Update of the guidelines for the pharmacological treatment of rheumatoid arthritis by the Mexican College of Rheumatology 2023.

OBJECTIVE: To develop updated guidelines for the pharmacological management of rheumatoid arthritis (RA). METHODS: A group of experts representative of different geographical regions and various medical services catering to the Mexican population with RA was formed. Questions based on Population, Intervention, Comparison, and Outcome (PICO) were developed, deemed clinically relevant. These questions were answered based on the results of a recent systematic literature review (SLR), and the evidence's validity was assessed using the GRADE system, considered a standard for these purposes. Subsequently, the expert group reached consensus on the direction and strength of recommendations through a multi-stage voting process. RESULTS: The updated guidelines for RA treatment stratify various therapeutic options, including different classes of DMARDs (conventional, biologicals, and JAK inhibitors), as well as NSAIDs, glucocorticoids, and analgesics. By consensus, it establishes the use of these in different subpopulations of interest among RA patients and addresses aspects related to vaccination, COVID-19, surgery, pregnancy and lactation, and others. CONCLUSIONS: This update of the Mexican guidelines for the pharmacological treatment of RA provides reference points for evidence-based decision-making, recommending patient participation in joint decision-making to achieve the greatest benefit for our patients. It also establishes recommendations for managing a variety of relevant conditions affecting our patients.

Comparison of Cost and Potency of Human Mesenchymal Stromal Cell Conditioned Medium Derived from 2- and 3-Dimensional Cultures.

Mesenchymal stromal cell (MSC)-derived products, such as trophic factors (MTFs), have anti-inflammatory properties that make them attractive for cell-free treatment. Three-dimensional (3D) culture can enhance these properties, and large-scale expansion using a bioreactor can reduce manufacturing costs. Three lots of MTFs were obtained from umbilical cord MSCs produced by either monolayer culture (Monol MTF) or using a 3D microcarrier in a spinner flask dynamic system (Bioreactor MTF). The resulting MTFs were tested and compared using anti-inflammatory potency assays in two different systems: (1) a phytohemagglutinin-activated peripheral blood mononuclear cell (PBMNC) system and (2) a lipopolysaccharide (LPS)-activated macrophage system. Cytokine expression by macrophages was measured via RT-PCR. The production costs of hypothetical units of anti-inflammatory effects were calculated using the percentage of TNF-α inhibition by MTF exposure. Bioreactor MTFs had a higher inhibitory effect on TNF (p < 0.01) than monolayer MTFs (p < 0.05). The anti-inflammatory effect of Bioreactor MTFs on IL-1ß, TNF-α, IL-8, IL-6, and MIP-1 was significantly higher than that of monolayer MTFs. The production cost of 1% inhibition of TNF-α was 11-40% higher using monolayer culture compared to bioreactor-derived MTFs. A 3D dynamic culture was, therefore, able to produce high-quality MTFs, with robust anti-inflammatory properties, more efficiently than monolayer static systems.

Dynamics of circulating follicular helper T cell subsets and follicular regulatory T cells in rheumatoid arthritis patients according to HLA-DRB1 locus.

B cells, follicular helper T (Tfh) cells and follicular regulatory T (Tfr) cells are part of a circuit that may play a role in the development or progression of rheumatoid arthritis (RA). With the aim of providing further insight into this topic, here we evaluated the frequency of different subsets of Tfh and Tfr in untreated and long-term treated RA patients from a cohort of Argentina, and their potential association with particular human leukocyte antigen (HLA) class-II variants and disease activity. We observed that the frequency of total Tfh cells as well as of particular Tfh subsets and Tfr cells were increased in seropositive untreated RA patients. Interestingly, when analyzing paired samples, the frequency of Tfh cells was reduced in synovial fluid compared to peripheral blood, while Tfr cells levels were similar in both biological fluids. After treatment, a decrease in the CCR7loPD1hi Tfh subset and an increase in the frequency of Tfr cells was observed in blood. In comparison to healthy donors, seropositive patients with moderate and high disease activity exhibited higher frequency of Tfh cells while seropositive patients with low disease activity presented higher Tfr cell frequency. Finally, we observed that HLA-DRB1*09 presence correlated with higher frequency of Tfh and Tfr cells, while HLA-DRB1*04 was associated with increased Tfr cell frequency. Together, our results increase our knowledge about the dynamics of Tfh and Tfr cell subsets in RA, showing that this is altered after treatment.

