1 2979 80 GENETIC BACKGROUND OF JUVENILE IDIOPATHIC ARTHRITIS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS THE MOST COMMON CHRONIC RHEUMATOLOGIC DISEASE IN CHILDREN. JIA IS A GROUP OF DISORDERS THAT SHARE THE CLINICAL MANIFESTATION OF CHRONIC JOINT INFLAMMATION. THE HUMAN LEUKOCYTE ANTIGEN REGION (HLA) SEEMS TO BE A MAJOR SUSCEPTIBILITY LOCUS FOR JIA THAT IS ESTIMATED TO ACCOUNT FOR 17% OF FAMILIAL SEGREGATION OF THE DISEASE. TO DATE, AROUND 20 NON-HLA LOCI CONFERRING SUSCEPTIBILITY TO JIA WERE FOUND. AT LEAST A HALF OF THOSE ARE SHARED BETWEEN JIA AND RHEUMATOID ARTHRITIS (RA), AN ADULT RHEUMATIC DISEASE, THEREBY SUGGESTING FOR SIMILARITY OF PATHOGENIC MECHANISMS OF BOTH DISEASES. NEW FINDINGS ALSO SUGGEST FOR A LIKELY ROLE OF EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF JIA THAT SHOULD BE INVESTIGATED IN THE FUTURE. 2014 2 6787 73 [CONTRIBUTION OF NON-HLA GENES TO JUVENILE IDIOPATHIC ARTHRITIS SUSCEPTIBILITY]. JUVENILE IDIOPATHIC ARTHRITIS (JAL4) IS THE MOST COMMON CHRONIC RHEUMATOLOGIC DISEASE IN CHILDREN. JIA IS A GROUP OF DISORDERS THAT SHARE THE CLINICAL MANIFESTATION OF CHRONIC JOINT INFLAMMATION. THE HUMAN LEUKOCYTE ANTIGEN REGION (HLA) SEEMS TO BE A MAJOR SUSCEPTIBILITY LOCUS FOR JIA THAT IS ESTIMATED TO ACCOUNT FOR 17% OF FAMILIAL SEGREGATION OF THE DISEASE. GENOME-WIDE ASSOCIATION STUDIES (GWAS), CASE-CONTROL STUDIES AND META-ANALYSES OF THE POST-GWAS ERA REVEALED OVER 20 NON-HLA LOCI CONFERRING SUSCEPTIBILITY TO JIA. AT LEAST A HALF OF THOSE ARE SHARED BETWEEN JIA AND RHEUMATOID ARTHRITIS, AN ADULT RHEUMATIC DISEASE, THEREBY SUGGESTING FOR SIMILARITY OF PATHOGENIC MECHANISMS OF BOTH DISEASES. NEW FINDINGS ALSO SUGGEST FOR A LIKELY ROLE OF EPIGENETIC ALTERATIONS IN THE PATHOGENESIS OF JIA THAT SHOULD BE INVESTIGATED IN THE FUTURE. 2014 3 3507 27 IDENTIFICATION OF TARGET GENES AT JUVENILE IDIOPATHIC ARTHRITIS GWAS LOCI IN HUMAN NEUTROPHILS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS THE MOST COMMON CHRONIC RHEUMATIC DISEASE AMONG CHILDREN WHICH COULD CAUSE SEVERE DISABILITY. GENOMIC STUDIES HAVE DISCOVERED SUBSTANTIAL NUMBER OF RISK LOCI FOR JIA, HOWEVER, THE MECHANISM OF HOW THESE LOCI AFFECT JIA DEVELOPMENT IS NOT FULLY UNDERSTOOD. NEUTROPHIL IS AN IMPORTANT CELL TYPE INVOLVED IN AUTOIMMUNE DISEASES. TO BETTER UNDERSTAND THE BIOLOGICAL FUNCTION OF GENETIC LOCI IN NEUTROPHILS DURING JIA DEVELOPMENT, WE TOOK AN INTEGRATED MULTI-OMICS APPROACH TO IDENTIFY TARGET GENES AT JIA RISK LOCI IN NEUTROPHILS AND CONSTRUCTED A PROTEIN-PROTEIN INTERACTION NETWORK VIA A MACHINE LEARNING APPROACH. WE IDENTIFIED GENES LIKELY TO BE JIA RISK LOCI TARGETED GENES IN NEUTROPHILS WHICH COULD CONTRIBUTE TO JIA DEVELOPMENT. 