ABO blood group and thrombotic vascular disease

The association between ABO blood types and peripherally inserted central catheter-related venous thrombosis for patients with cancer: A retrospective 7-year single-center experience and meta-analysis

BACKGROUND

This meta-analysis evaluated the association of ABO blood type on central venous catheter-related thrombosis (CRT).

METHODS

Data were derived from 8477 patients at Sichuan Cancer Hospital from January 2015 to December 2021 and articles previously published in Chinese and English databases. Data from our hospital were collected by reviewing electronic medical records. Searched databases included CNKI, VIP, Wan Fang, China Biomedical, PubMed, Cochrane Library, Web of Science, EMBASE, CINAHL, and OVID (up to July 2023). All statistical analyses were performed using SPSS 22.0 and Revman 5.3. The Bonferroni method was used to adjust the α test level for reducing the risk of I errors in the multiple comparisons. A P-value < 0.05 was considered statistically significant. Continuous variables were analyzed using a two-independent sample T test. The chi-squared test was used to analyze categorical data.

RESULTS

A total of 818 studies were identified in the search. However, only four studies met the inclusion criteria. Combined with data from our hospital, five studies were included with a total of 18407 cases. Those studies only focused on peripherally inserted central catheter (PICC). According to the data from our hospital, logistic regression revealed that myelosuppression [odds ratio (OR), 1.473; P = 0.005) and radiotherapy(OR, 1.524; P<0.001) were independent risk factors for symptomatic PICC- VTE. Blood types A (OR, 1.404; P = 0.008), B (OR, 1.393; P = 0.016), and AB (OR, 1.861; P<0.001) were associated with a significantly higher risk of symptomatic PICC-VTE than blood type O. And the hematologic tumor has a significantly higher risk of PICC-VTE than breast cancer (OR, 0.149; P < 0.001), and gynecological tumor (OR, 0.386; P = 0.002). In the meta-analysis of the association between ABO blood type and PICC related thrombosis, the I2 statistic was not significant in any of the pairwise comparisons, and a fixed-effects model was subsequently used for all analyses. The meta-analysis indicated that the incidence of symptomatic PICC related thrombosis was significantly lower in individuals with the O blood type (3.30%) than in those with the A (4.92%), B (5.20%), or AB (6.58%) blood types (all P < 0.0083). However, in the pairwise comparisons among A, B, and AB, the differences were nonsignificant (P > 0.0083).

CONCLUSIONS

According to the results from our single center analysis, we found that myelosuppression, radiotherapy, hematologic tumor, and non-O blood type were independent risk factors for symptomatic PICC related thrombosis. In the meta-analysis of further exploration of ABO blood type and PICC related thrombosis, we found that ABO blood type may influence PICC related thrombosis, and individuals with the O blood type had a lower risk of PICC related thrombosis than those with non-O blood type.

Association of blood group O with a recurrent risk for acute lower gastrointestinal bleeding from a multicenter cohort study

The relationship between blood group and rebleeding in acute lower gastrointestinal bleeding (ALGIB) remains unclear. This study aimed to investigate the association between blood group O and clinical outcomes in patients with ALGIB. The study included 2336 patients with ALGIB whose bleeding source was identified during initial endoscopy (from the CODE BLUE-J Study). The assessed outcomes encompassed rebleeding and other clinical parameters. The rebleeding rates within 30 days in patients with blood group O and those without blood group O were 17.9% and 14.9%, respectively. Similarly, the rates within 1 year were 21.9% for patients with blood group O and 18.2% for those without blood group O. In a multivariate analysis using age, sex, vital signs at presentation, blood test findings, comorbidities, antithrombotic medication, active bleeding, and type of endoscopic treatment as covariates, patients with blood group O exhibited significantly higher risks for rebleeding within 30 days (odds ratio [OR] 1.31; 95% confidence interval [CI] 1.04-1.65; P = 0.024) and 1 year (OR 1.29; 95% CI 1.04-1.61; P = 0.020) compared to those without blood group O. However, the thrombosis and mortality rates did not differ significantly between blood group O and non-O patients. In patients with ALGIB, blood group O has been identified as an independent risk factor for both short- and long-term rebleeding.

ABO blood group-related mechanism of infection of SARS-CoV-2: an overview of systematic reviews

Among the host genetic factors playing a role in the susceptibility to infectious diseases, the ABO blood group system is of utmost importance. Following the first reports in early 2020, the association between ABO blood groups and SARS-CoV-2 infection or COVID-19 severity has been thoroughly investigated. The aim of this narrative review is to provide an overview of systematic reviews regarding the link between ABO blood groups and such risks. The possible molecular mechanisms underlying these associations will also be discussed. ABO blood group has a robust association with susceptibility to infection but not with disease severity, and studies on long COVID anre still missing.Prov.

Association of ABO blood groups with venous thrombosis recurrence in middle-aged patients: insights from a weighted Cox analysis dedicated to ambispective design

BACKGROUND

In studies of time-to-events, it is common to collect information about events that occurred before the inclusion in a prospective cohort. When the studied risk factors are independent of time, including both pre- and post-inclusion events in the analyses, generally referred to as relying on an ambispective design, increases the statistical power but may lead to a selection bias. In the field of venous thromboembolism (VT), ABO blood groups have been the subject of extensive research due to their substantial effect on VT risk. However, few studies have investigated their effect on the risk of VT recurrence. Motivated by the study of the association of genetically determined ABO blood groups with VT recurrence, we propose a methodology to include pre-inclusion events in the analysis of ambispective studies while avoiding the selection bias due to mortality.

METHODS

This work relies on two independent cohorts of VT patients, the French MARTHA study built on an ambispective design and the Dutch MEGA study built on a standard prospective design. For the analysis of the MARTHA study, a weighted Cox model was developed where weights were defined by the inverse of the survival probability at the time of data collection about the events. Thanks to the collection of information on the vital status of patients, we could estimate the survival probabilities using a delayed-entry Cox model on the death risk. Finally, results obtained in both studies were then meta-analysed.

