Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Kotaro Otomo is active.

Publication


Featured researches published by Kotaro Otomo.


Arthritis & Rheumatism | 2012

Efficacy of the antiphospholipid score for the diagnosis of antiphospholipid syndrome and its predictive value for thrombotic events.

Kotaro Otomo; Tatsuya Atsumi; Olga Amengual; Yuichiro Fujieda; Masaru Kato; Kenji Oku; Tetsuya Horita; Shinsuke Yasuda; Takao Koike

OBJECTIVE To define the antiphospholipid score (aPL-S) by testing multiple antiphospholipid antibodies (aPL) and to evaluate its efficacy for the diagnosis of antiphospholipid syndrome (APS) and predictive value for thrombosis. METHODS This study comprised 2 independent sets of patients with autoimmune diseases. In the first set of patients (n = 233), the aPL profiles were analyzed. Five clotting assays for testing lupus anticoagulant and 6 enzyme-linked immunosorbent assays (IgG/IgM anticardiolipin antibodies, IgG/IgM anti-β(2)-glycoprotein I, and IgG/IgM phosphatidylserine-dependent antiprothrombin antibodies) were included. The association of the aPL-S with a history of thrombosis/pregnancy morbidity was assessed. In the second set of patients (n = 411), the predictive value of the aPL-S for thrombosis was evaluated retrospectively. Two hundred ninety-six of these patients were followed up for >2 years. The relationship between the aPL-S and the risk of developing thrombosis was analyzed. RESULTS In the first set of patients, the aPL-S was higher in those with thrombosis/pregnancy morbidity than in those without manifestations of APS (P < 0.00001). For the aPL-S, the area under the receiver operating characteristic curve value was 0.752. In the second set of patients, new thromboses developed in 32 patients. The odds ratio (OR) for thrombosis in patients with an aPL-S of ≥30 was 5.27 (95% confidence interval [95% CI] 2.32-11.95, P < 0.0001). By multivariate analysis, an aPL-S of ≥30 appeared to be an independent risk factor for thrombosis (hazard ratio 3.144 [95% CI 1.383-7.150], P = 0.006). CONCLUSION The aPL-S is a useful quantitative index for diagnosing APS and may be a predictive marker for thrombosis in autoimmune diseases.


Lupus | 2011

‘Criteria’ aPL tests: Report of a Task Force and preconference workshop at the 13th International Congress on Antiphospholipid Antibodies, Galveston, Texas, April 2010:

Silvia S. Pierangeli; P. G. De Groot; J Dlott; E Favaloro; Eon Nigel Harris; Gabriella Lakos; Thomas L. Ortel; P.L. Meroni; Kotaro Otomo; Vittorio Pengo; Angela Tincani; R Wong; Robert Roubey

Current classification criteria for definite antiphospholipid syndrome (APS) mandate the use of one or more of three positive ‘standardized’ laboratory assays to detect antiphospholipid antibodies (aPL) (viz: anticardiolipin [aCL] IgG and IgM; anti-β2glycoprotein I [anti-β2GPI] antibodies IgG and IgM; and/or a lupus anticoagulant [LAC]), when at least one of the two major clinical manifestations (thrombosis or pregnancy losses) are present. Although, efforts of standardization for these ‘criteria’ aPL tests have been conducted over the last 27 years, reports of inconsistencies, inter-assay and inter-laboratory variation in the results of aCL, LAC, and anti-β2GPI, and problems with the interpretation and the clinical value of the tests still exist, which affect the consistency of the diagnosis of APS. A Task Force of scientists and pioneers in the field from different countries, subdivided in three working groups, discussed and analyzed critical questions related to ‘criteria’ aPL tests in an evidence-based manner, during the 13th International Congress on Antiphospholipid Antibodies (APLA 2010, April 13–16, 2010, Galveston, TX). These included: review of the standardization and the need for international consensus protocol for aCL and anti-β2GPI tests; the use of monoclonal and/or polyclonal standards in the calibration curve of those tests; and the need for establishment of international units of measurement for anti-β2GPI tests. The group also reviewed the recently updated guidelines for LAC testing, and analyzed and discussed the possibility of stratification of ‘criteria’ aPL tests as risk factors for APS, as well as the clinical value of single positive vs. multiple aPL positivity. The group members presented, discussed, analyzed data, updated and re-defined those critical questions at a preconference workshop that was open to congress attendees. This report summarizes the findings, conclusions, and recommendations of this Task Force.


