TOMOAKI IWAI

TOMOAKI IWAI

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Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

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

Representative Publications

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31 December 2018 in PLOS ONE
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AKAkihiro Kosoku
Akihiro Kosoku
Junji UchidaJunji Uchida
Junji Uchida
SNShunji Nishide
Shunji Nishide
KKKazuya Kabei
Kazuya Kabei
HSHisao Shimada
Hisao Shimada
TNTatsuya Nakatani
Tatsuya Nakatani
Living donor kidney transplantation is preferable to deceased donor transplantation due to its superior long-term patient and graft survivals. However, ABO blood group incompatibility is a major barrier to living donor kidney transplantation. ABO-incompatible kidney transplantation has been performed in Japan since the late 1980’s, but it is still globally uncommon. The objective of this study is to compare the clinical outcomes of ABO-incompatible kidney transplantation (ABO-IKT) with that of ABO-compatible kidney transplantation (ABO-CKT) at an institution where only about two kidney transplants are performed a month on average. A single center propensity score-matched cohort study. We retrospectively collected and analyzed the data of 240 patients with end-stage kidney disease (ESKD) who underwent living donor kidney transplantation at Osaka City University Hospital from January 1999 to December 2016, of which 66 patients were ABO-IKT. The remaining 174 patients who underwent ABO-CKT were studied as the control group, and the clinical outcomes of ABO-IKT and ABO-CKT recipients were compared based on propensity score matching. After propensity score matching, there were no significant differences in both patient survival and death-censored graft survival rates between the ABO-IKT and ABO-CKT groups. Moreover, there were no significant differences in estimated glomerular filtration rate as well as frequency of acute cellular rejection, antibody-mediated rejection, infectious adverse events, malignancies, and post-operative bleeding between the two groups. Currently, ABO-IKT may be an acceptable treatment for patients with ESKD even at a low-volume transplant center.

19 March 2018 in Transplantation Proceedings
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TITOMOAKI IWAI
TOMOAKI IWAI
Junji UchidaJunji Uchida
Junji Uchida
YMYudai Matsuoka
Yudai Matsuoka
AKAkihiro Kosoku
Akihiro Kosoku
HSHisao Shimada
Hisao Shimada
TNTatsuya Nakatani
Tatsuya Nakatani
Introduction: Lymphatic leakage after kidney transplantation is a relatively frequent complication but sometimes resistant to treatment, and there is no fixed treatment algorithm. The effectiveness of therapeutic lymphangiography for postoperative lymphatic or chyle leakage has been reported, but few reports are available for that after kidney transplantation. In this study, we report our experience with lymphangiography as a therapeutic tool for lymphatic leakage after kidney transplantation. Patients and Methods Intranodal lymphangiography for lymphatic leakage was performed in 4 patients (3 male, 1 female; age range, 38-70 years old) after living kidney transplantation at Osaka City University Hospital in Japan. The amount of drainage before lymphangiography was 169 to 361 ml/day. The procedure for intranodal lymphangiography was as follows: The inguinal lymph node was punctured under ultrasound guidance, and the tip of the needle was instilled at the junction between the cortex and the hilum, after which Lipiodol was slowly and manually injected. Results: Lymphangiography was technically successful in 3 out of the 4 patients. In all successful cases, the amount of drainage decreased, and leakage finally stopped without additional therapy such as sclerotherapy or fenestration. In 2 cases, we were able to directly detect the leakage site using lymphangiography. The time between lymphangiography and cure was 8 to 13 days. There were neither complications of lymphangiography nor recurrence of lymphatic leakage. Conclusions: Intranodal lymphangiography may be not only a diagnostic tool but also an effective, minimally-invasive, and safe method for treatment of lymphatic leakage resistant to drainage after kidney transplantation.

