Influences of advanced age in rheumatoid arthritis: A multicentre ultrasonography cohort study.

OBJECTIVES: We aimed to evaluate the effects of age on clinical characteristics and outcomes in biologic or targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD)-naïve patients with rheumatoid arthritis (RA). METHODS: We analysed the cases of 234 Japanese b/tsDMARD-naïve RA patients who underwent b/tsDMARD treatment in a multicentre ultrasound prospective observational cohort. We compared the clinical characteristics at baseline and outcomes at 12 months between those aged ≥60 years and those <60 years. RESULTS: Compared to the <60-year-old group (n = 78), the ≥60-year-old group (n = 156) had higher inflammatory marker values and ultrasound combined scores, especially wrist joints, at baseline. Age at baseline positively correlated significantly with the ultrasound scores at baseline; however, age was not a significant variable by the multiple regression analysis. The patients treated with different MOAs in the ≥60-year-old group had comparable outcomes and multiple regression analysis revealed that mechanism of action (MOA) was not a significant contributor to the Clinical Disease Activity Index at 12 months. CONCLUSIONS: RA patients with advanced age demonstrated distinctive clinical characteristics. The MOAs were not associated with clinical outcomes and ultrasound outcomes in RA patients with advanced age.

The impact of glucocorticoid use on the outcomes of rheumatoid arthritis in a multicenter ultrasound cohort study.

OBJECTIVE: Glucocorticoids are effective in treating rheumatoid arthritis (RA) when used appropriately considering the balance of the risks and benefits, especially at low doses. We aimed to evaluate the response of biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in patients having already been treated with glucocorticoids. METHODS: We reviewed RA patients treated with b/tsDMARDs in a prospective multicenter ultrasound cohort study. We compared the differences in the clinical characteristics at baseline and outcomes at 12 months between the two groups having been treated with and without glucocorticoids at baseline. The differences in the clinical characteristics and the treatments were balanced by the inverse probability weighting (IPW) with the propensity score. RESULTS: Of 307 patients with RA, 160 patients were treated with glucocorticoids at baseline. The median dose of glucocorticoids was equivalent to 5.0 mg/day of prednisolone. Significant differences were in age and concomitant methotrexate use, composite measures for the disease activity, and the ultrasound grayscale score at baseline. Patients treated with glucocorticoids had less frequent remissions defined by composite measures and ultrasound findings than those treated without glucocorticoids. These significant differences in the achievement of remissions remained robust even after adjusting differences in the clinical characteristics and the treatments between the two groups by IPW. CONCLUSION: RA patients treated with glucocorticoids had a higher disease activity at baseline and a poorer response to treatments with b/tsDMARDs than those without glucocorticoids. The states of patients requiring glucocorticoids might be associated with the poor response to the b/tsDMARDs.

Effectiveness and safety of sarilumab in patients with rheumatoid arthritis: A multicenter, retrospective, inverse probability of treatment-weighted analysis based on the FRAB-registry.

OBJECTIVE: The efficacy and safety of sarilumab (SARI) were investigated in real-world clinical practice in Japan. METHOD: Subjects were 121 rheumatoid arthritis (RA) patients in 23 medical institutions in Fukuoka Prefecture, Japan, who started treatment with SARI between May 2018 and November 2021. Data on the SARI starting dose, patients' baseline characteristics, disease activity, and blood test data at the start of treatment, as well as follow-up data on the SARI dose, disease activity, and adverse events until Week 52. Safety and the continuation rate calculated by the Kaplan-Meier method were evaluated, and the effectiveness of treatment at 1 year was assessed using the clinical disease activity index (CDAI). Patients' baseline characteristics for which significant differences were evident were adjusted with a propensity score by using the inverse probability of treatment-weighting (IPTW) method. RESULTS: The continuation rate at Week 52 was 66.1%. The CDAI showed significant improvement from Week 4 that was maintained until Week 52. Comparisons conducted after IPTW adjustment for patients' baseline characteristics for which significant differences were evident revealed no significant differences at Week 52 between the groups classified by higher or lower body mass index (BMI) (p = 0.231), serious comorbidities (p = 0.973), MTX use (p = 0.321), or prior treatment with ≤ 1 or ≥ 2 biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) (p = 0.765). CONCLUSIONS: The results showed that the efficacy of SARI is not affected by BMI, comorbidities, MTX use, or the number of prior b/tsDMARDs, and no new safety concerns were apparent. Key Points • This is the first real-world clinical study to report on the efficacy and safety of SARI in Japan. The results of this study indicate that the efficacy of SARI was not affected by BMI, comorbidities, MTX use, or number of previous b/tsDMARDs. • It was shown that SARI can be used in a Japanese population without any new side effects.