Journal of Clinical Investigation | 2014

CaMK4-dependent activation of AKT/mTOR and CREM-α underlies autoimmunity-associated Th17 imbalance

Tomohiro Koga; Christian M. Hedrich; Masayuki Mizui; Nobuya Yoshida; Kotaro Otomo; Linda A. Lieberman; Thomas Rauen; José C. Crispín; George C. Tsokos

Tissue inflammation in several autoimmune diseases, including SLE and MS, has been linked to an imbalance of IL-17-producing Th (Th17) cells and Tregs; however, the factors that promote Th17-driven autoimmunity are unclear. Here, we present evidence that the calcium/calmodulin-dependent protein kinase IV (CaMK4) is increased and required during Th17 cell differentiation. Isolation of naive T cells from a murine model of lupus revealed increased levels of CaMK4 following stimulation with Th17-inducing cytokines but not following Treg, Th1, or Th2 induction. Furthermore, naive T cells from mice lacking CaMK4 did not produce IL-17. Genetic or pharmacologic inhibition of CaMK4 decreased the frequency of IL-17-producing T cells and ameliorated EAE and lupus-like disease in murine models. Inhibition of CaMK4 reduced Il17 transcription through decreased activation of the cAMP response element modulator α (CREM-α) and reduced activation of the AKT/mTOR pathway, which is known to enhance Th17 differentiation. Importantly, silencing CaMK4 in T cells from patients with SLE and healthy individuals inhibited Th17 differentiation through reduction of IL17A and IL17F mRNA. Collectively, our results suggest that CaMK4 inhibition has potential as a therapeutic strategy for Th17-driven autoimmune diseases.


Rheumatology | 2015

The efficacy of tacrolimus in patients with interstitial lung diseases complicated with polymyositis or dermatomyositis

Takashi Kurita; Shinsuke Yasuda; Koji Oba; Toshio Odani; Michihito Kono; Kotaro Otomo; Yuichiro Fujieda; Kenji Oku; Toshiyuki Bohgaki; Olga Amengual; Tetsuya Horita; Tatsuya Atsumi

OBJECTIVE Interstitial lung diseases (ILDs) complicated with PM or DM are frequently aggressive and refractory to treatment. Recently some reports have suggested the potential benefit of tacrolimus for severe ILD complicated with PM/DM. However, little evidence has yet shown the efficacy of tacrolimus in these settings. The aim of this study was to evaluate the efficacy of tacrolimus as a treatment for PM-/DM-related ILD. METHODS This retrospective study comprised 49 previously untreated patients diagnosed as PM-/DM-related ILD admitted to Hokkaido University Hospital from January 2000 to July 2013. These patients were treated with tacrolimus plus conventional therapy or only with conventional therapy (prednisolone, i.v. CYC and/or ciclosporin). The primary endpoint was defined as the time to relapse or death of respiratory cause or a serious adverse event. The secondary endpoint was defined as the time from the initiation of immunosuppressive treatment to relapse or death of respiratory cause. Endpoints were compared by adjusted Cox regression model by using inverse probability of treatment weighting in order to reduce the impact of these selection biases and potential confounding factors. RESULTS After adjustment, the tacrolimus group (n = 25) had significantly longer event-free survival as compared with the conventional therapy group (n = 24). The weighted hazard ratio (HR) was 0.32 (95% CI 0.14, 0.75, P = 0.008). In addition, the tacrolimus group had significantly longer disease-free survival as compared with the conventional therapy group. The weighted HR was 0.25 (95% CI 0.10, 0.66, P = 0.005). CONCLUSION The addition of tacrolimus to conventional therapy significantly improved the prognosis of patients with PM-/DM-related ILD.


