Polymorphism in Organic Anion-Transporting Polypeptide Gene Related to Methotrexate Response in Rheumatoid Arthritis Treatment.

BACKGROUND: Methotrexate (MTX) is still the first-choice drug for the treatment of rheumatoid arthritis (RA). In Japan, MTX doses of up to 16 mg/week were approved in 2011. In this study, we aimed to identify the gene polymorphisms that can predict therapeutic effects of MTX in Japanese patients in current clinical settings. METHODS: This study involved 171 patients with RA (all Japanese nationals, age 63.5±10.0 years) who had been administered MTX. The analyzed polymorphisms included 82 single nucleotide polymorphisms (SNPs) involved in the MTX pharmacological pathway or in the pathogenesis of RA. Responders were patients who showed high sustained remission or low disease activity with MTX or conventional disease-modifying anti-rheumatic drugs (DMARDs) treatment beyond 6 months. Non-responders were patients who showed moderate or high disease activity, who were prescribed biological DMARDs. A logistic model was constructed with Responder/Non-responder as the target variable, and minor allele frequency was set as an explanatory variable. RESULTS: None of the 82 SNPs targeted for analysis met the Bonferroni significance threshold of 6.098×10-4. However, we identified SLCO1B1 rs11045879 as an SNP that might yield significant results if the number of patients were to be increased (P=0.015). CONCLUSIONS: The rs11045879 minor allele in the SLCO1B1 gene is a potential predictor of non-responders to MTX treatment among Japanese RA patients. In future collaborative research, we will investigate whether the association with SLCO1B1 polymorphism is significant by performing statistical analysis with a larger study population.

Phosphoproteome analysis of synoviocytes from patients with rheumatoid arthritis.

AIM: To explore disease-associated molecules in rheumatoid arthritis (RA), we comprehensively analyzed phosphoproteins purified from RA synoviocytes. METHOD: Synoviocytes were obtained from three patients with RA and three patients with osteoarthritis (OA). Profiles of phosphoproteins purified from the synoviocytes were compared by two-dimensional differential gel electrophoresis (2D-DIGE) between the RA and OA groups. Protein spots with significantly different phosphorylation levels were identified by mass spectrometry. Recombinant protein of annexin A4 (ANXA4), one of the identified phosphoproteins, was transfected into synoviocytes from an OA patient to mimic RA synoviocytes and humoral factor secretion was compared between rANXA4-transfected and non-transfected synoviocytes under a tumor necrosis factor-α (TNFα)-stimulated condition. RESULTS: In 2D-DIGE, 318 phosphoprotein spots were detected, of which 94 spots showed significantly different intensities between the two groups (P < 0.05). Among the 94 spots, 22 spots showed two-fold or higher intensity and one spot showed less than 1/2-fold intensity in the RA group compared to the OA group. From the 22 spots, 11 phosphoproteins were identified, which included kinases, carrier and chaperone proteins, cytoskeletal proteins, proteases and calcium-binding proteins. One of the identified calcium-binding proteins was ANXA4, an exocytosis-regulating protein. The transfected rANXA4 was found to be phosphorylated intracellularly, and secretion of chemokine (C-X-C motif) ligand 1 and interleukin-8 induced by TNFα stimulation was significantly suppressed by the transfection (P < 0.01). CONCLUSION: The phosphoprotein profile of RA synoviocytes was different from that of OA synoviocytes. This difference would reflect the different pathophysiologies of the diseases. ANXA4 may be one of therapeutic targets in RA.

Neutrophil/Lymphocyte Ratio in Patients with Rheumatoid Arthritis Treated with Biological Agents.

BACKGROUND: Disease activity of rheumatoid arthritis (RA) is evaluated by composite measures, such as Disease Activity Score (DAS). Recently, much attention has been paid to a neutrophil-lymphocyte (N/L) ratio to evaluate the prognosis and the efficacy of intervention in various diseases. To determine whether the N/L ratio is a prognostic marker or a surrogate marker of response to biologics, this study investigated the N/L ratio in RA patients treated with biological agents. METHODS: The medical records were reviewed of 358 patients with RA in routine care who were treated with infliximab (144 patients), etanercept (120 patients), adalimumab (25 patients), tocilizumab (41 patients), or abatacept (28 patients). The 28-joint DAS (DAS28), a hemogram, erythrocyte sedimentation rate (ESR), and serum levels of C-reactive protein and matrix metalloproteinase 3 were assessed at baseline and 6 months after the treatment. RESULTS: The average N/L ratio significantly decreased from 5.9 at baseline to 4.5 6 months after the treatment. The N/L ratio and the DAS28-ESR, both at baseline and 6 months after the treatment, were modestly but significantly correlated. The N/L ratio was greater in patients with high disease activity than in patients with low disease sactivity. The change of the N/L ratio (ΔN/L) and the change of the DAS28-ESR were modestly but significantly correlated. Regarding the therapeutic response, the N/L ratio at baseline showed no significant difference between the response criteria; however, the N/L ratio after 6 months of treatment and the ΔN/L ratio differed significantly. The ΔN/L was also significantly correlated with the change of the serum level of C-reactive protein and the change of the DAS28-ESR. CONCLUSION: The N/L ratio is a marker of disease activity in RA. The ΔN/L ratio reflects the efficacy of biological agents but does not predict the response to biological agents.

Proteomic analysis of bone marrow-adherent cells in rheumatoid arthritis and osteoarthritis.

AIM: To elucidate the pathophysiology of rheumatoid arthritis (RA) as well as osteoarthritis (OA), we analyzed protein profiles of bone marrow-derived adherent cells (BMACs) from patients with these diseases. METHODS: Proteins, extracted from BMACs from three RA and three OA patients, were comprehensively analyzed by 2-dimensional differential image gel electrophoresis (2D-DIGE). Then a part of the detected proteins, differently expressed between the two diseases, were identified by mass spectrometric analysis. RESULTS: 2D-DIGE analysis detected more than 1600 protein spots in both RA and OA BMACs. Out of these, expression of 340 spots was significantly altered between the diseases (more than 1.5-fold: RA > OA, 26 spots; OA > RA, 314 spots; P < 0.05). Eleven protein spots the intensity of which were significantly altered by more than 2.0-fold were identified, which included vimentin and annexin A5 as increased proteins in RA rather than in OA. As increased proteins in OA compared to RA, alpha chain of collagen VI, a membrane anchor for acetylcholine esterase, heat shock protein 27, caldesmon and cytoskeletal proteins, such as beta actin and alpha tubulin, were identified. CONCLUSIONS: We here report different protein profiles of BMACs between RA and OA for the first time. BMACs possessing differently expressed proteins may be involved in the pathophysiology of the two diseases.

Elevation of serum KL-6 levels in 3 patients with rheumatoid arthritis treated with adalimumab.

We describe 3 cases of rheumatoid arthritis presenting with elevated serum KL-6 levels during treatment with adalimumab, which was discontinued because of suspected onset of complications. However, no complications were observed following discontinuation despite comprehensive assessments, and KL-6 levels subsequently returned to baseline levels. In our institutes, 3 out of 29 cases treated with adalimumab showed elevated KL-6 levels. The baseline levels were 445, 347, and 547 U/ml, while the peak levels were 1010, 546, and 2007 U/ml, respectively. The elevated KL-6 levels seem to have been innocuous; nevertheless, further careful observation is deemed necessary.

The effects of radiofrequency hyperthermia on pain and function in patients with knee osteoarthritis: a preliminary report.

BACKGROUND: The clinical evidence of the efficacy of hyperthermia on osteoarthritis (OA) has not yet been clearly established. In addition, the application of a modality that can control the temperature inside the joints has not been reported. The purpose of this study was to investigate the effect of percutaneous radiofrequency hyperthermia, which could safely raise the temperature of the body core, in patients with OA knees. METHODS: Temperature changes inside the knee joint without OA were measured during exposure to radiofrequency. Radiofrequency hyperthermia was performed on 12 OA knees by exposure to 8 MHz and 200 W for 20 min, 3 times, at 1-week intervals. The clinical outcome was evaluated by use of the Lequesne index (LI) and the Japan Orthopaedic Association (JOA) scale. The osteoarthritis research society international (OARSI) responder criteria were also analyzed. RESULTS: Radiofrequency hyperthermia of 8 MHz and 200 W for 20 min increased the temperature inside the joint from 34.4 to 39.4°C. The LI decreased by 3.55 points from baseline during the 3 weeks. The JOA scale improved significantly during the period, reaching 86.25 points at the final examination from baseline of 67.5 points. 67% of patients had a response to the therapy according to OARSI criteria. No side effects were observed. CONCLUSIONS: Radiofrequency hyperthermia can safely increase the temperature inside the knee joint. Radiofrequency hyperthermia on OA knees provides a remarkable pain relief effect and can improve the patients' daily life. In the future, clinical studies should be performed with a protocol containing more cases, with appropriate control groups.

Effects of glucosamine administration on patients with rheumatoid arthritis.

The purpose of this study was to examine whether glucosamine has an antirheumatic effect in a randomized placebo-controlled study. The subjects were 51 rheumatoid arthritis (RA) patients: 25 patients in the glucosamine group and 26 patients in the placebo group. Glucosamine hydrochloride at a daily dose of 1,500 mg and placebo, respectively, were administered for 12 weeks along with conventional medication. While significant improvement was not found in joint counts and in the rate of ACR20 responders, the face scale and a visual analogue scale pain were significantly in favor of the glucosamine group. ESR and CRP levels did not change, but serum MMP-3 levels decreased in the glucosamine group. Results of the patients' self-evaluations and the physicians' global evaluations indicated that the glucosamine treatment produced noticeable improvements in symptoms. Although glucosamine administration had no antirheumatic effect evaluated by conventional measures, it seemed to have some symptomatic effects on RA.