BACKGROUND: Live donor kidney transplantation is considered the optimal choice for renal replacement therapy, providing established benefits, such as superior patient survival and improved quality of life. However, immunological challenges, including ABO blood group incompatibility and, particularly, donor-specific HLA antibodies, may impact long-term outcomes considerably or even prevent safe direct transplantation with the intended donor.
METHODS: In this review, the authors discuss kidney paired donation (KPD) as a viable strategy to overcome immunological barriers to living donation through organ exchanges. We thereby lay special focus on the Czech-Austrian transnational KPD program.
RESULTS: While the benefits of KPD programs are well established for adult recipients, recent data suggest that this may hold true also for pediatric patients. Complex algorithms, considering factors like the intricate patterns of HLA sensitization, play a pivotal role in predicting suitable matches, but for pediatric patients also non-immunological factors including age and weight match may play a role. As pool size proves crucial for program efficacy, several countries in Europe have now initiated transnational collaborations to maximize match rates. Among those, the Czech-Austrian transnational joint program, established in 2015 and now expanded to a cooperation with the Israel transplant program to further increase transplant rates, represents a successful example.
CONCLUSIONS: KPD programs, with their innovative approaches and international partnerships, hold promise for enhancing outcomes and addressing the increasing demand for kidney transplantation.

BACKGROUND: Liver transplantation (LT) is a unique and effective method for treating end-stage liver diseases and acute liver failure, bringing hope to many patients with liver cancer. LT is currently widely used in the treatment of liver diseases. However, there have been no patients with liver cancer who have undergone ABO-incompatible (ABOi) LT after treatment with the programmed cell death protein 1 (PD-1) inhibitor reported in the literature.
METHODS: A patient with liver cancer who received sintilimab injection, an anti-PD1 therapy, before LT was admitted in the transplantation centre. This patient underwent ABOi LT. The perioperative treatment strategy of this patient was reported. A desensitisation protocol was conducted urgently for the patient before operation, and the immunosuppression programme of LT was adjusted. After operation, isoagglutinin titer and liver function indicators were strictly monitored. The patient recovered well after operation, and no sign of rejection reaction was observed.
CONCLUSIONS: We reported a patient with hepatocellular carcinoma (HCC) who received PD-1 inhibitor treatment before operation and successfully underwent ABOi LT. The present case report provides novel insights into the perioperative management of utilizing PD-1 inhibitors prior to ABOi LT in patients diagnosed with hepatocellular carcinoma (HCC).

OBJECTIVE: ABO incompatibility does not hinder bone marrow transplantation (BMT), but it has been associated with worse outcomes and additional adverse events. This study aimed to verify the impact of incompatible red blood cells (iRBCs) in allogeneic BMT and to determine a safe number of iRBCs to be infused.
METHODS: We compared ABO-incompatible (iABO) allogeneic BMT (n = 42) with ABO-compatible allogeneic BMT (n = 44) and evaluated the impact of the number of infused iRBCs on outcomes and adverse events.
RESULTS: The iABO patients demonstrated delayed time to transfusion independence at 30 days and 60 days, increased requirement for red blood cell (RBC) transfusion and greater hemolysis signals and incidence of pure red cell aplasia. Neutrophil/platelet engraftment, length of hospitalization post-transplant, platelet units required, graft-versus-host disease occurrence and overall survival were similar in both groups. Patients in the iABO group received 1.03 × 1010 iRBCs/kg (range, 0.36-3.88). Infusion of iRBCs >1.0 × 1010 /kg was related to graft failure or death before neutrophil engraftment or platelet engraftment or both as well as increased plasma requirement and increased creatinine. Our results also suggest that antibody titers impact the transplantation scenario.
CONCLUSIONS: The iABO transplantation showed some unfavorable outcomes. It is important to monitor the value of iRBCs to be infused, considering the recipient antibody titers. We propose using the number of iRBCs (iRBCs/kg) as a dose parameter with regard to infused iRBCs. Further studies are necessary to clarify the maximum safe number of iRBCs in iABO transplants.

