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The number of ABO-incompatible solid organ transplantations (ABOi SOTs) has markedly increased worldwide since the early 2000s. We investigated the choice of ABO group for blood component transfusion in ABOi SOT. We conducted a survey by e-mailing a questionnaire to blood bank specialists at 77 major hospitals in Korea, among whom 34 responded to the survey. In major ABOi SOT, for red blood cells (RBCs), the recipient's type (70.6%) was the most common choice, followed by group O (29.4%); for platelets, group AB (50.0%) was the most common choice, followed by the donor type (38.2%); for plasma, group AB (55.9%) was the most common choice, followed by the donor type (32.4%). In bidirectional ABOi SOT, for RBCs, the recipient's type (55.9%) was the most common choice, followed by group O (44.1%); for platelets and plasma, group AB was the most common choice (94.1% and 97.1%, respectively). The policies for transfusion in ABOi SOT were diverse. We suggest a guideline on the choice of ABO group for transfusion in ABOi SOT to secure patient health and enable an efficient use of blood components.

Background: Criteria for selection of FFP blood type has not been clearly established and use of group AB plasma is preferred by numerous transplantation protocols., Aims: This study assesses the safety and efficacy of alternative group A or B plasma in ABO incompatible solid organ transplantation., Materials & Methods: Alternative use of group A or B plasma (incompatible plasma) was inevitable during the shortage of group AB plasma. Experience from select number of patients during the period of extreme group AB plasma shortage is described., Results: The result of alternative use of group A or B plasma was within expectation, showing effective reduction of isoagglutinin titers for pre-operative desensitization and efficacy for treatment of post-operative patients. No immediate hemolytic transfusion reaction was reported., Discussion: While validation in a larger cohort of patients is necessary, our limited experience have shown satisfactory clinical outcomes without adverse events., Conclusions: Use of incompatible group A or B plasma is a viable option when group AB plasma is limited., (© 2021 Wiley Periodicals LLC.)

Haptoglobin, the product of the Hp gene, is a glycoprotein involved in the scavenging of free hemoglobin. Haptoglobin levels increase or decrease in response to various acquired conditions, and they are also influenced by genetic predisposition. There were 2 major alleles, Hp (1) and Hp (2), and 1 minor allele, Hp (del) . Many researchers have attempted to study the haptoglobin types and their association with disease; however, no definitive conclusions have been reached yet. It is reported that patients who are genetically deficient in haptoglobin are at risk of anaphylaxis against blood components containing haptoglobin. Haptoglobin genotypes also affect the reference intervals of haptoglobin levels. Many studies have attempted to establish simple and accurate typing methods. In this paper, we have broadly reviewed several methods for haptoglobin typing-phenotyping, Southern blotting, conventional PCR, real-time PCR, and loop-mediated isothermal amplification. We discuss their characteristics, clinical applications, and limitations. The phenotyping methods are time consuming and labor intensive and not designed to detect patients harboring Hp (del) . The rapid and robust haptoglobin genotyping may help in preventing fatal anaphylactic reactions and in establishing the relationships between the haptoglobin phenotypes and diseases.

Objective We compared the clinical outcomes of recipients of ABO-incompatible (ABOi) kidney transplantation (KT) according to the blood group of the plasma transfused. Materials and Methods We retrospectively analyzed the data of 60 recipients of ABOi-KT with blood type O and A or B donors. Demographic and clinical characteristics were compared between 2 groups of recipients: 1 group received AB plasma regardless of the donor's blood type (n = 30), and the other group received donor-type plasma (n = 30). Results There were no significant differences between the groups in terms of demographic characteristics. Transfusion of donor-type plasma was noninferior to transfusion of type AB plasma in terms of both rejection-free survival and rejection rate (P =.455, P =.335). Conclusion There was no significant prognostic difference between the 2 groups. In terms of blood supply and inventory management, we suggest that the blood group of the plasma should match the donor's type. [ABSTRACT FROM AUTHOR]

