Manabu Akazawa

Dr. Manabu Akazawa

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 December 2015 in Arthritis Research & Therapy
Verified
Journal Article
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KMKiyoshi Migita
Kiyoshi Migita
YAYukihiro Akeda
Yukihiro Akeda
MAManabu Akazawa
Manabu Akazawa
STShigeto Tohma
Shigeto Tohma
FHFuminori Hirano
Fuminori Hirano
KOKazunori Oishi
Kazunori Oishi
Patients with rheumatoid arthritis (RA) treated with abatacept (ABT) are at increased risk for vaccine-preventable infections. The aim of the present study is to evaluate the humoral response to 23-valent pneumococcal polysaccharide (PPSV23) vaccination in RA patients receiving ABT. The immunogenicity study was nested within a randomized, double-blind placebo-controlled study, designed to evaluate the efficacy of the PPSV23. PPSV23 was given to 111 RA patients, who were classified into three groups: RA control (n = 35), methotrexate (MTX) alone (n = 55), and ABT (n = 21). Before and 4–6 weeks after vaccination, we measured the patients’ concentrations of antibodies against pneumococcal serotypes 6B and 23F using an enzyme-linked immunosorbent assay and determined their antibody functionality using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI). The pneumococcal serotype-specific IgG concentrations and OIs were both significantly increased in all treatment groups in response to PPSV23 vaccination. In the ABT group, the IgG responses for the 6B serotype were lower compared with those in the MTX alone or control groups, whereas the OI responses were similar to those in the other two groups. In a subgroup analysis, the pneumococcal serotype-specific IgG responses were significantly lower in both serotypes (6B and 23F) in the ABT/MTX group; however, the OI responses in the ABT group were not different from the control group. There was no association between the pneumococcal serotype-specific IgG and OI responses for the 6B serotype in patients receiving ABT in contrast to the control or MTX alone patients. No severe adverse effects were observed in any of the treatment groups. OI responses indicate antibody functionality rather than simply their amount, so the similarity of these measurements between all three groups suggests that RA patients receiving ABT still benefit from receiving the PPSV23 vaccination, even though they produce less IgG in response to it. The results suggest an influence of ABT on the humoral response to PPSV23 vaccination under MTX treatment; however, preserved opsonin responses are expected in RA patients treated with ABT plus MTX. University Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

5 December 2017 in Pneumonia
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Journal Article
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KKKeiko Konomura
Keiko Konomura
HNHideaki Nagai
Hideaki Nagai
MAManabu Akazawa
Manabu Akazawa
This study aimed to estimate the economic burden of community-acquired pneumonia (CAP) among elderly patients in Japan. In addition, the study evaluated the relationship between total treatment cost and CAP risk factors. An administrative database was searched for elderly patients (≥ 65 years old) who had pneumonia (ICD-10 code: J12–J18) and an antibiotic prescription between 1 June 2014 and 31 May 2015. The all-cause total healthcare costs of outpatient and inpatient CAP episodes were calculated. This study evaluated data from 29,619 patients with CAP who experienced 14,450 outpatient CAP episodes and/or 20,314 inpatient CAP episodes. The mean ages were 77.5 ± 8.0 years and 81.5 ± 8.2 years among the outpatient and inpatient groups, respectively. The median treatment costs were US$346 (interquartile range: $195–551) per outpatient episode and US$4851 (interquartile range: $3313–7669) per inpatient episode. More severe cases had increased treatment costs at the treating hospitals. Male sex, diabetes, chronic obstructive pulmonary disease, and liver dysfunction were associated with increased total treatment costs, while dementia, dialysis, and rheumatism were associated with high costs of treating a CAP episode. The economic burden of CAP might be decreased by reducing the number of hospitalizations for mild CAP and the incidence of severe CAP. Therefore, preventative care (e.g. oral hygiene or pneumococcus vaccination) is recommended for patients with related risk factors, such as male sex, older age, diabetes, chronic obstructive pulmonary disease, liver dysfunction, rheumatism, dementia, or dialysis.