ABO incompatibility is not considered a contraindication for hematopoietic stem cell transplantation (HSCT). Approximately 30% of transplants from related donors and up to 50% of transplants from unrelated donors are ABO incompatible. Immuno-hematologic investigations allow to estimate donor/recipient ABO mismatch and anti-A/B isohemagglutinin (IHA) titration in the pre-HSCT phase. Immediate hemolysis or delayed complications (passenger lymphocyte syndrome and pure red cell aplasia) can occur post HSCT. Some preventive measures take into consideration either decision-making algorithms based on the recipient\'s IHA titration or clinical protocols for the removal/reduction of IHAs through plasma exchange or immunoadsorption procedures. Product manipulation through red blood cell (RBC) and/or plasma depletion can also be taken into account. Currently, the best approach in the management of ABO-incompatible transplant is not defined in expert consensus documents or with solid evidence. In addition, the methods for IHA titration are not standardized. A transfusion strategy must consider both the donor\'s and recipient\'s blood group systems until the RBC engraftment catches on and ABO conversion (forward and reverse typing) is confirmed on two consecutive and independent samples. Therefore, ABO incompatibility in HSCT represents a demanding immuno-hematologic challenge and requires all necessary preventive measures, including the appropriate selection of ABO blood components for transfusion.

BACKGROUND: Evaluating the ABO/RhD blood group and the direct antiglobulin Coombs test (DAT) at birth is recommended good practice, but there is variability in its universal implementation. This study aims to show the comparative results in various variables of clinical impact during the hospital stay of neonates with positive DAT compared with those with negative DAT, based on the systematic detection of the ABO/RhD group and DAT at birth.
METHODS: Newborns between 2017 and 2020 in a high-risk pregnancy care hospital were included. The ABO/RhD and DAT group was determined in umbilical cord samples or the first 24 hours of life. Demographic, maternal, and neonatal variables were recorded. The association between the variables was estimated using the odds ratio (OR).
RESULTS: 8721 pairs were included. The DAT was positive in 239 newborns (2.7%), with the variables associated with positive PDC being maternal age > 40 years (OR: 1.5; 95% CI: 1.0 to 2.3), birth by cesarean section (1.4; 1.1-2.0), mother group O (6.4; 3.8-11.8), prematurity (3.6; 2.6-5.0), birth weight < 2500 g (2.1; 1.6-2.8), newborn group A (15.7; 10.7-23.1) and group B (17.6; 11.4-27.2), hemoglobin at birth < 13.5 g/dl (4.5; 2.8-7.1) and reticulocytosis > 9% (1.9; 1.2 to 3.1).
CONCLUSIONS: The frequency of neonatal positive PDC was 2.7%, with a significant association with maternal/neonatal incompatibility to the ABO and RhD group, with a substantial impact on various neonatal variables. These results support the policy of universal implementation at the birth of the ABO/RhD and DAT determination.
UNASSIGNED: La determinación del grupo sanguíneo ABO/RhD y la prueba directa de Coombs (PDC) al nacimiento son una práctica recomendada, pero existe variabilidad en su implementación universal. Se presentan los resultados de la determinación al nacimiento del grupo ABO/RhD y la PDC en una cohorte institucional.
UNASSIGNED: Se incluyeron los recién nacidos entre 2017 y 2020 en un hospital de atención a embarazos de alto riesgo. Se determinó el grupo ABO/RhD y se realizó la PDC en muestras de cordón umbilical o en las primeras 24 horas de vida. Se registraron las variables demográficas, maternas y neonatales. Se estimó la asociación entre las variables mediante la razón de probabilidad (OR).
RESULTS: Se incluyeron 8721 binomios. La PDC fue positiva en 239 recién nacidos (2.7%), siendo las variables asociadas a la PDC positiva la edad materna > 40 años (OR: 1.5;IC95%: 1.0-2.3), el nacimiento por vía cesárea (1.4; 1.1-2.0), la madre del grupo O (6.4; 3.8-11.8), la prematuridad (3.6; 2.6-5.0); el peso al nacer < 2500 g (2.1; 1.6-2.8); el neonato del grupo A (15.7; 10.7-23.1) o del grupo B (17.6; 11.4-27.2), la hemoglobina al nacer < 13.5 g/dl (4.5; 2.8-7.1) y la reticulocitosis > 9% (1.9; 1.2 a 3.1).
UNASSIGNED: La frecuencia de PDC positiva neonatal es del 2.7%, con asociación significativa la incompatibilidad materna/neonatal al grupo ABO y RhD, con impacto significativo en diversas variables neonatales. Estos resultados apoyan la política de implementación universal al nacimiento de la determinación de ABO/RhD y PDC.