The Journal of Rheumatology | 2011

Hepatitis B Virus Reactivation by Immunosuppressive Therapy in Patients with Autoimmune Diseases: Risk Analysis in Hepatitis B Surface Antigen-negative Cases

Masaru Kato; Tatsuya Atsumi; Takashi Kurita; Toshio Odani; Yuichiro Fujieda; Kotaro Otomo; Tetsuya Horita; Shinsuke Yasuda; Takao Koike

Objective. To evaluate the risk of reactivation of resolved hepatitis B virus (HBV) by immunosuppressive therapy in patients with autoimmune diseases. Methods. Thirty-five patients with autoimmune diseases were included in our study; all were hepatitis B surface antigen (HBsAg)-negative and antibody against hepatitis B core antigen-positive. They were followed for 8–124 weeks and clinical outcomes were analyzed, including serum levels of HBV-DNA and aminotransferase every 4 weeks during their immunosuppressive therapy for underlying autoimmune diseases. If HBV-DNA was detected during the immunosuppressive therapy, HBsAg, antibody against HBsAg (anti-HBs), hepatitis B e antigen (HBeAg), and antibody against HBeAg were also monitored every 4 weeks. Results. HBV-DNA was detected in 6 out of 35 patients. Anti-HBs titer was significantly lower in the patients in whom HBV-DNA was detected compared with the others at baseline: 2.83 (range 0.24–168.50) mIU/ml vs 99.94 (range 0.00–5342.98) mIU/ml, respectively (p = 0.036). Outcomes of the 6 patients with HBV reactivation were as follows: HBV-DNA turned negative in 2 patients without nucleic acid analog (NAA) and 1 with NAA; 2 died due to bacterial sepsis; and 1 died due to autoimmune hemolytic anemia. Significant elevation of aminotransferase was found in only 1 patient, but HBsAg converted to positive in 2 patients and HBeAg converted to positive in 1 patient. Conclusion. Reactivation of resolved HBV can occur during standard immunosuppressive therapy for autoimmune diseases. The low titer of baseline anti-HBs may carry its risk.


Autoimmunity | 2014

KN-93, an inhibitor of calcium/calmodulin-dependent protein kinase IV, promotes generation and function of Foxp3+ regulatory T cells in MRL/lpr mice

Tomohiro Koga; Masayuki Mizui; Nobuya Yoshida; Kotaro Otomo; Linda A. Lieberman; José C. Crispín; George C. Tsokos

Abstract Objective: Foxp3+ regulatory T cells (Treg) are pivotal for the maintenance of peripheral tolerance and prevent development of autoimmune diseases. We have reported that calcium/calmodulin-dependent protein kinase IV (CaMK4) deficient MRL/lpr mice display less disease activity by promoting IL-2 production and increasing the activity of Treg cells. To further define the mechanism of CaMK4 on Treg cells in systemic lupus erythematosus (SLE), we used the Foxp3-GFP reporter mice and treated them with KN-93, an inhibitor of CaMK4. Methods: We generated MRL/lpr Foxp3-GFP mice to record Treg cells; stimulated naïve CD4+ T cells from MRL/lpr Foxp3-GFP mice under Treg polarizing conditions in the absence or presence of KN-93; evaluated the number of GFP positive cells in lymphoid organs and examined skin and kidney pathology at 16 weeks of age. We also examined the infiltration of cells and recruitment of Treg cells in the kidney. Results: We show that culture of MRL/lpr Foxp3-GFP T cells in the presence of KN-93 promotes Treg differentiation in a dose-dependent manner. Treatment of MRL/lpr Foxp3-GFP mice with KN-93 results in a significant induction of Treg cells in the spleen, peripheral lymph nodes and peripheral blood and this is accompanied by decreased skin and kidney damage. Notably, KN-93 clearly diminishes the accumulation of inflammatory cells along with reciprocally increased Treg cells in target organ. Conclusion: Our results indicate that KN-93 treatment enhances the generation of Treg cells in vitro and in vivo highlighting its potential therapeutic use for the treatment of human autoimmune diseases.


