Efficient integration of transmembrane domains depends on the folding properties of the upstream sequences.

The topology of most membrane proteins is defined by the successive integration of α-helical transmembrane domains at the Sec61 translocon. The translocon provides a pore for the transfer of polypeptide segments across the membrane while giving them lateral access to the lipid. For each polypeptide segment of ∼20 residues, the combined hydrophobicities of its constituent amino acids were previously shown to define the extent of membrane integration.

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.

Belgian recommendations on ANA, anti-dsDNA and anti-ENA antibody testing.

Autoantibodies to nuclear antigens, i.e. antinuclear antibodies (ANA), antibodies to double-stranded DNA (dsDNA) and extractable nuclear antigens (ENA), are useful as diagnostic markers for a variety of autoimmune diseases.

Are immunoglobulin A anti-gliadin antibodies helpful in diagnosing coeliac disease in children younger than 2 years?

The usefulness of immumoglobulin (Ig) A antibodies to gliadin (AGA-IgA) in addition to IgA anti-endomysium and tissue transglutaminase antibodies was evaluated in 4122 children younger than 2 years with a suspicion of coeliac disease (CD). Eight percent (312/4122) displayed IgA anti-endomysium and/or IgA anti-tissue transglutaminase, whereas 2.1% (85/4122) displayed only AGA-IgA.

Acute limbic encephalitis and glutamic acid decarboxylase antibodies: a reality?

Limbic encephalitis (LE) associated with glutamic acid decarboxylase antibodies (GAD-Ab) is rare. We describe a 30-year-old male with acute LE and GAD-Ab, with follow-up during 2 years of cognitive status including verbal episodic memory, number of seizures recorded by high-resolution video-EEG, brain MRI, 2-[18F]-fluoro-2-deoxyglucose PET and GAD-Ab titres. Treatment with corticosteroids, IV immunoglobulins, immunosuppressors and antiepileptic drugs resulted in improved memory status, disappearance of seizures and decreased GAD-Ab titres.

Current practices in antinuclear antibody testing: results from the Belgian External Quality Assessment Scheme.

Background: This study aimed to assess the state-of-the-art of antinuclear antibody (ANA) testing as practiced in the Belgian and Luxembourg laboratories, using the results obtained in the Belgian National External Quality Assessment Scheme from 2000 to 2005.

Methods: During this period, nine samples with different specificities were sent for analysis. Participants were surveyed for methodology used and were asked to report staining pattern and titer of ANAs.

[New autoanti-bodies in rheumatoid arthritis: anti-citrullinated protein or peptide autoanti-bodies and the others].

New treatment strategies require that rheumatoid arthritis (RA) be diagnosed as early as possible. New diagnostic markers were required, because rheumatoid factors (RF), until now criteria for classification of RA, are not sufficiently specific and sometimes appear late, thereby limiting their diagnostic usefulness. The objective of this review is to describe the current state of knowledge and more particularly to analyze the interest of new RA autoanti-bodies, called anti-peptide or anti-citrullinated protein anti-bodies (ACPA).

Prevalence of autoantibodies to cyclic citrullinated peptide in patients with rheumatic diseases other than rheumatoid arthritis: a French multicenter study.

Our objective was to evaluate the prevalence of autoantibodies to cyclic citrullinated peptides (anti-CCP aAbs) in a cohort of patients with a variety of inflammatory or non-inflammatory rheumatic diseases other than rheumatoid arthritis (RA). Six hundred and nine serum samples were tested for anti-CCP aAbs and for rheumatoid factor (RF) using enzyme-linked immunosorbent assays and immunonephelometry. The prevalence of anti-CCP aAbs and RF reached 10% and 25%, respectively, using the positive cutoff value suggested by the manufacturers.

A new line immunoassay for the multiparametric detection of antiganglioside autoantibodies in patients with autoimmune peripheral neuropathies.

A novel line immunoassay for the multiparametric detection of 11 antiganglioside autoantibodies (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, and GQ1b) was evaluated by comparing the reactivities in sera of 77 patients with suspected or definite autoimmune peripheral neuropathies (PNP), 60 blood donors, and 30 systemic lupus erythematodes (SLE) patients. At least one antiganglioside autoantibody was detectable in 97.4% of the patients with neuropathies compared to 12.

Update on Anti-Saccharomyces cerevisiae antibodies, anti-nuclear associated anti-neutrophil antibodies and antibodies to exocrine pancreas detected by indirect immunofluorescence as biomarkers in chronic inflammatory bowel diseases: results of a multicenter study.

Aim: Anti-Saccharomyces cerevisiae antibodies (ASCA), anti-nuclear associated anti-neutrophil antibodies (NANA) and antibodies to exocrine pancreas (PAB), are serological tools for discriminating Crohn's disease (CrD) and ulcerative colitis (UC). Like CrD, coeliac disease (CoD) is an inflammatory bowel disease (IBD) associated with (auto) antibodies. Performing a multicenter study we primarily aimed to determine the performance of ASCA, NANA and PAB tests for IBD diagnosis in children and adults, and secondarily to evaluate the prevalence of these markers in CoD.

[Historical vignettes. History of vasculitis].

This article gives a summary of the history of vasculitis through early and past descriptions. Known, reported and depicted since time immemorial those diseases are quite polymorphous, depending on type and localization of the affected vessels. Clear classification criteria were finally laid down at the end of the XXth century giving a new impulse as well to the detection and the identification of specific biological markers as to the way to treat effectively those severe diseases.

