Association of a complement receptor 1 gene variant with baseline erythrocyte sedimentation rate levels in patients starting anti-TNF therapy in a UK rheumatoid arthritis cohort: results from the Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate cohort

Conversion among the 28-joint count activity indices for rheumatoid arthritis

OBJECTIVE

Disease activity indices for rheumatoid arthritis (RA) are important in clinical practice and research. Although they are closely correlated, they are not in good agreement. We derived formulae to convert values from one of the four 28-joint count indices (disease activity score using erythrocyte sedimentation rate [DAS28-ESR], disease activity score using C-reactive protein [DAS28-CRP], clinical disease activity index [CDAI], and simple disease activity index [SDAI]) to any of the others.

METHODS

We obtained data from 175 patients from our RA registry with concurrent CRP and ESR and established the nature of relationships between the indices using these data. Subsequently, we developed empiric conversion formulae. Furthermore, we developed new cutoff values for classifying disease activity to minimize the disparity among indices, using an iterative method.

RESULTS

The relationships between DAS28-ESR and DAS28-CRP and between SDAI and CDAI were approximately linear; the others were quadratic. Quadratic equations approximated the relationship between DAS, SDAI, and CDAI, whereas natural logarithms function approximated the relationship between DAS28-ESR and DAS28-CRP. Patients are frequently categorized into inconsistent disease activity states with any two indices, with the disparity ranging from 9.7% to 40.6%. The new cutoff values were developed to minimize the discrepant activity state categorization, reducing the disparity range to 6.3%-32.6%.

CONCLUSION

We derived empiric formulae that connect DAS28-ESR, DAS28-CRP, SDAI, and CDAI. Moreover, we developed new cutoff values to minimize the discrepant activity state categorization with different indices.

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.

Efficacy and safety evaluation of a combination of iguratimod and methotrexate therapy for active rheumatoid arthritis patients: a randomized controlled trial

This study aimed to investigate the efficacy and safety of iguratimod (T-614) in combination with methotrexate (MTX) for active rheumatoid arthritis (RA) patients. Sixty active RA patients were enrolled according to the 2010 American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) classification criteria, and were randomized into MTX + T-614 group and MTX group. T-614 was orally administered at a dosage of 50 mg/day (25 mg twice daily) for 24 weeks. MTX was orally administered to RA patients at a stable weekly dosage of 10 mg/week for the first 4 weeks and subsequent 12.5 mg/week for the later 20 weeks. Clinical features at baseline and efficacy endpoints of the ACR 20 % response (ACR20), ACR50, ACR70, and adverse events at 24 weeks were evaluated, respectively. After 24 weeks of treatment, clinical features at baseline, including counts for tender joints and swelling joints, visual analog scale for pain, patient's and physician's global assessment, erythrocyte sedimentation rate, C-reactive protein, disease activity score 28, health assessment questionnaire, simplified disease activity index, and ACR50 in the MTX + T-614 group, showed statistically significant differences comparing with the MTX group (P < 0.05). There was no significant increase in adverse events in the MTX + T-614 group comparing with the MTX group (P > 0.05). The combination of MTX and T-614 therapy appeared to have a good efficacy and safety for active RA and was superior to MTX-alone therapy after 24 weeks of treatment.