Lupus | 2012

Predominant prevalence of arterial thrombosis in Japanese patients with antiphospholipid syndrome

Yuichiro Fujieda; Tatsuya Atsumi; Olga Amengual; Toshio Odani; Kotaro Otomo; Masaru Kato; Kenji Oku; Yujiro Kon; Tetsuya Horita; Shinsuke Yasuda; Takao Koike

Objective: To study the clinical and immunological manifestations of antiphospholipid syndrome (APS) in the Japanese population by a single-centre registration. Methods: In this retrospective cohort study, 141 consecutive patients with APS, fulfilling the Sydney revised Sapporo criteria for definite APS, who visited our autoimmune clinic from 1988 to 2010, were recruited and followed up. All the patients were interviewed and underwent a general physical examination by qualified rheumatologists on the day of blood sampling. Results: The population comprised 119 woman and 22 men with a mean age at diagnosis of 44 years (range 9–79 years). Seventy patients (49.6%) had primary APS, and 71 (50.4%) had systemic lupus erythematosus. The prevalence of thrombosis was 85.8 per cent, arterial thrombosis was found in 93 patients (66.0%) and venous thrombosis was found in 46 patients (32.6%). The most common thrombosis was cerebral infarction [86/141 (61.0%)] followed by deep vein thrombosis [33/141 (23.4%)]. Among 70 pregnant women, 45 (64.3%) had obstetric complications. Lupus anticoagulant was detected in 116 patients (82.3%), anticardiolipin antibodies in 83 (58.9%), anti-β2 glycoprotein I antibodies in 73 (51.8%) and phosphatidylserine-dependent antiprothrombin antibodies in 98 (69.5%). Conclusion: High prevalence of arterial thrombosis was noted in Japanese patients with APS. The profile of heterogeneous and complex clinical manifestations was substantiated in Japanese patients with APS.


Lupus | 2011

The short-term role of corticosteroid therapy for pulmonary arterial hypertension associated with connective tissue diseases: report of five cases and a literature review.

Mototsugu Kato; Hiroshi Kataoka; Toshio Odani; Yuichiro Fujieda; Kotaro Otomo; Kenji Oku; Tetsuya Horita; Shinsuke Yasuda; Tatsuya Atsumi; Hiroshi Ohira; Ichizo Tsujino; Masaharu Nishimura; Takao Koike

Pulmonary arterial hypertension (PAH) is a life-threatening complication in connective tissue diseases (CTD). It remains controversial whether immunosuppressive therapy is useful for PAH associated with CTD (PAH-CTD). The Dana Point algorithm does not refer such treatments in patients with PAH-CTD due to the lack of evidence. However, some case reports have shown the potential efficacy of immunosuppression for PAH-CTD. Here we report five cases of PAH-CTD treated with corticosteroids and discuss the current management of PAH-CTD with immunosuppressive agents. Our cases consisted of three active systemic lupus erythematosus (SLE), a quiescent SLE and an active polymyositis. WHO functional classes at baseline were class III in three cases and class II in two. Median follow-up period was 44 (28–92) weeks. PAH was diagnosed by right heart catheterization in all cases (median pulmonary arterial pressure was 45 (29–49) mmHg). All patients received 1 mg/kg of prednisolone (PSL) for 2–4 weeks, followed by appropriate dose reduction. Methylprednisolone pulse therapy was performed in patients resistant to the high dosage of PSL. Four patients received vasodilators in combination. The therapy as above improved WHO functional class 4 weeks after the initiation of PSL in all the patients. Two patients required dose increase or additional administration of vasodilators due to the dose reduction of PSL. Corticosteroid therapy may be effective for PAH-CTD at least in the short term, even in low general activity of CTD or moderate PAH. Our experience suggests that corticosteroid therapy, by itself or in conjunction with standard vasodilators, is effective for PAH-CTD patients.


