Benefits of fresh-frozen plasma as a replacement fluid to neutralize ABO antibodies

Comparative Analysis of AB vs. ABO-specific Plasma for Desensitization in Blood Group O Recipients: An In Vitro Study

Neutralizing capacity measurement (NCM) of soluble ABH substances (SAS) in plasma was assessed to guide the selection of the appropriate ABO group of fresh-frozen plasma (FFP) for plasma exchange (PE) in blood group O recipients with ABO-incompatible transplantations. Neutralizing capacity was assessed by measuring anti-A and/or anti-B titers in samples comprising one unit of O FFP and 10 O EDTA plasma samples and subtracting the binary logarithm of the titer in each group with a saline dilution. Ten EDTA plasma samples with Lewis b (Leb) antigen positivity and 10 sets of pooled FFP from each blood group were used as diluents. In O FFP, the NCM values (mean±SD) were 3.4±0.52 (2.6±0.52) and 2.6±0.52 (1.5±0.3) in B and AB for IgM (total antibody) anti-B (both P<0.001), and in the 10 O EDTA plasma samples, they were 3.9±0.88 (3.1±0.88) and 3.2±0.79 (2.4±0.97) for IgM (P=0.0013) and total anti-B (P=0.025), respectively. In vitro analysis revealed that B FFP is more effective than AB FFP in reducing IgM and total anti-B antibody titers in O recipients, regardless of Leb antigen positivity.

Natural soluble human leukocyte antigen class I in donor serum neutralizes donor-specific HLA alloantibodies in recipient serum

Background

Human leukocyte antigen (HLA) molecules are cell-bound but can be identified in a soluble form. These soluble HLA (sHLA) molecules have an immunomodulatory function. We investigated whether natural sHLA in donor serum can neutralize donor-specific HLA alloantibodies (DSAs) in recipient serum.

Methods

Neutralizing effects of donor serum on DSAs in recipient serum were measured using inhibition assay principle of flow cytometric crossmatch (FCXM), performed using sera from 143 kidney transplant recipients and their donors. The adding of donor serum to recipient serum yielded lower mean fluorescence intensity (MFI) ratios (test/control) than when diluent was added [Roswell Park Memorial Institute (RPMI) or third-party serum], which was presumed to be caused by the neutralizing effects of sHLA.

Results

In the recipient group with class I DSAs alone (N=14), donor serum addition to recipient serum resulted in lower T cell MFI ratios [2.25 (1.31‒32.51)] than those observed on RPMI addition [3.04 (1.33‒125.39), P<0.05]. In the recipient group with class II DSAs alone (N=27), donor serum addition showed no significant difference in B cell MFI ratios [5.03 (1.41‒103.53)] compared to diluent addition: RPMI [4.50 (1.34‒145.98)] or third-party serum [5.08 (1.44‒138.47)], P>0.05 for both.

Conclusion

Using inhibition FCXM, we verified that natural sHLA class I in donor serum neutralizes DSAs in recipient serum. However, no neutralizing effects of sHLA class II were revealed in this study. These potentially beneficial effects of sHLA infused via blood-derived products should be considered when desensitizing highly HLA-sensitized patients.

Blood Supply and Demand in Korea: What is in Store for the Future?

PURPOSE

Presently, Korea is facing new challenges associated with an imbalance in blood supply and demand. The purpose of this study was to examine trends in blood supply and demand in Korea over the past 10 years through 2018 and to propose what to prepare in the future.

MATERIALS AND METHODS

Age demographics in Korea were analyzed using data from the Statistics Korea. Blood donation and blood supply data were analyzed using Blood Services Statistics 2018 by the Korean Red Cross. Blood transfusion data from hospitals in 2018 were obtained from the Health Insurance Review and Assessment Service.

RESULTS

In 2018, 2883270 whole blood and apheresis units were collected in Korea. The Korean Red Cross supplied 4277762 blood components to 2491 hospitals. The overall blood donation rate was 5.6%, and the most frequent donors were young male donors. Leukoreduced red blood cells (RBCs) constituted 25% of all RBCs used, and 40% of all platelets were supplied by single-donor platelets. The self-sufficiency rate of domestic plasma with which to produce plasma-derived medicinal products was 68.7% in 2018. Blood use was the most frequent among patients aged 70-79 years.

CONCLUSION

Blood management in Korea is changing rapidly due to a low birth rate, rapid aging, and an increase in severely ill patients who require most of the blood supply. Therefore, future plans to promote donation at a national level and optimal use of blood in hospitals is necessary.