S. Dubucquoi

Prevalence of Anti–RNA Polymerase III Antibodies in Systemic Sclerosis: New Data From a French Cohort and a Systematic Review and Meta‐Analysis

Studies assessing the prevalence of anti–RNA polymerase III (anti–RNAP III) antibodies in systemic sclerosis (SSc) have yielded a wide range of results. The aim of the present study was to describe a new SSc cohort tested for presence of anti–RNAP III and perform a systematic review and meta‐analysis to assess the prevalence of anti–RNAP III in patients worldwide and the potential factors of variability.

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.

α-Fodrin autoantibodies in the differential diagnosis of MS and Sjögren syndrome

It is often difficult to diagnose Sjogren syndrome (SS) with neurologic manifestations as frequently only the nervous system is affected and anti-Ro (SSA) and anti-La (SSB) antibodies are found in fewer than 50% of cases.1,2⇓ In a recent study, we demonstrated that primary progressive multiple sclerosis (PPMS) should be the principal differential diagnosis for SS with CNS manifestations.2 However, the question remains as to whether SS is secondary to MS or whether the two are separate entities.3,4⇓ It was recently reported that antibodies against α-fodrin are both a sensitive and a specific marker for SS.5,6⇓ α-Fodrin is a cytoskeletal protein that binds to the cytoplasmic domains of a variety of molecules expressed on the cell surface. It is abundantly expressed in salivary glands but also other tissues including synapses and is probably involved in exocytosis. α-Fodrin is cleaved by caspase 3 upon apoptosis into …

Persistent triple antiphospholipid antibody positivity as a strong risk factor of first thrombosis, in a long-term follow-up study of patients without history of thrombosis or obstetrical morbidity.

Introduction The long-term risk of first thrombosis and benefit of prophylaxis in antiphospholipid antibody (aPL) carriers without history of thrombosis or obstetrical morbidity is poorly known. This study aimed to evaluate the long-term rate and risk factors associated with a first thrombosis in those patients. Patients and methods After a prior study ended in December 2005 and was already published, we extended the follow-up period of our cohort of aPL carriers. Results Ninety-eight of the 103 patients of the previous study were included. The annual first thrombosis rate was 2.3% per patient-year during a median of 13 years (6–17). None of the baseline characteristics was predictive of risk of first thrombosis, but persistent aPL over time were associated with an increased risk. The stronger association was found in triple aPL-positive carriers: OR 3.38 (95% CI: 1.24–9.22). Of note, conversely to our previous findings, no benefit of aspirin prophylaxis was observed. Conclusion The risk of first thrombosis in aPL carriers without history of thrombosis or obstetrical morbidity was significant, persisted linearly over time and was associated with persistent aPL. This risk was especially increased in triple aPL-positive carriers, in whom a close follow-up seems to be necessary. Nevertheless, the benefit of aspirin prophylaxis remained unclear.

Heterogeneous clinical spectrum of anti-SRP myositis and importance of the methods of detection of anti-SRP autoantibodies: a multicentric study.

Anti-signal recognition particle (SRP) antibodies are important serological markers for the diagnosis and the prognosis of idiopathic inflammatory myopathy (IIM), especially to distinguish immune-mediated necrotizing myopathy (IMNM). This study was set up to investigate the phenotype associated with anti-SRP antibodies and to evaluate the methods for detecting these antibodies. Clinical and biological data were retrospectively obtained from 60 adult patients with anti-SRP antibodies detected by a dot immunoassay from 12 centers. Thirty-six (60xa0%) out of these 60 patients suffered from an IIM, and among them, 21 patients were diagnosed as IMNM. Among patients with a definite IIM, proximal weakness and myalgia were prominent symptoms at the time of diagnosis. Only few patients displayed severe extra-muscular symptoms such as cardiac involvement or severe myositis. Mean creatine kinase levels were high for all patients except for two of them. When testing by indirect immunofluorescence (IIF) on HEp2 cells, the fraction of patients displaying the typical anti-SRP fine speckled staining of the cytoplasm was higher in patients with IIM (30/36) (83xa0%) than in patients with non-IIM (3/24) (12.5xa0%) (pxa0<xa00.0001). Thirty (91xa0%) out of 33 patients with a positive immunodot and a characteristic IIF cytoplasmic staining suffered from a clinical definite myositis, whereas only 6 (22xa0%) out of 27 patients with a positive immunodot but a negative cytoplasmic pattern suffered from a myositis (pxa0<xa00.00001). This series highlights the strong heterogeneity of anti-SRP positivity that encompassed IMNM and non-IMNM and supports the necessity of considering both IIF and dot immunoassay to confirm the diagnosis of anti-SRP-associated myositis.