Lupus | 2014

Long-term outcome in Japanese patients with lupus nephritis.

Michihiro Kono; Shinsuke Yasuda; Mototsugu Kato; Y. Kanetsuka; Takashi Kurita; Yuichiro Fujieda; Kotaro Otomo; Tetsuya Horita; Koji Oba; Makoto Kondo; M Mukai; M Yanai; Y Fukasawa; Tatsuya Atsumi

The objective of this study was to clarify the long-term outcome in patients with lupus nephritis (LN) according to the International Society of Nephrology and Renal Pathology Society classification. This retrospective analysis comprised 186 Japanese patients given a diagnosis of LN by renal specimen with a mean observation period of 12 years. Primary end point was defined as death or end-stage renal disease, and standardized mortality ratios were calculated. Five patients presented with histopathological class I, 62 with II, 21 with III or III+V, 73 with IV or IV+V and 25 with V. Fourteen deaths occurred, corresponding to an overall standardized mortality ratio of 3.59 (95% confidence interval 2.02–5.81, p < 0.0001). Kaplan-Meier analysis revealed a 10-year overall survival of 95.7%. Nephrotic proteinuria (≥3.5 g/day) at baseline was identified as an independent poor prognostic factor for overall survival in Cox regression analysis. Kaplan-Meier analysis revealed a 10-year renal survival as 94.3%. Male gender and nephrotic proteinuria at baseline were identified as independent poor prognostic factors for renal survival in Cox regression analysis. In conclusion, LN was associated with a 3.59-fold increase in mortality compared with the general population. Male gender and nephrotic proteinuria were predictive for poor renal outcome.


Lupus | 2017

Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study.

Olga Amengual; R Forastiero; Mayumi Sugiura-Ogasawara; Kotaro Otomo; Kenji Oku; Catarina Favas; J Delgado Alves; P. Žigon; A. Ambrožič; M. Tomšič; Ioana Ruiz-Arruza; Guillermo Ruiz-Irastorza; Maria Laura Bertolaccini; Gary L. Norman; Zakera Shums; J Arai; Atsuko Murashima; A E Tebo; Maria Gerosa; P. L. Meroni; I Rodriguez-Pintó; Ricard Cervera; J Swadzba; J Musial; Tatsuya Atsumi

Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected. Serum/plasma samples were tested for IgG aPS/PT at Inova Diagnostics (Inova) using two ELISA kits. A replication study (five centres, five countries) was carried out afterwards. Results In the initial study (n = 247), a moderate agreement between the IgG aPS/PT Inova and MBL ELISA kits was observed (k = 0.598). IgG aPS/PT were more prevalent in APS patients (51%) than in those without (9%), OR 10.8, 95% CI (4.0–29.3), p < 0.0001. Sensitivity, specificity, positive (LR+) and negative (LR–) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 91%, 5.9 and 0.5, respectively. In the replication study (n = 214), a moderate/substantial agreement between the IgG aPS/PT results obtained with both ELISA kits was observed (k = 0.630). IgG aPS/PT were more prevalent in APS patients (47%) than in those without (12%), OR 6.4, 95% CI (2.6–16), p < 0.0001. Sensitivity, specificity, LR + and LR– for APS diagnosis were 47%, 88%, 3.9 and 0.6, respectively. Conclusions IgG aPS/PT detection is an easily performed laboratory parameter that might contribute to a better and more complete identification of patients with APS.

Collaboration


Dive into the Kotaro Otomo's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

George C. Tsokos

Beth Israel Deaconess Medical Center

View shared research outputs
Top Co-Authors

Avatar

Nobuya Yoshida

Beth Israel Deaconess Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge