Meta-analysis of the association between PADI4 -92C/G polymorphism and rheumatoid arthritis in the Chinese population

Many studies have evaluated the correlation between peptidylarginine deiminase 4 (PADI4) -92C/G polymorphism and rheumatoid arthritis (RA), but the results remain inconclusive. Therefore, we performed a meta-analysis in the Chinese population to provide comprehensive data on the association between PADI4 -92C/G polymorphism and RA. Eligible studies published before May 2016 were identified in PubMed and Chinese databases. The strengths of these associations were assessed by pooled odds ratios (OR) and 95% confidence interval (CI). Eight studies documenting a total of 1351 RA cases and 1585 controls were included in this meta-analysis. In the overall analysis, a significant association between the PADI4 -92C/G polymorphism and RA was found in the Chinese population (G vs C: OR=1.32, 95%CI=1.02-1.71; GG+CG vs CC: OR=1.75, 95%CI=1.20-2.53). The subgroup analyses stratified by geographic area(s) and source of controls revealed significant results in South China, in hospital-based studies and population-based studies. In summary, this meta-analysis suggested that PADI4 -92C/G polymorphism may be associated with the RA incidence in the Chinese population, especially for South China. Further studies conducted on other ethnic groups are required for definite conclusions.

Polimorfismo do gene timidilato sintase e nível plasmático total de homocisteína em um grupo de pacientes turcos com artrite reumatoide: relação com a atividade da doença e toxicidade ao metotrexato / Thymidylate synthase genetic polymorphism and plasma total homocysteine level in a group of Turkish patients with rheumatoid arthritis: relationship with disease activity and methotrexate toxicity

Resumo Introdução: Relata-se que o polimorfismo do gene timidilato sintase (TS) e a homocisteína têm relação com o metabolismo do metotrexato (MTX), com achados conflitantes. O objetivo deste estudo foi determinar os níveis de homocisteína e a frequência de polimorfismos de repetição tripla (TS3R) e dupla (TS2R) do gene TS em um grupo de pacientes turcos com AR e avaliar sua associação com a toxicidade ao MTX e a atividade da doença. Métodos: Foram incluídos no estudo 64 pacientes com AR e 31 indivíduos no grupo controle, com média de 48,7 ± 12,5 e 46,2 ± 13,4 anos. Foram obtidas as características demográficas e foi registrado o número de pacientes que relataram efeitos adversos ao MTX no grupo AR. Foram analisados os níveis de homocisteína e os polimorfismos TS2R/TS3R. Foi determinada a distribuição de genótipos de acordo com a toxicidade ao MTX e a atividade da doença. Resultados: Os dados demográficos foram semelhantes entre os pacientes e controles. Todos faziam suplementação de ácido fólico a uma dose média de 5 mg/semana. Dos 64 pacientes, 36 apresentaram efeitos adversos ao tratamento com MTX. Encontrou-se uma frequência de polimorfismos TS2R e TS3R semelhante nos grupos AR e controle. Encontrou-se que os polimorfismos TS2R e TS3R eram semelhantes em pacientes com e sem eventos adversos relacionados com o MTX. O nível médio de homocisteína também foi similar em pacientes com e sem polimorfismo do gene TS, mas era mais elevado (12,45 μmol/L vs. 10,7 μmol/L) em pacientes com do que sem efeitos adversos relacionados com o MTX. O nível médio de homocisteína se correlacionou com o VHS no grupo AR. Conclusões: Os níveis de homocisteína podem afetar a atividade da doença e a toxicidade ao MTX, mas os polimorfismos 2 R e 3 R no gene TS não se correlacionaram com a toxicidade ao MTX em pacientes com AR que recebem suplementação de ácido fólico. São necessários mais estudos para esclarecer os polimorfismos em outras enzimas que podem ser responsáveis pela toxicidade ao MTX em pacientes com AR.

