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Dive into the research topics where Kunihiko Umekita is active.

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Featured researches published by Kunihiko Umekita.


Modern Rheumatology | 2009

Leukocytapheresis (LCAP) decreases the level of platelet-derived microparticles (MPs) and increases the level of granulocytes-derived MPs: a possible connection with the effect of LCAP on rheumatoid arthritis.

Kunihiko Umekita; Toshihiko Hidaka; Shiro Ueno; Ichiro Takajo; Yasufumi Kai; Yasuhiro Nagatomo; Akira Sawaguchi; Tatsuo Suganuma; Akihiko Okayama

Microparticles (MPs) are believed to play an important role in inflammatory diseases such as rheumatoid arthritis (RA). Leukocytapheresis (LCAP) is one of the options available for the treatment of RA. We analyzed the levels of MPs in RA, by flow cytometry, especially in relation to the effect of LCAP. Twenty female patients with RA were recruited into this study. Six of the 20 patients with RA further received LCAP. Plasma levels of platelet-derived MPs were high in patients with RA and are correlated with disease activity. LCAP significantly improved RA in all six patients. The numbers of platelet-derived MPs significantly decreased after the first session of LCAP, which was probably due to direct removal by LCAP. Mean numbers of platelet-derived MPs after four sessions of LCAP markedly decreased. The numbers of granulocyte-derived MPs, which are suggested to have an anti-inflammatory effect, were markedly increased after the first session of LCAP. These data suggest that removal of platelet-derived MPs and increase of granulocyte-derived MPs are novel mechanisms of LCAP as effective treatment in RA.


International Journal of Cancer | 2012

Proviral loads of human T-lymphotropic virus Type 1 in asymptomatic carriers with different infection routes

Shiro Ueno; Kazumi Umeki; Ichiro Takajo; Yasuhiro Nagatomo; Norio Kusumoto; Kunihiko Umekita; Kazuhiro Morishita; Akihiko Okayama

High human T‐lymphotropic virus Type 1 (HTLV‐1) proviral DNA load (PVL) has been reported to be one risk factor for the development of adult T‐cell leukemia/lymphoma (ATL). ATL is also believed to develop in HTLV‐1 carriers who acquire infection perinatally. ATL cells have been reported to frequently harbor defective provirus. In our study, PVLs for three different regions of HTLV‐1 provirus (5′LTR‐gag, gag and pX) were measured in 309 asymptomatic carriers with different infection routes. PVLs for the pX region in 21 asymptomatic carriers with maternal infection was significantly higher than in 24 carriers with spousal infection. Among 161 carriers with relatively high pX PVLs (equal to or greater than 1 copy per 100 peripheral blood mononuclear cells), 26 carriers (16%) had low gag PVL/pX PVL (less than 0.5) and four (2%) had low 5′LTR‐gag PVL/pX PVL (less than 0.5). Low gag PVL/pX PVL ratio, which reflects deficiency and/or polymorphism of HTLV‐1 proviral DNA sequences for the gag region, was also associated with maternal infection. These data suggest that HTLV‐1 carriers with maternal infection tend to have high PVLs, which may be related to provirus with deficiency and/or the polymorphism of proviral DNA sequences. In addition, there is a possibility that this ratio may be used as a tool to differentiate the infection routes of asymptomatic HTLV‐1 carriers, which supports the need for a large scale study.


Modern Rheumatology | 2015

Use of anti-tumor necrosis factor biologics in the treatment of rheumatoid arthritis does not change human T-lymphotropic virus type 1 markers: a case series

Kunihiko Umekita; Kazumi Umeki; Shunichi Miyauchi; Shiro Ueno; Kazuyoshi Kubo; Norio Kusumoto; Ichiro Takajo; Yasuhiro Nagatomo; Akihiko Okayama