Harnessing Inflammation Resolution in Arthritis: Current Understanding of Specialized Pro-resolving Lipid Mediators' Contribution to Arthritis Physiopathology and Future Perspectives.

The concept behind the resolution of inflammation has changed in the past decades from a passive to an active process, which reflects in novel avenues to understand and control inflammation-driven diseases. The time-dependent and active process of resolution phase is orchestrated by the endogenous biosynthesis of specialized pro-resolving lipid mediators (SPMs). Inflammation and its resolution are two forces in rheumatic diseases that affect millions of people worldwide with pain as the most common experienced symptom. The pathophysiological role of SPMs in arthritis has been demonstrated in pre-clinical and clinical studies (no clinical trials yet), which highlight their active orchestration of disease control. The endogenous roles of SPMs also give rise to the opportunity of envisaging these molecules as novel candidates to improve the life quality of rhematic diseases patients. Herein, we discuss the current understanding of SPMs endogenous roles in arthritis as pro-resolutive, protective, and immunoresolvent lipids.

Prevalence of hospital readmissions and related factors in patients with autoimmune diseases.

OBJECTIVE: Autoimmune diseases generate an impact on the morbidity and mortality of patients and are a burden for the health system through hospital admissions and readmissions. The prevalence of readmission of patients with these diseases has not yet been described as a group, but rather as sub-phenotype. The objective of this study is to determine the prevalence of hospital readmissions in a Colombian population with autoimmunity and the factors related to readmission. METHODS: All patients with autoimmune diseases who were evaluated by the rheumatology service and hospitalized between August 2018 and December 2019 at the Fundación Hospital Infantil Universitario De San José de Bogotá were described. A bivariate analysis was done, and three multivariate logistic regression models were built with the dependent variable being readmission. RESULTS: Of the total 199 admissions, 131 patients were evaluated and 32% were readmitted. The most frequent sub-phenotype in both groups (readmission and no readmission) was SLE (51% and 59%). The most frequent cause of hospitalization and readmission was disease activity (68.7% and 64.3%). History of hypertension was associated with readmission (adjusted OR: 2.98-95% CI: 1.15-7.72). In a second model adjusted for confounding variables, no factor was associated. In a third model analyzing the history of kidney disease and previous use of immunosuppressants (adjusted for confounding variables), the previous use of immunosuppressants was related to readmission (OR: 2.78-95% CI 1.12-6.89). CONCLUSION: Up to a third of patients with autoimmunity were readmitted and arterial hypertension was an associated factor. This suggested a greater systemic compromise and accumulated damage in patients who have these two conditions that may favor readmission. A history of immunosuppressant use may play a role in readmission, possibly by increasing the risk of developing infections.

Polymyalgia rheumatica: A case series from Colombia and analysis of Latin America.