Abstract Background: The polymorphism of thymidylate synthase (TS) gene and homocysteine are reported to have a relationship to methotrexate (MTX) metabolism, with conflicting results. The aim of this study was to determine homocysteine levels and the frequency of TS gene triple repeat (TS3R) and double repeat (TS2R) polymorphisms in a group of Turkish RA patients and evaluate its association with MTX toxicity and disease activity. Methods: Sixty-four patients with RA and 31 control subjects with a mean age of 48.7 ± 12.5 and 46.2 ± 13.4 years were enrolled for the study. Demographic characteristics were obtained and a number of patients with MTX-related adverse affects were recorded in the patient group. The homocysteine levels and TS2R/TS3R polymorphisms of the TS gene were analyzed and the distribution of genotypes according to MTX toxicity and disease activity was determined. Results: The demographic properties were similar between the patient and control subjects. Folic acid supplementation with a mean dose of 5 mg folic acid/week was present in all patients. Thirty-six of the 64 patients showed adverse effects to MTX treatment. The respective frequency of TS2R and TS3R polymorphisms was found to be similar in the patient and control groups. TS2R and TS3R gene polymorphisms were found to be similar in patients with and without MTX-related adverse events. The mean homocysteine level was also similar in patients with and without TS gene polymorphism, but was found to be higher (12.45 μmol/L vs 10.7 μmol/L) in patients with MTX-related side effects than in patients without side effects. The mean level of homocysteine was correlated with levels of ESR in the patient group. Conclusions: In conclusion, homocysteine levels might affect the disease activity and toxicity of MTX but 2R and 3R polymorphisms in the TS gene were not related with MTX-related toxicity in RA patients receiving folate supplementation. Further studies are needed to illuminate the polymorphisms in other enzymes that might be responsible for the MTX toxicity in patients suffering from RA.

Caspase-1 Level in Synovial Fluid Is High in Patients with Spondyloarthropathy but Not in Patients with Gout

Activation of caspase-1 by NALP3 inflammasomes has been shown to be important in initiating acute gouty arthritis. The objectives of this study were to measure the levels of caspase-1 in synovial fluid in gout and various arthritides, and to elucidate the clinical significance of caspase-1 levels in synovial fluid. Caspase-1, IL-1beta, IL-18, and uric acid were measured in synovial fluid from 112 patients with gout and other arthritides, such as rheumatoid arthritis, osteoarthritis, and spondyloarthropathy. Caspase-1 in synovial fluid from patients with crystal-induced arthritis, inflammatory arthritis, osteoarthritis, and spondyloarthropathy was 35.9 +/- 86.7, 49.7 +/- 107.7, 2.1 +/- 7.0, and 152.6 +/- 155.7 pg/mL, respectively. The mean level and the frequency of high levels (> or =125 pg/mL) of caspase-1 in spondyloarthropathy were significantly higher than those in the other arthritides including gout. Caspase-1 was detectible in the synovial fluid of patients with the various arthritides. Contrary to our hypothesis, the caspase-1 level in the synovial fluid of patients with gout was not higher than in that of other arthritides. High levels of caspase-1 may be helpful in differentiating spondyloarthropathy from other arthritides.

Over-expression of extracellular superoxide dismutase in mouse synovial tissue attenuates the inflammatory arthritis

Oxidative stress such as reactive oxygen species (ROS) within the inflamed joint have been indicated as being involved as inflammatory mediators in the induction of arthritis. Correlations between extracellular-superoxide dismutase (EC-SOD) and inflammatory arthritis have been shown in several animal models of RA. However, there is a question whether the over-expression of EC-SOD on arthritic joint also could suppress the progression of disease or not. In the present study, the effect on the synovial tissue of experimental arthritis was investigated using EC-SOD over-expressing transgenic mice. The over-expression of EC-SOD in joint tissue was confirmed by RT-PCR and immunohistochemistry. The degree of the inflammation in EC-SOD transgenic mice was suppressed in the collagen-induced arthritis model. In a cytokine assay, the production of pro-inflammatory cytokines such as, IL-1beta, TNFalpha, and matrix metalloproteinases (MMPs) was decreased in fibroblast-like synoviocyte (FLS) but not in peripheral blood. Histological examination also showed repressed cartilage destruction and bone in EC-SOD transgenic mice. In conclusion, these data suggest that the over-expression of EC-SOD in FLS contributes to the activation of FLS and protection from joint destruction by depressing the production of the pro-inflammatory cytokines and MMPs. These results provide EC-SOD transgenic mice with a useful animal model for inflammatory arthritis research.