Background and objectives: The ABO antibody (Ab) titration tests are used in monitoring in ABO-incompatible (ABOi) solid organ transplantation (SOT). However, currently developed ABO Ab tests show Ab binding reactions. This study attempted to measure ABO Ab level using complement-dependent cytotoxicity (CDC). Materials and methods: We studied 93 blood group O serum samples from patients who underwent ABOi SOT from January 2019 to May 2021. Patients' sera were incubated with A1 or B cells and added to a human complement solution. Supernatants were collected after centrifugation, and free hemoglobin (Hb) was measured by spectrophotometry. We converted plasma Hb value to hemolysis (%), which were compared with ABO Ab titer. Results: We found a mild correlation between hemolysis and ABO Ab titers. In simple regression analysis, the correlation coefficients were within 0.3660–0.4968 (p < 0.0001) before transplantation. In multiple linear regression analysis, anti-A hemolysis (%) was higher in immunoglobulin M (IgM) (β = 12.9) than in immunoglobulin G (IgG) (β = −3.4) (R2 = 0.5216). Anti-B hemolysis was higher in IgM (β = 8.7) than in IgG (β = 0.0) (R2 = 0.5114). There was a large variation in hemolysis within the same Ab titer. Conclusions: CDC can be used in a new trial for ABO Ab measurement. Furthermore, IgM rather than IgG seems to play a significant role in vivo activity, consistent with previous knowledge. Thus, this study may help in the development of the ABO Ab titration supplement test for post-transplant treatment policy establishment and pre-transplant desensitization. [ABSTRACT FROM AUTHOR]

Background: Recent advances in desensitization techniques and immunosuppressive therapy have led to improved outcomes after ABO-incompatible (ABO-i) kidney transplantation (KT). However, questions remain unanswered, particularly regarding which type of ABO isoagglutinin-immunoglobulin M (IgM) or immunoglobulin M (IgG)-is significantly involved in antibody-mediated rejection (AMR).Study Design and Methods: We retrospectively analyzed data from 120 patients who underwent ABO-i KT between 2012 and 2014. Preoperative plasma exchange was performed until the IgM isoagglutinin titer was 4 or less, regardless of the IgG titer. Clinical data were compared between patient groups with pre-KT IgG isoagglutinin titer 16 or greater (high IgG; titer range, 16-256; n = 39) and 8 or less (low IgG; titer range, -8; n = 81).Results: The median follow-up periods were 59 (high IgG) and 55 (low IgG) months. Patient survival at 5 years (p = 0.314) was 100% (high IgG) and 97.4% (low IgG). Graft survival at 5 years (p = 0.480) was 100% (high IgG) and 98.7% (low IgG). AMR by anti-ABO antibody occurred in only one patient in the low-IgG group.Conclusion: Patients with high pre-KT IgG isoagglutinin titers had equally successful outcomes as those with low IgG titers. ABO-i KT can be successfully performed by reducing the pre-KT IgM isoagglutinin titer to 4 or less, as determined by the immediate spin tube method. [ABSTRACT FROM AUTHOR]

Objectives: We reanalyzed the data from proficiency testing (PT) to assess the effect of the geometric mean in the statistical analysis of immunohematologic data.Methods: Using the five most recent anti-blood group antibody titer participant summary results, the geometric mean (GM) ±2 × geometric standard deviation (GSD) was used as the comparative consensus criterion to mode ±2 titers.Results: Using the PT evaluation criterion of mode ±2 titers, the mean percentages of participants with acceptable results were 97.5% and 97.8% for anti-A and anti-D, respectively. When applying GM ±2 GSD, the mean percentages of acceptable results were 96.1% (anti-A) and 96.1% (anti-D). The percentages of responses included in each consensus criterion were lower using GM ±2 GSD, with a few exceptions.Conclusions: Geometric means are more robust and precise in visualizing the central tendency. This method can improve the statistical robustness of PT evaluations. [ABSTRACT FROM AUTHOR]