Abstract Anti-tumor necrosis factor (anti-TNF) biologics are effective in the treatment of rheumatoid arthritis (RA); however, it is still not clear whether this treatment promotes the development of malignancies such as lymphoma. Human T-lymphotropic virus type 1 (HTLV-1), which is a causative agent of adult T-cell lymphoma (ATL), is prevalent in Japan. Many HTLV-1-positive patients with RA are assumed to exist; however, there have thus far been no reports on the effect of anti-TNF biologics on HTLV-1-positive patients. We analyzed the response to treatment with anti-TNF biologics and change of HTLV-1 markers in two cases of RA. The two cases showed no response based on the European League Against of Rheumatism response criteria 60–96 weeks after administration of anti-TNF biologics (infliximab and etanercept). No signs of ATL were observed and HTLV-1 markers, such as proviral load and clonality of HTLV-1-infected cells, showed no significant change in either of two cases. Therefore, treatment with anti-TNF biologics did not induce activation of HTLV-1, although the effect on RA was not as effective as in HTLV-1-negative patients in this limited study. Further long-term study with a greater number of patients is necessary to clarify the safety and efficacy of anti-TNF biologics in HTLV-1-positive patients with RA.


Arthritis Care and Research | 2014

Treatment with anti–tumor necrosis factor biologic agents in human T lymphotropic virus type I–positive patients with rheumatoid arthritis.

Kunihiko Umekita; Toshihiko Hidaka; Shunichi Miyauchi; Shiro Ueno; Kazuyoshi Kubo; Ichiro Takajo; Yayoi Hashiba; Yasufumi Kai; Yasuhiro Nagatomo; Akihiko Okayama

To investigate the response to and safety of anti–tumor necrosis factor (anti‐TNF) therapy in human T lymphotropic virus type I (HTLV‐I)–positive patients with rheumatoid arthritis (RA).


Journal of Infection and Chemotherapy | 2016

Severe fever with thrombocytopenia syndrome with myocardial dysfunction and encephalopathy: A case report

Takeshi Kawaguchi; Motohiro Matsuda; Ichiro Takajo; Ayako Kawano; Yumi Kariya; Kazuyoshi Kubo; S. Miyauchi; Kunihiko Umekita; Yasuhiro Nagatomo; Takao Yano; Kouji Yano; Akihiko Okayama

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease in China, Korea and Japan caused by a novel bunyavirus, SFTS virus (SFTSV). Although central nervous system manifestations are common in SFTS patients, the pathogenesis has not been elucidated; and there are few reports of myocardial dysfunction. Here we report an elderly Japanese patient with reversible myocardial dysfunction and encephalopathy. A previously healthy 65-year-old male engaged in forestry got a tick bite and developed fever and fatigue in 3 days. Three days after onset, he presented to a local hospital where the diagnosis of SFTS with hemophagocytotic syndrome was made. The blood test showed leukopenia and thrombocytopenia as well as elevated levels of alanine aminotransferase and aspartate aminotransferase. Marked hemophagocytosis was found on bone marrow smear. Peripheral blood was positive for SFTSV gene by reverse-transcription polymerase chain reaction. On day 7, the patient was transferred to our hospital. We observed disturbance of consciousness, Kernig sign and myoclonus to face and limbs. Decreased blood flow of whole cerebral cortex was detected by single photon emission computed tomography (SPECT). Chest X-ray revealed cardiomegaly and electrocardiography (ECG) showed abnormal T waves. These data suggested acute encephalopathy and myocardial dysfunction. We treated him with corticosteroid and blood transfusion, which resulted in the complete recovery of the above abnormal symptoms and laboratory data including the findings in SPECT and ECG in about a month. This case demonstrated transient myocardial dysfunction and encephalopathy can occur in addition to typical clinical manifestation of SFTS.


