suggerant un mecanisme plus general de rupture de tolerance lymphocytaire B envers les auto-antigenes. Conclusion A la lumiere de nos resultats, l’exploration des tumeurs devrait etre recommandee pour les patients ayant des Ac anti-pseudo-PCNA de type 1. Aucune association de ces auto-anticorps avec le lupus n’a pu etre montree.

International audience; BACKGROUND:Primary immunodeficiencies (PIDs) are inherited diseases associated with a considerable increase in susceptibility to infections. It is known that PIDs can also predispose to cancer and immune diseases, including allergy, autoimmunity, and inflammation.OBJECTIVE:We aimed at determining the incidence of autoimmunity and inflammation in patients with PIDs.METHODS:We have retrospectively screened 2183 consecutive cases of PID in the Centre de Référence Déficits Immunitaires Héréditaires registry (CEREDIH; the French national PID registry) for the occurrence of autoimmunity and inflammation.RESULTS:One or more autoimmune and inflammatory complications were noted in 26.2% of patients, with a risk of onset throughout the patient's lifetime. The risk of autoimmune cytopenia was at least 120 times higher than in the general population, the risk of inflammatory bowel disease in children was 80 times higher, and the risk of other autoimmune manifestations was approximately 10 times higher. Remarkably, all types of PIDs were associated with a risk of autoimmune and inflammatory complications, although the greatest risk was associated with T-cell PIDs and common variable immunodeficiency. The occurrence of autoimmune disease is a negative prognostic factor for survival.CONCLUSIONS:Our results provide the basis for a detailed prospective evaluation of autoimmunity and inflammation in the context of PIDs, with a view to accurately assessing these risks and describing the possible effect of medical intervention.

The antiphospholipid syndrome is an acquired autoimmune syndrome characterized by arterial and/or venous thrombosis and/or pregnancy morbidity in association with the prolonged presence of serum autoantibodies, including the so-called lupus anticoagulant and anticardiolipin antibodies, which are mainly directed against complexes of proteins and anionic phospholipids.

Lupus treatment has evolved considerably with spectacular advances that can be summarized in 10 points. Hydroxychloroquine and cyclophosphamide are still standard drugs, provided their use is optimized. Contraception and postmenopausal hormone replacement therapy have finally been tested in randomized studies with fairly reassuring results, although prudence remains essential in patients with severe lupus and above all in those with thrombotic complications (antiphospholipid syndrome). Mycophenolic acid has been shown to be useful in the treatment of lupus nephropathies, but its specific place in the therapeutic strategy remains to be defined. Other drugs (sirolimus, abatacept) are currently being evaluated. Anti-lymphocyte B therapies are growing in popularity. Rituximab and other drugs (anti-BAFF, TACI-Fc) are also being evaluated and their results appear very interesting. Interferon alpha (type I) inhibition is an attractive therapeutic approach in lupus but its use in humans is still premature. Peptide vaccination with fragments of autoantibodies or autoantigens is an elegant strategy, and preliminary results justify further studies. Anti-TNF molecules may be beneficial in lupus. Complement inhibition can be useful in lupus and antiphospholipid syndrome but drugs usable in humans (anti-C5) must be developed. Atheromatosis in lupus is the principal cause of morbidity and mortality and must be managed. Smoking cessation is essential, but other approaches (statins) should also be discussed. Many futuristic types of immune manipulation may be envisioned (proteasome inhibition, modulation of Fc gammaRIIB, and modulation of cell signaling (PI3kgamma)). Hence the perspectives are numerous. We will soon be able to optimize the treatment of our patients. Nevertheless, rigorous evaluation of the risk/benefit ratio of new drugs and of their most appropriate place in the therapeutic strategy against systemic lupus is indispensable.

Key points The antiphospholipid syndrome is characterized by the association of clinical events (thrombosis and/or obstetrical complications) and heterogeneous autoantibodies reacting with complexes of proteins and anionic phospholipids. Most of these recognized proteins can bind to anionic phospholipids and play a role in natural regulation of coagulation. Inhibition by these autoantibodies of the natural regulators of excessive coagulation is probably responsible for the prothrombotic state that characterizes this disease. Animal models have helped explain the mechanisms of obstetrical complications . Human antiphospholipid antibodies passively transferred to pregnant mice directly cause fetal resorption. This effect is mediated by complement fractions and neutrophil activation and is inhibited by heparin. The origin of these autoantibodies is still debated. Physiologically, the cause may be associated with exposure to anionic phospholipids on the surface of apoptotic cells. The affinity maturation process, which leads to the acquisition of somatic mutations, can then generate highly pathogenic antiphospholipid antibodies.