2019 4 4656 27 NEW ADVANCES IN JUVENILE IDIOPATHIC ARTHRITIS. JUVENILE IDIOPATHIC ARTHRITIS (JIA) COMPRISES A GROUP OF HETEROGENEOUS DISORDERS OF CHRONIC ARTHRITIS IN CHILDHOOD WITH NO APPARENT ETIOLOGY. JUVENILE IDIOPATHIC ARTHRITIS IS THE MOST COMMON PEDIATRIC RHEUMATIC DISEASE AND IS ASSOCIATED WITH SIGNIFICANT LONG-TERM MORBIDITY AND MORTALITY. THERE HAVE BEEN MAJOR ADVANCES IN RECENT YEARS IN OUR UNDERSTANDING OF THE PATHOGENESIS OF JIA, THE DEFINITION OF DISEASE CONTROL, AND BIOLOGICAL TREATMENTS FOR JIA. MULTIPLE ENVIRONMENTAL AND GENETIC FACTORS HAVE BEEN LINKED WITH THE ONSET AND / OR THE EXACERBATION OF JIA, INCLUDING PERINATAL FACTORS, VIRAL AND BACTERIAL INFECTIONS, EPIGENETIC FACTORS, AND MALNUTRITION. HOWEVER, NO SINGLE CAUSATIVE FACTOR HAS BEEN IDENTIFIED TO DATE. AS OUR UNDERSTANDING OF THE COMPLEX NETWORK OF IMMUNE CELLS AND INFLAMMATORY CYTOKINES HAS IMPROVED, BIOLOGICS HAVE BEEN DEVELOPED TO MODULATE THE INFLAMMATORY PROCESSES. INDEED, A NUMBER OF SUCH BIOLOGICS HAVE BEEN DEMONSTRATED EFFECTIVE FOR THE TREATMENT OF JIA. ALTHOUGH BIOLOGIC AGENTS MAY ALLEVIATE THE INFLAMMATION ASSOCIATED WITH JIA AND PREVENT DISABILITY CAUSED BY JOINT DESTRUCTION, CONTINUED AND COMPREHENSIVE OBSERVATION IS REQUIRED TO DETERMINE THE LONG-TERM OUTCOMES ASSOCIATED WITH SUCH TREATMENT. 2012 5 5041 25 PHARMACOGENETICS: CAN GENES DETERMINE TREATMENT EFFICACY AND SAFETY IN JIA? JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS THE MOST COMMON CHRONIC RHEUMATIC CONDITION IN CHILDHOOD, WITH MANY CHILDREN REQUIRING IMMUNOMODULATORY THERAPIES FOR MANY YEARS FOLLOWING DIAGNOSIS. A CONSIDERABLE PROPORTION OF CHILDREN EXPERIENCE THERAPEUTIC INEFFICACY OR SUBSTANTIAL ADVERSE EFFECTS, OR BOTH, BUT A LACK OF RELIABLE CLINICAL INDICATORS AND BIOMARKERS TO PREDICT TREATMENT RESPONSE PREVENTS OPTIMIZATION OF EXISTING THERAPIES. THE IDENTIFICATION OF VALID CANDIDATE GENE VARIANTS INVOLVED IN THE PATHWAYS OF METHOTREXATE AND ETANERCEPT, THE MOST COMMONLY USED MEDICATIONS IN JIA, HAS SEEN LITTLE SUCCESS TO DATE. THE LIMITED SUCCESS OF THESE STUDIES IS POSSIBLY DUE TO THE PRESENCE OF CONFOUNDING VARIABLES IN THE STUDY POPULATIONS, THE HETEROGENEITY OF OUTCOME PARAMETERS USED TO DETERMINE TREATMENT RESPONSE AND THE SMALL NUMBER OF CANDIDATE GENE VARIANTS ANALYSED. THE FIRST GENOME-WIDE PHARMACOGENETIC STUDY IN JIA HAS IDENTIFIED GENE REGIONS OF PARTICULAR BIOLOGICAL INTEREST, BUT THESE FINDINGS REQUIRE VALIDATION. MOREOVER, EPIGENETIC MECHANISMS AS WELL AS ONTOGENY PROCESSES MIGHT BE ADDITIONAL FACTORS INFLUENCING DRUG RESPONSES. ACCESS TO LARGE, WELL-DOCUMENTED JIA COHORTS AND THE RAPID DEVELOPMENT OF ADVANCED GENOME ANALYTICS IS USHERING IN A PERSONALIZED APPROACH TO TREATMENT. THE DISCOVERY OF NEW PHARMACOGENOMIC BIOMARKERS AND SYSTEMS PATHWAYS CAN PROVIDE NEW DRUG TARGETS AND PREDICTIVE TOOLS FOR IMPROVED DRUG RESPONSE AND FEWER ADVERSE DRUG REACTIONS IN JIA. 2014 6 3031 33 GENETICS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS AN INFLAMMATORY AUTOIMMUNE DISEASE INVOLVING SYMMETRIC JOINTS AND IS GENERALLY CHARACTERIZED BY PERSISTENT PAIN, TENDERNESS, AND DESTRUCTION OF JOINTS. THE VAST MAJORITY OF RA PATIENTS PRODUCE AUTOANTIBODIES, AND IMMUNE CELL INVOLVEMENT IN DISEASE DEVELOPMENT IS WELL RECOGNIZED, AS IS THE CONTRIBUTION OF OTHER TYPES OF CELLS IN SYNOVIAL TISSUE, LIKE FIBROBLASTS. IT