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SHShimada Hisao
Shimada Hisao
Junji UchidaJunji Uchida
Junji Uchida
SNShunji Nishide
Shunji Nishide
KKKazuya Kabei
Kazuya Kabei
AKAkihiro Kosoku
Akihiro Kosoku
TNTatsuya Nakatani
Tatsuya Nakatani
Post-transplant hyperglycemia and new-onset diabetes mellitus after transplantation (NODAT) are common and important metabolic complications. Decreased insulin secretion and increased insulin resistance are important to the pathophysiologic mechanism behind NODAT. However, the progression of glucose intolerance diagnosed late after kidney transplantation remains clearly unknown. Enrolled in this study were 94 kidney transplant recipients and 134 kidney transplant donors, as the healthy controls, who were treated at our institution. The 75 g-oral glucose tolerance test (OGTT) was performed in the recipients, and the healthy controls received an OGTT before donor nephrectomy. We assessed the prevalence of glucose intolerance including impaired fasting glucose and/or impaired glucose tolerance, as well as insulin secretion and insulin resistance using the homeostasis model assessment, and compared the results between the two groups. Multivariate analysis after adjustment for age, gender, body mass index, estimated glomerular filtration rate, and systolic blood pressure showed that the prevalence of glucose intolerance, insulin resistance, insulin secretion, and 2 h plasma glucose levels were significantly higher in the kidney transplant recipients compared to the healthy controls. Elevation of insulin secretion in kidney transplant recipients may be compensatory for increase of insulin resistance. Impaired compensatory pancreas β cell function may lead to glucose intolerance and NODAT in the future.

10 January 2022 in Transplantation Proceedings
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Journal Article
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AKAkihiro Kosoku
Akihiro Kosoku
TITakuma Ishihara
Takuma Ishihara
TITOMOAKI IWAI
TOMOAKI IWAI
SNShunji Nishide
Shunji Nishide
KKKazuya Kabei
Kazuya Kabei
JUJunji Uchida
Junji Uchida

6 June 2019 in BMC Nephrology
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AKAkihiro Kosoku
Akihiro Kosoku
Junji UchidaJunji Uchida
Junji Uchida
KMKeiko Maeda
Keiko Maeda
YYYuki Yoshikawa
Yuki Yoshikawa
Akihiro HamuroAkihiro Hamuro
Akihiro Hamuro
TNTatsuya Nakatani
Tatsuya Nakatani
Successful pregnancy outcomes after in vitro fertilization in kidney transplant recipients have been reported, but few cases of successful pregnancy after ABO-incompatible kidney transplantation have been described. Herein, we report on a successful pregnancy after in vitro fertilization in an ABO-incompatible kidney transplant recipient with rituximab, focusing on the changes in immunity. A 35-year-old woman with end-stage kidney disease caused by IgA nephropathy was referred for kidney transplantation and successfully underwent an ABO-incompatible living-donor kidney transplant using rituximab from her 66-year-old father at the age of 36. Because she and her husband desired childbearing, they received fertility treatments, and embryo cryopreservation was performed before transplantation. Two years after the transplant, she desired pregnancy. Although immunoglobulin levels such as IgG, IgA and IgM had recovered to almost normal range, the peripheral CD19+ cells and CD20+ cells remained depleted. At 6 months after conversion from mycophenolate mofetil to azathioprine, frozen embryo transfer was performed during the hormone replacement cycle. At 37 weeks and 4 days gestation, a healthy baby girl weighing 2220 g was delivered by cesarean section for arrest of labor. There were no complications in both the recipient and her baby during the perinatal period. At 5 years after the transplant, the recipient has had no major complications including rejection or infection. It is possible for women receiving ABO-incompatible kidney transplantation with rituximab to successfully become pregnant and deliver a heathy baby after in vitro fertilization, if IgG levels recover to normal range despite depleted peripheral blood B cells.

1 April 2003 in Urologia Internationalis
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Journal Article
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TNTatsuya Nakatani
Tatsuya Nakatani
Junji UchidaJunji Uchida
Junji Uchida
TYTakeshi Yamazaki
Takeshi Yamazaki
TITOMOAKI IWAI
TOMOAKI IWAI
TNToshihidei Naganuma
Toshihidei Naganuma
KSKazunobu Sugimura
Kazunobu Sugimura
Introduction: The use of cadaveric pediatric kidneys has been suggested as a means to overcome organ shortage, but is debated because of technical complications and an increased incidence of functional allograft impairment. Methods: We experienced 2 cases of cadaveric renal transplantation from a non-heart-beating pediatric donor. Results: In our cases, transplanted kidneys achieved good graft function and proteinuria due to glomerulosclerosis was not recognized. Conclusion: Previous reports indicate that in transplantation from pediatric donors into adults recipients, glomerular sclerosis occurs as the reason for impairment of grafts. Further, cadaveric renal transplantation from a non-heart-beating donor has a warm ischemia time and an increased risk of hyperfiltrated injury and graft failure. If transplantation of pediatric kidneys into adults from a non-heart-beating donor is performed, BMI and BSA must be carefully considered in the selection of recipients in order to avoid imbalance between nephron supply and metabolic demands and to insure successful, healthy grafts.