Laboratory tests for detecting irregular antibodies are necessary for safe blood transfusions. However, it is difficult to test for irregular antibodies in infants due to difficulties with blood sampling. Over the past 10 years, we have resolved this problem by adopting a "Micro Typing System" for infants under four months of age. This system is based on the column cohesion method and can detect irregular antibodies using only 25% of the blood sample required for tube tests. Using the Micro Typing System, between January 2007 and December 2016, we successfully completed 552 irregular antibody tests from 554 samples (99.6%) from infants under four months of age, the majority of whom had heart disease (55.4%). We detected 16 cases (2.9%) of irregular antibodies: 14 maternal, one natural (an IgM-type anti-M antibody), and one antibody whose origin was unknown. Furthermore, 358 erythrocyte transfusions were performed after the irregular antibody tests. Following the transfusions, 230 irregular antibody tests (64.2%) showed no findings of irregular antibodies. The Micro Typing System can be used for irregular antibody tests in most patients, including infants, and is a useful method to assure safe blood transfusions in infants.

Cryoprecipitate contains a higher concentration of fibrinogen than fresh frozen plasma (FFP) and is known to markedly improve hemostatic disorders. While cryoprecipitate can be prepared in the hospital for internal use, this is limited to sites equipped with a large cooling centrifuge. In this study, we investigated on the feasibility of obtaining concentrated fibrinogen from FFP using a membrane-type plasma separator (separator) instead of a centrifuge. Two experiments were conducted using different volumes of FFP, and the products were named M1 and M2. The outer compartment of the hollow fiber of the separator was filled with FFP (458 ml for M1, 878 ml for M2), and subsequently washed with 1,200 ml of saline. The remaining liquid in the outer compartment was recovered (M1: 51 ml, M2: 99 ml). The fibrinogen concentration of M1 was 695 mg/dl and that of M2 was 953 mg/dl. The average preparation time was 23 minutes for M1 and 71 minutes for M2. M2 had about 2.6-times higher FXIII activity and about 4.4-times higher FV activity than cryoprecipitate prepared from the same plasma using the conventional method. The new method described here does not require a centrifuge or a liquid transfer pump, and can therefore be performed at a large number of medical institutions.

We report 217 cases in which blood alternatives and surgery based on Patient Blood Management (PBM) were performed in patients who are Jehovah's Witnesses. The diseases included 4 cases of esophageal cancer, 51 of gastric cancer, 75 of colorectal cancer, 37 of liver cancer, 16 of bile duct cancer, 25 of pancreatic cancer and 10 of other organ tumors. Forty-one patients with anemia were treated by employing preoperative blood augmentation, all of whom were enabled to receive planned resection. The frequency of using autologous blood transfusion was 48% overall, in which most of the high-level hepato-biliary-pancreatic surgeries were integrated by a combination of hemodilutional and salvaged autotransfusion. Postoperative care included administration of an iron infusion and minor components if needed. Postoperative complications were observed at the rate of 3.1%, all of which were well-managed by closemonitoring of surgical drainage. PBM, which consists of multidisciplinary management involving blood augmentation and autologous blood transfusion, enabled surgical treatment of Jehovah's Witness patients that contributed to their better prognosis.

Accurate estimation of CD34-positive cell count is important for predicting engraftment in peripheral blood stem cell (PBSC) transplantation. We evaluated two methods of counting CD34-positive cells-dual platform (DP) and single platform (SP) analyses. Samples were obtained from patients who were scheduled to undergo PBSC harvest. SP and DP analyses yielded similar results, with a strong correlation coefficient value greater than 0.98 for peripheral blood (PB) and PBSC samples. SP has the advantage of a shorter time (i.e., 40 minutes) to perform and higher accuracy than DP. Accordingly, SP is more useful in determining the timing and volume of PBSC harvest.