IS KNOWN THAT THERE ARE MAJOR GENETIC ASSOCIATIONS WITH THE HLA LOCUS, WHILE MULTIPLE NON-HLA GENETIC VARIANTS DISPLAY RELATIVELY LOW RISK OF RA. BOTH HLA AND NON-HLA ASSOCIATIONS SUGGEST THAT THE PROFILES OF GENETIC ASSOCIATIONS FOR AUTOANTIBODY-POSITIVE VS. AUTOANTIBODY-NEGATIVE RA ARE DIFFERENT. SEVERAL ALLELES OF HLA-DRB1 ARE ASSOCIATED WITH HIGH RISK FOR AUTOANTIBODY-POSITIVE RA, WITH THE STRONGEST RISK CHARACTERIZED BY VALINE AT POSITION 11 OF THE PROTEIN SEQUENCE (HLA-DRB1*04 AND *10 ALLELES). THERE IS A STRONG PROTECTIVE EFFECT FOR THE RISK OF AUTOANTIBODY-POSITIVE RA ASSOCIATED WITH HLA-DRB1*13 ALLELES. ALTHOUGH MAJOR GENETIC ASSOCIATIONS HAVE BEEN KNOWN FOR SEVERAL YEARS, UNDERSTANDING OF THE SPECIFIC MECHANISMS IN THE DEVELOPMENT OF INCREASED RISK OF RA FOR THESE VARIATIONS IS WORK IN PROGRESS. CURRENT STUDIES FOCUS ON THE BINDING OF IMMUNE RECEPTORS INVOLVED IN RECOGNITION OF PUTATIVE PEPTIDES IN ACTIVATION OF T CELLS, AS WELL AS INVESTIGATION OF CELL SIGNALING MECHANISMS. AT LEAST A PART OF RA RISK COULD BE EXPLAINED BY GENE-GENE AND GENE-ENVIRONMENT INTERACTIONS. THERE ARE CURRENTLY MORE THAN 150 CANDIDATE LOCI WITH POLYMORPHISMS THAT ASSOCIATE WITH RA, MAINLY RELATED TO SEROPOSITIVE DISEASE, AND NEW DISCOVERIES ARE ANTICIPATED IN THE FUTURE FROM INVESTIGATION OF DIVERSE HUMAN POPULATIONS. THIS NEW RESEARCH WILL HELP CREATE A STRONG FOUNDATION FOR THE CONTINUING PROCESS OF INTEGRATING GENETIC, EPIGENETIC, TRANSCRIPTOMIC, AND PROTEOMIC DATA IN STUDIES OF RA. 2022 7 5473 31 RESPONSES OF PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS TO METHOTREXATE: A GENOMIC OUTLOOK. INTRODUCTION: JUVENILE IDIOPATHIC ARTHRITIS (JIA) IS A CHRONIC DISEASE CHARACTERIZED BY PERSISTENT JOINT INFLAMMATION. JIA IS THE MOST COMMON PEDIATRIC CHRONIC RHEUMATIC DISEASE AND NO CURATIVE THERAPY IS CURRENTLY AVAILABLE. METHOTREXATE (MTX) IS AN IMPORTANT TREATMENT FOR JIA EVEN THOUGH A HIGH INTER-INDIVIDUAL VARIABILITY IN RESPONSE IS OBSERVED IN PATIENTS. AMONG THE FACTORS OF THIS VARIABILITY, GENETICS AND EPIGENETICS MIGHT PLAY AN IMPORTANT ROLE. AREAS COVERED: THIS REVIEW SUMMARIZES THE RESULTS OF PHARMACOGENETIC AND PHARMACOEPIGENETIC STUDIES REGARDING MTX RESPONSE IN JIA. STUDIES CONSIDERING EPIGENETIC FACTORS IN JIA PATIENTS ARE STILL VERY LIMITED, THEREFORE THIS REVIEW INCLUDES ALSO STUDIES PERFORMED IN ADULT PATIENTS WITH RHEUMATOID ARTHRITIS. MOREOVER, THE RELEVANCE OF BIOMARKERS MEASURED IN BLOOD OR URINE OF JIA PATIENTS IN RELATION TO MTX TREATMENT IS DISCUSSED. EXPERT OPINION: NOWADAYS, EVEN THOUGH MANY PHARMACOGENOMICS STUDIES HAVE BEEN PUBLISHED, A SPECIFIC GENETIC MARKER PREDICTOR OF MTX EFFICACY OR ADVERSE EVENTS HAS NOT YET BEEN IDENTIFIED. ENCOURAGING RESULTS ARE AVAILABLE AND GREAT EXPECTATIONS RELY ON THE STUDY OF EPIGENETICS. FUTURE STUDIES ARE NEEDED IN ORDER TO IDENTIFY GENETIC AND EPIGENETIC BIOMARKERS THAT CAN BE IMPLEMENTED IN THE CLINICAL PRACTICE. 