The effect of 677C>T and 1298A>C MTHFR polymorphisms on sulfasalazine treatment outcome in rheumatoid arthritis

Despite the availability of several new agents for the treatment of rheumatoid arthritis (RA), sulfasalazine remains the mainstay because of both cost and experience with its use. Methylenetetrahydrofolate reductase (MTHFR) is involved in folate metabolism and several polymorphisms have been described in the MTHFR gene. Of these, the 677C>T and 1298A>C polymorphisms have been associated with altered enzyme activity. To examine the association between 677C>T and 1298A>C MTHFR polymorphisms and sulfasalazine efficacy for the treatment of RA, a total of 117 RA patients treated with sulfasalazine (1 g daily; duration of treatment 17 ± 5 months) were analyzed. The 677C>T and 1298 A>C polymorphisms were detected using a PCR-RFLP method. RA was diagnosed according to the criteria of the American College of Rheumatology (ACR). The remission of RA symptoms was evaluated according to the ACR 20% response criteria. Allele and genotype frequencies were compared by the two-sided Fisher exact test. The frequency of remission was 47.2% and 44.6% in carriers of 677T and 1298C alleles, compared to 40.7% and 42.0% in carriers of 677C and 1298A alleles, respectively. These differences were statistically non-significant. When the multivariate analysis was additionally adjusted for patients’ age, gender and RA duration, the association of the MTHFR 677T allele with increased frequency of remission was statistically significant. Although RA remission rate in carriers of the MTHFR 677T and 1298C alleles was more frequently observed, it does not seem that 677C>T and 1298A>C MTHFR polymorphisms have a major influence on treatment outcome in RA patients treated with sulfasalazine.

Expression of cyclooxygenase-1 and -2 in rheumatoid arthritis synovium

The aim of this study was to investigate the expression and localization of cyclooxygenase-1 and -2 (COX-1 and COX-2) in synovial tissues from patients with rheumatoid arthritis (RA). Synovial tissues from 9 patients with RA and 5 patients with osteoarthritis (OA) were examined for COX-1 and COX-2 expressions by immunohistochemical staining using 2 polydonal COX-1 and COX-2 antibodies. In RA synovia, synovial lining cells showed intense immunostaining for COX-1, whereas slight to moderate staining was observed in inflammatory cells, stromal fibroblast-like cells and vascular endothelial cells. There was no significant difference in COX-1 expression between RA and OA synovia. The localization of COX-2 expression dearly differed from that of COX-1 expression, being most intense in inflammatory cells. However, there was no difference in COX-1 and COX-2 expressions between RA and OA synovial tissues. Our observations support that inflammatory mechanisms modulated by COX-1 and COX-2 in chronic RA synovium might be similar to those in chronic OA synovium.

Incremento en la produccion de colagenasa en incubado de sinoviocitos de pacientes com artritis reumatoidea y osteoartrosis / Collagenase production increases in rheumatoid arthritis and ostheoarthritis synoviocytes incubated