RESULTS

In the combined sample totalling 2,752 patients including 993 recurrences, the A1 blood group has an increased risk (Hazard Ratio (HR) of 1.18, p = 4.2 × 10^-3) compared with the O1 group, homogeneously in MARTHA and in MEGA. The same trend (HR = 1.19, p = 0.06) was observed for the less frequent A2 group.

CONCLUSION

The proposed methodology increases the power of studies relying on an ambispective design which is frequent in epidemiologic studies about recurrent events. This approach allowed to clarify the association of ABO blood groups with the risk of VT recurrence. Besides, this methodology has an immediate field of application in the context of genome wide association studies.

ABO Blood Groups in Systemic Sclerosis: Distribution and Association with This Disease's Characteristics

Systemic sclerosis (SSc) is an autoimmune disease associated with endothelial activation and fibrosis. Non-O blood group patients carry an increased risk of thrombosis, fibrosis and autoimmune diseases. The aim of our work was to evaluate the distribution of ABO groups in SSc patients and their association with the disease's characteristics. ABO groups were determined in 504 SSc patients (with 131 completed by a genotypic analysis). The distribution of ABO groups and their diplotypes in SSc patients was comparable to that of the general population, except for haplotypes O1 and B (65.6% vs. 61.6% and 8.8% vs. 5.8% in SSc patients vs. the general population, respectively, p = 0.01). The frequency of interstitial lung disease, pulmonary hypertension, calcinosis, digital ulcers, digestive diseases and venous thrombosis, and the Medsger score, were higher in non-O than in O-SSc patients, although they did not display statistical significance. Patients in the non-O group had higher levels of inflammation and endothelial activation biomarkers. In conclusion, the ABO blood group distribution of SSc patients did not differ significantly from that of the general population, but non-O blood groups were associated with inflammation and endothelial activation, and with a non-significant higher frequency of pulmonary and vascular complications in SSc.

Blood group B and decreased risk of coronary artery disease in hypertensive elderly

Although ABO blood groups have been associated with cardio-vascular disease, little is known about whether ABO blood groups contribute to the risk of the presence and severity of coronary artery disease (CAD) in elderly individuals with hypertension. This study was aimed to explore this as-sociation. A total of 793 hypertensive patients aged ≥60 years out of 2095 patients who underwent primary coronary angiography were retrospectively included. They were divided into CAD and non-CAD groups. Demographic and clinical characteristics, ABO blood groups and other biochemical parameters were compared. Further evaluation was performed to determine the impact of ABO blood groups on CAD severity using the Gensini score and the number of significantly diseased vessels. A logistic regression model was constructed to identify the association of ABO blood groups with CAD. There was a substantial difference in the distribution of ABO blood groups in elderly and hypertensive adults with and without CAD (p=0.022). Hypertensive patients with CAD had a significantly lower proportion of the blood group B than those without CAD (p=0.008). Compared to those with non-Blood group B, hypertensive elderly with a blood group B tended to have significantly lower concentrations of TC, LDL -C and Apo B, and a lower number of significantly stenosed vessels. The blood group B was found to be an independent protective factor for CAD in elderly with hypertension. The blood group B is significantly associated with a decreased risk of CAD and is inversely correlated with the severity of coronary stenosis in the elderly with hypertension.

Association Between ABO Blood Group and Gestational Diabetes Mellitus in Pregnant Women at King Abdulaziz University Hospital: A Retrospective Study

Objective Gestational diabetes mellitus (GDM) can occur during pregnancy. One of the leading causes of it is a hormone produced by the placenta that interferes with glucose absorption and causes glucose buildup in the bloodstream. Genetic variations between ethnicities are believed to be associated with GDM, and there has been some research on the association of ABO blood group with GDM in different populations. However, the results so far are inconsistent, and there is no conclusive evidence on how ABO blood group affects the occurrence of GDM. This study aims to examine the link between ABO blood group and GDM in pregnant women at King Abdulaziz University Hospital. Methodology A retrospective cohort study was conducted on a group of GDM patients between 2019 and 2022 using data collected from the patients' medical records at King Abdulaziz University Hospital. Results The overall prevalence of GDM was high at 74.7%, and the percentage of patients with A, O, B, and AB blood group who had GDM was 42.9%, 41.41%, 12.1%, and 3.59%, respectively. However, there was no significant difference in Rh status or any other clinical characteristic between the participants who had GDM and those who did not have GDM. Conclusion The present findings indicate that blood group is not associated with the development of GDM in this cohort from Saudi Arabia. However, more studies are required in the future to corroborate these findings.

Predictors of thrombosis in children receiving therapy for acute lymphoblastic leukemia: Results from Dana-Farber Cancer Institute ALL Consortium trial 05-001

BACKGROUND/OBJECTIVES

Although thromboembolism (TE) is a serious complication in patients with acute lymphoblastic leukemia (ALL), thromboprophylaxis is not commonly used due to the inherent bleeding risk in this population. Identifying prothrombotic risk factors will help target thromboprophylaxis to those at highest thrombotic risk. We aimed to define predictors and the impact of TE on ALL outcome in children (1-18 years) treated on the Dana-Farber Cancer Institute ALL 05-001 trial.

METHODS

Clinical and laboratory data including TE events were prospectively collected. PCR-based allelic discrimination assay identified single-nucleotide polymorphisms (SNP) for prothrombin G20210A (rs1799963) and Factor V G1691A (rs6025). Univariate and multivariable competing risk regression models evaluated the effect of diagnostic clinical (age, sex, body mass index, ALL-immunophenotype, risk group) and laboratory variables (presenting leukocyte count, blood group, SNPs) on the cumulative incidence of TE. Cox regression modeling explored the impact of TE on survival.

RESULTS

Of 794 patients [median age 4.97 (range, 1.04-17.96) years; males 441], 100 developed TE; 25-month cumulative incidence 13.0% (95% CI, 10.7%-15.5%). Univariate analyses identified older age (≥10 years), presenting leucocyte count, T-ALL, high-risk ALL, and non-O blood group as risk factors. Age and non-O blood group were independent predictors of TE on multivariable regression; the blood group impact being most evident in patients 1-5 years of age (P = 0.011). TE did not impact survival. Induction TE was independently associated with induction failure (OR 6.45; 95% CI, 1.64-25.47; P = 0.008).

CONCLUSION

We recommend further evaluation of these risk factors and consideration of thromboprophylaxis for patients ≥10 years (especially those ≥15 years) when receiving asparaginase.

Venous thrombosis risk factors in pregnant women

Venous thromboembolism (VTE) is the third most common cause of death on Earth after myocardial infarctions and strokes, according to the World Health Organization (WHO). Pregnancy is a unique condition of woman, when enormous changes occur in functioning of the most important systems of homeostasis in a relatively short time. These are physiological hypercoagulation, slowing of blood flow, increase in circulating blood volume, etc. However, while being physiological, these changes increase the risks of venous thromboembolism by almost 6 times. In some cases, there appears an imbalance or dissociation between the functioning of natural antithrombotic systems and the activation of coagulation as a consequence of genetically or acquired determined causes (genetic thrombophilia, antiphospholipid syndrome, comorbidities, obstetric complications and other exogenous and endogenous factors). Accordingly, identification of risk factors, their systematization, and determination of VTE risks in pregnancy and puerperium is one of the most important tasks of clinical medicine. Various recommendations have appeared for practitioners during the last 10-15 years on the basis of the risk factors analysis in order to prevent VTE in pregnant women more effectively. Nevertheless, none of these recommendations can yet take into account all risk factors, although convenient scoring systems have emerged for risk assessment and clear recommendations on anti-thrombotic prophylaxis regimens in risk groups in recent years. This article will review historical understanding of thrombosis in pregnant women, progress in understanding VTE risk factors in pregnant women, and available reserves in identifying new risk factors during pregnancy and puerperium in order to stratify risks more efficiently.

The Clinical Utility of ABO and RHD Systems as Potential Indicators of Health Status, a Preliminary Study in Greek Population

Objective: The objective of this study is to further highlight the differences between different ABO blood groups and Rhesus types with health biomarkers. Methods: In total 150 active healthy blood donors participated in our study comprising of 80 males from 19–61 years and 70 females aged from 21 to 64. Participants carrying blood group A were 55 individuals, blood group B 32, blood group O 51, and blood group AB 12, RHD+ 132, and RHD- 18. All the volunteer regular blood donors were selected recognizing them as a healthy population excluding drug and supplements intake. Their blood samples were analyzed just before blood donation for biochemical, hematological, and antioxidant markers. Statistical computations were performed using the SPSS tool, specifically, the one-way ANOVA test, Chi-square statistics, and logistic regression were used as statistical models. Results: O blood donors presented better iron absorption and the worst lipid profile. Indeed, a significant trend of high atheromatic index values revealed an increased risk for hyperlipidemia, in contrast with blood group A presenting a better lipid profile with lower atheromatic index values. There was also a gender related association for blood group A compared with O that was further highlighted using binary logistic regression. Conclusion: In this study, a significant difference was observed among the ABO blood groups in several of the examined biochemical and hematological biomarkers. O blood group appeared different behavior in comparison to all the tested blood groups and furthermore the RHD-group presented a better lipid profile in comparison to the RHD+ group. In order to obtain a more comprehensive view of the correlation between the ABO blood group and biochemical markers, further studies are required.

ABO Blood Type Is Associated with Thrombotic Risk in Patients with Nonvalvular Atrial Fibrillation

Blood type is reportedly correlated with the occurrence of cardiovascular diseases, presumably because of its effect on thrombogenicity. However, the relationship between blood type and thrombotic complications in atrial fibrillation (AF) remains unclear. This retrospective study analyzed the blood types of 1170 AF patients (mean age, 70 years; 58% men) who were followed up for up to 4 years. Patients with greater than mild mitral stenosis or prosthetic valves were excluded. The cohort included 305 (26%) type O, 413 (35%) type A, 333 (28%) type B, and 119 (10%) type AB patients. The primary endpoint of major adverse cerebrovascular events (MACE) occurred in 52 (4.4%) patients. When longitudinal outcomes were plotted, AB blood type patients had worse prognosis than non-AB blood type patients (p = 0.039), particularly type O blood patients (p = 0.049). Multivariate Cox regression analysis revealed that AB blood type was associated with higher MACE rates (adjusted hazard ratio, 2.01; 95% confidence interval, 1.01–4.00; p = 0.048) than non-AB blood types independent of anticoagulation therapy duration or CHA2DS2-VASc score. These indicate that AF patients with AB blood type are at an increased risk of MACE compared to those with non-AB blood type independent of the duration of anticoagulation or the CHA₂DS₂-VASc score.

Parent Joint AB Blood Group Is Associated With Clinical Outcomes of in vitro Fertilization and Intracytoplasmic Sperm Injection Treatment in Chinese Women

Background

A number of publications have examined the relation between blood group and female infertility including ovarian reserve, recurrent miscarriage, and live birth. However, there is a lack of literature investigating joint mother/father ABO blood type in a large cohort. This study aimed to investigate the association between couple combinations for ABO blood groups and assisted reproductive technology (ART) outcomes in patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

Methods

This retrospective cohort study included 30,717 couples who underwent IVF cycles between 2010 and 2019. The clinical outcomes of IVF treatment were the primary outcome. History of spontaneous miscarriage, embryo quality, and birth sex, weights, defects rate were also studied.

Results

There was no difference in the baseline demographics between the blood type groups. There was a statistically significant positive association between the combination of female blood type AB and male blood type AB with biochemical pregnancy, clinical pregnancy, and live birth rate (OR 1.36; 95% CI, 1.05–1.78; P = 0.02 and OR 1.31; 95% CI, 1.0–1.68; P = 0.031 and OR 1.28; 95% CI, 1.01–1.63; P = 0.041 respectively). No statistically significant difference was observed between joint mother/father ABO blood types and high-quality embryo rate, early abortion rate, birth sex, birth weights, and birth defect rate.

Conclusions

Our findings suggest that the success rate of IVF/ICSI cycles in parent mating AB blood type is higher than that in other blood type combination groups.

Validation of a predictive model for identifying an increased risk for recurrence in adolescents and young adults with a first provoked thromboembolism

BACKGROUND

To develop and validate a predictive model to determinate patients at increased risk to suffer from recurrence following a first provoked deep vein thrombosis (VTE).

METHODS

Predictive variables, i.e. male sex [1 point], inherited thrombophilia (IT) status (none [0 points], single [1 point], combined variants [2 points]), blood group non-0, and age at first VTE onset were included into a risk assessment model, which was derived in 511 patients and then validated in 509 independent subjects.

RESULTS

VTE recurrence risk score (maximum 4 points, range 0-3) was below two for patients scored as low-risk (LRS) and ≥2 for patients at high-risk (HRS). Within a median time of 3 years after withdrawal of anticoagulation (AC) recurrence rate in LRG (derivation) was 11.8% versus 26.0% in HRS (p < 0.001). In the validation cohort within 2.2 years the recurrence rate was 9.8% in LRS versus 30.1% in HRS (p < 0.001). In multivariable analysis adjusted for age at first VTE and blood group the recurrent risk in HRS was significantly increased compared with the LRS (derivation: hazard/95% confidence interval: 3.7/1.75-7.91; validation: 4.7/2.24-9.81; combined 5.2/1.92-13.9). Model specificity (sensitivity) was 79.0% (52.0%) in the derivation cohort compared with 78.0% (43.0%) in the validation group. In conclusion, in the prediction model presented here the risk of VTE recurrence was associated with male gender and combined ITs. Based on the negative predictive value calculated the model may identify patients with a first provoked VTE not being at risk for recurrence.

Assessment of post-partum haemorrhage risk among women with moderate thrombocytopenia

It is unknown whether moderate thrombocytopenia represents a risk factor for post‐partum haemorrhage (PPH). We assessed PPH risk among women with a platelet count of between 100 and 50 × 10⁹/l and stratified the risk for O/non‐O blood group. We included consecutive women undergoing vaginal delivery or caesarean section with moderate thrombocytopenia. Women with >150 × 10⁹/l platelets at delivery were selected as controls and matched for age, type of birth and ethnicity. Odds ratios (ORs) with their 95% confidence intervals (95% CIs) were calculated as risk estimates. A total of 94 thrombocytopenic women and 94 controls were included in the study. The rate of PPH was significantly higher in thrombocytopenic women than in controls (37% vs. 10%, p < 0.001); there was a higher risk of PPH in the thrombocytopenic group when compared to the control group (adjusted OR 4.7, 95% CI 2.1–10.8, p < 0.01) and this association was stronger in blood group O carriers (adjusted OR 11.0, 95% CI 2.4–49.6, p < 0.01). In conclusion, our study shows that a moderate thrombocytopenia is a risk factor for PPH, especially in blood group O carriers.

The Potential Impact of Blood System on Dietary Habits and Smoking

The ‘Blood-Type’ diet advises individuals to eat according to their ABO blood group to improve their health and decrease the risk of chronic diseases. However, the food preferences of individuals with different blood groups have not been examined. The aim of our study was to investigate, in healthy regular blood donors (rBDs), the associations of smoke, alcohol, caffeine, vitamin and fat intake with their different blood groups and if ABO groups could be a potential predictor tool for disease prevention. A total of 329 volunteers were divided into four groups according to their ABO types: Group 1 (A) comprised 141 rBDs; Group 2 (B), 65 rBDs; Group 3 (O), 96 rBDs; and Group 4, 27 rBDs. Additionally, they were divided into two groups according to their rhesus types and their preferences for smoke, too. Dietary intake was assessed using 3-day food recall and the Food Processor computer program for nutrient analysis. Alcohol, caffeine, sugar and Vitamin D consumption were significantly (p < 0.05) higher in the O group. The A group presented statistically significantly (p < 0.05) greater preferences for cholesterol intake and a higher trend for smoking (25%) habits compared with all the other groups, whereas Group B preferred more fatty foods. The blood group AB appeared to be the most controlled food intake group. Regarding the rhesus comparisons, alcohol; caffeine; and Vitamin C, D, E and K consumptions were significantly (p < 0.05) higher in rhesus-positive individuals than their rhesus-negative counterparts. For the non-smoker group, compared with the smokers, a higher consumption of Vitamin D and fibers was found. In conclusion, in the present study, statistically significant correlations of the ABO and rhesus system with some dietary parameters were found, indicating a consequent influence of these preferences on the progression of different diseases.

Six splice site variations, three of them novel, in the ABO gene occurring in nine individuals with ABO subtypes

Background

Nucleotide mutations in the ABO gene may reduce the activity of glycosyltransferase, resulting in lower levels of A or B antigen expression in red blood cells. Six known splice sites have been identified according to the database of red cell immunogenetics and the blood group terminology of the International Society of Blood Transfusion. Here, we describe six distinct splice site variants in individuals with ABO subtypes.

Methods

The ABO phenotype was examined using a conventional serological method. A polymerase chain reaction sequence-based typing method was used to examine the whole coding sequence of the ABO gene. The ABO gene haplotypes were studied using allele-specific primer amplification or cloning technology. In silico analytic tools were used to assess the functional effect of splice site variations.

