Rheumatoid Arthritis: Venables PJ

Lundberg K, Venables PJ. · No affiliation provided · Arthritis Res Ther. · Pubmed #19090965 links to  free full text

Abstract: The paradigm for pathogenic autoimmunity is the generation of high-titre, affinity-matured autoantibodies to a restricted family of autoantigens, in the appropriate genetic context. Genetic determinants of autoimmunity are largely found within the major histocompatibility complex (MHC) and the 'genotype to serotype to phenotype' concept is supported in a number of autoimmune diseases, where both genotype and serotype are well established. The serotype is autoantigen-driven, with evidence of epitope spreading as the disease evolves from asymptomatic to pathogenic autoimmunity. In rheumatoid arthritis and multiple sclerosis, where the autoantigens are poorly characterised, the use of an array in animal models may produce a hint of what happens in human disease. A more complete picture will be obtained from animals transgenic for human MHC, immunised with known human autoantigens.

Wegner N, Wait R, Venables PJ. · Kennedy Institute of Rheumatology Division, Imperial College London, 65 Aspenlea Road, London W6 8LH, UK. · Int J Biochem Cell Biol. · Pubmed #18926919 No free full text.

Abstract: The immune system has evolved to eliminate or inactivate infectious organisms. An inappropriate response against self-components (autoantigens) can result in autoimmune disease. Here we examine the hypothesis that some evolutionarily conserved proteins, present in pathogenic and commensal organisms and their hosts, provide the stimulus that initiates autoimmune disease in susceptible individuals. We focus on seven autoantigens, of which at least four, glutamate decarboxylase, pyruvate dehydrogenase, histidyl-tRNA synthetase and alpha enolase, have orthologs in bacteria. Citrullinated alpha-enolase, a target for autoantibodies in 40% of patients with rheumatoid arthritis, is our main example. The major epitope is highly conserved, with over 90% identity to human in some bacteria. We propose that this reactivity of autoantibodies to shared sequences provides a model of autoimmunity in rheumatoid arthritis, which may well extend to other autoimmune disease in humans.

Venables PJ. · Kennedy Institute Division, Imperial College, London, UK. · Best Pract Res Clin Rheumatol. · Pubmed #16979538 No free full text.

Abstract: Sjogren's syndrome is an autoimmune exocrinopathy that predominantly affects salivary and lachrymal glands, leading to dry eyes and mouth. The most common clinical problems faced by the rheumatologist are those of dry eyes and mouth, parotid swelling, fatigue and extraglandular manifestations. The first stage in management is to make an accurate diagnosis based on the American/European consensus criteria. The most frequent differential diagnoses are dry eyes and mouth symptoms, a variant of chronic fatigue syndrome and fibromyalgia, and sialosis, which causes a non-inflammatory enlargement of the parotid glands. The mainstay of treatment for the sicca symptoms is local therapy, and that for the milder systemic symptoms is hydroxychloroquine. Steroids and immunosuppressive drugs are reserved for more severe extraglandular disease. In spite of intensive research in other systemic treatments including biologic therapies, there is limited evidence to support their use in routine clinical practice.

Venables PJ. · Kennedy Institute of Rheumatology Division, Imperial College School of Medicine, 1 Aspenlea Road, London W6 8LH, UK. · Best Pract Res Clin Rheumatol. · Pubmed #15158743 No free full text.

Abstract: Sjögren's syndrome is an autoimmune disease characterized by inflammation of the exocrine glands, leading to impaired function. Here, I review the relatively short history of the syndrome and explain why it is frequently underdiagnosed, undertreated and under-researched. Attempts to provide classification criteria have culminated in the revised American-European Consensus Criteria, which provide a sound basis for both clinical management and research. The recognition that Sjögren's syndrome is a disease of considerable morbidity has led to a more aggressive approach to therapy ranging from topical therapies to systemic treatment with secretagogues such as pilocarpine and cemiveline, and immunomodulatory drugs such as hydroxychloroquine and interferon-alpha. The central role of the glandular epithelial cell is identified as the key to understanding the pathogenesis of the disease. Hypofunction rather than destruction of these cells is now regarded as the main mechanism of secretory failure in Sjögren's syndrome.

Lundberg K, Kinloch A, Fisher BA, Wegner N, Wait R, Charles P, Mikuls TR, Venables PJ. · Kennedy Institute of Rheumatology, Imperial College London, London, UK. · Arthritis Rheum. · Pubmed #18821669 No free full text.