El cartílago articular es un tejido paucicelular, con colágeno y proteoglicanos en la matriz extracelular. Su degradación es función de los sinoviocitos, que segregan metaloproteasas que catabolizan a los proteoglicanos. Se distinguen los sinoviocitos A o macrofágicos y los sinoviocitos B o fibroblásticos. La destrucción de proteoglicanos puede ser LT- dependiente o independiente. Nuestro objetivo fue estudiar ex vívo el rol de los sinoviocitos, sin la influencia del sistema inmune. Líquido sinovial de pacientes de ambos sexos, 70ñ2años, con OA(6) y AR(6), vírgenes de tratamiento, se centrifugó 30 minutos a 1500 g, para aislar sinoviocitos. El sedimento se incubó 6 hs en medio Dulbecco-Eagles, con 26 mM de HEPES Gibco, NaHCO3 ( 0.5g/l), glutamina (2 mM), estreptomicina (100mg/l), penicilina (1 U/ml) y anfotericina B (2.5mg/l). Identidad y viabilidad celulares se determinaron con técnicas citopatológicas. Las muestras control provinieron de artritis traumática o patología osteoarticular no-inflamatoria. Con anticuerpos monoclonales anti-MMPs(10mg/ml), previo bloqueo de producción de proteínas inespecíficas con albúmina sérica bovina, se midió actividad colagenasa (MMP-1) antes y después de incubar con ELISA-doble-sandwich. Con streptavidin-peroxidasa se desarrolló color y por absorbancia a 410 nm, se leyó la complejación de los anticuerpos marcados. La secreción de MMP-1 por sinovio-citos AR fue 1373ñ115 ng/ml. Con 6 hs de incubado aumentó hasta 2143ñ132ng/l (-56 por ciento)(p<0.0001), probablemente por la hipercelularidad. Los sinoviocitos OA secretaron 276 ñ 23 ng/ml , y 542 ñ 47 ng/ml tras la incubación (96 por ciente)(p<0.001). Hay paralelismo entre la producción de MMP-1 y la observación microscópica. Sinoviocitos con abundante citoplasma corresponden a altos niveles de enzima. La baja secreción de MMPs responde a escasa población celular y núcleos picnóticos. Aunque en AR la producción de MMPs fue 4.6 veces mayor que en OA, en cambio el incremento porcentual tras la incubación fue casi el doble en OA que en AR. Esos resultados confirman que la producción enzimática varía con la inflamación, que es mayor en los procesos agudos, y que la incubación de sinoviocitos permite detectar cambios patológicos locales

Urinary N-acetyl-beta-D-glucosaminidase in rheumatoid arthritis

Excretion of urinary N-acetyl beta-D-glucosaminidase (NAG) and its isoenzyme patterns were studied in two groups of patients with rheumatoid arthritis (RA) and in normal control subjects. Urine samples were collected from 30 seropositive RA patients, 19 seronegative RA patients, and 15 normal healthy subjects. All the patients and normal subjects were assessed to have normal liver and kidney functions. A small portion of the urine sample was dialyzed against 0.01 M phosphate buffer, pH 7.0 and NAG activity was monitored. Mean +/- SD values of urinary NAG in seropositive RA patients, in seronegative RA patients and in normal healthy subjects were found to be 4.20 +/- 3.73 U/g creatinine, 2.96 +/- 2.11 U/gm creatinine, and 1.71 +/- 0.6 U/g creatinine, respectively. The mean urinary, NAG value in RA patients was found to be significantly higher (P < 0.05) in seropositive RA compared to the mean NAG value in normal healthy subjects and patients with seronegative RA when analyzed by one way ANOVA and Tukey-HSD test. The mean proportion of isoenzyme form B to isoenzyme form A in seropositive RA patients was also found to be significantly different (P < 0.05) from the mean proportion of these forms in normal healthy subjects and seronegative RA patients. There also appears to be a correlation between the concentration of urinary NAG and severity of the disease in seropositive RA.

Aminotransferases em pacientes com artrite reumatoide tratados com metotrexate / Aminotransferases levels in rheumatoid arthritis patients in treatment with methotrexate

Avaliou-se o comportamento das aminotransferases sericas em pacientes com artrite reumatoide (AR) tratados com metotrexate (MTX), atraves de estudo retrospectivo com 53 pacientes selecionados aleatoriamente, em uso regular de MTX; e a elevacao das aminotransferases sericas e sua influencia na conduta terapeutica. A dose media de MTX foi 7,46 mg/sem (2,5-15) e o tempo medio de 123,7 semanas (30-373,5). Em 13 pacientes observou-se elevacao das aminotransferases sericas. Em nenhum dos casos este aumento foi superior a tres vezes os valores normais; em dez casos este aumento foi transitorio, em 3 (5,6 por cento) persistente. Em relacao a estes tres pacientes: no primeiro a analise histologica da biopsia hepatica evidenciou esteatose, a terapeutica foi mantida por ser considerada indispensavel e os niveis enzimaticos continuaram discretamente elevados; nos outros dois casos o uso de MTX foi interrompido e os valores retornaram a normalidade apos a retirada da droga...