Preliminary study for predicting better methotrexate efficacy in Japanese patients with rheumatoid arthritis

Risk factors associated with relapse after methotrexate dose reduction in patients with rheumatoid arthritis receiving golimumab and methotrexate combination therapy

AIM

To identify risk factors for relapse after methotrexate (MTX) dose reduction in rheumatoid arthritis (RA) patients receiving golimumab (GLM)/MTX combination therapy.

METHOD

Data on RA patients ≥20 years old receiving GLM (50 mg) + MTX for ≥6 months were retrospectively collected. MTX dose reduction was defined as a reduction of ≥12 mg from the total dose within 12 weeks of the maximum dose (≥1 mg/wk average). Relapse was defined as Disease Activity Score in 28 joints using C-reactive protein level (DAS28-CRP) score ≥3.2 or sustained (≥ twice) increase of ≥0.6 from baseline.

RESULTS

A total of 304 eligible patients were included. Among the MTX-reduction group (n = 125), 16.8% of patients relapsed. Age, duration from diagnosis to the initiation of GLM, baseline MTX dose, and DAS28-CRP were comparable between relapse and no-relapse groups. The adjusted odds ratio (aOR) of relapse after MTX reduction was 4.37 (95% CI 1.16-16.38, P = 0.03) for prior use of non-steroidal anti-inflammatory drugs (NSAIDs), and the aORs for cardiovascular disease (CVD), gastrointestinal disease and liver disease were 2.36, 2.28, and 3.03, respectively. Compared to the non-reduction group, the MTX-reduction group had a higher proportion of patients with CVD (17.6% vs 7.3%, P = 0.02) and a lower proportion of prior use of biologic disease-modifying antirheumatic drugs (11.2% vs. 24.0%, P = 0.0076).

CONCLUSION

Attention should be given to RA patients with history of CVD, gastrointestinal disease, liver disease, or prior NSAIDs-use when considering MTX dose reduction to ensure benefits outweigh the risks of relapse.

Glycolysis aggravates methotrexate toxicity by fueling RFC1-controlled intestinal absorption in rheumatic rats

Methotrexate (MTX) is a first line anti-rheumatic drug. This study was designed to investigate the impact of rheumatoid arthritis (RA) conditions on its oral absorption, and clarify the relevance with changes of MTX absorption-related transporters in rheumatic models. MTX was orally administered to healthy, collagen-induced arthritis (CIA), and adjuvant-induced arthritis (AIA) rats. MTX plasma concentrations were determined by a validated liquid chromatography-mass spectrometry method. We found that intestinal MTX absorption was significantly increased in CIA/AIA rats versus healthy controls. This finding was supported by small intestine-based MTX uptake assay in vitro. Meanwhile, intestinal expression of both reduced folate carrier 1 (RCF1) and proton-coupled folate transporter (PCFT) remained unchanged. The everted intestinal sac assay confirms RFC1 is the key transporter accounting for intestinal MTX absorption, as its antagonist salicylazosulfapyridine showed potent capacity in reducing MTX uptake. No correlation between RA-related cytokines and RCF1 expression was observed in clinical samples. We further revealed that when cultured with AIA rat or RA patient serum, lactate and adenosine triphosphate (ATP) production as well as MTX uptake in MDCKII cells were significantly increased, and this increase was completely abrogated by ATP production-related metabolic inhibitors. Thanks to its inhibitory effects on MTX bioavailability, the glycolysis inhibitor shikonin diminished MTX-induced injuries of kidney and liver in AIA rats. These data demonstrate that glycolysis-driven high energy metabolism increases MTX absorption in rheumatic subjects, leading to the exacerbated toxicity. These findings will have important implications in optimizing MTX regimens for RA treatment with better efficacy and lower toxicity.

Membrane-Spanning Protein Genetic Polymorphisms Related to Methotrexate Therapeutic Outcomes in a Chinese Rheumatoid Arthritis Population

Methotrexate (MTX) is a first-line disease-modifying antirheumatic drug for rheumatoid arthritis (RA), but individual variation in treatment response remains unexplained. The differences in drug efficacy and adverse drug reactions may be caused by genetic variations. We investigated the effects of single-nucleotide polymorphisms (SNPs) in 2 genes encoding membrane-spanning proteins, namely, reduced folate carrier-1 RFC-1/SLC19A1 (G>A [rs7499], A>G [rs2838956] and 180G>A [rs1051266]) and adenosine triphosphate-binding cassette B1 (rs1045642). Tagged SNPs were genotyped in 162 patients with RA in China. Then, we analyzed the relationships between these SNPs and therapeutic outcomes related to MTX in Chinese RA patients. No significant associations were found between the RFC-1/SLC19A1 (G>A [rs7499] and A>G [rs2838956]) and adenosine triphosphate-binding cassette B1 (rs1045642) gene polymorphisms and the response to MTX in RA patients. However, MTX-related toxicity was associated with one SNP, RFC-1 rs1051266 AA vs GG (odds ratio, 6.523; 95% confidence interval, 1.596-26.565; P = .009). SLC19A1 A>G rs2838956 showed a trend toward a significant association (odds ratio, 0.377; 95% confidence interval, 0.124-1.143; P = .085) with toxicity. Our results suggest that the RFC-1 80G>A (rs1051266) SNP exerts a potentially protective effect against the risk of adverse drug reactions in Chinese RA patients treated with MTX. Further studies are required to validate these findings.

Association of MTHFR C677T and A1298C gene polymorphisms with methotrexate efficiency and toxicity in Algerian rheumatoid arthritis patients

Methotrexate (MTX) is the most used drug in rheumatoid arthritis (RA) treatment. However, it shows variability in clinical response, which is explained by an association with genetic polymorphisms. This study aimed to elucidate the role of the two gene polymorphism C677T and A1298C of the methylenetetrahydrofolate reductase (MTHFR) in response to MTX in Algerian RA patients. Study included 54 early RA patient treated with MTX for one year. MTX efficiency and toxicity were evaluated at 6 and 12 months respectively and the two gene polymorphisms were genotyped. No association was found between A1298C polymorphism and MTX toxicity. However, T allele of the C677T polymorphism was associated with the occurrence of MTX adverse effects (p = 0,019, OR: 3,63, 95% CI [1,12 - 12,80]). No association was found between C677T polymorphism and MTX efficiency, while A allele of the A1298C polymorphism was associated with good and moderate response (p = 0,02, OR = 3,28, 95% CI: [1,11– 9,42]). The study of RA biological markers kinetics showed that MTX did not affect antibodies rate unlike inflammatory markers. Our study suggests that MTHFR C677T and A1298C genotyping are associated to MTX toxicity and efficiency, respectively, in RA patients. This offers new perspectives in the personalization of RA treatment in Algeria.

ATIC missense variant affects response to methotrexate treatment in rheumatoid arthritis patients

AIM

The study was aimed at investigation of several gene variants of folate pathway enzymes for their potential association with methotrexate (MTX) treatment response in patients with rheumatoid arthritis.

PATIENTS & METHODS

Four hundred and twenty two Caucasian patients were classified as good or poor responders, and subsequently genotyped for common SNPs in DHFR, FPGS and ATIC genes.

RESULTS

No significant differences were observed in case of DHFR and FGPS SNPs. As for ATIC rs2372536 (Thr116Ser), GG minor genotype was significantly associated with good response to MTX (OR: 2.40; 95% CI: 1.30-4.42; p = 0.005), which was confirmed by multivariate analysis.

CONCLUSION

The results of the study suggest that ATIC missense rs2372536 SNP may influence response to MTX therapy in rheumatoid arthritis patients.