ABO Blood Group Incompatibility Protects Against SARS-CoV-2 Transmission

ABO blood groups appear to be associated with the risk of SARS-CoV-2 infection, but the underlying mechanisms and their real importance remain unclear. Two hypotheses have been proposed: ABO compatibility-dependence (neutralization by anti-ABO antibodies) and ABO-dependent intrinsic susceptibility (spike protein attachment to histo-blood group glycans). We tested the first hypothesis through an anonymous questionnaire addressed to hospital staff members. We estimated symptomatic secondary attack rates (SAR) for 333 index cases according to spouse ABO blood group compatibility. Incompatibility was associated with a lower SAR (28% vs. 47%; OR 0.43, 95% CI 0.27–0.69), but no ABO dependence was detected in compatible situations. For the second hypothesis, we detected no binding of recombinant SARS-CoV-2 RBD to blood group-containing glycans. Thus, although no intrinsic differences in susceptibility according to ABO blood type were detected, ABO incompatibility strongly decreased the risk of COVID-19 transmission, suggesting that anti-ABO antibodies contribute to virus neutralization.

Case Report: First Case of Cefotaxime-Sulbactam-Induced Acute Intravascular Hemolysis in a Newborn With ABO Blood Type Incompatibility by the Mechanism of Non-Immunologic Protein Adsorption

BackgroundABO blood type incompatibility hemolytic disease of newborn (ABO-HDN) and drug-induced immune hemolytic anemia (DIIHA) due to non-immunologic protein adsorption (NIPA) mainly cause extravascular hemolysis. All the reported severe DIIHA were caused by drug-induced antibodies, and rare report of acute intravascular hemolysis was caused by the NIPA mechanism or ABO-HDN.Case presentationWe report the first case of acute intravascular hemolysis induced by cefotaxime sodium - sulbactam sodium (CTX - SBT) in a case of ABO-HDN which resulted in death at 55 h after birth. The mother’s blood type was O and RhD-positive, and the newborn’s blood type was B and RhD-positive. No irregular red blood cell (RBC) antibodies or drug-dependent antibodies related to CTX or SBT was detected in the mother’s plasma and the plasma or the RBC acid eluent of the newborn. Before the newborn received CTX - SBT treatment, the result of direct antiglobulin test (DAT) was negative while anti-B was positive (2 +) in both plasma and acid eluent. After the newborn received CTX - SBT treatment, the results of DAT for anti-IgG and anti-C3d were both positive, while anti-B was not detected in plasma, but stronger anti-B (3 +) was detected in acid eluent. In vitro experiments confirmed that NIPA of SBT promoted the specific binding of maternal-derived IgG anti-B to B antigen on RBCs of the newborn, thereby inducing acute intravascular hemolysis.ConclusionThe NIPA effect of SBT promoted the specific binding of mother-derived IgG anti-B in newborn’s plasma to the newborn’s RBC B antigens and formed an immune complex, and then activated complement, which led to acute intravascular hemolysis. Drugs such as SBT with NIPA effect should not be used for newborns with HDN.

Demographic and Clinical Factors Associated with Reactivity of Anti-SARS-CoV-2 Antibodies in Serbian Convalescent Plasma Donors

Passive immunotherapy with convalescent COVID-19 plasma (CCP) is used as a therapeutic procedure in many countries, including Serbia. In this study, we analyzed the association between demographic factors, COVID-19 severity and the reactivity of anti-SARS-CoV-2 antibodies (Abs) in Serbian CCP donors. Individuals (n = 468) recovered from confirmed SARS-CoV-2 infection, and who were willing to donate their plasma for passive immunization of COVID-19 patients were enrolled in the study. Plasma samples were tested for the presence of IgG reactive to SARS-CoV-2 spike glycoprotein (S1) and nucleocapsid antigens. Individuals were characterized according to age, gender, comorbidities, COVID-19 severity, ABO blood type and RhD factor. Total of 420 candidates (420/468; 89.74%) reached the levels of anti-SARS-CoV-2 IgG that qualified them for inclusion in CCP donation program. Further statistical analysis showed that male individuals (p = 0.034), older age groups (p < 0.001), existence of hypertension (p = 0.008), and severe COVID-19 (p = 0.000) are linked with higher levels of anti-SARS-CoV-2 Abs. These findings will guide the selection of CCP donors in Serbia. Further studies need to be conducted to assess the neutralization potency and clinical efficiency of CCP collected from Serbian donors with high anti-SARS-CoV-2 IgG reactivity.