Clinical course of patients with rheumatoid arthritis who continue or discontinue biologic therapy after hospitalization for infection: a retrospective observational study.

BACKGROUND: To analyse the subsequent clinical course of patients with rheumatoid arthritis (RA) who either continued or discontinued biologic agents after hospitalization for infections. METHODS: We retrospectively reviewed the clinical records of 230 RA patients with 307 hospitalizations for infections under biologic therapy between September 2008 and May 2014 in 15 institutions for up to 18 months after discharge. The risks of RA flares and subsequent hospitalizations for infections from 61 days to 18 months after discharge were evaluated. RESULTS: Survival analyses indicated that patients who continued biologic therapy had a significantly lower risk of RA flares (31.4% vs. 60.6%, P < 0.01) and a slightly lower risk of subsequent infections (28.7% vs. 34.5%, P = 0.37). Multivariate analysis showed that discontinuation of biologic therapy, diabetes, and a history of hospitalization for infection under biologic therapy were associated with RA flares. Oral steroid therapy equivalent to prednisolone 5 mg/day or more and chronic renal dysfunction were independent risk factors for subsequent hospitalizations for infections. CONCLUSIONS: Discontinuation of biologic therapy after hospitalization for infections may result in RA flares. Continuation of biologic therapy is preferable, particularly in patients without immunodeficiency.

Factors affecting patient satisfaction related to cost and treatment effectiveness in rheumatoid arthritis: results from the multicenter observational cohort study, FRANK Registry.

BACKGROUND: To further improve rheumatoid arthritis (RA) treatment, it is necessary to understand each RA patient's satisfaction and to identify the factors affecting their satisfaction. Despite the rise in medical costs for RA, little is known about the factors that influence patient satisfaction with the cost of treatment in RA patients. METHODS: This is a multicenter observational study of Japanese RA patients from the FRANK Registry with data analyzed from March 2017 to August 2020. We collected data on demographic characteristics, clinical data, quality of life which was evaluated using the EuroQol 5-dimensional questionnaire (EQ5D), and patient satisfaction. The four categories of patient satisfaction were evaluated individually (i.e., cost, treatment efficacy, activities of daily living [ADL], and global treatment satisfaction). We analyzed the factors that affected each patient's satisfaction, such as age, sex, EQ5D, disease duration, disease activity, and treatment. RESULTS: This study included 2235 RA outpatients (406 males, 1829 females). In RA patients, "very satisfied" and "satisfied" were given for nearly half of each satisfaction aspect (cost 49%; efficacy 72%; ADL 58%; global treatment 66%) at the time of the initial registration. To investigate the factors influencing each satisfaction, multivariate analysis has revealed that the use of b/tsDMARDs increased satisfaction of treatment effect (odds ratio [OR] 0.66) and ADL (OR 0.78) but decreased cost satisfaction (OR 2.21). Age (50-64 years; OR 0.91; 65-74 years, 0.55: ≥ 75 years, 0.35), female (OR 0.81), and history of musculoskeletal surgery (OR 0.60) all increased cost satisfaction. Patients with lower disease activity and higher EQ5D scores had higher levels of satisfaction in all areas. CONCLUSIONS: In this study, patient satisfaction in terms of cost, treatment effect, ADL, and overall treatment was generally higher, but some patients were dissatisfied. The cost of satisfaction increased with age and a history of musculoskeletal surgery, while it decreased with a lower EQ5D score and the use of b/tsDMARDs.

SARS-CoV-2 Seroprevalence among Healthcare Workers in General Hospitals and Clinics in Japan.