OBJECTIVE: Polymyalgia rheumatica (PMR) is the most common inflammatory disease in patients over 50 years. Information about the disease in Latin America (LATAM) is scarce. We aimed to evaluate a group of Colombian patients with PMR and to conduct a systematic review of PMR in LATAM. METHODS: A multicentric retrospective study was performed. Medical records of 256 PMR patients were evaluated. Patients were divided into two groups, those fulfilling the 2012 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for PMR and those who did not (i.e., clinical diagnosis). A systematic literature review and meta regression was performed comparing Colombian vs LATAM patients. RESULTS: From 256 patients, 145 (56.6%) fulfilled the 2012 EULAR/ACR criteria, and 111 (43.3%) were classified by clinical diagnosis. Inflammatory bilateral shoulder pain, pelvic girdle aching, morning stiffness >45 min, elevated erythrocyte sedimentation rate (ESR), and C-reactive protein (CPR), and Methotrexate (MTX) prescription were more common in the 2012 EULAR/ACR group. None of the included patients presented overt polyautoimmunity (PolyA), whereas up to 24% exhibited latent PolyA. In addition, these patients showed high frequency of malignancy (7.59%). In the meta regression analysis, Colombian patients exhibited lower ESR levels, and were less likely to develop giant cell arteritis (GCA) as compared to the rest of LATAM data. CONCLUSION: Patients with PMR in LATAM exhibit similar phenotypes from other cohorts worldwide. Malignancy, GCA and latent PolyA should be considered in the routine clinical follow-up of patients with PMR.

Current and Emerging DMARDs for the Treatment of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is the most prevalent form of inflammatory arthritis. It is a profoundly serious and severe disease that if it goes untreated could have severe consequences to the joints and health of the patient who carries this diagnosis. The treatment of RA has dramatically changed since the year 2000, with the discovery of the TNFis, then other biologics, and finally the JAKi. All these new medications with or without methotrexate in combination, tight control and treat to target have produced a revolution in the outcome of this disease. We reviewed and summarized the treatment options, and the most significant papers for each one of these new drugs. The reader could have a full picture with all the references of the recent publications. We also updated the biosimilar situation in RA, as well as the new drugs that will be coming to the market in the next 5 years.

Trabecular and cortical bone involvement in rheumatoid arthritis by DXA and DXA-based 3D modelling.

Rheumatoid arthritis (RA) patients had a higher risk of developing low bone mineral density (BMD) or osteoporosis. RA patients on classic disease-modifying antirheumatic drug (c-DMARD) therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving biological disease-modifying antirheumatic drugs (b-DMARDs) and controls. The 3D analysis allowed us to find changes in the trabecular and cortical compartments. INTRODUCTION: To evaluate cortical and trabecular bone involvement of the hip in RA patients by dual-energy X-ray absorptiometry (DXA) and 3D analysis. The secondary end-point was to evaluate bone involvement in patients treated with classic (c-DMARD) or biological (b-DMARD) disease-modifying antirheumatic drug therapies and the effect of the duration of the disease and corticosteroid therapy on 3D parameters. METHODS: A cross-sectional study of 105 RA patients and 100 subjects as a control group (CG) matched by age, sex, and BMI was carried out. BMD was measured by DXA of the bilateral femoral neck (FN) and total hip (TH). The 3D analyses including trabecular and cortical BMD were performed on hip scans with the 3D-Shaper software. RESULTS: FN and TH BMD and trabecular and cortical vBMD were significantly lower in RA patients. The c-DMARD (n = 75) group showed significantly lower trabecular and cortical vBMD than the CG. Despite the lower values, the b-DMARD group (n = 30) showed no significant differences in most parameters compared with the CG. The trabecular and cortical 3D parameters were significantly lower in the group with an RA disease duration of 1 to 5 years than in the CG, and the trabecular vBMD was significantly lower in the group with a duration of corticosteroid therapy of 1 to 5 years than in the CG, while no significant differences were found by standard DXA in the same period. CONCLUSIONS: RA patients had a higher risk of developing low BMD or osteoporosis than controls. RA patients receiving c-DMARD therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving b-DMARDs and controls. 3D-DXA allowed us to find changes in trabecular and cortical bone compartments in RA patients.

DMARDs-Gut Microbiota Feedback: Implications in the Response to Therapy.