International Journal of Cancer | 2011

Defective human T‐lymphotropic virus type 1 provirus in asymptomatic carriers

Hiroyuki Takenouchi; Kazumi Umeki; Daisuke Sasaki; Ikuo Yamamoto; Hajime Nomura; Ichiro Takajo; Shiro Ueno; Kunihiko Umekita; Shimeru Kamihira; Kazuhiro Morishita; Akihiko Okayama

Few studies have specifically examined defective provirus in asymptomatic human T‐lymphotropic virus Type 1 (HTLV‐1) carriers and its relation to proviral DNA loads (PVLs). To assess the significance of defective provirus in asymptomatic carriers, we examined PVLs in peripheral blood mononuclear cells of 208 asymptomatic HTLV‐1 carriers. The mean PVLs determined using primers for the pol region were less than that for the pX region in these carriers. Analysis of seven carriers with high PVLs for the pX region but lower PVLs for the pol region showed that four had single nucleotide polymorphisms of proviral genomes for the pol region and three had HTLV‐1‐infected cells with defective provirus. Three carriers with defective provirus showed high PVLs at their initial screens, and PVLs increased after a 10‐ to 12‐year interval in two carriers. Southern blot assay showed clonal expansion of HTLV‐1‐infected cells, and the predominant clones changed during the observation period. These data suggest that although HTLV‐1‐infected cells with defective provirus may have a growth advantage, the predominant clones of HTLV‐1‐infected cells do not always survive for many years in asymptomatic carriers.


Human Cell | 2017

Infection of defective human T-lymphotropic virus type 1.

Yuuki Hashikura; Kazumi Umeki; Kunihiko Umekita; Hajime Nomura; Akiteru Yamada; Ikuo Yamamoto; Hiroo Hasegawa; Katsunori Yanagihara; Akihiko Okayama

In a previous study, we reported that an identical defective provirus had integrated into multiple sites of the genome of a representative human T-lymphotropic virus type 1 (HTLV-1) cell line, MT-2. A possible explanation for this may be the repeated infection of this defective provirus to a cell. Therefore, we attempted to determine whether a defective provirus could transmit during the co-culture of HTLV-1 uninfected human T-cell line, Jurkat, with MT-2 cells treated with mitomycin C. As a result, we established not only a cell line with the integration of one complete provirus, but also a cell line with the integration of one defective provirus. The rearrangement of the T-cell receptor -γ gene of these cell lines showed them to be derived from Jurkat cells. Both HTLV-1 Tax/Rex and HBZ RNA were detected in the cell line, which harbors a complete provirus. On the other hand, HBZ RNA and transcriptional product specific for the defective provirus were detected in the cell line, which harbors a defective HTLV-1 provirus only. These results suggested that a defective HTLV-1 provirus with large depletion of internal sequence could transmit to other cells. Moreover, the defective provirus can be transcriptionally active. This suggested the possibility that the defective HTLV-1 provirus found in the lymphocytes of HTLV-1 carriers and patients with adult T-cell leukemia may transmit to other T-cells in vivo. The results also suggested that defective provirus in HTLV-1 carriers could be functional and may play a role in leukemogenesis.


Clinical Laboratory | 2017

Evaluation of Line Immunoassay to Detect HTLV-1 Infection in an Endemic Area, Southwestern Japan; Comparison with Polymerase Chain Reaction and Western Blot.

Kazumi Umeki; Kunihiko Umekita; Yuuki Hashikura; Ikuo Yamamoto; Kazuyoshi Kubo; Yasuhiro Nagatomo; Akihiko Okayama