2021 8 3039 24 GENOME ENGINEERING FOR PERSONALIZED ARTHRITIS THERAPEUTICS. ARTHRITIS REPRESENTS A FAMILY OF COMPLEX JOINT PATHOLOGIES RESPONSIBLE FOR THE MAJORITY OF MUSCULOSKELETAL CONDITIONS. NEARLY ALL DISEASES WITHIN THIS FAMILY, INCLUDING OSTEOARTHRITIS, RHEUMATOID ARTHRITIS, AND JUVENILE IDIOPATHIC ARTHRITIS, ARE CHRONIC CONDITIONS WITH FEW OR NO DISEASE-MODIFYING THERAPEUTICS AVAILABLE. ADVANCES IN GENOME ENGINEERING TECHNOLOGY, MOST RECENTLY WITH CRISPR-CAS9, HAVE REVOLUTIONIZED OUR ABILITY TO INTERROGATE AND VALIDATE GENETIC AND EPIGENETIC ELEMENTS ASSOCIATED WITH CHRONIC DISEASES SUCH AS ARTHRITIS. THESE TECHNOLOGIES, TOGETHER WITH CELL REPROGRAMMING METHODS, INCLUDING THE USE OF INDUCED PLURIPOTENT STEM CELLS, PROVIDE A PLATFORM FOR HUMAN DISEASE MODELING. WE SUMMARIZE NEW EVIDENCE FROM GENOME-WIDE ASSOCIATION STUDIES AND GENOMICS THAT SUBSTANTIATES A GENETIC BASIS FOR ARTHRITIS PATHOGENESIS. WE ALSO REVIEW THE POTENTIAL CONTRIBUTIONS OF GENOME ENGINEERING IN THE DEVELOPMENT OF NEW ARTHRITIS THERAPEUTICS. 2017 9 4845 22 ONE YEAR IN REVIEW 2020: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. THE DISCOVERY OF NEW GENE POLYMORPHISMS AND THEIR ASSOCIATION WITH DISEASE SUSCEPTIBILITY HAVE ADDED NEW ELEMENTS TO BETTER CLARIFY RA PATHOGENESIS. IN THE LAST YEAR, IMPORTANT ELEMENTS HAVE BEEN ADDED TO THE CURRENT KNOWLEDGE OF MECHANISMS REGULATING INNATE AND ADAPTIVE IMMUNITY IN RA, LEADING TO DISCOVERING NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE SUMMARISE THE NEW INSIGHTS RESULTING FROM A LITERATURE RESEARCH DATA PUBLISHED IN THE LAST YEAR. 2020 10 2556 20 EPIGENETICS IN RHEUMATOID ARTHRITIS. EPIGENETICS IS A STEADILY GROWING RESEARCH AREA. IN MANY HUMAN DISEASES, ESPECIALLY IN CANCERS, BUT ALSO IN AUTOIMMUNE DISEASES, EPIGENETIC ABERRATIONS HAVE BEEN FOUND. RHEUMATOID ARTHRITIS IS AN AUTOIMMUNE DISEASE CHARACTERIZED BY CHRONIC INFLAMMATION AND DESTRUCTION OF SYNOVIAL JOINTS. EVEN THOUGH THE ETIOLOGY IS NOT YET FULLY UNDERSTOOD, RHEUMATOID ARTHRITIS IS GENERALLY CONSIDERED TO BE CAUSED BY A COMBINATION OF GENETIC PREDISPOSITION, DEREGULATED IMMUNOMODULATION, AND ENVIRONMENTAL INFLUENCES. TO GAIN A BETTER UNDERSTANDING OF THIS DISEASE, RESEARCHERS HAVE BECOME INTERESTED IN STUDYING EPIGENETIC CHANGES IN RHEUMATOID ARTHRITIS. HERE, WE WANT TO REVIEW THE CURRENT KNOWLEDGE ON EPIGENETICS IN RHEUMATOID ARTHRITIS. 2010 11 2294 32 EPIGENETIC REGULATION IN THE PATHOGENESIS OF SJOGREN SYNDROME AND RHEUMATOID ARTHRITIS. AUTOIMMUNE RHEUMATIC DISEASES, SUCH AS SJOGREN SYNDROME (SS) AND RHEUMATOID ARTHRITIS (RA), ARE CHARACTERIZED BY CHRONIC INFLAMMATION AND AUTOIMMUNITY, WHICH CAUSE JOINT TISSUE DAMAGE AND DESTRUCTION BY TRIGGERING REDUCED MOBILITY AND DEBILITATION IN PATIENTS WITH THESE DISEASES. INITIATION AND MAINTENANCE OF CHRONIC INFLAMMATORY STAGES ACCOUNT FOR SEVERAL MECHANISMS THAT INVOLVE IMMUNE CELLS AS KEY PLAYERS AND THE INTERACTION OF THE IMMUNE CELLS WITH OTHER TISSUES. INDEED, THE OVERLAPPING OF CERTAIN CLINICAL AND SEROLOGIC MANIFESTATIONS BETWEEN SS AND RA MAY INDICATE THAT NUMEROUS IMMUNOLOGIC-RELATED MECHANISMS ARE INVOLVED IN THE PHYSIOPATHOLOGY OF BOTH THESE DISEASES. IT IS WIDELY ACCEPTED THAT EPIGENETIC PATHWAYS PLAY AN ESSENTIAL ROLE IN THE DEVELOPMENT AND FUNCTION OF THE IMMUNE SYSTEM. ALTHOUGH MANY PUBLISHED STUDIES HAVE ATTEMPTED TO ELUCIDATE THE RELATION BETWEEN EPIGENETIC MODIFICATIONS (E.G. DNA METHYLATION, HISTONE POST-TRANSLATIONAL MODIFICATIONS, MIRNAS) AND AUTOIMMUNE DISORDERS, THE CONTRIBUTION OF EPIGENETIC REGULATION TO THE PATHOGENESIS OF SS AND RA IS AT PRESENT POORLY UNDERSTOOD. THIS REVIEW ATTEMPTS TO SHED LIGHT FROM A CRITICAL POINT OF VIEW ON THE IDENTIFICATION OF THE MOST RELEVANT EPIGENETIC MECHANISMS RELATED TO RA AND SS BY EXPLAINING INTRICATE REGULATORY PROCESSES AND PHENOTYPIC FEATURES OF BOTH AUTOIMMUNE DISEASES. MOREOVER, WE POINT OUT SOME EPIGENETIC MARKERS WHICH CAN BE USED TO MONITOR THE INFLAMMATION STATUS AND THE DYSREGULATED IMMUNITY IN SS AND RA. FINALLY, WE DISCUSS THE INCONVENIENCE OF USING EPIGENETIC DATA OBTAINED FROM BULK IMMUNE CELL POPULATIONS INSTEAD SPECIFIC IMMUNE CELL SUBPOPULATIONS. 2019 12 4844 26 ONE YEAR IN REVIEW 2019: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. OVER THE LAST FEW YEARS, PARTICULAR ATTENTION HAS BEEN GIVEN TO NOVEL GENES AND TO THE CLOSE INTERACTION BETWEEN GENETIC FACTORS AND EPIGENETIC MECHANISMS. RESEARCH HAS ALSO FOCUSED ON THE INFLUENCE OF ENVIRONMENTAL FACTORS ON DISEASE DEVELOPMENT, AND ON NEW MECHANISMS OF THE INNATE AND ADAPTIVE IMMUNE SYSTEM THAT CAN INFLUENCE THE DIFFERENT STAGES OF RA. HOWEVER, THERE ARE STILL SEVERAL ASPECTS OF THE DISEASE THAT NEED FURTHER INVESTIGATION. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IMPROVE THE CURRENT DIAGNOSTIC TOOLS AND TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE SUMMARISE THE NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM LITERATURE RESEARCH DATA PUBLISHED IN THE LAST YEAR. 2019 13 5739 22 SMOKING AND RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY DISEASE CAUSED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. SMOKING HAS BEEN IMPLICATED AS ONE OF THE MOST IMPORTANT EXTRINSIC RISK FACTORS FOR ITS DEVELOPMENT AND SEVERITY. RECENT DEVELOPMENTS HAVE SHED LIGHT ON THE PATHOPHYSIOLOGY OF RA IN SMOKERS, INCLUDING OXIDATIVE STRESS, INFLAMMATION, AUTOANTIBODY FORMATION AND EPIGENETIC CHANGES. THE ASSOCIATION OF SMOKING AND THE DEVELOPMENT OF RA HAVE BEEN DEMONSTRATED THROUGH EPIDEMIOLOGIC STUDIES, AS WELL AS THROUGH IN VIVO AND ANIMAL MODELS OF RA. WITH INCREASED USE OF BIOLOGICAL AGENTS IN ADDITION TO STANDARD DISEASE-MODIFYING ANTIRHEUMATIC DRUGS (DMARDS), THERE HAS BEEN INTEREST IN HOW SMOKING AFFECTS DRUG RESPONSE IN RA TREATMENT. RECENT EVIDENCE SUGGESTS THE RESPONSE AND DRUG SURVIVAL IN PEOPLE TREATED WITH ANTI-TUMOUR NECROSIS FACTOR (ANTI-TNF) THERAPY IS POORER IN HEAVY SMOKERS, AND POSSIBLE IMMUNOLOGICAL MECHANISMS FOR THIS EFFECT ARE PRESENTED IN THE CURRENT PAPER. 