Neonatal hyperbilirubinemia is a common concern in newborns, with ABO blood group incompatibility serving as a significant risk factor for severe jaundice. This case report outlines the successful management of a 2.5 kg female infant born to a primigravida mother with ABO incompatibility-induced hyperbilirubinemia. The neonate, born at 38.4 weeks via lower segment cesarean section, exhibited signs of jaundice at 91 hours of life, prompting screening and subsequent confirmation of serum bilirubin levels 26.4. The decision was made using the American Academy of Pediatrics (AAP) and categorized the child under high risk according to age and bilirubin level to implement a complete exchange transfusion using a novel approach with two infusion pumps. The unique aspect of this case lies in introducing a two-infusion pump technique, one to infuse and one to extract blood by inserting the IV set in opposite directions in the infusion pump to perform the exchange transfusion, aiming to minimize complications associated with traditional methods. Careful handling of umbilical venous and arterial lines, coupled with aseptic precautions, sought to mitigate the risk of sepsis. The procedure, conducted over two hours, demonstrated stability in vital signs and was monitored with a transcutaneous bilirubinometer. Post-transfusion, repeat serum bilirubin tests showed a decrease in bilirubin of 10.1, indicating the success of the novel exchange transfusion method. The infant was discharged after a five-day hospital stay, showcasing this innovative approach\'s potential efficacy and safety. This case contributes to the evolving strategies in neonatal care and emphasizes the importance of tailored interventions in managing hyperbilirubinemia associated with ABO incompatibility.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) has emerged as a curative measure for life-threatening hematological disorders. It can be autologous or allogeneic depending on the disease characteristics. Providing transfusion support to the transplant patients can be challenging, especially in AB-mismatched allogeneic HSCT. In this study, we investigated the impact of ABO incompatibility in patients undergoing allogeneic HSCT.
METHODS: A retrospective review was conducted in 76 patients with hematological diseases who underwent allogeneic HSCT. Transfusion requirements, engraftment profile, incidence of graft versus host disease (GvHD), and mortality for a period of 1 year were analyzed.
RESULTS: ABO incompatibility between donor and the patient did not significantly affect the neutrophil and platelet (PLT) engraftment time (P = 0.389, 0.349, respectively), packed red blood cells transfusion requirement, and duration of initial hospital stay. However, patients of ABO-incompatible HSCT received more PLT transfusions posttransplant which was statistically significant. 29.1% of ABO compatible and 16.7% incompatible HSCT patients developed GVHD. Mortality rates in the two groups were 16.7% and 8.3%, respectively. However, differences in both the parameters were not statistically significant.
CONCLUSIONS: Our study showed that ABO incompatibility does not significantly affect the outcome and should not be a limiting factor for selection of donor. Donor availability and human leukocyte antigen (HLA) matching remain the critical selection criteria.