BACKGROUND Human T-lymphotropic virus type 1 (HTLV-1) has been recognized as a cause of adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy/tropical spastic paraparesis, and HTLV-1-associated uveitis. HTLV-1 infection is normally detected by screening for HTLV-1 antibodies, and positive samples are confirmed by Western blot (WB). However, WB fails to confirm some samples that were positive for HTLV-1 antibodies on screening. Line immunoassay (LIA) is commonly used in Europe and Brazil, but not in Japan. Therefore, we evaluated the performance of LIA as a method of confirming HTLV-1 antibodies using samples in Japan. METHODS LIA was compared with polymerase chain reaction (PCR) and WB using 50 negative and 70 positive samples tested by chemiluminescent enzyme immunoassay (CLEIA) in Miyazaki, Japan, an HTLV-1 endemic area. LIA (INNO-LIA HTLVI/II Score) and WB (Problot HTLV-I) were performed according to the manufacturers instructions. Real-time PCR for HTLV-1 pX region was performed using DNA derived from white blood cells. The samples that tested negative by real-time PCR were further tested by nested PCR. RESULTS All 50 CLEIA negative samples were determined to be negative by LIA and PCR. Of the 70 positive samples, 66 tested positive by both of LIA and PCR. Three samples tested negative by LIA and PCR, and the remaining sample (PCR negative) showed non-specific staining in LIA and WB. WB showed more indeterminate results than LIA. Gp21 antibody in LIA demonstrated a high ability to discriminate between positive and negative PCR results. Furthermore, the degree of gp21 antibody reaction by LIA showed correlation with HTLV-1 proviral loads (PVLs). CONCLUSIONS Our results indicate that LIA performs well in confirming HTLV-1 seropositivity by showing a low incidence of indeterminate results and good agreement with PCR using samples in Japan, although the number of samples tested was small. In addition, semi-quantitative antibody titer to gp21 correlated well with HTLV-1 PVLs. Further study including larger samples is necessary to determine the positioning of LIA for HTLV-1 detection in Japan.


Emerging Infectious Diseases | 2016

Possible Case of Novel Spotted Fever Group Rickettsiosis in TravelerReturning to Japan from India

Ichiro Takajo; Tsuyoshi Sekizuka; Hiromi Fujita; Ayako Kawano; Takeshi Kawaguchi; Motohiro Matsuda; Kazuyoshi Kubo; Shunichi Miyauchi; Kunihiko Umekita; Yasuhiro Nagatomo; Makoto Kuroda; Tomohiko Takasaki; Akihiko Okayama; Shuji Ando

A 60-year-old woman experienced fever, headache, rash, and altered vision after returning to Japan from India. Testing detected elevated antibody titers to spotted fever group rickettsia; PCR on blood yielded positive results for the rickettsial outer membrane protein A gene. We isolated a unique rickettsial agent and performed a full-genome analysis.


Rheumatology | 2014

Increased plasma lactoferrin levels in leucocytapheresis therapy in patients with rheumatoid arthritis

Shunichi Miyauchi; Kunihiko Umekita; Toshihiko Hidaka; Kazumi Umeki; Yatsuki Aratake; Nobuyasu Takahashi; Akira Sawaguchi; Ayako Nakatake; Itsuki Morinaga; Kazuhiro Morishita; Akihiko Okayama

OBJECTIVE The aim of this study was to clarify the mechanism of leucocytapheresis (LCAP) in patients with RA. METHODS Protein profiles of blood samples from two patients with RA obtained via LCAP column inlet and outlet lines were analysed by two-dimensional fluorescence difference gel electrophoresis and mass spectrometry. The lactoferrin (LTF) levels of peripheral and circulating blood samples from seven patients obtained via the LCAP column blood circuit were then determined by ELISA. Peripheral blood samples from 14 patients with RA were exposed to unwoven polyester fibre filters and the LTF level was determined. In addition, morphological changes in neutrophils after exposure to the filter were examined by optical microscopy, electronic microscopy and LTF immunostaining. RESULTS LTF levels were increased in both samples from the LCAP column outlet and peripheral blood at the end of LCAP treatment. Furthermore, peripheral blood samples exposed to the filter revealed a decreased number of neutrophils and an increased level of LTF. Morphological analysis of the exposed neutrophils showed vacuolization of the cytoplasm and degranulation of LTF-positive granules. These data suggest that LTF stored in the granules of neutrophils is released from the neutrophils caught in the LCAP column. CONCLUSION Because LTF has been reported to have multiple anti-inflammatory properties, increased levels of LTF may contribute to the clinical effect of LCAP in patients with RA.

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Shiro Ueno

University of Miyazaki

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S. Miyauchi

University of Miyazaki

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