Abstract: OBJECTIVE: To map the antibody response to human citrullinated alpha-enolase, a candidate autoantigen in rheumatoid arthritis (RA), and to examine cross-reactivity with bacterial enolase. METHODS: Serum samples obtained from patients with RA, disease control subjects, and healthy control subjects were tested by enzyme-linked immunosorbent assay (ELISA) for reactivity with citrullinated alpha-enolase peptides. Antibodies specific for the immunodominant epitope were raised in rabbits or were purified from RA sera. Cross-reactivity with other citrullinated epitopes was investigated by inhibition ELISAs, and cross-reactivity with bacterial enolase was investigated by immunoblotting. RESULTS: An immunodominant peptide, citrullinated alpha-enolase peptide 1, was identified. Antibodies to this epitope were observed in 37-62% of sera obtained from patients with RA, 3% of sera obtained from disease control subjects, and 2% of sera obtained from healthy control subjects. Binding was inhibited with homologous peptide but not with the arginine-containing control peptide or with 4 citrullinated peptides from elsewhere on the molecule, indicating that antibody binding was dependent on both citrulline and flanking amino acids. The immunodominant peptide showed 82% homology with enolase from Porphyromonas gingivalis, and the levels of antibodies to citrullinated alpha-enolase peptide 1 correlated with the levels of antibodies to the bacterial peptide (r2=0.803, P<0.0001). Affinity-purified antibodies to the human peptide cross-reacted with citrullinated recombinant P gingivalis enolase. CONCLUSION: We have identified an immunodominant epitope in citrullinated alpha-enolase, to which antibodies are specific for RA. Our data on sequence similarity and cross-reactivity with bacterial enolase may indicate a role for bacterial infection, particularly with P gingivalis, in priming autoimmunity in a subset of patients with RA.

Kinloch A, Lundberg K, Wait R, Wegner N, Lim NH, Zendman AJ, Saxne T, Malmström V, Venables PJ. · Imperial College London, London, UK. · Arthritis Rheum. · Pubmed #18668562 links to  free full text

Abstract: OBJECTIVE: To examine synovial fluid as a site for generating citrullinated antigens, including the candidate autoantigen citrullinated alpha-enolase, in rheumatoid arthritis (RA). METHODS: Synovial fluid was obtained from 20 patients with RA, 20 patients with spondylarthritides (SpA), and 20 patients with osteoarthritis (OA). Samples were resolved using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by staining with Coomassie blue and immunoblotting for citrullinated proteins, alpha-enolase, and the deiminating enzymes peptidylarginine deiminase type 2 (PAD-2) and PAD-4. Proteins from an RA synovial fluid sample were separated by 2-dimensional electrophoresis, and each protein was identified by immunoblotting and mass spectrometry. Antibodies to citrullinated alpha-enolase peptide 1 (CEP-1) and cyclic citrullinated peptide 2 were measured by enzyme-linked immunosorbent assay. RESULTS: Citrullinated polypeptides were detected in the synovial fluid from patients with RA and patients with SpA, but not in OA samples. Alpha-enolase was detected in all of the samples, with mean levels of 6.4 ng/microl in RA samples, 4.3 ng/microl in SpA samples, and <0.9 ng/microl in OA samples. Two-dimensional electrophoresis provided evidence that the alpha-enolase was citrullinated in RA synovial fluid. The citrullinating enzyme PAD-4 was detected in samples from all 3 disease groups. PAD-2 was detected in 18 of the RA samples, in 16 of the SpA samples, and in none of the OA samples. Antibodies to CEP-1 were found in 12 of the RA samples (60%), in none of the SpA samples, and in 1 OA sample. CONCLUSION: These results highlight the importance of synovial fluid for the expression of citrullinated autoantigens in inflammatory arthritis. Whereas the expression of citrullinated proteins is a product of inflammation, the antibody response remains specific for RA.

Snir O, Widhe M, von Spee C, Lindberg J, Padyukov L, Lundberg K, Engström A, Venables PJ, Lundeberg J, Holmdahl R, Klareskog L, Malmström V. · Department of Medicine, Rheumatology Unit, Karolinska University Hospital, Karolinska Institute, Solna, Stockholm, Sweden. · Ann Rheum Dis. · Pubmed #18635594 No free full text.