Blood products for transfusion may undergo structural or chemical changes when mixed with other infusion fluids, potentially causing hemolysis or coagulation. Therefore, it is generally preferable to use a single infusion route. However, it is often difficult to secure multiple infusion routes in clinical settings. Case: A one-year-old infant was admitted to our hospital for infusions of fresh frozen plasma (FFP; 20 ml/h infusion) for the treatment of solid tumor. A string-like structure was observed in the infusion route after administration of FFP. The structure disappeared after the degradation test using plasmin, leading to the conclusion that it was composed of fibrin. Discussion: Reacting FFP with calcium results in fibrin precipitation. Given that Ringer's solution which contains calcium was used as the main infusion in this patient, we hypothesize that the saline washout of Ringer's solution after the prior infusion was insufficient at the time of FFP administration. It is also possible that a slow infusion rate and FFP stagnation in the infusion route contributed to fibrin deposition. Conclusion: This case emphasizes the importance of performing a thorough saline washout of the infusion fluid prior to the transfusion and preventing blood products from mixing with other infusion drugs.

Polyagglutination (PA) is a phenomenon in which erythrocyte antigens that are latent in ordinary erythrocytes are exposed to enzymes such as those of bacterial origin, causing erythrocyte aggregations by IgM-type natural antibodies in adult serum. We encountered a case of PA in a woman in her 60s. She was hospitalized for abdominal trauma due to a traffic accident. On the 4th day of hospitalization, she underwent small bowel resection following diagnosis of peritonitis and developed disseminated intravascular coagulation (DIC) due to septicemia. After platelet transfusion, anemia rapidly worsened and the cross match test for red blood cell (RBC) transfusion was performed. No agglutination was observed in the main test but in the minor test, an aggregation reaction was observed in all plasma except autologous plasma. Examinations using anti-T antibody and lectins showed PA by T antigens. To avoid hemolysis and agglutination of blood cells by allogeneic plasma, blood products containing plasma were abstained. PA was most severe on the 5th day of hospitalization, and gradually decreased as sepsis improved. While PA does not necessarily cause hemolysis, care should be taken because PA due to S.pneumonia can induce hemolysis.

There is increasing demand for daratumumab (DARA), a humanized IgG1κ monoclonal antibody to CD38 approved for the treatment of relapsed and/or refractory multiple myeloma (MM). However, DARA interference in indirect antiglobulin tests (IATs) may persist for up to 6 months after discontinuation of DARA. Here, we describe a patient with MM with pan-reactive antibody in an antibody screening test and no history of DARA administration at Osaka University Hospital. We confirmed that the suspected pan-reactive antibody was due to DARA interference based on her medical history of DARA administration in a previous hospital and negated the positive reaction in IATs using the Osaka method (0.01 mol/l DTT).

The patient was a 60-year-old Japanese female who had been suffering from MM. She was referred to Osaka University Hospital for allogeneic bone marrow transplantation following relapse despite treatment at a previous hospital. The antibody screening test performed at admission was positive and pan-reactive. However, there was no indication of any history of DARA administration at our hospital. We tried to obtain her medical history in the previous hospital further and noted that DARA had been administered for 6 months, and that 3 months had elapsed since the discontinuation of DARA. By employing the newly developed Osaka method, we confirmed that the suspected pan-reactive reaction was due to DARA interference. This case report suggests that the Osaka method is easy to perform and effective for negating DARA interference.

Alloantibodies against human platelet antigen-15 (HPA-15) residing on CD109 reportedly cause platelet transfusion refractoriness (PTR) and neonatal alloimmune thrombocytopenia. However, detection of anti-HPA-15 antibodies is difficult using the mixed passive hemagglutination (MPHA) test, the most popular method for detecting platelet-specific antibodies in Japan. Furthermore, concomitant expression of human leukocyte antigen (HLA) antibodies makes anti-HPA-15a detection using the MPHA test even more difficult. In this case report, we present the case of a 63-year-old woman with acute myelogenous leukemia who had HLA antibodies. She developed PTR during chemotherapy, and anti-HPA-15a positivity was identified using the monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay. Transfusions of platelet preparations from random donors were not effective. However, HLA-matched and HPA-mismatched platelet transfusions were clinically effective against thrombocytopenia, similar to both HLA and HPA-matched transfusions. Further studies are needed to evaluate the clinical significance of anti-HPA-15a antibodies in PTR.