Due to its immunomodulatory effects and the limitation in the radiological damage progression, disease-modifying antirheumatic drugs (DMARDs) work as first-line rheumatoid arthritis (RA) treatment. In recent years, numerous research projects have suggested that the metabolism of DMARDs could have a role in gut dysbiosis, which indicates that the microbiota variability could modify the employment of direct and indirect mechanisms in the response to treatment. The main objective of this review was to understand the gut microbiota bacterial variability in patients with RA, pre and post-treatment with DMARDs, and to identify the possible mechanisms through which microbiota can regulate the response to pharmacological therapy.

Los niveles séricos de Interleucina 22 e Interleucina 6 disminuyen luego del tratamiento en pacientes con artritis reumatoidea / Interleukin 22 and Interleukin 6 Serum Levels Decrease After Treatment in Rheumatoid Arthritis Patients

Introducción: La artritis reumatoidea se caracteriza por inflamación de la membrana sinovial debido al infiltrado de células inmunitarias que secretan citocinas relacionadas a perfil Th17 como IL-22 e IL-6. La dinámica de estas citocinas durante el tratamiento permanece incomprendida. El objetivo fue evaluar los niveles séricos y en líquido sinovial (LS) de IL-22 e IL-6, correlacionarlos con diferentes parámetros bioquímicos y clínicos y medir sus cambios post-tratamiento. Material y métodos: Se estudiaron 77 pacientes con AR y 30 controles. A 30 pacientes se los evaluó nuevamente luego de 3 meses de tratamiento y a 12 se les extrajo LS. Se midió VSG, PCR, FR, anti-CCPhs, IL-22 e IL-6. Se evaluó la actividad con DAS28 y respuesta al tratamiento con criterios EULAR. Resultados: IL-22 e IL-6 fueron similares entre pacientes y controles. Sus niveles disminuyeron luego del tratamiento, principalmente en pacientes respondedores. IL-22 fue menor e IL-6 mayor en LS que en sangre. IL-6 correlacionó positivamente con PCR y anti-CCPhs. Los niveles de VSG, PCR y DAS28 fueron mayores en pacientes con valores dosables de IL-6 que en no dosables. Conclusión: En pacientes con valores basales dosables de IL-22 e IL-6, los niveles de estas citocinas podrían utilizarse como marcador adicional de respuesta al tratamiento.

Introduction: Rheumatoid arthritis is characterized by synovium inflammation due to the infiltration of immune cells that secrete Th17 cytokines like IL-22 and IL-6. The dynamics of these cytokines during the treatment remain unknown. The aim of this study was to evaluate the levels of IL-22 and IL-6 serum and synovial fluid (SF) in correlation with different biochemical and clinical parameters and treatment-associated changes. Material and methods: Seventy-seven RA patients and 30 controls were recruited. Thirty patients were evaluated after 3 months of treatment and SF was collected of 12 patients. ESR, CRP, RF, anti-CCP hs, IL-22 e IL-6 were measured. DAS28 was used to assess disease activity and response to treatment followed EULAR criteria. Results: There were not differences in serum IL-22 and IL-6 levels between patients and controls. Cytokine levels decreased after treatment, mainly in responder patients. IL-22 was decreased and IL-6 was increased in SF compared to serum. IL-6 correlated positively with CRP and anti-CCPhs. ESR, CRP and DAS28 were increased in patients with detectable IL-6 compared to those with undetectable IL-6. Conclusion: In patients with detectable serum IL-22 and IL-6 levels before treatment initiation, follow-up of cytokine levels could be an useful additional tool to evaluate treatment response.

Comparative persistence of anti-tumor necrosis factor therapy in ankylosing spondylitis patients: a multicenter international study.

