Based on the results of an annual nationwide survey on transfusion medicine in Japan, we analyzed the usage and discard rates of blood products over the past 6 years. Response rate to this annual questionnaire survey was 52.6% of hospitals in the current fiscal year, which accounted for 80.5% of all blood products delivered in Japan.

The use of red blood cell products increased consistently in hospitals with 200 beds or more. The discard rate improved from 1.4% to 0.7% in 2023, likely due to the 7-day extension made to the usage period of red blood cells. The decrease in discard rate tended to be greater in hospitals with a higher number in beds.

In terms of the characteristics of platelet concentrate usage, the number of higher unit products decreased annually, particularly in the Hokkaido, Kanto Koshinetsu, Tokai and Kinki regions. The discard rate remained at around 0.3% over the past 6 years.

The use of FFP120 product decreased gradually. The discard rate decreased from 1.9% in 2019 to 1.4%. This improvement may be due to the extension in usage period after thawing from 3 to 24 hours. The decrease in discard rate was greater in hospitals with fewer beds. This finding was contrary to that for red blood cells.

In blood services, hemoglobin (Hb) is measured prior to donation to prevent blood collection from anemic donors. However, Hb alone cannot detect latent iron deficiency. The reticulocyte hemoglobin equivalent (RET-He) reflects the hemoglobin content in reticulocytes, which indicates iron utilization over approximately the past 2 days and responds promptly to iron supplementation, making it a sensitive indicator.

We evaluated the utility of RET-He measurement among 523 apheresis donation candidates with no history of whole blood donation during the past year. RET-He demonstrated good diagnostic performance for detecting sFer < 12 ng/ml (AUC 0.85; cut-off 31.6 pg; sensitivity 71.6%; specificity 86.5%). RET-He significantly decreased as iron deficiency progressed. Using RET-He ≤ 31.6 pg, 67% of latent iron deficiency cases, namely those meeting the hemoglobin eligibility criteria, were detected among blood donors. Frequent donors among men showed low RET-He values, while no difference was observed in women, suggesting differing underlying causes of iron deficiency between sexes.

RET-He can be measured alongside Hb at donation sites using the same sample, and therefore enables immediate identification and counseling of donors at risk of iron deficiency, particularly frequent donors, and younger females.

Objective: This study aimed to enhance undergraduate transfusion medicine education by evaluating the effectiveness of blood donation education through small-group transfusion medicine training implemented in collaboration between a university and blood center.

Methods: Participatory transfusion medicine training for 108 fourth-year medical students was conducted at the Jikei University School of Medicine in fiscal year 2024. The curriculum included on-campus training covering fundamentals of transfusion therapy, lectures on blood donation, and practical training in blood collection and transfusion testing. Off-campus training consisted of visits to blood product manufacturing facilities and blood donation rooms where students experienced blood donation or participated in donor recruitment activities. Participation rates and student satisfaction were collected and learning outcomes were assessed qualitatively through post-training surveys.

Results: Ninety-six students (89%) participated in on-campus training, and 92 students (85%) participated in off-campus training. Fifty-one students (53% of on-campus participants) expressed a willingness to donate blood, and 32 students (33/35% of on-/off-campus participants) actually donated blood, of whom 29 (91%) were first-time donors. Training satisfaction was high with an average score of 4.5 (5-point scale). Students demonstrated deep learning regarding blood product preparation processes and the importance of blood donation.

Discussion: This participatory transfusion medicine training effectively promoted changes in students' attitudes toward blood donation and actual donation behavior. It represents an important educational practice that contributes to enhancing undergraduate transfusion medicine education and building a sustainable blood supply system.

Traditional cryoprecipitate preparation requires large centrifuges, limiting the number of available facilities. We improved the siphon method, a gravity-based alternative, with two approaches: a simplified siphon method (overnight siphoning of FFP in a blood refrigerator) and a double-freezing siphon method (thawing, and refreezing FFP before siphoning). The simplified method achieved about 49.2% Fbg recovery and 56.4% purification, comparable to the traditional method using centrifugation. The double-freezing method yielded approximately 72.9% recovery and 74.9% purification, providing over 1g Fbg from 480ml FFP. These methods enable effective cryoprecipitate production without using large centrifuges, aiding bleeding management and promoting proper blood product use.

Accurate determination of ABO blood type is important to the prevention of hemolytic transfusion side effects. With the cisAB type, A and B genes are present on one chromosome. Three types are known to exist in combination with the other chromosomes. In ABO blood type testing, discrepancies between the front and back tests may occur, making accurate determination difficult in some cases.

In the present case, the gel column agglutination method showed anti-A (4+), anti-B (0), anti-D (4+), control (0) in the front test, and A₁ blood cells (0), B blood cells (0) in the back test, resulting in a discrepancy between the front and back tests. On retesting with the test tube method, the front test showed anti-A (4+), anti-B (3+) and the back test showed A₁ blood cells (0), B blood cells (w+). It was therefore decided to put the testing on hold. Since differences in agglutination strength were observed between anti-B and B blood cells in the gel column agglutination method and test tube method, we referred the case to the Japanese Red Cross Society for ABO subtype testing, and the final diagnosis came back as cisAB type.

Here, we report this first case of cisAB type testing we have experienced in which the results varied depending on the testing method used.