Results

Six distinct variants in the ABO gene splice sites were identified in nine individuals with ABO subtypes, including c.28 + 1_2delGT, c.28 + 5G > A, c.28 + 5G > C, c.155 + 5G > A, c.204-1G > A and c.374 + 5G > A. c.28 + 1_2delGT was detected in an A_w individual, while c.28 + 5G > A, c.28 + 5G > C, and c.204-1G > A were detected in B_el individuals. c.155 + 5G > A was detected in one B₃ and two AB₃ individuals, whereas c.374 + 5G > A was identified in two A_el individuals. Three novel splice site variants (c.28 + 1_2delGT, c.28 + 5G > A and c.28 + 5G > C) in the ABO gene were discovered, all of which resulted in low antigen expression. In silico analysis revealed that all variants had the potential to alter splice transcripts.

Conclusions

Three novel splice site variations in the ABO gene were identified in Chinese individuals, resulting in decreased A or B antigen expression and the formation of ABO subtypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03141-5.

A comprehensive review of vascular complications in COVID-19

This study aims to review the available literature pertinent to vascular complications in COVID-19. A systematic search was performed using PubMed and Google Scholar to identify all relevant studies based on our study objective. Multiple studies have reported widespread systemic inflammation and procoagulant/hypercoagulable state in COVID-19, including thrombotic microangiopathy, endothelial dysfunction, bleeding disorder, and thrombosis. However, large specialised studies on vascular complications are lacking despite current evidence indicating dysfunctional coagulation pathways. Furthermore, there are no clear and definitive recommendations regarding thromboprophylaxis or full therapeutic anticoagulation in COVID-19. Several studies have reported hypercoagulability and vascular complications as important predictors of patient outcome in COVID-19. Therefore, it is important to understand the pathogenesis, epidemiology, management, and outcomes of patients who develop venous or arterial thrombosis and those with a pre-existing thrombotic disease who contract COVID-19 for risk stratification, thromboprophylaxis, optimal antithrombotic therapy during active infection and long-term anticoagulation following discharge or recovery.

Impact of ABO Blood Group on the Development of Venous Thromboembolism in Children With Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Few studies have evaluated the impact of ABO blood group on the risk of venous thromboembolism (VTE) in pediatric populations. We performed a systematic review to determine whether children (0 to 18 y old) with non-O blood group have an increased risk of developing VTE compared with those with O blood group.

METHODS

We searched Ovid Medline, Embase, PubMed, Cochrane, Web of Science, and CINAHL online databases from inception to December 2018 to find studies involving blood grouping and VTE. Data was collected regarding patients' underlying diseases, sex, age, ABO blood group, and VTE frequency. A meta-analysis using the random effect model was performed, and heterogeneity was assessed with the I2 value.

RESULTS

Among 1280 unique articles identified, 7 studies (3 conference abstracts, 4 peer-reviewed journal articles) involving 609 VTE cases were included in the systematic review. Six studies were eligible for a meta-analysis; all involved patients with cancer. Blood group O was protective against VTE (odds ratio, 0.56; 95% confidence interval, 0.43-0.79). Findings were similar across sensitivity analyses.

CONCLUSIONS

This systematic review has documented that O blood group is protective against new-onset VTE in children with cancer. Larger studies across different ethnic backgrounds and disease categories are needed to confirm these findings.

The Association Between ABO Blood Group and Preeclampsia: A Systematic Review and Meta-Analysis

Objective: This meta-analysis comprehensively evaluated the association between ABO blood group and the risk of preeclampsia (PE).

Design: Systematic review and meta-analysis.

Data sources: PubMed, Web of Science, and ScienceDirect databases from their inception to September 23, 2020.

Methods: Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were obtained through random-effects and fixed-effects models according to heterogeneity. Meta-regression analysis was applied to explore the source of heterogeneity. We conducted a subgroup analysis by the publication year, study design, state, and Newcastle-Ottawa Scale (NOS) score. In addition, we calculated the rate of each ABO blood group in PE by total pooled effects.

Results: A total of 12 articles with 714,153 patients were included in our analysis. Compared with people without PE (control group), the O blood group presented a lower risk of PE (OR 0.95, 95% CI 0.93–0.97). The AB (OR 1.46, 95% CI 1.12–1.91) blood group presented a higher risk. However, the total pooled OR and 95% CI for the A (OR 1.02, 95% CI 0.90–1.16) and B (OR 1.02, 95% CI 0.98–1.05) blood groups were not significant. The funnel plot and linear regression equation showed that there was no publication bias for the O, A, or B blood groups (all P > 0.05). However, the funnel plot and linear regression equation for the AB blood group were obviously asymmetric (P < 0.05), and the publication bias persisted even after the trim-and-fill method was applied (P < 0.05). Multivariable meta-regression analysis did not find a specific source of heterogeneity. The A blood group showed an association with early-onset PE (OR 0.53, 95% CI 0.33–0.83), and the other blood groups showed no significant differences. In PE, the rates of the O, A, B, and AB blood groups decreased gradually (0.39, 0.33, 0.19, 0.07).

Conclusion: These findings suggest that pregnant women with AB blood group are more likely to develop PE, and more attention should be paid to AB blood group whose blood pressure is high but not sufficient to diagnose PE.

Systematic Review Registration: Prospero CRD42021227930.