Abstract: BACKGROUND: Autoantibodies to cyclic citrullinated peptides (anti-CCP) are present in most patients with rheumatoid arthritis (RA), and associate with HLA-DRB1 shared epitope (SE) alleles. OBJECTIVE: To investigate reactivities of anti-CCP to various citrullinated proteins/peptides, which represent potential autoantigens in RA, and to examine the relationship between such antibodies, and their association with genetic variants within HLA-DRB1 SE alleles. METHODS: Serum samples from 291 patients with established RA and 100 sex- and age-matched healthy subjects were included in this study. Sera were first analysed for presence of anti-CCP antibodies and further for IgG and IgA antibodies towards candidate autoantigens in both their native and citrullinated form including: fibrinogen, alpha-enolase peptide-1 and the C1-epitope of type II collagen (C1(III)). Antibody specificity was confirmed by cross-reactivity tests. HLA-DR genotyping was performed. RESULTS: 72% of patients with RA were anti-CCP positive. Among the candidate autoantigens examined, IgG antibodies to citrullinated fibrinogen were found in 66% of patients' sera and in 41% for both citrullinated alpha-enolase peptide-1 and citrullinated C1(III). These antibodies were mainly seen in the anti-CCP-positive patient group; they were specific for their respective antigen and displayed limited cross reactivity. IgA responses were also detected, but less frequently than IgG. Anti-CCP and anti-citrullinated protein antibodies were associated with HLA-DRB1*04 rather than with HLA-DRB1*01 alleles. CONCLUSIONS: Antibodies directed against several citrullinated antigens are present in CCP-positive RA, with many patients displaying multireactivity. All specific reactivities were primarily associated with the HLA-DRB1*04 alleles, suggesting common pathways of anti-citrulline immunity.

Kinloch A, Tatzer V, Wait R, Peston D, Lundberg K, Donatien P, Moyes D, Taylor PC, Venables PJ. · Kennedy Institute of Rheumatology, Imperial College London, Charing Cross Hospital Campus, 1 Aspenlea Road, London W6 8LH, UK. · Arthritis Res Ther. · Pubmed #16277695 links to  free full text

Abstract: Antibodies against citrullinated proteins are highly specific for rheumatoid arthritis (RA), but little is understood about their citrullinated target antigens. We have detected a candidate citrullinated protein by immunoblotting lysates of monocytic and granulocytic HL-60 cells treated with peptidylarginine deiminase. In an initial screen of serum samples from four patients with RA and one control, a protein of molecular mass 47 kDa from monocytic HL-60s reacted with sera from the patients, but not with the serum from the control. Only the citrullinated form of the protein was recognised. The antigen was identified by tandem mass spectrometry as alpha-enolase, and the positions of nine citrulline residues in the sequence were determined. Serum samples from 52 patients with RA and 40 healthy controls were tested for presence of antibodies against citrullinated and non-citrullinated alpha-enolase by immunoblotting of the purified antigens. Twenty-four sera from patients with RA (46%) reacted with citrullinated alpha-enolase, of which seven (13%) also recognised the non-citrullinated protein. Six samples from the controls (15%) reacted with both forms. Alpha-enolase was detected in the RA joint, where it co-localised with citrullinated proteins. The presence of antibody together with expression of antigen within the joint implicates citrullinated alpha-enolase as a candidate autoantigen that could drive the chronic inflammatory response in RA.

Moyes DL, Martin A, Sawcer S, Temperton N, Worthington J, Griffiths DJ, Venables PJ. · Kennedy Institute of Rheumatology, Imperial College London, 1 Aspenlea Road, London W6 8LH, UK. · Genomics. · Pubmed #16024218 No free full text.

Abstract: The human endogenous retroviruses HERV-K113 and HERV-K115 are full-length proviruses but unusual in being found in only a proportion of the population. Here, we study the geographic distribution of these HERVs and their prevalence in autoimmune disease. The frequency of HERV-K113 and HERV-K115 in 174 individuals from Africa was 21.8 and 34.1%, respectively, compared to 4.16 and 1% in 96 people in the United Kingdom (p < 0.001). Prevalence in Yemen (n = 56) was 8 and 7.14% and in Papua New Guinea (n = 54) 0% for both. In the United Kingdom, HERV-K113 was found in 15.6% of 96 Sjögren's syndrome patients (p < 0.01) and 11.9% of 109 multiple sclerosis patients (p < 0.05). No increase in prevalence in either disease was seen with HERV-K115. These data suggest that both viruses are recently integrated and/or under positive evolutionary selection pressure. HERV-K113 may be a genetic risk factor for some types of autoimmunity.