AI-based Analysis on Relationship between Genes and Personality

AI can be applied in various ways to the measurement of personality in psychology. Measuring the impact of a single gene on personality can be handled by AI technologies, at least technically, i.e., using supervised learning models of machine learning. The ABO blood type is a relatively easy biological marker to examine; therefore, people in many countries know their type, and its impact on the relationship with personality has been the subject of a large amount of research. In this study, we selected the ABO blood type as the target gene, examined its association with personality, and cross-checked the results with previous works. Two scales were used to measure personality: a) blood type personality traits extracted from previous studies, and b) the TIPI-J, a simplified version of the Big Five personality test. In the former, the AI was able to predict the respondents’ blood types with a higher probability than chance, while in the latter, the accuracy was within the range of chance. These obtained results were also discussed.

Impact of ABO Blood Group Type on Risk of Venous Thromboembolism in Patients with Cancer

Introduction: Venous thromboembolism (VTE) is common in patients with cancer. Non-O blood type is associated with higher levels of factor FVIII activity and von Willebrand factor compared to blood type O, and has been identified as a risk factor for VTE in the general population. However, the impact of ABO blood type on risk of cancer-associated VTE has not been clarified. Methods: To determine the influence of non-O blood type on risk of cancer-associated VTE, we utilized the dataset of the Vienna Cancer and Thrombosis Study (CATS), which is a single center, prospective observational cohort study including patients with newly diagnosed or recurrent cancer. Patients were followed for objectively diagnosed, independently adjudicated VTE for a maximum of 2 years. VTE was quantified in competing risk analysis, accounting for all-cause mortality as competing outcome event. A proportional sub-hazard regression model according to Fine & Gray was used for between-group comparisons. Based on the violation of the proportional sub-hazard assumption, we explored potential time-dependent effects of non-O blood type on VTE risk in a restricted cubic spline analysis, modeling differences in risk estimates over follow-up time. Further, time-restricted subdistribution hazard ratios (SHR) were obtained specifically for the &lt;3 months and ≥3 months follow-up intervals. In a subgroup analysis, differences in VTE risk according to ABO-blood type were analyzed for patients with very high thrombotic risk tumor types (pancreatic, gastric, glioblastoma), compared to the remainder of patients. Results: In total, 1,708 patients were included in our analysis (46% female, median age: 61 years [interquartile range, IQR: 52-68]). The most common tumor types were lung (19%), breast (16%), and brain (14%) cancer, with 32% of solid tumor patients having metastatic disease at study inclusion. Over a median follow-up of 24 months (IQR: 10-24), 151 patients were diagnosed with VTE (cumulative 2-year incidence: 9.2%, 95% confidence interval [CI]: 7.9-10.7) and 649 patients died (2-year mortality: 38%). Overall, blood type O was present in 38% of patients, A in 40%, B in 15%, and AB in 7%. The cumulative incidence of VTE at 3-, 6-, 12-, and 24-months for patients with blood type O was 3.8% (95% CI: 2.5-5.5), 5.7% (95% CI: 4.1-7.7), 7.0% (95% CI: 5.1-9.1), and 7.6% (95% CI: 5.7-9.9), compared to 3.4% (95% CI: 2.4-4.7), 6.5% (95% CI: 5.1-8.1), 8.4% (95% CI:6.8-10.2), and 10.2% (95% CI: 8.4-12.2) in patients with non-O blood type (Gray´s test: p=0.103, Figure 1). Upon visual inspection of cumulative incidence functions, a violation of the proportional sub-hazard assumption was suspected. In restricted cubic spline analysis, estimating hazard ratio (HR) for VTE of patients with non-O compared to O blood type, a time-varying effect of non-O blood type towards an increased VTE risk was observed (Figure 2). Based on that, time-restricted competing risk regression models were performed. During the first 3 months of follow-up, no differences in VTE risk were found (SHR for non-O vs. O blood type: 1.00, 95% CI: 0.60-1.67, p=0.992). Beyond the first 3-month follow-up, patients with non-O blood type had an increased VTE risk compared to patients with blood type O (SHR 1.79, 95%CI: 1.12-2.85, p=0.015). In a subgroup analysis, no association with VTE risk was found in patients with very high thrombotic risk tumor types (SHR 0.94, 95% CI: 0.55-1.61, p=0.824). In contrast, in patients with low/intermediate risk cancer, non-O blood type was associated with increased risk of VTE (SHR 1.73, 95% CI: 1.09-2.73, p=0.019). Conclusion: Non-O blood type was identified as a time dependent risk factor for cancer-associated VTE. In the first 3 months after study inclusion, characterized as the highest VTE risk period in our cancer cohort, no differences in VTE risk between blood types were found. Afterwards, beyond the first 3 months of follow-up, an increased VTE-risk in non-O blood types was observed, comparably in magnitude to the risk difference in the general non-cancer population. Further, an association of non-O blood type with VTE risk in patients with low/intermediate thrombotic risk cancers was observed, whereas no effect was present in those with very high-risk tumors. These findings indicate non-O blood type as a putative risk factor for VTE in patients with cancer in comparably low thrombotic risk scenarios. Figure 1 Figure 1. Disclosures Pabinger: Pfizer: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Alexion: Consultancy, Honoraria; Daiichi Sanchyo: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Bayer: Consultancy, Honoraria; NovoNordisk: Consultancy, Research Funding; CSL Behring: Consultancy, Honoraria, Research Funding.

