Response to methotrexate predicts long-term patient-related outcomes in rheumatoid arthritis

Associations Between Genetic Polymorphisms Within Transporter Genes and Clinical Response to Methotrexate in Chinese Rheumatoid Arthritis Patients: A Pilot Study

Purpose

To investigate the associations between genetic polymorphisms within transporter genes and clinical response to methotrexate (MTX) in Chinese rheumatoid arthritis (RA) patients.

Patients and Methods

A total of 100 RA patients receiving MTX were prospectively followed up for approximately 3 months to determine the clinical response based on several criteria, including European League Against Rheumatism (EULAR) good and moderate response, disease activity score in 28 joint counts – erythrocyte sedimentation rate (DAS28-ESR) low disease activity (LDA), change in DAS28-ESR (ΔDAS28-ESR) and ΔDAS28-ESR >0.6. Fifty-four single nucleotide polymorphisms (SNPs) within seven transporter genes, including SLC19A1, ABCB1, ABCC1~4 and ABCG2, were genotyped.

Results

Multivariable analysis revealed that SLC19A1 rs12659 and rs3788200, ABCC2 rs3740066, rs4148396 and rs717620 were significantly associated with EULAR good and moderate response, and ABCC2 rs3740066 and rs717620 were significantly associated with DAS28-ESR LDA, and ABCB1 rs1128503, rs4148737 and ABCC3 rs2277624, rs4148416 were significantly associated with ΔDAS28-ESR. Moreover, 12 genetic polymorphisms were found to be significantly associated with ΔDAS28-ESR >0.6. With adjustment for corresponding confounders, SLC19A1 TGAA haplotype consisting of rs1051266, rs1131596, rs12659 and rs3788200 was significantly associated with EULAR good and moderate response and ΔDAS28-ESR >0.6 compared with the most common haplotype CAGG. The ABCC2 haplotype TTT composed of rs717620, rs4148396 and rs3740066 was significantly associated with EULAR good and moderate response and ΔDAS28-ESR >0.6 compared with the most common haplotype CCC.

Conclusion

Our results highlight the potential of genetic polymorphisms within transporter genes, particularly SLC19A1 and ABCC2, as predictors of clinical response to MTX in Chinese RA patients.

[Getting older with rheumatoid arthritis-is there a burnout of the disease?]

Rheumatoid arthritis (RA) is a chronic inflammatory disease. Synovitis is the main pathology and can lead to a progressive destruction of the joints. It is often said that RA "burns out", implying that the inflammation decreases spontaneously in the long term, mostly severe course of RA and reaches a stage with a stable absence of joint inflammation, even without treatment. To test this concept we analyzed the published evidence. Data of historic long-term inception cohorts of patients who have never been treated with antirheumatic drugs and patients who received conventional disease-modifying antirheumatic drugs (DMARD), show that the disease stays active with sustained radiological progression in the majority of patients. At best, the disease can show a milder course with time or a stage of absence of joint inflammation can be reached if patients responded very well to initial drug treatment. Terminating DMARD treatment in this situation bears the risk of a latent progressive joint destruction, the appearance of extra-articular manifestations and an increase in the cardiovascular risk. Hence there is no evidence for the existence of a "burnt out" RA with stable inactive disease without drug treatment in the long-term course. In a modern treatment strategy of RA following the treat-to-target principle and aiming at remission, the term "burnt out" RA should no longer be used.

Predictors for orthopaedic surgery in patients with rheumatoid arthritis: results from a retrospective cohort study of 1010 patients diagnosed from 1972 to 2009 and followed up until 2015

OBJECTIVES

To investigate how patient characteristics, time of diagnosis, and treatment affect the need for orthopaedic surgery in patients with rheumatoid arthritis (RA).

METHOD

We reviewed the medical history of 1544 patients diagnosed with RA at Haukeland University Hospital in Bergen, Norway, from 1972 to 2009, of whom 1010 (mean age 57 years, 69% women) were included in the present study. Relevant orthopaedic procedures were obtained from the Norwegian Arthoplasty Register and the hospital's administrative patient records. In total, 693 procedures (joint synovectomies 22%, arthrodeses 21%, prostheses 41%, and forefoot procedures 12%) were performed in 315 patients. Survival analyses were completed to evaluate the impact of different factors such as age, gender, radiographic changes, and year of diagnosis, on the risk of undergoing surgery.

RESULTS

Patients diagnosed in 1972-1985 and 1986-1998 had a relative risk of undergoing surgery of 2.4 and 2.2 (p < 0.001), respectively, compared to patients diagnosed in 1999-2009. Radiographic changes at diagnosis and female gender were also significant risk factors. Anti-rheumatic medication was significantly different in the three time periods.

CONCLUSION

Patients with a diagnosis in the early years had a greatly increased risk of having orthopaedic surgery performed. This is probably due to the year of diagnosis being a proxy for the type and intensity of medical treatment.