Coronavirus disease 2019 (COVID-19) has become a serious public health problem worldwide. In general, healthcare workers are considered to be at higher risk of COVID-19 infection. However, the prevalence of COVID-19 among healthcare workers in Japan is not well characterized. In this study, we aimed to examine the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies among 2160 healthcare workers in hospitals and clinics that are not designated to treat COVID-19 patients in Japan. The prevalence of SARS-CoV-2 immunoglobulin G was 1.2% in August and October 2020 (during and after the second wave of the pandemic in Japan), which is relatively higher than that in the general population in Japan (0.03-0.91%). Because of the higher risk of COVID-19 infection, healthcare workers should be the top priority for further social support and vaccination against SARS-CoV-2.

The adjuvanted recombinant zoster vaccine is efficacious and safe in Asian adults ≥ 50 years of age: a sub-cohort analysis of the ZOE-50 and ZOE-70 randomized trials.

In two large clinical trials (ZOE-50 [NCT01165177] and ZOE-70 [NCT01165229]), two doses of the adjuvanted recombinant zoster vaccine (RZV) demonstrated >90% efficacy (VE) against herpes zoster (HZ) in adults ≥50 years of age (YOA). This post-hoc analysis assessed the VE against HZ and postherpetic neuralgia (PHN), in participants from Asian study sites enrolled in ZOE-50/70. Reactogenicity and safety were also assessed. Participants ≥50 YOA were randomized 1:1 to receive 2 doses of either RZV or placebo, 2 months apart. VE was evaluated for a median follow-up of 4 years post-vaccination overall and by age in the ZOE-50 Asian population ≥50 YOA and in the pooled ZOE-50/70 Asian population ≥70 YOA. Of the 2,729 participants included in the ZOE-50 Asian population ≥50 YOA, 3 RZV and 66 placebo recipients reported a confirmed HZ episode. Overall VE was 95.6% (95% confidence interval [CI]: 86.4-99.1) against HZ and 100% (95% CI: 35.44-100) against PHN. In the pooled ZOE-50/70 Asian population ≥70 YOA, 4 RZV and 75 placebo recipients out of the 2,723 participants reported a confirmed HZ episode. Overall VE was 94.7% (95% CI: 85.9-98.6) against HZ and 89.8% (95% CI: 28.39-99.77) against PHN. Pain and myalgia were the most frequent solicited local and general adverse events, respectively, in both populations. No safety concern was identified during the study periods. RZV is highly efficacious against HZ and PHN and has an acceptable safety profile in Asian populations ≥50 YOA, similar to what was observed in the general ZOE-50/70 populations.Trademark statement: Shingrix is a trademark owned by or licensed to the GSK group of companies.

Utility of a simplified ultrasonography scoring system among patients with rheumatoid arthritis: A multicenter cohort study.

ABSTRACT: We aimed to evaluate the utility of a simplified ultrasonography (US) scoring system, which is desired in daily clinical practice, among patients with rheumatoid arthritis (RA) receiving biological/targeted synthetic disease-modifying antirheumatic drugs (DMARDs).A total of 289 Japanese patients with RA who were started on tumor necrosis factor inhibitors, abatacept, tocilizumab, or Janus kinase inhibitors between June 2013 and April 2019 at one of the 15 participating rheumatology centers were reviewed. We performed US assessment of articular synovia over 22 joints among bilateral wrist and finger joints, and the 22-joint (22j)-GS and 22-joint (22j)-PD scores were evaluated as an indicator of US activity using the sum of the GS and PD scores, respectively.The top 6 most affected joints included the bilateral wrist and second/third metacarpophalangeal joints. Therefore, 6-joint (6j)-GS and -PD scores were defined as the sum of the GS and PD scores from the 6 synovial sites over the aforementioned 6 joints, respectively. Although the 22j- or 6j-US scores were significantly correlated with DAS28-ESR or -CRP scores, the correlations were weak. Conversely, 6j-US scores were significantly and strongly correlated with 22j-US scores not only at baseline but also after therapy initiation.Using a multicenter cohort data, our results indicated that a simplified US scoring system could be adequately tolerated during any disease course among patients with RA receiving biological/targeted synthetic DMARDs.

Comparison of immunogenicity between candidate influenza A(H3N2) virus vaccine strains in Japan: A randomized controlled trial using a monovalent vaccine of A/Saitama/103/2014 (CEXP-002) and A/Hong Kong/4801/2014 (X-263).