Blood type association with bleeding outcomes at delivery in a large multi-center study

Postpartum hemorrhage is a leading cause of maternal death globally. Recent studies have associated Type-O group to increased risk of bleeding. We aimed to determine if women with Type-O blood are at higher risk of PPH. This is a retrospective cohort analysis of a multi-center database included women admitted to labor and delivery from January 2015 to June 2018. All deliveries resulting in live birth were included. Association between Type-O and non Type-O were examined using chi-square test and fishers exact test. Prevalence of postpartum hemorrhage, estimated blood loss, drop in hematocrit and red blood cell transfusion were compared. The matched sample included 40,964 Type-O and the same number of no Type-O. The overall prevalence of postpartum hemorrhage was 6.4%, and there was no difference in the prevalence of PPH among Type-O compared to non Type-O (6.38% vs. 6.37% respectively; p = 0.96). There was no difference in hematocrit drop and estimated blood loss between Type-O and non Type-O in all deliveries. However, in cesarean delivery there was a significant difference in blood loss among the two groups. Finally, Type-O had 1.09-fold increased risk for transfusion compared to non Type O (95% CI 0.9-1.34). There is an association between Type-O group and risk of bleeding in women undergoing cesarean delivery. More prospective studies, taking into account coagulation profile, platelet count and tissue factors, are needed to draw a conclusion on whether ABO system can be considered a heritable risk of postpartum hemorrhage.

ABO blood group and COVID-19: an updated systematic literature review and meta-analysis

BACKGROUND

Following the first reports in the literature, the association between the ABO blood group and SARS-CoV-2 infection has been investigated by a number of studies, although with varying results. The main object of this systematic review was to assess the relationship between the ABO blood group and the occurrence and severity of COVID-19.

MATERIALS AND METHODS

A systematic literature search using appropriate MeSH terms was performed through Medline and PubMed. The outcomes considered were the prevalence of the blood group O vs non-O types in SARS-CoV-2 infected and non-infected subjects, and the severity of SARS-CoV-2 infection according to ABO group. The methodological quality of the studies included in the analysis was assessed with the Newcastle-Ottawa Scale, and the overall quality of the available evidence using the GRADE system. Benchmarks used to evaluate the effect size were odd ratios (ORs) for case control studies and risk ratios (RRs) for cohort studies.

RESULTS

Twenty-one studies were included in the analysis. Overall, individuals with group O had a lower infection rate compared to individuals of non-O group (OR: 0.81; 95% CI: 0.75, 0.86). However, the difference in the effect size was significantly lower in cohort studies compared to case control studies. No evidence was found indicating an effect of the O type on the disease severity in the infected patients.

DISCUSSION

We have found low/very low evidence that group O individuals are less susceptible to SARS-CoV-2 infection compared to those in the non-O group. No evidence was found indicating an effect of the O type on disease severity in SARS-CoV-2 infection.

Associations of ABO blood type and galactose-deficient immunoglobulin A1 with adverse outcomes in patients with IgA nephropathy

BACKGROUND

Both ABO blood group antigens and pathogenic immunoglobulin A1 (IgA1) in patients with IgA nephropathy (IgAN) are influenced by modifications of N-acetylgalactosamine and galactose. The purpose of this study was to assess whether ABO blood type is associated with galactose-deficient IgA1 (Gd-IgA1) in the progression of kidney disease in patients with IgAN.

METHODS

We enrolled 1313 IgAN patients with a median of 44 months follow-up and measured the plasma Gd-IgA1 levels. Multivariate Cox regression models were used to estimate the association between all variables and adverse outcomes. Using the propensity score matching method, 718 IgAN patients with blood type either A or B were selected, and their data were used to assess the association of blood type and Gd-IgA1/serum complement 3 (sC3) with outcomes.

RESULTS

We found that the risk of adverse outcomes was significantly higher in patients with blood type A than in those with type B (hazard ratio = 1.82, 95% confidence interval 1.23-2.71; P = 0.003) after multivariate adjustment. The Gd-IgA1 levels showed trends similar to the multivariate-adjusted event-free curves for the blood types. However, this higher risk of adverse outcomes in type A than in type B patients was no longer significant after the addition of Gd-IgA1/sC3 to the model.

CONCLUSIONS

IgAN patients with blood type A had a higher risk of adverse outcomes than those with type B, and this risk was associated with Gd-IgA1/sC3. Thus, the ABO blood type may provide a reference for the prognostic factors for individuals with IgAN.

Prevalence of thrombophilia-associated genetic risk factors in blood donors of a regional hospital in southern Brazil

Introduction

Thromboembolic events occur due to an imbalance in the hemostasis and some factors associated with this condition can be inherited. In order to evaluate the frequency of genotypes considered to be common hereditary risk factors for thrombophilia associated with venous thrombosis (g.1691G > A and g.20210G > A) and hyperhomocysteinemia (g.677C > T and g.1298A > C), samples from voluntary healthy blood donors at the Hospital de Clínicas de Porto Alegre were tested.

Methods

We examined 325 blood samples from blood donors collected from October 2017 to July 2018. Blood was collected on filter paper and the DNA was extracted for single nucleotide polymorphisms (SNPs) analysis using the qualitative real time polymerase chain reaction.

Results

The calculated frequencies of each genetic variant in heterozygosity were 4% for the FV gene (g.1691G > A), 4% for the F2 gene (g.20210G > A) and 42% and 39% for methylenetetrahydrofolate reductase (MTHFR), g.677C > T and g.1298A > C, respectively. Only the genetic variants of MTHFR were found in homozygosity, with frequencies of 14% and 6% (g.677C > T and g.1298A > C), respectively.

Discussion

Altogether, these results describe the frequencies of genetic variants associated with venous thrombosis and hyperhomocysteinemia in the analyzed group and are important to enhance our current knowledge about the genetic profiles of Brazilian blood donors.

Association of ABO blood group with postoperative total bleeding volume in patients undergoing total hip arthroplasty

BACKGROUND AND OBJECTIVES

As individuals with blood types A, B and AB have approximately 25% higher levels of vWF than those with type O, the risk of developing venous thrombotic events has been investigated in a number of clinical studies, but whether individuals with type O blood experience increased bleeding remains to be clarified. The purpose of this study was to evaluate an association of ABO blood group with intraoperative bleeding and postoperative total bleeding in patients undergoing total hip arthroplasty.