Joint Bone Spine - In Press.Proof corrected by the author Available online since mardi 30 decembre 2014

Polyreactive antibodies able to bind various apparently unrelated structures represent a frequent antibody population in autoimmune diseases. In this work, the structural basis of the double reactivity of such autoantibodies was investigated using as models polyclonal and monoclonal human rheumatoid factors (RF) reacting with histones. Both direct ELISA binding and competitive inhibition experiments were performed. A more precise delineation of the histone regions recognized by the RFs was made by means of 27 synthetic peptides of these proteins. Anti-idiotope (Id) murine antibodies were used to map the binding sites involved on RF in the interaction with IgG and histones. Among the 13 polyclonal and six monoclonal RFs tested, four and two respectively were found to cross-react with IgG and histones. The fragments shown to be the most frequently recognized by RFs were located in residues 1–16 and 204–218 of H1, 1–20 and 65–85 of H2A, and 1–21 and H3. The results obtained by competitive ELISA assays using IgG, histone peptides and anti-Id monoclonal antibodies led us to confirm and characterize more precisely our previous finding suggesting the existence of topographically distinct binding sites for the different targets recognized by RFs.

In vitro stimulation of peripheral blood lymphocytes from two rheumatoid arthritis patients with pokeweed mitogen (PWM) and Epstein-Barr virus (EBV) induced differing sets of IgM rheumatoid factor (IgM-RF) idiotypes. Thus, in either patient. 71–82% of the IgM-RF induced by PWM, but only 30% of the IgM-RF induced by EBV, shared individually specific idiotypes with serum IgM-RF. These results suggest that differing populations of autoreactive B lymphocytes were induced by the two mitogens. PWM, a T-cell-dependent mitogen, induced the same RF-bearing B cells that were active in vivo . In contrast, EBV, a T-cell-independent mitogen, stimulated predominantly an inactive population of RF precursor B lymphocytes.

The effects of levamisole (LMS) on immunoglobulin (Ig) production were studied in vitro using peripheral blood lymphocytes from normal subjects stimulated with pokeweed mitogen (PWM). Cells were cultured for 9 days with varying concentrations of LMS and PWM, and immunoglobulin secretion in the supernatants was quantified by solid phase radioimmunoassay. The results showed that 1) the effect of LMS in vitro depends upon the degree of lymphocyte stimulation by PWM. When PWM stimulation is optimal, typical pharmacologic concentrations of LMS (0.5 micro/ml) decrease both IgM and IgG production by 50%. However, at lower suboptimal doses of PWM, LMS, at similar concentrations, enhances immunoglobulin production by 24% (p less than 0.01). Unstimulated lymphocytes are not affected by LMS. 2) The target cell upon which LMS acts is present among a T subpopulation that lacks the Fc receptor for aggregated rabbit IgG (T gamma -negative). We suggest that the diverse effects of LMS on autoimmune disease in vivo may depend upon both the size and degree of activation of the T gamma -negative lymphocyte pool.

The effects of DL -α-difluoromethylornithine (DFMeOrn), an irreversible inhibitor of L -ornithine decarboxylase, on immunoglobulin production were studied in vitro using human peripheral blood lymphocytes stimulated with pokeweed mitogen. DFMeOrn inhibits in a concentation-dependent manner the usual pokeweed mitogen-induced increases of polyamine contents (putrescine, spermidine, spermine) and of [ 3 H]thymidine incorporation. In parallel with the reduction of polyamine content and of thymidine incorporation, IgG and IgM productions are diminished, a 70% decrease being observed at 5 mM DFMeOrn concentration. Therefore, it appears that inhibition of polyamine biosynthesis may ultimately interfere with the cellulr immunologic response by blocking cell proliferation. These findings certainly deserve further consideration both under in vitro and in vivo conditions.