BACKGROUND: For the 2017-18 influenza season, A/Saitama/103/2014 (CEXP-002) (Saitama strain) was antigenically more similar to prior circulating strains than A/Hong Kong/4801/2014 (X-263) (Hong Kong strain) in a ferret model and was selected as the A(H3N2) vaccine virus strain in Japan. However, the Saitama strain grew poorly, and the Japanese government switched to the Hong Kong strain, raising public concerns of poor effectiveness. To enhance understanding of the correlation between antigenicity in experimental models and immunogenicity, as a surrogate measure of vaccine effectiveness, in the human population, we compared the immunogenicity of specially-prepared single dose monovalent influenza A(H3N2) vaccines containing the Saitama or the Hong Kong strain. METHODS: A randomized controlled trial of 100 healthy adults aged 20-64 years (n = 50/group) was conducted. Virus neutralization assay was performed on sera from days 0 (pre-vaccination) and 21 (post-vaccination). Geometric mean titer (GMT), mean fold rise (MFR), seroconversion proportion (SCP), and seroprotection proportion (SPP) were calculated for vaccine strains and a representative circulating A(H3N2) virus strain (A/Osaka/188/2017). RESULTS: For the Hong Kong strain, post-vaccination GMT was significantly higher in the Hong Kong vaccine recipients (1:546 vs 1:260, p < 0.01), but MFR, SCP, and SPP were similar for both vaccine groups. For the Saitama strain, post-vaccination GMT (1:116 vs 1:61, p = 0.01) and SPP (86% vs 68%, p = 0.03) were significantly higher in the Hong Kong vaccine recipients, but MFR and SCP were similar for both vaccine groups. Against A/Osaka/188/2017, post-vaccination GMT and MFR were similar in both vaccine groups, but SCP (32% vs 4%, p < 0.01) and SPP (28% vs. 6%, p < 0.01) were significantly higher in the Hong Kong vaccine recipients. CONCLUSION: The Hong Kong vaccine induced better or equivalent immunogenicity in comparison to the Saitama vaccine. Our trial showed that antigenic similarity in experimental models does not necessarily correlate with immunogenicity in the human population. CLINICAL TRIAL REGISTRATION: UMIN000029293.

Non-TNF inhibitor switchers versus TNF inhibitor cyclers from multicentre rheumatoid arthritis ultrasonography prospective cohort in Japan.

To compare therapeutic efficacy of tumour necrosis factor inhibitor (TNFi) cyclers and non-TNFi switchers in patients with rheumatoid arthritis (RA) having inadequate response to previous TNFis (TNF-IR patients) using composite measures including imaging assessment with power Doppler ultrasonography (PDUS). Patients with RA who had inadequate response to one or more previous TNFi agents with moderate or higher disease activity were enrolled. The outcomes of 56 TNF-IR patients were analysed. Patients were divided into 19 TNFi cyclers and 37 non-TNFi switchers (16 abatacept [ABT] and 21 tocilizumab [TCZ] switchers). Retention ratio at 6 months was significantly higher in non-TNFi switchers than in TNFi cyclers (p < .05). Although there was no significant difference, non-TNFi switchers tended to have a larger decrease than TNFi cyclers in efficacy indicators based on clinical disease activity index and PDUS. Multivariate logistic regression analysis identified a following independent factor associated with both EULAR good response and retention of a biologic agent: non-TNFi switch (p < .05 for both). Non-TNFi switchers were shown to have significantly higher percentage of EULAR good response and higher retention than TNFi cyclers. A non-TNFi biologic agent may hence be a preferential next-line treatment for TNF-IR patients.

Abatacept reduces disease activity of rheumatoid arthritis independently of modulating anti-citrullinated peptide antibody production.

Abatacept may exert its clinical effect on rheumatoid arthritis (RA) by suppressing anti-cyclic citrullinated peptide (CCP) antibody production. This study was undertaken to test this hypothesis by examining the changes of disease activity of RA and anti-CCP antibody levels over time after starting abatacept. Sixty Japanese RA patients who started abatacept were included in this multicenter, prospective observational study. Simple Disease Activity Index (SDAI) and anti-CCP antibody levels were evaluated at 12, 24, and 52 weeks. The mean SDAI score significantly decreased within 12 weeks after starting abatacept and was maintained thereafter. On the contrary, the mean anti-CCP antibody levels did not change until 52 weeks. At the individual level, there were substantial changes of anti-CCP antibody levels, but these were not correlated with the changes of disease activity at any time points. Thus, abatacept reduces the disease activity of RA independently of modulating anti-CCP antibody production.