UNASSIGNED: With the improvement of immunosuppressive regimens, the success rate and availability of ABO-incompatible (ABO-i) kidney transplantation (KT) have gradually increased. However, the management of immunosuppression protocols and complications associated with ABO-i KT is complex. Here, we report a clinical case of ABO-i living donor KT with allograft dysfunction caused by acute blood group antibody-dependent rejection triggered by human parvovirus B19 (B19V).
UNASSIGNED: The ABO blood group of the recipient was O, and that of the donor was B. The recipient had high baseline anti-B antibody titers (IgM, 1:1024; IgG, 1:64). Before transplantation, he completed a desensitization protocol comprising plasma exchange, double-filtration plasmapheresis, and rituximab, which maintained a low blood group antibody level and resulted in successful transplantation. Two weeks after surgery, the recipient developed a B19V infection combined with acute T-cell-mediated rejection. After the anti-rejection regimen, acute rejection (AR) was successfully reversed, but B19V persisted. One week after AR stabilization, the patient experienced acute antibody-mediated rejection that was more severe and refractory, resulting in the loss of the transplanted kidney.
UNASSIGNED: Desensitization combined with immunosuppressants can lead to overimmunosuppression and cause various infections. Infections could break the accommodation state of the patient, thereby inducing AR and resulting in the loss of the transplanted kidney.

BACKGROUND: Intravenous immunoglobulin G (IVIG) is used to treat blood-type incompatibility hemolytic disease of newborns (BTHDN). Although IVIG\'s efficacy for treating BTHDN has been challenged, as an updated systematic review suggests, IVIG could significantly reduce exchange transfusions. We conducted a mail-in questionnaire survey to ascertain actual use of IVIG for BTHDN in Japan.
METHODS: The survey, conducted in 2014, included infants born between January 1, 2009, and December 31, 2013. Questionnaires were sent to the heads of neonatal intensive care units (NICUs) at perinatal centers of the Japan Neonatologist Association.
RESULTS: A total of 195 centers (64.6%) responded to the questionnaire. During the study period, 170 centers (87.2%) reported incidences of BTHDN. Among these centers, there were 1726 diagnosed cases of BTHDN in neonates. Of these cases, 419 infants were treated with IVIG in 127 centers, representing approximately 74.7% of all centers. After the exclusion of cases with missing data and those where consent for data usage was not obtained, a total 916 infants were included in this study. Of these, 219 (23.9%) were treated with IVIG after phototherapy, and 187 (20.4%) of these infants did not require further blood exchange transfusion. The IVIG dosages ranged from 40 to 1200 mg/kg/dose, but the majority were between 500 and 1000 mg/kg/dose, with a median of 800 mg/kg/dose. About 20% of the infants treated with IVIG showed late-onset anemia and required treatment. Adverse events were reported in less than 1% of infants.
CONCLUSIONS: For the treatment of BTHDN, IVIG administration was widely used in NICUs in Japan without severe adverse events.

Blood group B kidney transplant candidates have lower transplantation rates and longer waiting times compared to other blood groups. Kidney transplantation from blood group A2-to-B has offered a solution for these patients. This study aimed to investigate the impact of Basiliximab and Alemtuzumab induction therapies on kidney function and de novo donor-specific antibodies (DSA) in blood type A2-to-B kidney transplant recipients within the first 12 months of post-transplant.
A retrospective analysis was conducted on 110 consecutive A2-to-B kidney transplant recipients between January 2015 and December 2022. Of these, 46 (41.8%) received Basiliximab, while 64 (58.2%) received Alemtuzumab as induction therapy. Demographics and comorbidities data were collected and compared between the two groups. Serum samples collected at 4- and 12-month intervals post-transplant were used to assess the presence of de novo DSA. Kidney allograft function was evaluated by monitoring serum creatinine levels and assessing Creatinine Clearance based on 24-h urine collection at various time points.
During the follow-up period, 20.00% of patients who received Alemtuzumab developed de novo DSA, whereas none of the patients induced with Basiliximab developed de novo DSA (p = 0.038). Recipients who received Basiliximab were older (mean age = 72.00) and received higher Kidney Donor Profile Index (KDPI) kidneys (mean = 75) compared to those induced with Alemtuzumab (mean age = 58.00, mean KDPI = 49) (p < 0.001), with no significant difference observed in the last follow-up creatinine clearance or creatinine levels between the two groups (p = 0.28).
The use of Basiliximab as induction immunosuppression in A2-to-B kidney transplant recipients is associated with a lower incidence of de novo HLA DSA formation without significant differences in overall renal function compared to Alemtuzumab.