MATERIALS AND METHODS

We prospectively recruited 84 women who were undergoing total hip arthroplasty. The differences between blood groups in mean age, body weight, preoperative and postoperative Hct levels, and postoperative/preoperative Hct ratio, intraoperative bleeding volume (IBV), and total bleeding volume (TBV) were evaluated.

RESULTS

Twenty-six patients had type A blood, 17 had type B, 9 had type AB, and 30 had type O. There were no significant differences in mean age, body weight or operating time between the different ABO blood groups. While there was no significant difference in these Hct levels or IBV among the different blood groups, there was a significant difference in TBV between type O and type AB, and between type O and non-type O.

CONCLUSION

Our study in patients undergoing total hip arthroplasty suggests that patients in blood group O tend to have large amounts of bleeding.

Potential mechanisms of action of convalescent plasma in COVID-19

The COVID-19 pandemic will be remembered as one of the worst catastrophic events in human history. Unfortunately, no universally recognized effective therapeutic agents are currently available for the treatment of severe SARS-CoV-2 infection. In this context, the use of convalescent plasma from recovered COVID-19 patients has gained increasing interest thanks to the initially positive clinical reports. A number of mechanisms of action have been proposed for convalescent plasma, including direct neutralization and suppression of viremia, anti-inflammatory and immunomodulation effects and mitigation of the COVID-19-associated hypercoagulable state. These immune and non-immune mechanisms will be critically discussed in this narrative review.

Association of ABO blood groups with ovarian reserve, and outcomes after assisted reproductive technology: systematic review and meta-analyses

BACKGROUND

There has been an interest in the relationship between ABO blood groups and infertility. Many studies have investigated the association of ABO blood groups with diminished ovarian reserve (DOR), ovarian hyperstimulation syndrome (OHSS), and outcomes of assisted reproductive technology (ART), with controversial results.

METHODS

A systematic review and meta-analysis was conducted to evaluating the association of ABO blood groups with DOR, OHSS, and outcomes of ART.

RESULTS

Thirteen studies performed between 2010 and 2018 were included in this meta-analysis. DOR, OHSS, live birth rate (LBR), clinical pregnancy rate (CPR), miscarriage rate (MR) were reported in 9, 2, 4, 3, 2 studies, respectively. The combined results showed similar risk of DOR among individuals with blood group A (RR, 0.98; 95% confidence interval [CI], 0.85, 1.13), B (RR, 0.96; 95% CI, 0.76, 1.20), AB (RR, 1.00; 95% CI, 0.76, 1.30), and non-O (RR, 0.94; 95% CI, 0.79, 1.11) as compared to those with blood group O. Meta-analysis showed that the incidences of OHSS were similar in women with blood group A (RR, 1.05; 95% CI, 0.66, 1.66), B (RR, 1.04; 95% CI, 0.46, 2.35), AB (RR, 0.51; 95% CI, 0.10, 2.56), non-O (RR, 1.02; 95% CI, 0.65, 1.57) with blood group O. As to the clinical outcomes, meta-analysis showed no difference in LBR among individuals with blood group A (RR, 1.27; 95% CI, 0.74, 2.17), B (RR, 1.47; 95% CI, 0.95, 2.29), AB (RR, 1.48; 95% CI, 0.76, 2.90), non-O (RR, 1.28; 95% CI, 0.83, 1.98) when compared to those with blood group O. Similarly, the results also found that there were no difference in CPR and MR between women with blood A (CPR: RR, 1.12), B (CPR: RR, 1.08), AB (CPR: RR, 1.05), non-O (CPR: RR, 1.05; MR: RR, 0.94) and blood group O.

CONCLUSIONS

ABO blood groups may not be associated with DOR, OHSS, LBR, CPR, and MR of ART. Infertility and ART outcomes are influenced by multiple factors. Blood groups should not be taken into account excessively during diagnosis and treatment of infertile women.

Non-O blood group is associated with lower risk of in-hospital mortality in non-surgically managed patients with type A aortic dissection

BACKGROUND

The association between different ABO blood groups and mortality of aortic dissection (AD) remains controversial. This study aimed to examine whether different ABO blood groups affect the prognosis of AD.

METHODS

Demographic and clinical data were collected from 877 patients diagnosed with AD from 2015 to 2019 in the First Affiliated Hospital of Shantou University Medical College. The association between in-hospital mortality of AD patients and ABO blood group was analyzed using Cox proportional hazards regression models.

RESULTS

This retrograde cohort study demonstrated that for 877 patients, male gender, non-O blood group, Stanford type B AD (TBAD), higher presenting systolic and diastolic blood pressure, and being a recipient of aortic arch replacement surgery (surgery) or endovascular stent-graft implantation (stent-graft) were associated with decreased in-hospital mortality of AD. In Cox proportional hazards models, non-O blood group was associated with lower risk of early mortality regardless of adjustment (HR = 0.668, 95% confidence interval [CI] 0.473-0.944 before adjustment, HR = 0.662, 95% CI 0.468-0.935 after adjustment for age and sex, and HR = 0.641, 95% CI 0.453-0.906 after adjustment for AD types, SBP and surgery). Further analyses revealed that for patients diagnosed with type A AD (TAAD), non-O blood group renders a significant 34.3% decrease in the risk of in-hospital mortality compared with blood group O. Specifically, this difference in mortality risk was found among TAAD patients who did not undergo surgery (HR = 0.579, 95% CI 0.377-0.889), rather than those who did. There was no significant difference in early mortality for patients with TBAD, whether or not stent-grafts were implanted.

CONCLUSIONS

Non-O blood type decreases the risk of in-hospital mortality, especially for TAAD, in AD patients without surgical intervention. More attention must be paid to blood type O TAAD patients without surgical interventions, and early surgical intervention may be an effective means to decrease in-hospital mortality of TAAD.