ABO-incompatible transplantation has expanded the limited donor pool for kidney transplantation. Despite the successful desensitization protocols and immunosuppression, undesirable cases of hyperacute rejection occurs. Flow cytometry was used to measure isoagglutinin titer and its IgG subclasses in assessment of the cause of hyperacute rejection in ABO-incompatible kidney transplantation. The recipient was admitted for kidney transplantation due to end-stage renal disease. Pre-transplantation work-up for ABO-incompatible kidney transplantation included blood group typing, HLA DNA typing and HLA antibody analyses. HLA crossmatch analysis was conducted using donor lymphocytes and anti-HLA antibody assay using Luminex panel reactive antibody test (One Lambda, Inc., Canoga Park, CA). Desensitization protocol was composed of therapeutic plasma exchange sessions and rituximab. Despite negative HLA crossmatch results, a case of hyperacute rejection occurred after living donor kidney transplantation. Rejection resulted in immediate removal of graft, and the patient later received a second kidney transplantation. Retrospective evaluation of isoagglutinin titer and its subclasses using flow cytometry identified the cause of rejection to increased IgG1 subclass. Desensitization protocol for ABO-incompatible kidney transplantation now implements further caution for blood group O recipients. Hyperacute rejection resulting from increased IgG1 isoagglutinin subclass has not been previously confirmed using flow cytometry. Unfortunate outcome of this rejection case provides insight to how we should approach and ensure successful ABO-incompatible kidney transplantation. • We report a case of hyperacute rejection after ABO-i kidney transplantation. • Unexpected high IgG1 isoagglutinin might cause the rejection. • Physicians should take the necessary precautions to ensure successful ABOi KT. [ABSTRACT FROM AUTHOR]

• Exchange transfusion (ET) is effective for neonatal hyperbilirubinemia and leukocytosis. • Adverse events included thrombocytopenia, hypoxemia and hypotension. • Bilirubin levels decreased immediately after ET. • Electrolyte and C-reactive protein levels showed no significant changes after ET. Exchange transfusion (ET) is an established, efficacious, and reliable practice for severe neonatal hyperbilirubinemia, hemolytic disease of the newborn, and neonatal sepsis. This study assessed the indications and clinical outcomes of ET performed in a tertiary hospital in Korea. We studied 64 ET sessions performed on 23 neonates between March 1999 and March 2018. ET was performed based on estimated double volume exchange transfusion using fresh red blood cells and fresh frozen plasma. Patients' clinical information, including demographic data and ET indication, and laboratory data were collected pre- and post-ET. The most common ET indication was hyperbilirubinemia with hemolytic anemia due to non-ABO maternal blood group discrepancies. In three preterm babies, ETs were performed for severe anemia, leukocytosis, and hyperkalemia cases. Before ET, the patients showed slightly high WBC counts, low hemoglobin levels, and low platelet counts. After ET, blood examination revealed normal WBC counts, increased hemoglobin levels, and decreased platelet counts (all P < 0.001). Bilirubin levels decreased immediately after ET (P < 0.001). Electrolyte and C-reactive protein levels showed no significant changes after ETs. Adverse events occurred in 11 (47.8 %) patients; the most common were hypoxemia and hypotension. One infant experienced cardiorespiratory arrest due to hypercalcemia and was successfully resuscitated. No one died within 24 h of ET. However, five infants showed hyperbilirubinemia aggravation. ET is an effective treatment modality for leukocytosis and hyperbilirubinemia with low mortality but involves common adverse events post-ET. This report provides an overview of current ET practices in Korea. [ABSTRACT FROM AUTHOR]

The Jra antigen of the JR blood group system is a highly prevalent red blood cell antigen. Although anti-Jra–associated hemolytic disease of the fetus and newborn (HDFN) is generally considered mild-to-moderate, a rare fatal case was recently reported. We report the third example of HDFN-related anti-Jra with fatal outcomes. The clinical significance of anti-Jra antibody as a cause of HDFN should be reassessed. [ABSTRACT FROM AUTHOR]