Objective: To evaluate persistence on conventional DMARDs (cDMARDs) and anti-TNF therapies, and to identify potential determinants of discontinuation among individuals with ankylosing spondylitis (AS) living in Brazil and Quebec, Canada.Methods: We conducted a cohort study of AS patients using health administrative data (2010-2015). One-year and 2-year persistence rates were assessed. Cox regression was used to identify potential determinants of therapy discontinuation.Results: One-year persistence was less likely in Brazil for both anti-TNF and cDMARDs (Brazil: 62.1 and 30.7%, Quebec: 66.9 and 67.0%). The 2-year persistence rates were lower for both anti-TNF and cDMARD, but remained higher in Quebec (Brazil: 47.9 and 18.1%, Quebec: 51.5 and 53.5%). In multivariate Cox regression analysis, age, sex and comorbidities were associated with persistence in both countries. In Quebec, persistence did not differ between rural and urban regions or with socioeconomic status. While in Brazil, patients in regions with higher Human Development Index and those in cities with lower Gini index were less likely to discontinue therapy.Conclusions: Canadian AS patients were more likely to persist on therapy compared to Brazilian patients, although rates were lower at 2 years in both countries. Socioeconomic disparity in persistence was found in Brazil, but not in Quebec.

Reumatología y COVID-19: una oportunidad única / Rheumatology and COVID-19: a unique opportunity

Las pandemias han sido inherentes a la presencia del ser humano en el planeta tierra. Desde el inicio del siglo actual ha destacado la aparición de varias enfermedades virales de relevancia mundial, siendo la enfermedad provocada por el SARS-CoV2 la más importante de ellas (COVID-19). La comunidad científica y los distintos países no estaban preparados para un desafío de esta envergadura. Desde el punto de vista de la reumatología se desconoce las implicancias de este nuevo virus en los pacientes con enfermedades reumatológicas y sus tratamientos. Como reumatólogos nos encontramos frente a una oportunidad única de participar activamente para disipar esas interrogantes.

Pandemics have been inherent to our condition as inhabitants on this planet. Several viral diseases of worldwide concern have been reported since beginning of the actual century, being COVID-19 due to SARS-CoV2 the most important. The scientific community and the different countries have not been prepared for this kind of challenge. The potential issues about this novel virus and rheumatologic patients and their treatments are unknown. As rheumatologist we can actively participate in dissipate those questions.

Cost-minimization analysis of biological disease-modifying antirheumatic drugs in the Brazilian public health system (SUS) considering patients' weight / Análise de custo-minimização de medicamentos modificadores de curso da doença biológicos no Sistema Único de Saúde (SUS) no Brasil considerando o peso dos pacientes

Objective: To perform a cost-minimization analysis comparing the cohort with the current average patient weight of 70 kg (MoH current assumption). Since most rheumatoid arthritis (RA) patients in Brazil are women (60 kg or less), we also aimed to define this percentage at Brazilian public healthcare system (SUS). Methods: Treatment-naïve RA patients using biologics from January 2008 to November 2018 were retrieved from Datasus as well as the number of patients ≤ 60 kg and their drug use distribution. Data on drug costs were assessed from the last payment reported by MoH and then recalculated using the weighted average of 60 kg and a 52-weeks a year to assess cost-minimization. Results: In the studied cohort, 33,646 patients (33.3%) were classified as ≤ 60 kg. Annual cost per patient, considering an average weight of 60 kg, ranged from 2,872,29 USD to 4,223.93 USD. Tocilizumab 80 mg was the only drug demonstrating a reduction in annual cost per patient (-526.79 USD). Conclusion: Cost-minimization analysis based on weight-dependent dosage showed that tocilizumab could reduce MoH costs with RA treatment in 14.28%. By adopting weight-dependent dose of 60 kg, the Brazilian government could save up to 916,651.31 USD per year using tocilizumab versus other biological disease-modifying antirheumatic drugs (DMARDs). In ten years, it represents an accumulative saving of 9,166,513.57 USD.