2014 14 3402 27 HOW DOES AGE DETERMINE THE DEVELOPMENT OF HUMAN IMMUNE-MEDIATED ARTHRITIS? DOES AGE SUBSTANTIALLY AFFECT THE EMERGENCE OF HUMAN IMMUNE-MEDIATED ARTHRITIS? CHILDREN DO NOT USUALLY DEVELOP IMMUNE-MEDIATED ARTICULAR INFLAMMATION DURING THEIR FIRST YEAR OF LIFE. IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS, THIS APPARENT 'IMMUNE PRIVILEGE' DISINTEGRATES, AND CHRONIC INFLAMMATION IS ASSOCIATED WITH VARIABLE AUTOANTIBODY SIGNATURES AND PATTERNS OF DISEASE THAT RESEMBLE ADULT ARTHRITIS PHENOTYPES. NUMEROUS MECHANISMS MIGHT BE INVOLVED IN THIS SHIFT, INCLUDING GENETIC AND EPIGENETIC PREDISPOSING FACTORS, MATURATION OF THE IMMUNE SYSTEM WITH A PROGRESSIVE MODULATION OF PUTATIVE TOLEROGENIC CONTROLS, PARALLEL DEVELOPMENT OF MICROBIAL DYSBIOSIS, ACCUMULATION OF A PRO-INFLAMMATORY BURDEN DRIVEN BY ENVIRONMENTAL EXPOSURES (THE EXPOSOME) AND COMORBIDITY-RELATED DRIVERS. BY EXPLORING THESE MECHANISMS, WE EXPAND THE DISCUSSION OF THREE (NOT MUTUALLY EXCLUSIVE) HYPOTHESES ON HOW THESE FACTORS CAN CONTRIBUTE TO THE DIFFERENCES AND SIMILARITIES BETWEEN THE LOSS OF IMMUNE TOLERANCE IN CHILDREN AND THE DEVELOPMENT OF ESTABLISHED IMMUNE-MEDIATED ARTHRITIS IN ADULTS. THESE THREE HYPOTHESES RELATE TO A CRITICAL WINDOW IN GENETICS AND EPIGENETICS, IMMUNE MATURATION, AND THE ACCUMULATION OF BURDEN. THE VARIED MANIFESTATION OF THE UNDERLYING MECHANISMS AMONG INDIVIDUALS IS ONLY BEGINNING TO BE CLARIFIED, BUT THE ESTABLISHMENT OF A FRAMEWORK CAN FACILITATE THE DEVELOPMENT OF AN INTEGRATED UNDERSTANDING OF THE PATHOGENESIS OF ARTHRITIS ACROSS ALL AGES. 2022 15 4842 26 ONE YEAR IN REVIEW 2017: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. IT HAS BEEN POSTULATED THAT A HIGH-RISK GENETIC BACKGROUND, IN COMBINATION WITH EPIGENETIC MARKS AND ENVIRONMENTAL EXPOSURES, LEADS TO A CASCADE OF EVENTS INDUCING SYNOVITIS AND CONSEQUENT DESTRUCTIVE ARTHRITIS. THE CLINICAL PICTURE OF JOINT INVOLVEMENT IN RA IS THE RESULT OF CHRONIC INFLAMMATION OF THE SYNOVIUM, CHARACTERISED BY INTERACTIONS OF RESIDENT CELLS SUCH AS FIBROBLAST-LIKE SYNOVIOCYTES (FLS) WITH CELLS OF THE INNATE (E.G. MACROPHAGES, DENDRITIC CELLS, MAST CELLS AND NK CELLS, NEUTROPHILS) AND ADAPTIVE IMMUNE SYSTEM (E.G. B AND T LYMPHOCYTES). CURRENTLY, OUR UNDERSTANDING OF THE ROLE OF INNATE AND ADAPTIVE IMMUNITY IN THE PATHOGENESIS OF RA IS EXPANDING. THE CONCEPT OF HOW IMMUNE RESPONSES CONTRIBUTE TO THE DISEASE HAS DRAMATICALLY EVOLVED OVER THE LAST 50 YEARS. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE REPORT NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM A LITERATURE RESEARCH DATE PUBLISHED IN THE LAST YEAR. 2017 16 6884 24 [RHEUMATOID ARTHRITIS]. RHEUMATOID ARTHRITIS ABSTRACT. RHEUMATOID ARTHRITIS (RA) IS THE MOST FREQUENT CHRONIC INFLAMMATORY JOINT DISEASE WITH A PREVALENCE OF APPROXIMATELY 1% WORLDWIDE. THE PATHOGENESIS IS A COMPLEX INTERPLAY OF GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS, WHICH ARE STILL INCOMPLETELY UNDERSTOOD. THE DISEASE IS CHARACTERIZED BY A POLYARTICULAR SYNOVITIS WITH SYMMETRICAL INVOLVEMENT OF SMALL AND LARGE JOINTS. THE MAJORITY OF PATIENTS HAS DETECTABLE AUTOANTIBODIES IN THE