Suppression of joint destruction with subcutaneous tocilizumab for Japanese patients with rheumatoid arthritis in clinical practice.

Objectives: To investigate the efficacy of suppressing joint destruction with subcutaneous tocilizumab (TCZ-SC) for Japanese rheumatoid arthritis (RA) patients in the real-world clinical setting.Methods: This 1-year prospective, multicenter study included 110 RA patients in whom TCZ-SC was newly initiated. Primary endpoint was the change from baseline in vdH-modified total Sharp score (mTSS) at week 52. Structural remission was defined as yearly mTSS of 0.5 or less. Disease activity was evaluated using the disease activity score (DAS28-ESR) and clinical disease activity index (CDAI).Results: At baseline, the patients' mean age was 58.6 years, and the mean disease duration was 10.6 years. The proportion of patients who were naïve for biologics was 44.5%, and 64.5% concomitantly received methotrexate. The yearly mTSS showed significant improvement from 9.41 before TCZ-SC initiation to -0.15 after 52 weeks. The structural remission rate was 76.1%. After 52 weeks, the DAS28-ESR and CDAI remission rates were 52% and 21%, respectively. Although the previous usage of biologics and baseline disease activity significantly affected the clinical remission, no factors with significant effects on structural remission were identified.Conclusion: These findings support the efficacy of TCZ-SC in suppressing disease activity as well as joint destruction over a 1-year period.

Effects of Zinc Acetate on Serum Zinc Concentrations in Chronic Liver Diseases: a Multicenter, Double-Blind, Randomized, Placebo-Controlled Trial and a Dose Adjustment Trial.

The essential trace element zinc maintains liver functions. Liver diseases can alter overall zinc concentrations, and hypozincemia is associated with various hepatic pathologies. Modulating systemic zinc through dietary supplementation is potentially useful for liver diseases. We evaluated the usefulness of zinc (NPC-02; acetate formulation) supplementation. We conducted two NPC-02 studies on zinc-deficient patients (serum zinc < 70 µg/dL). Study 1: double-blind, randomized, placebo-controlled trial on 57 subjects with chronic liver diseases comparing serum zinc in patients given NPC-02 (NPC-02 group) versus placebo (Placebo group). Study 2: dose adjustment study on 43 subjects with/without liver diseases to determine proportions maintaining serum zinc target (≥ 80 µg/dL but < 200 µg/dL). In study 1, NPC-02 subjects had higher serum zinc concentrations at week 8 than Placebo subjects (83.2 ± 20.2 and 61.3 ± 12.0, respectively; P < 0.0001), and more NPC-02 than Placebo subjects achieved the serum zinc target (15/27 vs. 1/26). In study 2, the NPC-02-induced serum zinc increase was dose-dependent in subjects both with and without liver diseases (r = 0.5143, P = 0.0022 and r = 0.5753, P = 0.0005, respectively). Interestingly, there was a marginally positive correlation between serum zinc and albumin levels in subjects with but not in those without liver diseases (r = 0.4028, P = 0.0631 and r = 0.1360, P = 0.5567, respectively). NPC-02 dose-dependently increases serum zinc in hypozincemic patients, regardless of liver disease. NPC-02 is a potentially effective therapy for liver cirrhosis, in which zinc deficiency is common. Clinical trial registry number: NCT02337569, NCT02321865.

Ultrasonographic Efficacy of Biologic and Targeted Synthetic Disease-Modifying Antirheumatic Drug Therapy in Rheumatoid Arthritis From a Multicenter Rheumatoid Arthritis Ultrasound Prospective Cohort in Japan.