Myopathy associated with anti-signal recognition peptide antibodies: clinical heterogeneity contrasts with stereotyped histopathology.

We report three patients with anti-signal recognition particle antibodies who had different presenting clinical pictures, mimicking acute polymyositis, limb-girdle muscular dystrophy, and acute rhabdomyolysis. Muscle biopsies typically showed necrotizing myopathy with little or no inflammation and deposits of membrane attack complex (C5b-9) in endomysial capillaries. The clinical course was severe in two patients and mild in one.

Anti-pm/scl antibodies in connective tissue disease: Clinical and biological assessment of 14 patients.

Introduction: Anti-PM/Scl antibodies (Anti-PM/Scl) represent a rarely encountered type of antinuclear antibodies. They have mainly been reported in association with idiopathic inflammatory myositis - systemic sclerosis overlap syndromes (also called scleromyositis or sclerodermatomyositis) but also with polymyositis, dermatomyositis and systemic sclerosis without features of overlap syndromes. Studies concerning characteristics of patients with anti-PM/SCl are rare and include small numbers of patients.

Probably anti-Tr associated paraneoplastic cerebellar degeneration as initial presentation of a squamous cell carcinoma of the lung.

Paraneoplastic cerebellar degeneration (PCD) is the most frequent paraneoplastic syndrome affecting the brain. Until now, anti-Tr associated PCD was only seen in patients with Hodgkin's disease. We report a male patient who presented with a progressive ataxia, affecting predominantly the lower limbs and a cerebellar dysarthria.

Diagnostic value of anti-F-actin antibodies in a French multicenter study.

According to international criteria, autoimmune hepatitis (AIH) type 1 is characterized by the presence of antinuclear or anti-smooth muscle antibodies (SMA) with F-actin specificity. SMA have been found in 85% of AIH patients, but are not specific to this disease, and anti-F-actin specificity is not always verified when SMA are detected. The objective of this study was to determine the diagnostic value of anti-F-actin antibodies in a large population.

Dermatomyositis-like syndrome following acute toxoplasmosis.

The case of a patient who developed an acute dermatomyositis-like syndrome upon infection by Toxoplasma gondii is reported. Emphasis is given on the chronology of the anti-Toxoplasma IgM and IgG antibody rise, the muscle enzyme movements, the antinuclear antibody development in comparison to the clinical symptoms and their follow-up after Toxoplasma treatment. The close monitoring of the sequential clinical and biological pattern allows insights into the infectious and auto-immune diseases presented by this patient.

Combined search for anti-beta2-glycoprotein I and anticardiolipin antibodies in antiphospholipid syndrome: contribution to diagnosis.

In this study we sought to assess (1) the diagnostic value of a combined search for anti-beta(2)-glycoprotein (abeta(2)-GPIs) and anticardiolipin antibodies (aCLs) in primary (APS I) and secondary (APS II) antiphospholipid syndrome and (2) the influence of the beta(2)-GPI preparation in the ELISA's results. abeta(2)-GPI and aCL concentrations were assessed in 70 patients with APS and compared with those in 65 patients with systemic lupus erythematosus (SLE) without clinical features of APS. In APS patients (38 with APS I, 32 with APS II), the diagnosis had to have been made at least 3 years earlier; in subjects with SLE, the diagnosis had to have been made at least 5 years earlier.

Autoantibodies and human immunodeficiency viruses infection: a case-control study.

Objective: To determine the prevalence of organ-specific and non-specific autoantibodies in HIV-infected patients.

Design: A multicentric collaborative case-control study including 105 HIV patients and 100 sex- and age-matched HIV-negative healthy volunteers.

Methods: Antinuclear, anti-ds DNA, anti-histone, anti-Sm, rheumatoid factor(IgM), anti-beta 2 glycoprotein 1, antineutrophil cytoplasmic, anti-LKM1, anti-LCA1, anti-gastric parietal cell, antiplatelet, anti-intermediate filament, anti-mitotic spindle apparatus, anti-Golgi, anti-ribosome and anti-thyroid autoantibodies were screened in six European laboratories.

Anti-Ro52 reactivity is an independent and additional serum marker in connective tissue disease.

Objective: To determine whether anti-Ro52 is an independent serum marker in connective tissue disease.

Methods: Over a two year period, 1727 consecutive antinuclear antibody (ANA) positive serum samples were analysed in parallel by double immunodiffusion with thymus/spleen nuclear extract and by line immunoassay with recombinant Ro52, recombinant La/SSB, and natural Ro60. Sera that were only reactive towards Ro52 were further analysed by a variety of additional anti-SSA/Ro detection methods and by specific anti-Ro52 and anti-Ro60 assays.

Identification of citrullinated rheumatoid arthritis-specific epitopes in natural filaggrin relevant for antifilaggrin autoantibody detection by line immunoassay.

Objective: To identify immunodominant epitopes in natural filaggrin that are reactive with antifilaggrin autoantibodies (AFA) in the sera of patients with rheumatoid arthritis (RA) and to explore their use in a diagnostic assay format.

Methods: Based on the results of epitope mapping of human natural filaggrin as well as molecular modeling and computational chemistry, synthetic peptides together with recombinant citrullinated filaggrin were evaluated by a line immunoassay (LIA) for AFA detection. Diagnostic performance was assessed using 336 RA and 253 disease control sera and was compared with that of reference methods.