SERUM, RHEUMATOID FACTOR AND ANTI-CCP ANTIBODIES WHICH ARE SPECIFIC FOR RA. THE UNCONTROLLED CHRONIC JOINT INFLAMMATION RESULTS IN DESTRUCTIVE CHANGES OF JOINT CARTILAGE AND BONE. AN EARLY DIAGNOSIS AND INITIATION OF TREATMENT IS THEREFORE OF CENTRAL IMPORTANCE. DISEASE-MODIFYING ANTI-RHEUMATIC DRUGS (DMARD) ARE ABLE TO INHIBIT JOINT DESTRUCTION AND SHOULD BE STARTED AS SOON AS POSSIBLE. THERAPY SHOULD BE TARGETED TO REACH A STATE OF REMISSION. THE INTRODUCTION OF HIGHLY EFFECTIVE BIOLOGIC AND TARGETED SYNTHETIC DMARD HAS ALLOWED TO REACH THIS GOAL OF THERAPY IN MANY PATIENTS AND TO PREVENT DISABILITY. HOWEVER, RISKS OF MEDICATION NEED TO BE CONSIDERED, AS WELL AS COMORBIDITIES. 2023 17 1608 26 DNA METHYLATION-GOVERNED GENE EXPRESSION IN AUTOIMMUNE ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE HALLMARKED BY PROGRESSIVE AND IRREVERSIBLE JOINT DESTRUCTION. RA PATHOGENESIS IS A T CELL-REGULATED AND B CELL-MEDIATED PROCESS IN WHICH ACTIVATED LYMPHOCYTE-PRODUCED CHEMOKINES AND CYTOKINES PROMOTE LEUKOCYTE INFILTRATION THAT ULTIMATELY LEADS TO DESTRUCTION OF THE JOINTS. THERE IS AN OBVIOUS NEED TO DISCOVER NEW DRUGS FOR RA TREATMENT THAT HAVE DIFFERENT BIOLOGICAL TARGETS OR MODES OF ACTION THAN THE CURRENTLY EMPLOYED THERAPEUTICS. ENVIRONMENTAL FACTORS SUCH AS CIGARETTE SMOKE, CERTAIN DIET COMPONENTS, AND ORAL PATHOGENS CAN SIGNIFICANTLY AFFECT GENE REGULATION VIA EPIGENETIC FACTORS. EPIGENETICS OPENED A NEW FIELD FOR PHARMACOLOGY, AND DNA METHYLATION AND HISTONE MODIFICATION-IMPLICATED FACTORS ARE FEASIBLE TARGETS FOR RA THERAPY. EXPLORING RA PATHOGENESIS INVOLVED EPIGENETIC FACTORS AND MECHANISMS IS CRUCIAL FOR DEVELOPING MORE EFFICIENT RA THERAPIES. HERE WE REVIEW EPIGENETIC ALTERATIONS ASSOCIATED WITH RA PATHOGENESIS INCLUDING DNA METHYLATION AND INTERACTING FACTORS. ADDITIONALLY, WE WILL SUMMARIZE THE LITERATURE REVEALING THE INVOLVED MOLECULAR STRUCTURES AND INTERACTIONS. FINALLY, POTENTIAL EPIGENETIC FACTOR-BASED THERAPIES WILL BE DISCUSSED THAT MAY HELP IN BETTER MANAGEMENT OF RA IN THE FUTURE. 2019 18 5002 25 PERIODONTITIS AND PERIODONTOPATHIC BACTERIA AS RISK FACTORS FOR RHEUMATOID ARTHRITIS: A REVIEW OF THE LAST 10 YEARS. RHEUMATOID ARTHRITIS (RA) IS CHARACTERIZED BY CHRONIC INFLAMMATORY DESTRUCTION OF JOINT TISSUE AND IS CAUSED BY AN ABNORMAL AUTOIMMUNE RESPONSE TRIGGERED BY INTERACTIONS BETWEEN GENETICS, ENVIRONMENTAL FACTORS, AND EPIGENETIC AND POSTTRANSLATIONAL MODIFICATIONS. RA HAS BEEN SUGGESTED TO BE INTERRELATED WITH PERIODONTITIS, A SERIOUS FORM OR STAGE OF CHRONIC INFLAMMATORY PERIODONTAL DISEASE ASSOCIATED WITH PERIODONTOPATHIC BACTERIAL INFECTIONS, GENETIC PREDISPOSITION, ENVIRONMENTAL FACTORS, AND EPIGENETIC INFLUENCES. OVER THE LAST DECADE, A NUMBER OF ANIMAL AND CLINICAL STUDIES HAVE BEEN CONDUCTED TO ASSESS WHETHER OR NOT PERIODONTITIS AND ASSOCIATED PERIODONTOPATHIC BACTERIA CONSTITUTE RISK FACTORS FOR RA. THE PRESENT REVIEW INTRODUCES RECENT ACCUMULATING EVIDENCE TO SUPPORT THE ASSOCIATIONS OF PERIODONTITIS AND PERIODONTOPATHIC BACTERIA WITH THE RISK OF RA OR THE OUTCOME OF RA PHARMACOLOGICAL TREATMENT WITH DISEASE-MODIFYING ANTIRHEUMATIC DRUGS. IN ADDITION, THE RESULTS FROM INTERVENTION STUDIES HAVE SUGGESTED AN IMPROVEMENT IN RA CLINICAL PARAMETERS AFTER NONSURGICAL PERIODONTAL TREATMENT. FURTHERMORE, THE POTENTIAL CAUSAL MECHANISMS UNDERLYING THE LINK BETWEEN PERIODONTITIS AND PERIODONTOPATHIC BACTERIA AND RA ARE SUMMARIZED. 