Objetivo: Realizar uma análise de custo-minimização comparando a coorte com o peso médio de pacientes de 70 kg (atual premissa do Ministério da Saúde ­ MS). Como a maioria dos pacientes são mulheres (≤ 60 kg), também se objetivou definir esse percentual no sistema público de saúde brasileiro (SUS). Métodos: Pacientes com artrite reumatoide (AR) virgens de tratamento utilizando biológicos de janeiro/2008 a novembro/2018 foram retirados do Datasus, assim como o número de pacientes com ≤ 60 kg e a distribuição de uso das drogas. Os custos dos medicamentos foram avaliados a partir do último pagamento relatado pelo MS e recalculados utilizando a média de 60 kg e um ano de 52 semanas para estimar a custo-minimização. Resultados: Na coorte estudada, 33.646 pacientes (33,3%) foram classificados com ≤ 60 kg. O custo anual por paciente, considerando o peso médio de 60 kg, variou de 2.872.29 a 4.223,93 USD. Tocilizumabe 80 mg foi o único que demonstrou redução no custo anual por paciente (-526,79 USD). Conclusão: A custo-minimização baseada em dose peso-dependente mostrou que o tocilizumabe poderia reduzir os custos do MS no tratamento de AR em 14,28%. Ao adotar o peso de 60 kg, o governo poderia economizar até 916.651,31 USD ao ano utilizando tocilizumabe vs. outros medicamentos modificadores do curso da doença biológicos (MMCDb). Em 10 anos, isso representa uma economia acumulada de 9.166.513,57 USD.

Comorbidity of Type 1 Diabetes Mellitus in Patients with Juvenile Idiopathic Arthritis.

OBJECTIVES: To determine the prevalence of type 1 diabetes mellitus (T1D) in patients with juvenile idiopathic arthritis (JIA) and to characterize patients having both. STUDY DESIGN: Diabetes comorbidity was recorded in the National Pediatric Rheumatologic Database since 2012. Data from the North Rhine-Westphalian diabetes registry served as the reference population for the prevalence of diabetes in the general population. The National Pediatric Rheumatologic Database data were indirectly standardized for age and sex for comparison with the general population. The diabetes prevalence ratio was calculated using the Poisson regression model. RESULTS: The analysis included 12 269 patients with JIA. A total of 58 patients had comorbid T1D, and the diabetes prevalence was 0.5%. The mean age was 11.6 years at the time of documentation, and the mean disease duration was 4.2 years. Compared with the general population, the prevalence of diabetes in patients with JIA was significantly increased (prevalence ratio 1.76 [95% CI 1.34; 2.28], P < .001). The onset of diabetes in patients with JIA was earlier than that reported in the reference data. Sixty-three percent of patients developed T1D before JIA. On average, diabetes onset was 56 months before the onset of JIA. Patients who first developed JIA developed T1D on average 40 months later. The majority of patients had not received disease-modifying antirheumatic drugs before diabetes onset. CONCLUSIONS: T1D occurs more frequently in patients with JIA than in the general population. The likelihood of T1D occurrence appears to be slightly higher before JIA manifestation and without disease-modifying antirheumatic drug therapy after JIA onset.

Outcomes after rheumatoid arthritis patients complete their participation in a long-term observational study with tofacitinib combined with methotrexate: practical and ethical implications in vulnerable populations after tofacitinib discontinuation.

To describe disease activity and disability during the first year of follow-up, from rheumatoid arthritis (RA) patients who discontinue tofacitinib after they end participation in a clinical trial. From 2008 to 2016, 36 patients were enrolled in the "Long term follow-up study with tofacitinib (and methotrexate) for RA treatment". At the end of the study, tofacitinib was discontinued and patients were proposed to enter an observational study; 35 agree and had scheduled evaluations at baseline, at 15 and 30 days of follow-up, at month 2 and 3, and thereafter every 3 months. Disease activity was evaluated as per DAS28-ESR and disability as per HAQ. During follow-up, treatment was treat-to-target oriented, only conventional DMARDs were indicated. Descriptive statistics and nonparametric test were used. The study was approved by IRB. Patients were primarily females (N = 34), had median (Q25-75) age of 52 years (45-58), and had received tofacitinib for a median of 7.9 years (6.3-8.3). The proportion of patients with remission and low disease activity decreased from day 30 of follow-up and recovered after 270 days, meanwhile patients with high disease activity increased from 0% at baseline to 6.3% at 1 year. At study entry, 20 patients had remission/low disease activity; during follow-up, 85% deteriorated after (median) 30 days; among them, 23.5% recovered their baseline status after a median of 172.5 days. The HAQ showed a similar behavior, but 66.7% recovered. A substantial proportion of RA patients deteriorated outcomes early after tofacitinib cessation; some patients recovered baseline status with traditional DMARDS.