11 April 2013 in BMJ Open
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Journal Article
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CCChia-Hsien Chang
Chia-Hsien Chang
MKMakiko Kusama
Makiko Kusama
SOShunsuke Ono
Shunsuke Ono
YSYuichi Sugiyama
Yuichi Sugiyama
TOTakao Orii
Takao Orii
MAManabu Akazawa
Manabu Akazawa
Objective To estimate the incidence of muscle toxicity in patients receiving statin therapy by examining study populations, drug exposure status and outcome definitions. Design A retrospective cohort study. Setting 16 medical facilities in Japan providing information on laboratory tests performed in and claims received by their facilities between 1 April 2004 and 31 December 2010. Participants A database representing a cohort of 35 903 adult statin (atorvastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin) users was studied. Use of interacting drugs (fibrates, triazoles, macrolides, amiodarone and ciclosporin) by these patients was determined. Main outcome measure Statin-associated muscle toxicity (the ‘event’) was identified based on a diagnosis of muscle-related disorders (myopathy or rhabdomyolysis) and/or abnormal elevation of creatine kinase (CK) concentrations. Events were excluded if the patients had CK elevation-related conditions other than muscle toxicity. Incidence rates for muscle toxicity were determined per 1000 person-years, with 95% CI determined by Poisson regression. Results A total of 18 036 patients accounted for 42 193 person-years of statin therapy, and 43 events were identified. The incidence of muscle toxicity in the patients treated with statins was 1.02 (95% CI 0.76 to 1.37)/1000 person-years. The estimates varied when outcome definitions were modified from 0.09/1000 person-years, which met both diagnosis and CK 10× greater than the upper limit of normal range (ULN) criteria, to 2.06/1000 person-years, which met diagnosis or CK 5× ULN criterion. The incidence of muscle toxicity was also influenced by the statin therapies selected, but no significant differences were observed. Among 2430 patients (13.5%) received interacting drugs with statins, only three muscle toxicity cases were observed (incidence: 1.69/1000 person-years). Conclusions This database study suggested that statin use is generally well tolerated and safe; however, the risk of muscle toxicity related to the use of interacting drugs requires further exploration.

3 June 2015 in Arthritis Research & Therapy
Verified
Journal Article
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KMKiyoshi Migita
Kiyoshi Migita
YAYukihiro Akeda
Yukihiro Akeda
MAManabu Akazawa
Manabu Akazawa
STShigeto Tohma
Shigeto Tohma
FHFuminori Hirano
Fuminori Hirano
KOKazunori Oishi
Kazunori Oishi
Introduction: In rheumatoid arthritis (RA) patients receiving immunosuppressive treatments, vaccination against Streptococcus pneumoniae is recommended. The objective of the study was to evaluate the effects of tacrolimus (TAC) on immune response following administration of a 23-valent pneumococcal polysaccharide vaccine (PPSV23) in patients with established RA. Methods: Patients with RA (n = 133) were vaccinated with PPSV23. Patients were classified into TAC (n = 29), methotrexate (MTX) (n = 55), control (n = 35), and TAC/MTX (n = 14) treatment groups. We measured the concentrations of pneumococcal serotypes 6B and 23F by using an enzyme-linked immunosorbent assay and determined antibody functionality by using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI), before and 4 to 6 weeks after vaccination. A positive antibody response was defined as at least a twofold increase in the IgG concentration or as at least a 10-fold increase in the OI. Results: IgG concentrations and OIs were significantly increased in all treatment groups after PPSV23 vaccination. The TAC treatment group appears to respond in a manner similar to that of the RA control group in terms of 6B and 23F serotype concentration and function. In contrast, the MTX group had the lowest immune response. Patients who received a combination of TAC and MTX (TAC/MTX) also had a diminished immune response compared with those who received TAC alone. Conclusions: TAC monotherapy does not appear to impair PPSV23 immunogenicity in patients with RA, whereas antibody production and function may be reduced when TAC is used with MTX. Thus, PPSV23 administration during ongoing TAC treatment should be encouraged for infection-prone TAC-treated patients with rheumatic diseases. Trial registration: University Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