OBJECTIVE: To explore the variables associated with initial favorable power Doppler (PD) ultrasound (US) response induced by biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in patients with rheumatoid arthritis (RA). METHODS: We have been prospectively investigating the course of active RA patients using US after the introduction of b/tsDMARDs in the Kyushu region of Japan since June 2013. A total of 150 patients have completed the first 6 months of observation at present and have been evaluated. US was assessed in 22 joints of bilateral hands using gray-scale and PD images on a scale from 0-3. The sum of these scores was used as the indicator of US disease activity. We defined PD remission as attaining a total PD score of 0 at 6 months and investigated the associated variables by multivariate logistic regression analysis. RESULTS: The total PD and gray-scale scores and the clinical composite measures significantly improved at 6 months, whereas these reductions were less in bDMARD switchers as compared with bDMARD-naive patients. Multivariate logistic regression analysis showed that short disease duration, the absence of any previous use of bDMARDs, and low total PD scores at baseline were independent predictors of PD remission at 6 months. CONCLUSION: This present prospective US cohort has for the first time shown the variables that are associated with initial PD response to b/tsDMARDs.

Immunogenicity study to investigate the interchangeability among three different types of polio vaccine: A cohort study in Japan.

In Japan, the routine immunization program with oral polio vaccine (OPV) has been suspended since September 2012, when a program with 4 doses of inactivated monovalent polio vaccine (IPV) or quadrivalent vaccine against diphtheria, pertussis, and tetanus with IPV (DTaP-IPV) was introduced. The aim of this study was to examine the interchangeability among these 3 types of polio vaccines.We conducted a prospective cohort study at 5 pediatric clinics in Japan. A total of 153 infants were assigned to 1 of the 4 groups by considering the vaccination history of OPV and trivalent vaccine against DTaP. Eleven infants with a history of OPV received 3 doses of DTaP-IPV; 49 infants with a history of OPV and DTaP received 3 doses of IPV; 50 polio vaccine-naïve infants received 2 doses of IPV followed by 2 doses of DTaP-IPV; and 43 polio vaccine-naive infants received 2 doses of DTaP-IPV followed by IPV. The immunogenicity after polio vaccination was evaluated among these 4 groups.After 2 doses of polio vaccination, more than 80% of the infants exhibited a neutralization antibody titer ≥1:8 for all Sabin strains and wild strains in all groups. After the third dose, the seroprotection proportion (i.e., a neutralization antibody titer ≥1:8) reached about 100%. After the fourth dose, a neutralization antibody titer exceeded the required protective levels (i.e., a neutralization antibody titer ≥1:8) considerably in all groups.Four doses of polio vaccines induced a sufficient level of immunity in Japanese infants, irrespective of vaccine combinations or order.

Impact of methotrexate dose on efficacy of adalimumab in Japanese patients with rheumatoid arthritis: Results from registered data analyses.

OBJECTIVE: Upper limit of methotrexate (MTX) for patients with rheumatoid arthritis (RA) was recently increased from 8 to 16 mg/week in Japan. We therefore examined the effect of concomitant MTX dose on the efficacy of adalimumab (ADA) in clinical practice. METHOD: Sixty-one consecutive RA patients treated with ADA were followed for minimum 52 weeks and retrospectively compared by MTX dose; patients receiving concomitant MTX of 10 mg/week or more (MTX ≥10 mg group) and <10 mg/week (MTX <10 mg group). Disease activity and remission were evaluated by the disease activity score 28 (DAS28) criteria. RESULTS: The MTX ≥10 mg group consistently showed better improvement in DAS28 and resulted in more patients (52.8%) with DAS28-remission compared with the MTX <10 mg group (26.1%). Multivariate analysis showed that MTX ≥10 mg had a significant effect on DAS28 remission with odds ratio of 5.12. ADA retention rate was 72.2% in MTX ≥10 mg group compared with 52.0% in MTX <10 mg group. Discontinuation of ADA due to adverse events were comparable in the MTX ≥10 mg and MTX <10 mg groups (11.1% vs. 12.0%). CONCLUSIONS: These findings support the critical role of concomitant MTX in the efficacy of ADA, and recommend use of MTX ≥10 mg in Japanese RA patients.

Genetic polymorphisms of enzyme proteins and transporters related to methotrexate response and pharmacokinetics in a Japanese population.

