Several reports have explored the value of electronic identification systems (EISs) in reducing incorrect blood recipient identification. Here, we report a multi-institutional study to clarify the usage and limitation of EISs for pretransfusion sample collection and blood administration. From October 2020 to March 2022, 26 institutions were registered in the study. 15 (58%) used EISs for blood collection, and 25 (96%) for administration. In several institutions, EISs were not implemented in departments in which massive bleeding may occur, such as the emergency department, operating room and angiography room. 12 institutions reported 52 cases of error and near-miss events of wrong blood in tubes and wrong component transfusion. Blood samples were collected from the wrong patient in 17 cases, EISs were not used before blood administration in 8, and the wrong component was transfused to patients in 7. Of 52 errors and near-miss events, EISs were not used properly in 41 (79%). Clinical staff did not understand the use of EISs before blood collection and administration in 9 and forgot electronic patient identification before blood collection or administration in 5, and electronic patient identification was not performed before blood collection or administration due to an emergency situation in 3. Further efforts are needed to improve patient safety in the transfusion process.

Pooled platelet concentrate (PC) that is prepared from whole blood may be a solution to the shortage of blood donors caused by the declining birthrate and aging population. Here, we prepared a pooled platelet additive solution (PAS)-PC from 400 ml whole blood by replacing a portion of the plasma with PAS using TACSI, a European-specification large-capacity centrifuge with an automatic blood separation function. We then compared quality during storage at room temperature (22°C) and refrigeration (4°C) over 21 days.

Pooling of four buffy coats (BCs) yielded more than 10 units of pooled PAS-PC (n=4), and pooling of five BCs yielded more than 15 units of pooled PAS-PC (n=4). Each pooled PAS-PC met the quality standard of PC in Japan. On room temperature storage, pooled PAS-PC maintained good platelet aggregation, % hypotonic shock response (%HSR), and clot formation capacity for up to 5 days. On refrigerated storage, %HSR decreased early after storage, but aggregation and clot formation capacity remained similar to those on day 5 of room temperature storage until day 14.

These findings suggest that pooled PAS-PC of good quality can be obtained from 400 ml whole blood using the European specification TACSI. In addition, pooled PAS-PC can be stored for up to 14 days by refrigerated storage.

Most Kell blood group antigens have been shown to be due to amino acid substitutions associated with single nucleotide variants. Currently, 37 Kell blood group antigens are recognized by the International Society of Blood Transfusion (ISBT). KEL26 (TOU) is a high-frequency antigen recognized as the 26th antigen by the ISBT, and was reported in a Native American male and a Latino female in 1995.

Here, we report a case in which a Kell-related antibody was suggested by serological tests, and the specificity of the antibody could be estimated by KEL genotyping.

The KEL genotype was KEL*02N.24/KEL*02.-26 heterozygote determined by Sanger sequencing. KEL*02.-26 has c.1217G>A missense variant in exon 11 which leads to an Arg406Gln substitution. From these results, the Kell-related antibody was presumed to be an anti-KEL26.

There have been several reports from other countries regarding post-transfusion iron overload in pediatric patients with cancer. Similar to adults, a correlation between pre-transplantation ferritin levels and complications in pediatric patients receiving allogeneic hematopoietic cell transplantation has been reported overseas, but not in Japan. We experienced two cases of liver injury in which MRI was useful in discriminating between post-transfusion iron overload and hepatic graft versus host disease (GVHD). Both patients had acute myeloid leukemia, and despite immunosuppressive therapy for hepatic GVHD, they presented with persistent liver damage and hyperferritinemia. On MRI, both had typical findings of post-transfusion iron overload. In pediatric patients with cancer who have a long myelosuppression period and require frequent blood transfusion, post-transfusion iron overload accompanied by organ damage may occur in the acute phase. A large-scale survey of this issue in Japan is required.

We report the successful prevention of recurrent anaphylaxis with washed cord blood (CB) at second cord blood transplantation (CBT) in a patient who experienced severe anaphylactic events during infusion at the first CBT.

A Japanese woman in her 30s diagnosed with acute myelogenous leukemia (AML) received the first CBT (nucleated cell count (NCC) 1.72×10⁷/kg). When the approximate 80% compartment of the CB unit was infused, anaphylaxis with dyspnea, hypoxia and hypotension occurred. The infusion was immediately stopped and she was treated with intramuscular injection of epinephrine. Although the remaining 20% portion was not infused, engraftment was achieved at day 25 after transplantation. At 18 months after the first CBT, retransplantation was planned for AML relapse using washed CB to prevent recurrence of anaphylaxis. After one CB unit (NCC 3.20×10⁷/kg) was thawed in a 37°C water bath, it was slowly diluted with a solution containing albumin and dextran (ALB/D) and centrifuged while cooling. The supernatant was removed, and the ALB/D solution was added to a final volume of 50ml. The washed CB was infused into the patient as soon as possible. No anaphylactic reaction was observed, and CB cells were successfully engrafted at day 13 after the second CBT.