Herve CA, Wait R, Venables PJ. · Kennedy Institute, Immunology, London, UK. · Rheumatology (Oxford). · Pubmed #12730513 links to  free full text

Abstract: OBJECTIVE: To test the hypothesis that glucose-6-phosphate isomerase (GPI) is a novel autoantigen in RA. METHODS: Eighty-eight serum samples from 23 patients with rheumatoid arthritis (RA), 25 with Sjögren's syndrome, 20 with systemic lupus erythematosus and 20 healthy controls were tested by enzyme-linked immunosorbent assay (ELISA) using a commercially available, partially purified rabbit GPI as antigen. Beside each duplicate well containing antigen (10 micro g/ml), uncoated blocked duplicate wells (phosphate-buffered saline only) were included as controls for non-specific binding for every serum tested. We also examined antibodies binding to various polypeptides in the GPI preparation by immunoblotting in 73 of the sera. RESULTS: By ELISA, binding levels were low and there was no difference between serum from patients with RA, other rheumatic diseases and normal controls. By immunoblotting, antibodies binding to the GPI polypeptide were present in 70-80% of all groups tested. In addition, we showed that another polypeptide identified as phosphoglucomutase was also present in the preparation and reacted with human immunoglobulins. CONCLUSION: Our findings suggest that GPI is not a specific autoantigen in RA.

Vincent TL, Richardson MP, Mackworth-Young CG, Hawke SH, Venables PJ. · Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College, London, United Kingdom. · Am J Med. · Pubmed #12586236 No free full text.

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Brand A, Griffiths DJ, Herve C, Mallon E, Venables PJ. · Chelsea and Westminster Hospital, London, UK. · J Autoimmun. · Pubmed #10441180 No free full text.

Abstract: It has long been suggested that retroviral infection may play a role in the pathogenesis of autoimmune rheumatic disease. Particles resembling retroviruses have been reported in tissue from patients with Sjögren's syndrome, lupus and rheumatoid arthritis, and molecular mimicry between retroviral antigens and host proteins has been proposed as a mechanism of induction of autoimmunity. Since 1980, four distinct human infectious retroviruses have been discovered, HTLV-I, HTLV-II, HIV-1 and HIV-2. We recently cloned part of a new human retrovirus genome, designated human retrovirus-5 (HRV-5) and demonstrated that this is not endogenous and is therefore a novel infectious retrovirus. Because symptoms resembling arthritis, polymyositis and Sjögren's syndrome occur in individuals infected with HTLV-I and HIV-1, we investigated the possibility that HRV-5 was associated with idiopathic rheumatic disease. Using nested PCR, HRV-5 we demonstrated that proviral DNA was present in approximately 50% of synovial samples of arthritic joints and was also found in over 10% of blood samples of patients with rheumatoid arthritis and systemic lupus erythematosus. HRV-5 proviral DNA was not detectable in affected tissues of autoimmune diseases and was found in only one of over 200 tissues taken at autopsy from non-rheumatoid patients. Sequence analysis of the amplified viral segment showed genetic variation between samples with maintenance of the open reading frame typical of a replicating infectious retrovirus. Thus HRV-5 appears to be a human retrovirus found with a very low genome copy number in most tissues, but which is increased to detectable levels in inflamed joints and blood from patients with rheumatic disease. Whether HRV-5 is aetiologically important in these diseases remains to be determined.

Griffiths DJ, Cooke SP, Hervé C, Rigby SP, Mallon E, Hajeer A, Lock M, Emery V, Taylor P, Pantelidis P, Bunker CB, du Bois R, Weiss RA, Venables PJ. · Institute of Cancer Research, Chester Beatty Laboratories, London, UK. · Arthritis Rheum. · Pubmed #10088767 links to  free full text

Abstract: OBJECTIVE: To examine whether human retrovirus 5 (HRV-5) infection is associated with autoimmune rheumatic disease. METHODS: DNA from patients with various disorders including inflammatory diseases and from normal subjects was tested by nested polymerase chain reaction (PCR) for HRV-5 proviral DNA. Positive results were confirmed by DNA sequencing. RESULTS: HRV-5 proviral DNA was detected in 53% of synovial samples from arthritic joints, in 12% of blood samples from patients with rheumatoid arthritis (RA), and in 16% of blood samples from patients with systemic lupus erythematosus. In contrast, it was not detectable by PCR of affected tissues from patients with several other autoimmune diseases and was found in only 1 of >200 tissue specimens obtained at autopsy from non-RA patients. Sequence analysis of the amplified viral segment showed genetic variation between samples with maintenance of the open reading frame, typical of a replicating infectious retrovirus. CONCLUSION: This is the first report of the frequent detection of HRV-5 in any disease. We propose that the possible involvement of HRV-5 in autoimmune and rheumatic disease should be investigated further.

Sofat N, Venables PJ. · No affiliation provided · Ann Rheum Dis. · Pubmed #18408117 No free full text.

This publication has no abstract.

Venables PJ, Hajeer A. · No affiliation provided · Arthritis Rheum. · Pubmed #10616029 links to  free full text

This publication has no abstract.