【Objective】 In Japan, 800 cases per year of organ donation after brain death (BD) are expected, but only 100 cases per year have materialized. Thus, we have identified patients both willing and able to donate and have assessed their need for confirming the intention for potential donors (PDs).

【Design】 Single-center retrospective observation study.

【Methods】 Patients who have visited emergency rooms were surveyed to determine how many: had indicated their intention to donate on their identification cards; were PDs; had confirmed patient and family intentions; and who wished to donate. We investigated patients able to donate among those who died after hospital admission.

【Results】 Of the 2,749 patients confirmed via their identification cards, 30 (1.1%) wished to donate after BD and 3 (0.1%) after cardiac death (CD). 71 (2.8%) of the 2,527 emergency transfers were PDs. Of these, 34 (47.9%) were interviewed about their intentions and 8 of 34 (23.5%) confirmed their wish to donate. Of a total of 261 deceased patients, 14 (5.4%) were considered able to donate after BD, 20 (7.7%) after CD, and 153 (58.6%) to donate only their eyes.

【Conclusion】 An organ donation system and education are needed to identify PDs and actively confirm their intentions to the medical staff when explaining their terminal medical conditions.

The number of organ donations from brain death has been steadily increasing since the revision of the Organ Transplant Law in 2010; however, the current situation of the waiting list for each organ, which is increasing year by year, indicates that the shortage of donors is an ongoing problem. The first priority is to increase the number of donations after brain death (DBDs), but as an alternative, organ donation from donation after circulatory death (DCD) has been attracting attention and controlled DCD (cDCD), in which withdrawal of life support therapy (WLST) is the mainstay of such donation, has rapidly spread overseas in recent years. In Japan, however, the definition of death is still under debate, and careful consideration is required. In this environment, the AMED study on DCD (Margin Donor for Clinical Application and Heart Transplantation from Cardiac Arrest Donors) was conducted. The introduction of cDCD has been an inevitable and urgent issue, and has been the subject of much discussion. In addition, there is an erroneous understanding among medical professionals, including transplant physicians, that the introduction of cDCD requires revision of related laws, and we believe that one of the important objectives of this proposal is to create guidelines for the correct understanding and realization of donation. Against these backgrounds, we have summarized the issues involved in the introduction of cDCD for heart and lung transplantation and prepared a draft proposal that will serve as a basis for discussion on how to proceed with cDCD in Japan.

【Objective】 Tacrolimus (TAC) is an immunosuppressant drug that has been used to prevent organ rejection after transplantation and to control autoimmune diseases. TAC has a narrow therapeutic window, requiring therapeutic drug monitoring. Lumipulse Presto iTACT tacrolimus, based on the chemiluminescent enzyme immunoassay method (CLEIA), is a newly developed reagent for the measurement of TAC concentration in whole blood. The iTACT technology automatically pretreats whole blood samples before measuring TAC concentration, which can considerably reduce the laboratory workload. In this study, we evaluated the performance of this new CLEIA-based TAC measurement system.

【Methods】 The performance of Lumipulse Presto iTACT tacrolimus was evaluated in terms of the repeatability, the intermediate precision, the linearity, the limit of quantitation (LoQ), the interferences by bilirubin, chyle, and hematocrit, and the correlation with chemiluminescence immunoassay (CLIA)-based measurement.

【Results】 Lumipulse Presto iTACT tacrolimus showed good analytical performance; the coefficients of variation were 0.6-1.6% for the repeatability and 1.7-2.5% for the intermediate precision. The linearity was observed up to 33.0 ng/mL, whereas the LoQ was 0.24 ng/mL. The regression equation of this CLEIA -based measurement (y) on the CLIA-based one (x) was y＝1.05x＋0.06 (n＝203, r＝0.99).

【Conclusion】 The performance of Lumipulse Presto iTACT tacrolimus was good enough for routine clinical use.

Tertiary hyperparathyroidism (THPT) is characterized by elevated parathyroid hormone and serum calcium levels after kidney transplantation (KTx). To ascertain whether pre-transplant calcimimetic use and dose information would improve THPT prediction accuracy, this retrospective cohort study evaluated patients who underwent KTx between 2010 and 2022. The primary outcome was the development of clinically relevant THPT. Logistic regression analysis was used to evaluate pre-transplant calcimimetic use as a determinant of THPT development. Participants were categorized into four groups according to calcimimetic dose, developing two THPT prediction models (with or without calcimimetic information). Continuous net reclassification improvement (CNRI) and integrated discrimination improvement (IDI) were calculated to assess ability to reclassify the degree of THPT risk by adding pre-transplant calcimimetic information. Of the 554 patients, 87 (15.7%) developed THPT, whereas 139 (25.1%) received pre-transplant calcimimetic treatment. Multivariate logistic regression analysis revealed that pre-transplant calcimimetic use was significantly associated with THPT development. Pre-transplant calcimimetic information significantly improved the predicted probability accuracy of THPT (CNRI and IDI were 0.91 [P<0.001], and 0.09 [P<0.001], respectively). The THPT prediction model including pre-transplant calcimimetic information as a predictive factor can contribute to the prevention and early treatment of THPT in the era of calcimimetics.