25 January 2017 in Arthritis Research & Therapy
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Journal Article
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YIYasumori Izumi
Yasumori Izumi
MAManabu Akazawa
Manabu Akazawa
YAYukihiro Akeda
Yukihiro Akeda
STShigeto Tohma
Shigeto Tohma
FHFuminori Hirano
Fuminori Hirano
KMKiyoshi Migita
Kiyoshi Migita
Pneumococcal pneumonia is the most frequent form of pneumonia. We herein assessed the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in the prevention of pneumonia overall in rheumatoid arthritis (RA) patients at risk for infections. We hypothesized that PPSV23 vaccination is superior in preventing pneumococcal pneumonia compared with placebo in RA patients. A prospective, multicenter, double-blinded, randomized, placebo-controlled (1:1) trial was conducted across departments of rheumatology in Japanese National Hospital Organization hospitals. RA patients (n = 900) who had been treated with biological or immunosuppressive agents were randomly assigned PPSV23 or placebo (sodium chloride). The primary endpoints were the incidences of all-cause pneumonia and pneumococcal pneumonia. The secondary endpoint was death from pneumococcal pneumonia, all-cause pneumonia, or other causes. Cox regression models were used to estimate the risk of pneumonia overall for the placebo group compared with the vaccine group. Seventeen (3.7%) of 464 patients in the vaccine group and 15 (3.4%) of 436 patients in the placebo group developed pneumonia. There was no difference in the rates of pneumonia between the two study groups. The overall rate of pneumonia was 21.8 per 1000 person-years for patients with RA. The presence of interstitial pneumonia (hazard ratio: 3.601, 95% confidence interval: 1.547–8.380) was associated with an increased risk of pneumonia in RA patients. PPSV23 does not prevent against pneumonia overall in RA patients at relative risk for infections. Our results also confirm that the presence of interstitial lung disease is associated with pneumonia in Japanese patients with RA. UMIN-CTR UMIN000009566 . Registered 17 December 2012.

1 May 2019 in Journal of Pain Research
Verified
Journal Article
Open access
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MAManabu Akazawa
Manabu Akazawa
WMWataru Mimura
Wataru Mimura
KTKanae Togo
Kanae Togo
NENozomi Ebata
Nozomi Ebata
NHNoriko Harada
Noriko Harada
KFKoichi Fujii
Koichi Fujii
Purpose: Musculoskeletal diseases, including osteoarthritis (OA) and low back pain (LBP), are the leading causes of years lived with disability, and are associated with lowered quality-of-life, lost productivity, and increased healthcare costs. However, information publicly available regarding the Japanese real-world usage of prescription medications is limited. This study aimed to describe the clinical characteristics of patients with OA and chronic LBP (CLBP), and to investigate the patterns of medications and opioid use in Japanese real-world settings. Materials and methods: A retrospective study was conducted using a Japanese administrative claims database between 2013 and 2017. The outcomes were patient characteristics and prescription medications, and they were evaluated separately for OA and CLBP. Results: The mean age of 118,996 patients with OA and 256,402 patients with CLBP was 68.8±13.1 years and 64.8±16.4 years, respectively. Approximately 90% of patients with OA and CLBP were prescribed non-steroidal anti-inflammatory drugs (NSAIDs). Other prescriptions included hyaluronate injection (35.6%), acetaminophen (21.4%), and steroid injection (20.0%) in patients with OA, and pregabalin (39.0%) and acetaminophen (22.4%) in patients with CLBP. Weak opioids were prescribed to 10.7% and 20.6% of patients with OA and CLBP, respectively. The prescription of COX-2 inhibitors (OA: +6.5%; CLBP: +6.7%) and acetaminophen (OA: +16.4%; CLBP: +14.4%) increased between 2013 and 2017. The first commonly prescribed medication among patients with OA and CLBP were NSAIDs; hyaluronate injection (patients with OA) and pregabalin (patients with CLBP) were also common first-line medications. Acetaminophen, steroid injection (patients with OA), and weak opioids were prescribed more in the later phases of treatment. Conclusion: Most patients were prescribed limited classes of pain drugs, with NSAIDs being the most common pain medication in Japan for patients with OA and CLBP. Opioid prescription was uncommon, and were weak opioids when prescribed.