Difference in Therapeutic Effects between Roxadustat and Daprodustat, HIF-Ph Inhibitors, Depending on the Blood Type in Hemodialysis (HD) Patients

Human blood group antigens are glycoproteins and glycolipids expressed on the surface of red blood cells and a variety of human tissues. This study aimed to determine if there is an association between ABO blood type and the efficacy of HIF-PH inhibitors. Roxadustat and daprodustat are potent inhibitors of HIF-PH and capable of stimulating erythropoiesis in patients on patients with impaired renal function. These two compounds are reported to act mechanistically similar but display differences in their effects on cells, and the differences may affect their efficacy in the treatment of renal anemia in HD patients. In this study we compared the response rate by blood type between roxadustat and daprodustat, respectively. Sixty-eight HD patients treated with roxadustat (20-100mg, 3/week) and ninety-five treated with daprodustat (1-12mg, daily) were recruited in our observational study. We defined &gt;1.5g/dL increase in hemoglobin as effective, and &lt;1.5g/dL decrease as ineffective. As shown in the figure, type A had a significantly high response rate at 47% in HD patients treated with roxadustat. On the other hand, type O had a significantly high response rate at 55% in those who were treated with daprodustat. We found the association in the effectiveness of roxadustat on the treatment for anemia in HD patients in type A, while the effectiveness was higher in type O treated with daprodustat. The results suggest that the therapeutic effect of HIF-PH inhibitors may differ depending on the blood type. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Patient ABO blood type is a major predictor of a positive DAT following a transfusion reaction

Background: A direct antiglobulin test (DAT) checks for antibody or complement on the surface of RBCs and is often done following a transfusion reaction. While passive anti-A and anti-B antibodies are known to cause positive DATs, the extent this occurs following transfusion is unknown. Study Design and methods: DAT results, ABO type and blood product information was recorded on 1097 transfusion reactions at a large academic hospital over 8 years. The effect of patient blood type, product type and plasma compatibility of blood product transfused on DAT results were determined. Statistical significance was determined using Chi-squared testing. Results: Plasma compatibility of the product was a strong predictor of a positive DAT with plasma compatible transfusions having a 9.4% positive rate while plasma incompatible transfusions were positive 44% of the time (P<0.0001). Patient ABO blood type was a strong predictor of a positive DAT with Type O patients having 6.6% positive rate and non-O patients having a positive rate of 20.6% (P <0.0001). These results were significant for individual blood types as well. Type A, B or AB patients had higher DAT positive rates even when plasma incompatible transfusions were excluded from the analysis (P<0.0001). Platelets were significantly more likely to be associated with a positive DAT when compared to RBC transfusions. Conclusions: These results show plasma compatibility and ABO types are strong predictors of positive DAT results following a transfusion reaction. Anti-A and anti-B antibodies are estimated to account for about 50% of positive DATs in this study.

TP9.2.24Is preoperative ABO blood typing required in emergency appendicectomies?

Aims Intra-operative bleeding is very rarely a complication of laparoscopic appendicectomy. Despite this, it is often mandatory for any patient undergoing an emergency appendicectomy to have pre-operative ABO blood type sampling. This could be an unnecessary expense and may lead to patients being delayed for theatre. The aim of this study was to see how many patients who underwent an appendicectomy required a blood transfusion intra-operatively or within 30 days of their operation. Methods Data were collected retrospectively for patients of all ages who underwent an appendicectomy for suspected appendicitis at a single centre from March 2018 to May 2020. The primary outcome measure was intra-operative and post-operative blood transfusion up until 30 days after the operation. Results Over 26 months, 698 appendicectomies were performed. Preoperative ABO blood typing was performed in 95% (n = 663) of patients. Collectively, 1,305 blood samples were obtained at a combined total cost of £13,703 to the hospital. None of the patients required blood transfusion intra- or post-operatively. Pre-operative blood transfusion was performed in only three patients, all due to chronic anaemia. 21 (3%) patients were delayed in going to theatre whilst awaiting two valid ABO blood typing results. Conclusions Emergency appendicectomies very rarely experience complications associated with bleeding or requiring blood transfusion. Clinical guidelines should reflect this by avoiding recommendation of such tests in emergency appendicectomies, reducing delays to surgery and resulting in a more efficient allocation of financial and staff resources.