Is the Treatment with Biological or Non-biological DMARDS a Modifier of Periodontal Condition in Patients with Rheumatoid Arthritis?

BACKGROUND AND OBJECTIVE: Experimental models suggest the use of different therapy protocols in rheumatoid arthritis (RA) as modulators on periodontal condition. This study evaluated the effects of conventional drug treatment and anti-TNF therapy in patients with RA on microbiological and periodontal condition, establishing the association of markers of periodontal infection with indexes of rheumatic activity. MATERIALS AND METHODS: One hundred seventy nine individuals with RA were evaluated (62 with anti-TNF-. and 115 with only DMARDs). The periodontal evaluation included plaque and gingival indexes, bleeding on probing (BOP), clinical attachment loss (CAL), pocket depth (PD) and subgingival plaque samples for microbiological analysis. Rheumatologic evaluations included a clinical examination, rheumatoid factor (RF), antibodies against cyclic-citrullinated peptides (ACPAs), and activity markers (DAS28-ERS), high sensitive C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR). RESULTS: Anti-TNF-alpha therapy influenced periodontal microbiota with a higher frequency of T. denticola (p=0.01). Methotrexate combined with leflunomide exhibited a higher extension of CAL (p=0.005), and anti-TNF-alpha therapy with methotrexate was associated with a lower extension of CAL (p=0.05). The use of corticosteroids exerted a protective effect on the number of teeth (p=0.027). The type of DMARD affected P. gingivalis, T. forsythia and E. nodatum presence. Elevated ACPAs titers were associated with the presence of red complex periodontal pathogens (p=0.025). Bleeding on probing was associated with elevated CPR levels (p=0.05), and ESR was associated with a greater PD (p=0.044) and presence of red complex (p=0.030). CONCLUSION: Different pharmacological treatments for RA affect the clinical condition and subgingival microbiota.

Lapachol, a compound targeting pyrimidine metabolism, ameliorates experimental autoimmune arthritis.

BACKGROUND: The inhibition of pyrimidine biosynthesis by blocking the dihydroorotate dehydrogenase (DHODH) activity, the prime target of leflunomide (LEF), has been proven to be an effective strategy for rheumatoid arthritis (RA) treatment. However, a considerable proportion of RA patients are refractory to LEF. Here, we investigated lapachol (LAP), a natural naphthoquinone, as a potential DHODH inhibitor and addressed its immunosuppressive properties. METHODS: Molecular flexible docking studies and bioactivity assays were performed to determine the ability of LAP to interact and inhibit DHODH. In vitro studies were conducted to assess the antiproliferative effect of LAP using isolated lymphocytes. Finally, collagen-induced arthritis (CIA) and antigen-induced arthritis (AIA) models were employed to address the anti-arthritic effects of LAP. RESULTS: We found that LAP is a potent DHODH inhibitor which had a remarkable ability to inhibit both human and murine lymphocyte proliferation in vitro. Importantly, uridine supplementation abrogated the antiproliferative effect of LAP, supporting that the pyrimidine metabolic pathway is the target of LAP. In vivo, LAP treatment markedly reduced CIA and AIA progression as evidenced by the reduction in clinical score, articular tissue damage, and inflammation. CONCLUSIONS: Our findings propose a binding model of interaction and support the ability of LAP to inhibit DHODH, decreasing lymphocyte proliferation and attenuating the severity of experimental autoimmune arthritis. Therefore, LAP could be considered as a potential immunosuppressive lead candidate with potential therapeutic implications for RA.