Hisato Ishikawa

The effect of recombinant human bone morphogenetic protein-2 on the osteogenic potential of rat mesenchymal stem cells after several passages

Background Since the osteogenic potential of bone marrow derived mesenchymal stem cells (BMSCs) becomes reduced with passage, establishment of culture condition that permit the rapid expansion of BMSCs while retaining their potential for differentiation is needed for clinical application. Bone morphogenetic proteins stimulate osteogenic differentiation in mesenchymal progenitor cells as well as increase stem cell numbers. Thus, we analyzed the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the osteogenic potential of rat BMSCs over several passages. Material and methods Osteogenic differentiation in vitro was evaluated in terms of the alkaline phosphatase (ALP) activity and the osteocalcin (OC) concentration in the supernatants, and the expression of ALP and OC mRNA in the cultured cells. For in-vivo osteogenesis, BMSCs cultured with and without rhBMP-2 through all passages were implanted into athymic mice. Results  The levels of osteogenic markers were significantly higher in the cells of the BMP(+) group than in the cells of the BMP(–) group, although they decreased with passage irrespective of whether or not rhBMP-2 was added. Similar to the in-vitro experiments, there was a greater degree of bone and cartilage tissue formation in the BMP(+) group over all passages. Interpretation  From our results, osteogenic potential can be maintained even in BMSCs that have been passaged several times in the presence of rhBMP-2. These cells are capable of inducing and participating in bone formation and can be used for clinical applications.

Study protocol of a multicenter registry of patients with rheumatoid arthritis starting biologic therapy in Japan: Tsurumai Biologics Communication Registry (TBCR) Study

Biologic agents have proven to be effective against rheumatoid arthritis (RA) in clinical trials and post-marketing surveillance (PMS) studies. However, limited follow-up periods and strict criteria for recruitment might lead to an underestimation of adverse events. To document the long-term course of patients with RA treated with biologics in clinical settings, we established the Tsurumai Biologics Communication Registry (TBCR). First, we retrospectively collected data of patients registered for any biologic PMS study or clinical trial at participating institutes. Thus far, thirteen institutes have joined the registry and 860 patients have been identified. Comparing baseline characteristics by age and initiation year of biologics, young patients had significantly less joint damage and dysfunction and a higher dose of concomitant methotrexate (MTX) compared to older patients. Older age and functional class were significantly related to the incidence of adverse events that resulted in discontinuation of the 1st biologic treatment. The TBCR is in its initial stages, and information on all patients newly starting biologic therapy at participating institutes is being collected prospectively. Differences in baseline characteristics by age and initiation year of biologics need to be carefully evaluated in order to report on drug-related survival and long-term prognosis, using follow-up data in the near future.

Longterm Retention Rate and Risk Factor for Discontinuation Due to Insufficient Efficacy and Adverse Events in Japanese Patients with Rheumatoid Arthritis Receiving Etanercept Therapy

Objective. Assessing retention rate and risk factor for drug discontinuation is important for drug evaluation. We examined a 3-year retention rate and the risk factor for discontinuation due to insufficient efficacy (IE) and adverse events (AE) in Japanese patients with rheumatoid arthritis (RA) who are receiving etanercept (ETN). Methods. Data were collected from 588 patients treated with ETN as a first biologic from the Tsurumai Biologics Communication Registry. Baseline characteristics for the incidence of both IE and AE were analyzed using the Cox proportional-hazards regression model. Patients were divided into groups based on age and concomitant methotrexate (MTX). Drug retention rates were calculated using the Kaplan-Meier method and compared among groups using the log-rank test. Results. ETN monotherapy without concomitant MTX [MTX(–)] was significantly related to a higher incidence of discontinuation due to IE [hazard ratio (HR) = 2.226, 95% CI 1.363–3.634]. Older age and MTX(–) were significantly related to a higher incidence of discontinuation due to AE [HR = 1.040, 1.746, 95% CI 1.020–1.060, 1.103–2.763, respectively]. The MTX(–)/≥ 65 years group had the lowest retention rate (p < 0.001). The discontinuation rate due to IE was lower in the MTX(+)/< 65 years group compared to < 65 years/MTX(–), ≥ 65 years/MTX(–) group (p = 0.006, p < 0.001, respectively). The discontinuation rate due to AE was highest in the MTX(–)/≥ 65 years group (p < 0.001). Conclusion. Our findings suggest that the risk of discontinuation due to IE was high in the patients who did not use concomitant MTX and that the risk of discontinuation due to AE was high in elderly patients who did not use concomitant MTX.

High rate of improvement in serum matrix metalloproteinase-3 levels at 4 weeks predicts remission at 52 weeks in RA patients treated with adalimumab

Abstract Objective: This study aimed to determine whether serum matrix metalloproteinase-3 (MMP-3) levels can predict remission in rheumatoid arthritis (RA) patients treated with adalimumab (ADA). Methods: Subjects were 114 RA patients continuously treated with ADA for 52 weeks. Predictive factors at baseline and 4 weeks after initiation of ADA therapy for the achievement of remission (28-point count Disease Activity Score-CRP (DAS28-CRP) < 2.3) at 52 weeks were evaluated by multivariate logistic regression analysis. Results: DAS28-CRP at 4 weeks (odds ratio (OR) 0.614, 95% confidence interval (CI) 0.382–0.988) and improvement in serum MMP-3 levels at 4 weeks (OR 1.057, 95% CI 1.002–1.032) were independent predictors of remission at 52 weeks. The best cut-off level of DAS28-CRP and improvement in serum MMP-3 levels at 4 weeks for predicting remission at 52 weeks was 3.73 (sensitivity: 90%, specificity: 50%, area under the receiver operating characteristic curve (AUC): 62%) and 39.93% (sensitivity: 47%, specificity: 83%, AUC: 64%), respectively. Conclusion: Our findings suggest that a high rate of improvement in serum MMP-3 levels at 4 weeks after initiation of ADA therapy can predict remission at 52 weeks in RA patients.

Longterm Retention Rate and Risk Factors for Adalimumab Discontinuation Due To Efficacy and Safety in Japanese Patients with Rheumatoid Arthritis: An Observational Cohort Study

Objective. To evaluate the rates of retention and discontinuation of adalimumab (ADA) due to efficacy and safety in Japanese patients with rheumatoid arthritis (RA). Methods. All patients with RA (n = 476) who were treated with ADA in the Tsurumai Biologics Communication Registry were enrolled. Results. The retention rate of ADA was 46% at 5 years. When focusing on insufficient efficacy, previous biologics use and high baseline disease activity were significant risk factors for up to 1 year. Methotrexate (MTX) use was a significantly low risk factor after 1 year of treatment. Conclusion. Concomitant MTX contributes to the longterm efficacy of ADA therapy.