Specific Polysaccharide Antibody Deficiency Revealed by Severe Bacterial Infections in Adulthood: A Report on 11 Cases

We report on 11 cases of specific polysaccharide antibody deficiency (SPAD) revealed in adulthood by severe infections with encapsulated bacteria. Given that immunoglobulin replacement therapy can effectively prevent the recurrence of bacterial infections in this context, SPAD should be considered once other antibody deficiencies have been ruled out.

CD3−CD4+ lymphoid variant of hypereosinophilic syndrome: nodal and extranodal histopathological and immunophenotypic features of a peripheral indolent clonal T-cell lymphoproliferative disorder

The CD3−CD4+ lymphoid variant of hypereosinophilic syndrome is characterized by hypereosinophilia and clonal circulating CD3−CD4+ T cells. Peripheral T-cell lymphoma has been described during this disease course, and we observed in our cohort of 23 patients 2 cases of angio-immunoblastic T-cell lymphoma. We focus here on histopathological (n=12 patients) and immunophenotypic (n=15) characteristics of CD3−CD4+ lymphoid variant of hypereosinophilic syndrome. Atypical CD4+ T cells lymphoid infiltrates were found in 10 of 12 CD3−CD4+ L-HES patients, in lymph nodes (n=4 of 4 patients), in skin (n=9 of 9) and other extra-nodal tissues (gut, lacrymal gland, synovium). Lymph nodes displayed infiltrates limited to the interfollicular areas or even an effacement of nodal architecture, associated with proliferation of arborizing high endothelial venules and increased follicular dendritic cell meshwork. Analysis of 2 fresh skin samples confirmed the presence of CD3−CD4+ T cells. Clonal T cells were detected in at least one tissue in 8 patients, including lymph nodes (n=4 of 4): the same clonal T cells were detected in blood and in at least one biopsy, with a maximum delay of 23 years between samples. In the majority of cases, circulating CD3−CD4+ T cells were CD2hi (n=9 of 14), CD5hi (n=12 of 14), and CD7−(n=4 of 14) or CD7low (n=10 of 14). Angio-immunoblastic T-cell lymphoma can also present with CD3−CD4+ T cells; despite other common histopathological and immunophenotypic features, CD10 expression and follicular helper T-cell markers were not detected in lymphoid variant of hypereosinophilic syndrome patients, except in both patients who developed angio-immunoblastic T-cell lymphoma, and only at T-cell lymphoma diagnosis. Taken together, persistence of tissular clonal T cells and histopathological features define CD3−CD4+ lymphoid variant of hypereosinophilic syndrome as a peripheral indolent clonal T-cell lymphoproliferative disorder, which should not be confused with angio-immunoblastic T-cell lymphoma.

Soluble form of receptor for advanced glycation end-products (sRAGE): do sRAGE ligands or anti-sRAGE auto-antibodies interfere with sRage quantification?

