Phase III, multicenter, open-label, long-term study of the safety of abatacept in Japanese patients with rheumatoid arthritis and an inadequate response to conventional or biologic disease-modifying antirheumatic drugs.

Objectives: To examine the long-term safety of intravenous (IV) abatacept treatment in Japanese patients with rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX) or other conventional or biologic disease-modifying antirheumatic drugs.

Methods: This Phase III, open-label, long-term study (NCT00484289) comprised Japanese patients with RA who had completed abatacept Phase I or Phase II studies, and new patients intolerant to MTX. Patients from Phase I and Phase II studies received a weight-tiered dosing equivalent of 10 mg/kg abatacept, with MTX at doses up to 8 mg/week; newly enrolled patients received weight-tiered 10 mg/kg abatacept monotherapy.

Sensitive monitoring of volatile chemical warfare agents in air by atmospheric pressure chemical ionization mass spectrometry with counter-flow introduction.

A new method for sensitively and selectively detecting chemical warfare agents (CWAs) in air was developed using counter-flow introduction atmospheric pressure chemical ionization mass spectrometry (MS). Four volatile and highly toxic CWAs were examined, including the nerve gases sarin and tabun, and the blister agents mustard gas (HD) and Lewisite 1 (L1). Soft ionization was performed using corona discharge to form reactant ions, and the ions were sent in the direction opposite to the airflow by an electric field to eliminate the interfering neutral molecules such as ozone and nitrogen oxide.

ACPA-negative RA consists of two genetically distinct subsets based on RF positivity in Japanese.

HLA-DRB1, especially the shared epitope (SE), is strongly associated with rheumatoid arthritis (RA). However, recent studies have shown that SE is at most weakly associated with RA without anti-citrullinated peptide/protein antibody (ACPA). We have recently reported that ACPA-negative RA is associated with specific HLA-DRB1 alleles and diplotypes.

Phase II dose-response study of abatacept in Japanese patients with active rheumatoid arthritis with an inadequate response to methotrexate.

Objective: The objective of this study was to assess the response to abatacept at doses of 2 mg/kg and 10 mg/kg compared to placebo in patients with active rheumatoid arthritis (RA) with an inadequate clinical response to methotrexate (MTX).

Methods: In this multicenter, placebo-controlled, double-blind, parallel-group, dose-response study, 195 Japanese patients with active RA with an inadequate response to MTX were randomized 1:1:1 to receive 10 mg/kg or 2 mg/kg abatacept plus MTX, or placebo plus MTX, for 24 weeks.

Results: Abatacept demonstrated a dose-response relationship when given at 2 and 10 mg/kg.

Meta-analysis identifies nine new loci associated with rheumatoid arthritis in the Japanese population.

Rheumatoid arthritis is a common autoimmune disease characterized by chronic inflammation. We report a meta-analysis of genome-wide association studies (GWAS) in a Japanese population including 4,074 individuals with rheumatoid arthritis (cases) and 16,891 controls, followed by a replication in 5,277 rheumatoid arthritis cases and 21,684 controls. Our study identified nine loci newly associated with rheumatoid arthritis at a threshold of P < 5.

A large-scale association study identified multiple HLA-DRB1 alleles associated with ACPA-negative rheumatoid arthritis in Japanese subjects.

Background: HLA-DRB1 is associated with rheumatoid arthritis (RA). However, it has recently been suggested that HLA-DRB1 is only associated with patients with RA who have anticitrullinated peptide/protein antibodies (ACPA), which are specific to RA.

Objective: To elucidate whether specific HLA-DR alleles are associated with ACPA-negative RA development.

Anti-citrullinated peptide antibody-negative RA is a genetically distinct subset: a definitive study using only bone-erosive ACPA-negative rheumatoid arthritis.

Objectives: ACPA is a highly specific marker for RA. It was recently reported that ACPA can be used to classify RA into two disease subsets, ACPA-positive and ACPA-negative RA. ACPA-positive RA was found to be associated with the HLA-DR shared epitope (SE), but ACPA negative was not.

Fluoroscopic analysis of knee arthroplasty kinematics during deep flexion kneeling.

Achieving deep knee flexion >145 degrees is a goal of many patients receiving knee arthroplasty in Asia and the Middle East, yet it is unknown whether knees with implants move similar to the natural knee in these postures. We studied 18 of 36 consecutively operated knees that were able to flex >145 degrees using fluoroscopic analysis during kneeling to maximum flexion. An average of 9 degrees tibial internal rotation was observed in deep flexion.