We examined the efficacy of intraoperative blood salvage-type autotransfusion using a blood salvage device during cardiovascular surgery with respect to homologous blood reduction. The subjects were 1,075 patients who underwent cardiovascular surgery between April 1, 2012 and March 31, 2015. Of these, blood salvage-type autotransfusion was performed in 831 (77.3%) subjects. When the subjects were divided into 12 groups based on techniques used, the mean blood-salvage-type autotransfusion rate was 98.8% in 11 primary technique groups. With respect to volume of blood loss, the autotransfusion rate increased with increasing volume of blood loss. The autotransfusion rate was 100.0% at blood loss volume ≥4,000 ml. The retransfusion volume increased in accordance with the volume of blood loss, but the blood salvage rate was low. Overall, the blood salvage rate was 52.1%. There were no marked differences in the blood salvage rate among techniques. The correlation coefficient between blood loss and retransfusion volume (r) was 0.9.

In the blood salvage-type autotransfusion group, the red blood cell (RBC), fresh frozen plasma (FFP), and PC volumes increased in proportion with the volume of blood loss. There were no significant differences in FFP or albumin (ALB) volumes with respect to the presence or absence of blood salvage-type autotransfusion. The use of RBC homologous blood could be avoided in 15.6% of patients for whom blood salvage-type autotransfusion was performed. The total retransfusion volume in the blood salvage-type autotransfusion group during the 3-year period was 1,302,135 ml. Since 140 ml is equivalent to 1 U, this indicates that approximately 9,301 U of RBC homologous blood was reduced during the 3-year period.

Accurate ABO blood group typing is critical for blood transfusion medicine. The ABO group is determined when forward group typing detects blood antigens and reverse group typing detects the presence or absence of anti-A or anti-B antibodies in serum. However, ABO type discrepancies are occasionally observed under a variety of conditions, such as the subtype of ABO group, various malignancies, including hematologic diseases, and autoimmune disorders. Here, we performed a single institute retrospective analysis of patients who presented with ABO discrepancies from January 1, 2003, to September 30, 2015. Patients who received hematopoietic stem cell transplantation with ABO-incompatible grafts were excluded from this study. Out of 2,455 patients, 61 had ABO discrepancies, most of whom also had a hematologic disease. Of the 61 ABO discrepancies, 20 were detected in forward group typing, 35 in reverse group typing, 4 in both, and 2 were due to unidentified factors. Eighteen (90%) patients with discrepancies in forward group typing had myelodysplastic syndrome and acute myeloid leukemia and 18 (51%) with discrepancies in reverse group typing had lymphoid malignancies. ABO type discrepancies are observed in hematological diseases, indicating the need for repeated tests.

Delayed reactions (DRs) occurring after autologous blood donation are recognized as off-site adverse reactions associated with fainting and severe injury, but DR incidence and risk factors remain unclear. To assess DR rates and risk factors, we retrospectively investigated 294 patients after their initial autologous donation at our hospital. We defined DRs as occurring outside the transfusion department, but within one week following autologous donation. After DR rates and patient characteristics were collated, multivariate logistic regression analyses were conducted to identify the factors associated with DRs. The DR prevalence was 33.7% (99/294 patients). Patients reported DRs most frequently on the day of blood donation (26.9%, 79/294). Many patients with DRs complained of headache, lightheadedness, fatigue, or dizziness. Most symptoms had improved by the fourth day after autologous donation. DRs were associated with the female sex (odds ratio [OR] 2.72, 95% confidence interval [CI] 1.22–6.05), low estimated blood volume (<3,300 ml: OR 2.58, 95%CI 1.01–6.58; 3,300-3,899 ml: OR 2.66, 95%CI 1.13–6.23), and high pre-donation pulse rate (75–89 beats/min: OR 2.08, 95%CI 1.13–3.86). These results suggest that changes in circulation dynamics and modulation of autonomic nerve system components associated with autologous donation are related to DR occurrence.

There are some reports of severe anaphylactic shock after the transfusion of blood products containing a plasma protein in haptoglobin (Hp)-deficient patients with an anti-Hp antibody. We encountered two Hp-deficient patients who were homozygous for a deleted allele of the Hp gene. These two patients did not have an adverse reaction to the transfusion of two-time washed red cells. We examined the correlation between the number of washes and the haptoglobin concentration remaining in blood products. We measured the Hp concentration in five blood products of washed red cells (WRC), frozen-thawed red cells (FTRC), and washed platelet concentrate (WPC). The mean Hp concentration of red blood cells (RBC) was 98.800 μg/ml, that of the one-time washed WRC was 3.044 μg/ml, that of the two-time washed WRC was 0.233 μg/ml, and that of the three-time washed WRC was 0.038 μg/ml. The p-values of the one-, two-, and three-time washed WRC were 0.0089, 0.0019, and <0.0001, respectively. The mean Hp concentration of FTRC was 5.116 μg/ml. The mean Hp concentration of platelet concentrate (PC) was 656.600 μg/ml, that of the one-time washed WPC was 7.262 μg/ml, and that of the two-time washed WPC was 0.463 μg/ml. The p-values of the one- and two-time washed WPC were <0.0001 and 0.0016, respectively. Based on these results, it is desirable to transfuse two-time washed WRC and WPC to Hp-deficient patients with an anti-Hp antibody.

The Japanese Red Cross Society (JRCS) has been conducting investigations of blood samples from patients who have developed non-hemolytic transfusion reactions (NHTRs). The test items are anti-plasma protein antibodies, plasma protein deficiency, total IgE content, elevation of tryptase and anti-HLA. No significant causal relationships were found between patients' anti-plasma protein antibodies and categories of adverse reactions or severity of adverse reactions. However, deficiency of IgA or Haptoglobin (Hp) can be a risk factor for adverse reactions. Results of the tryptase test showed significantly higher prevalence of allergic reactions, but the timing of sampling from patients may have affected the test results. On the other hand, tests of IgE and anti-HLA did not show a significant difference in prevalence among the categories of adverse reactions, which suggests that these factors are unrelated to NHTRs.

Based on these results, JRCS will continue IgA or Hp antibody and deficiency and tryptase testing with samples withdrawn within 6 hours of the reaction to improve the accuracy of the test, which will contribute to the safety of transfusion medicine. In addition, the tests will be conducted on patients who developed severe adverse reactions.

JRCS will establish a more efficient testing system, along with the implementation of new potential test items.

Low-titer cold agglutinin disease (CAD) is a hemolytic disorder characterized by low-titer cold agglutinin with increased thermal amplitude in the presence of albumin. Autoagglutination often occurs in CAD, and is usually reversed by warming to 37°C. In this study, we showed strong autoagglutination even at 37°C in a patient with low-titer CAD, which prevented ABO and RhD typing. To reverse the autoagglutination, we first tried to perform every step at or above 37°C, which was ineffective. Flow cytometric analysis revealed that IgM, but not IgG, was detected on the patient's erythrocytes. Next, we applied 0.01M dithiothreitol to disrupt the disulfide bonds of the IgM antibodies on the patient's erythrocytes. DTT successfully prevented autoagglutination, which enabled us to perform ABO and RhD typing. In addition, the patient's plasma interfered with alloantibody screening because of the cold agglutinin. Again, DTT treatment of the plasma was effective for inactivating IgM cold agglutinin. Our data suggest that DTT treatment is easy and effective for preventing IgM-mediated strong autoagglutination.