BACKGROUND: Methotrexate (MTX) is currently the anchor drug widely used worldwide in the treatment of rheumatoid arthritis (RA). However, the therapeutic response to MTX has been shown to vary widely among individuals, genders and ethnic groups. The reason for this has been not clarified but it is considered to be partially due to several mechanisms in the cellular pathway of MTX including single-nucleotide polymorphisms (SNPs). The purpose of this study was to investigate the allelic frequencies in different ethnic and/or population groups in the 10 polymorphisms of enzyme proteins and transporters related to the MTX response and pharmacokinetics including MTHFR, TYMS, RFC1, FPGS, GGH, ABCB1, ABCC2 and ABCG2 in unrelated healthy Japanese adults and patients with RA. METHODS: Ten polymorphisms, methylenetetrahydrofolate reductase (MTHFR) 1298, thymidylate synthase (TYMS) 3'-UTR, reduced folate carrier 1 (RFC1) 80 and-43, folypolyglutamyl synthase (FPGS) 1994, γ-glutamyl hydrolase (GGH) 452 and-401, the ABC transporters (ABCB1 3435, ABCC2 IVS23 + 56, ABCG2 914) of enzyme proteins and transporters related to MTX response and pharmacokinetics in 299 unrelated healthy Japanese adults and 159 Japanese patients with RA were investigated to clarify their contributions to individual variations in response and safety to MTX and establish personalized MTX therapy. SNPs were evaluated using real-time polymerase chain reaction (PCR). RESULTS: Comparison of allelic frequencies in our study with other ethnic/population groups of healthy adults and RA patients showed significant differences in 10 polymorphisms among healthy adults and 7 among RA patients. Allelic frequencies of MTHFR 1298 C, FPGS 1994A and ABCB1 3435 T were lower in Japanese than in Caucasian populations and those of ABCC2 IVS23 + 56 C and ABCG2 914A were higher in Japanese than in Caucasian/European populations in both healthy adults and RA patients. Allelic frequencies of MTHFR 1298 C, GGH-401 T, ABCB1 3435 T, and ABCG2 914A were higher in healthy Japanese adults than in an African population, and those of RFC1 80A, RFC1-43C and ABCC2 IVS23 + 56 C in healthy Japanese adults were lower than in Africans. However, no significant differences were seen in the distribution of allelic frequencies between healthy Japanese adults and RA patients. CONCLUSION: The variations in allelic frequencies in different ethnic and/or population groups in healthy adults and RA patients may contribute to individual variations in MTX response and toxicity.

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

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammatory status, joint destruction, disability, and pain. Methotrexate (MTX) has been confirmed to reduce disease activity and delay or stabilize the development of bone erosions. However, major drawbacks are that patients show great interindividual variability in response to MTX and the unpredictable occurrence of side effects. A strategy for personalized MTX treatment to predict its efficacy and toxicity has not yet been determined. To establish personalized MTX therapy in Japanese patients with rheumatoid arthritis, we performed a preliminary study for predicting better methotrexate efficacy including single-nucleotide polymorphisms (SNPs) for MTX-related transporters/enzymes. METHODS: Disease control status (good or poor) was judged by the number of Disease Activity Scores (DAS28) of <2 for 6-12 months. The response index R was calculated by the improved area under the curve (AUC) of the DAS28 score for 0-3 or 0-6 months by dividing the cumulative dose of MTX during 0-3 or 0-6 months, respectively. Genotyping of alleles of RFC1 80G > A, RFC1 -43 T > C, FPGS 1994G > A, GGH 401C > T, MTHFR 1298A > C, and TYMS 3'-UTR (-6/+6) was performed using the real-time PCR system. RESULTS: Seven of 21 patients were judged as good responders in terms of disease control, and the remainder as poor responders. For 0-3 months after starting MTX administration, the median cumulative dose and improved DAS28 AUC in the good and poor response groups were 96.0 mg and 25.4 and 118.0 mg and 23.4, respectively. For 0-6 months, the median cumulative dose and improved DAS28 AUC in the good and poor response groups were 192.0 mg and 51.0 and 214.0 mg and 47.6, respectively. Statistically significant differences between the 2 groups in the 0-6-month period were observed in DAS28 AUC improvement and index R. A slight tendency for a correlation between G/G genotypes and A allele genotypes in RFC1 80 genotypes was observed, although it did not reach statistical significance. CONCLUSION: This study suggested that aggressive RA treatment with MTX from the early period of administration is necessary to obtain a good response after 6 months, although no SNPs predicting a better treatment response to MTX were identified.