2023 19 5372 28 RECENT ADVANCES IN UNDERSTANDING THE PATHOGENESIS OF RHEUMATOID ARTHRITIS: NEW TREATMENT STRATEGIES. RHEUMATOID ARTHRITIS (RA) IS CONSIDERED A CHRONIC SYSTEMIC, MULTI-FACTORIAL, INFLAMMATORY, AND PROGRESSIVE AUTOIMMUNE DISEASE AFFECTING MANY PEOPLE WORLDWIDE. WHILE PATIENTS SHOW VERY INDIVIDUAL COURSES OF DISEASE, WITH RA FOCUSING ON THE MUSCULOSKELETAL SYSTEM, JOINTS ARE OFTEN SEVERELY AFFECTED, LEADING TO LOCAL INFLAMMATION, CARTILAGE DESTRUCTION, AND BONE EROSION. TO PREVENT JOINT DAMAGE AND PHYSICAL DISABILITY AS ONE OF MANY SYMPTOMS OF RA, EARLY DIAGNOSIS IS CRITICAL. AUTO-ANTIBODIES PLAY A PIVOTAL CLINICAL ROLE IN PATIENTS WITH SYSTEMIC RA. AS BIOMARKERS, THEY COULD HELP TO MAKE A MORE EFFICIENT DIAGNOSIS, PROGNOSIS, AND TREATMENT DECISION. BESIDES AUTO-ANTIBODIES, SEVERAL OTHER FACTORS ARE INVOLVED IN THE PROGRESSION OF RA, SUCH AS EPIGENETIC ALTERATIONS, POST-TRANSLATIONAL MODIFICATIONS, GLYCOSYLATION, AUTOPHAGY, AND T-CELLS. UNDERSTANDING THE INTERPLAY BETWEEN THESE FACTORS WOULD CONTRIBUTE TO A DEEPER INSIGHT INTO THE CAUSES, MECHANISMS, PROGRESSION, AND TREATMENT OF THE DISEASE. IN THIS REVIEW, THE LATEST RA RESEARCH FINDINGS ARE DISCUSSED TO BETTER UNDERSTAND THE PATHOGENESIS, AND FINALLY, TREATMENT STRATEGIES FOR RA THERAPY ARE PRESENTED, INCLUDING BOTH CONVENTIONAL APPROACHES AND NEW METHODS THAT HAVE BEEN DEVELOPED IN RECENT YEARS OR ARE CURRENTLY UNDER INVESTIGATION. 2021 20 1565 23 DNA METHYLATION OF T LYMPHOCYTES AS A THERAPEUTIC TARGET: IMPLICATIONS FOR RHEUMATOID ARTHRITIS ETIOLOGY. RHEUMATOID ARTHRITIS (RA) IS AN AUTOIMMUNE DISEASE THAT CAN CAUSE JOINT DAMAGE AND DISABILITY. EPIGENETIC VARIATION, ESPECIALLY DNA METHYLATION, HAS BEEN SHOWN TO BE INVOLVED IN ALMOST ALL THE STAGES OF THE PATHOLOGY OF RA, FROM AUTOANTIBODY PRODUCTION TO VARIOUS SELF-EFFECTOR T CELLS AND THE DEFECTS OF PROTECTIVE T CELLS THAT CAN LEAD TO CHRONIC INFLAMMATION AND EROSION OF BONES AND JOINTS. GIVEN THE CRITICAL ROLE OF T CELLS IN THE PATHOLOGY OF RA, THE REGULATORY FUNCTIONS OF DNA METHYLATION IN T CELL BIOLOGY REMAIN UNCLEAR. IN THIS REVIEW, WE ELABORATE ON THE RELATIONSHIP BETWEEN RA PATHOGENESIS AND DNA METHYLATION IN THE CONTEXT OF DIFFERENT T CELL POPULATIONS. WE SUMMARIZE THE RELEVANT METHYLATION EVENTS IN T CELL DEVELOPMENT, DIFFERENTIATION, AND T CELL-RELATED GENES IN DISEASE PREDICTION AND DRUG EFFICACY. UNDERSTANDING THE EPIGENETIC REGULATION OF T CELLS HAS THE POTENTIAL TO PROFOUNDLY TRANSLATE PRECLINICAL RESULTS INTO CLINICAL PRACTICE AND PROVIDE A FRAMEWORK FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED RA THERAPEUTICS. 2022