Background The soluble form of the receptor for advanced glycation end-products (sRAGE) has been studied in various diseases. It is not clear why sRAGE levels vary between studies, with controversial results. What also remains to be determined is whether receptor for advanced glycation end-products (RAGE) ligands could affect sRAGE assessment by epitope masking. Recently described anti-sRAGE autoantibodies may play an interfering role. The aim of this study was therefore to investigate the influence of RAGE ligands and anti-sRAGE autoantibodies on sRAGE quantification. Methods The RAGE ligands carboxymethyllysine (CML; AGEs with a high affinity for RAGE), S100 proteins, high-mobility group protein B1 (HMGB1) and β-amyloid peptide (aβ) were tested by enzyme-linked immunosorbent assay (ELISA) with recombinant sRAGE (rHu-sRAGE) or serum from healthy controls. Using ELISA, anti-sRAGE autoantibodies (IgGs) were identified in haemodialysis (HD) patients, then purified and incubated with rHu-sRAGE or serum to investigate their effects on sRAGE levels. Results RAGE ligands, either alone at three different concentrations (CML was also tested at different glycation levels) or a mixture of all these ligands, did not affect sRAGE levels when incubated with rHu-sRAGE or control serum. Compared with healthy controls, HD patients had higher levels of sRAGE (Pu2009<u20090.001) and anti-sRAGE IgGs (Pu2009<u20090.05). However, incubation of rHu-sRAGE with purified IgGs from HD patients had no effect on sRAGE quantification. Conclusions RAGE ligands or anti-sRAGE autoantibodies did not interfere with sRAGE quantification. Further studies are required to elucidate the variability in sRAGE levels reported in the literature and to define the potential of sRAGE for use as a reliable biomarker.

Value of the Overall Pneumococcal Polysaccharide Response in the Diagnosis of Primary Humoral Immunodeficiencies

Background An overall response assay [OVA, based on a 23-valent pneumococcal polysaccharide vaccine (PPV23)] is widely used to screen for anti-pneumococcal antibodies. Given the heterogeneity of response from one polysaccharide (PS) to another, a World Health Organization-standardized serotype-specific enzyme-linked immunosorbent assay (SSA) is considered to be the only reliable method for testing anti-PS antibody responses in individuals with suspected primary immunodeficiencies (PIDs). Objective To evaluate the OVA relative to the reference SSA. Methods Serum samples of adult patients referred for a suspected PID were collected before and then 4–8u2009weeks after immunization with PPV23. The anti-pneumococcal response was systematically assessed with an SSA (7–16 serotypes) and interpreted according to the American Academy of Asthma, Allergy and Immunology’s current guidelines. We used receiver operating characteristic curves and agreement indices to assess the OVA’s diagnostic value in a first cohort. In order to validate these findings, a second (validation) cohort was then prospectively included. Results Sixty-two adult patients were included, and 42 (67.7%) were defined as poor responders according to the SSA. Only the post-immunization titer in the OVA was able to correctly identify poor responders; a titer below 110u2009mg/L gave a positive predictive value of 100% [identifying 24 (57.1%) of the 42 poor responders], and similar levels of diagnostic performance were observed in the validation cohort. The pre-vaccination antibody titer, the post/pre-vaccination antibody titer ratio and a post-vaccination titer above 110u2009mg/L in the OVA were not predictive of the response in the SSA. Conclusion A post-vaccination antibody titer below 110u2009mg/L in the OVA was constantly associated with a poor PPV23 response using the SSA. In all other cases, SSA is the only reliable method for assessing diagnostic vaccination with PPV23.

Prise en charge de la polyarthrite rhumatoïde en 2008 : la biologie peut-elle répondre aux attentes des cliniciens ?

Resume Les douleurs articulaires constituent un motif frequent de consultation medicale. Ces manifestations peuvent etre banales et sans consequences fonctionnelles majeures, mais certains elements de lexamen clinique doivent orienter la prise en charge du patient vers une consultation specialisee. Il est maintenant acquis que le pronostic fonctionnel de la polyarthrite rhumatoide se definit des les premiers mois devolution de la maladie, alors que la symptomatologie clinique reste fruste et limagerie medicale souvent muette. Ces douleurs articulaires doivent alors justifier la mise en place, dans les meilleurs delais, dune therapeutique appropriee. Dans cette dimension, la biologie occupe une place de choix car de nouveaux tests serologiques sont venus completer utilement les marqueurs de diagnostic et de suivi de la polyarthrite rhumatoide. La question reste dapprecier dans quelle mesure ces tests sont fiables pour lutilisation que les cliniciens pourraient en faire.