Evaluation of ABO blood group in subjects with CVD risk factors in a population sample from northeastern Iran

BACKGROUND AND AIMS

The ABO blood group system is a genetic polymorphism which can affect the clearance of von Willebrand factor. We aimed to assess the levels of newer biomarkers of cardiovascular disease (CVD) risk; pro-oxidant-antioxidant balance (PAB), high sensitivity C-reactive protein (hs-CRP) and anti-heat-shock protein27 (anti-Hsp27) antibody titers in subjects with various blood groups (A, B, AB and O) and with or without traditional CVD risk factors.

METHODS

The cross-sectional study comprised 6910 subjects. Antigen-antibody agglutination was evaluated by the slide test method for identification of ABO blood groups.

RESULTS

Among three markers, only Serum anti-Hsp27 titers significantly differed between the four blood groups and showed the highest and lowest values in AB and O blood groups (0.26 ± 0.22 and 0.23 ± 0.18 OD, respectively; P < 0.05). Serum anti-Hsp27 was higher in individuals with an AB blood group with metabolic syndrome (MetS), dyslipidemia, hypertension (HTN) and obesity and it was lower in subjects with O blood group; though, two other biomarkers, serum PAB and hs-CRP, were not significantly different between the ABO blood groups. However, they were not different among blood groups in participants with or without diabetes mellitus (DM) (P > 0.05).

CONCLUSION

Individuals with an AB blood group and high levels of anti-Hsp27 antibody titers may be predisposed to CVDs that can be mediated through the traditional CVD risk factors among middle-aged subjects from northeastern Iran. The fact that differences in anti Hsp27 are only found in the subgroup with other risk factors suggest that the difference between ABO blood groups is a consequence rather than a cause.

Identifying Genetic and Biological Determinants of Race-Ethnic Disparities in Stroke in the United States

In the United States, causes of racial differences in stroke and its risk factors remain only partly understood, and there is a long-standing disparity in stroke incidence and mortality impacting Black Americans. Only half of the excess risk of stroke in the United States Black population is explained by traditional risk factors, suggesting potential effects of other factors including genetic and biological characteristics. Here, we nonsystematically reviewed candidate laboratory biomarkers for stroke and their relationships to racial disparities in stroke. Current evidence indicates that IL-6 (interleukin-6), a proinflammatory cytokine, mediates racial disparities in stroke through its association with traditional risk factors. Only one reviewed biomarker, Lp(a) (lipoprotein[a]), is a race-specific risk factor for stroke. Lp(a) is highly genetically determined and levels are substantially higher in Black than White people; clinical and pharmaceutical ramifications for stroke prevention remain uncertain. Other studied stroke risk biomarkers did not explain racial differences in stroke. More research on Lp(a) and other biological and genetic risk factors is needed to understand and mitigate racial disparities in stroke.

Venous thrombosis risk factors in pregnant women

OBJECTIVES

Assess all risk factors of venous thromboembolism (VTE) in pregnancy and puerperium.

METHODS

Different guidelines for VTE prevention have been analyzed.

RESULTS

Various recommendations have appeared for practitioners during the last 10-15 years on the basis of the risk factors analysis in order to prevent VTE in pregnant women more effectively. Nevertheless, none of these recommendations can yet take into account all risk factors, although convenient scoring systems have emerged for risk assessment and clear recommendations on anti-thrombotic prophylaxis regimens in risk groups in recent years.

CONCLUSIONS

VTE is the third most common cause of death on Earth after myocardial infarctions and strokes, according to the World Health Organization. Pregnancy is a unique condition of woman, when enormous changes occur in functioning of the most important systems of homeostasis in a relatively short time. These are physiological hypercoagulation, slowing of blood flow, increase in circulating blood volume, etc. However, while being physiological, these changes increase the risks of venous thromboembolism by almost six times. In some cases, there appears an imbalance or dissociation between the functioning of natural antithrombotic systems and the activation of coagulation as a consequence of genetically or acquired determined causes (genetic thrombophilia, antiphospholipid syndrome, comorbidities, obstetric complications and other exogenous and endogenous factors). Accordingly, identification of risk factors, their systematization, and determination of VTE risks in pregnancy and puerperium is one of the most important tasks of clinical medicine. This article will review historical understanding of thrombosis in pregnant women, progress in understanding VTE risk factors in pregnant women, and available reserves in identifying new risk factors during pregnancy and puerperium in order to stratify risks more efficiently.

Association between polymorphisms in ABO gene and stroke patients with small artery occlusion in southern Chinese Han population

OBJECTIVE

The purpose of this study was to investigate associations between two single nucleotide polymorphisms (SNPs) rs505922 and rs532436 in ABO gene and the risk of small artery occlusion stroke (SAO) in southern Chinese Han population.

METHODS

Our case-control study comprising 121 patients with SAO and 136 controls. All participants were Han population of southern China. IS sub-type was defined on the basis of the TOAST criteria. SAO was strictly diagnosed after a systematic physical examination and neuroimaging via MRI. Genotype analysis was conducted by the snapshot technique.

RESULTS

The distribution of rs532436 genotype between these two groups showed a statistically significant difference (P = 0.048) while that of rs505922 genotype showed no significant difference (P = 0.572). SNP rs532436 was significantly associated with SAO in overdominant model (GA vs. GG + AA) after adjusting for age, hypertension history, diabetes history and cigarette smoking (adjusted OR = 2.03, 95% CI: 1.14-3.62, P = 0.016). However, under all genetic models, the rs505922 polymorphism failed to show association with SAO.

CONCLUSION

The resultsindicate that rs532436 polymorphism in ABO gene may have association with SAO in southern Chinese Han population.

Possible Link Between the ABO Blood Group of Bioprosthesis Recipients and Specific Types of Structural Degeneration

Background Pigs/bovines share common antigens with humans: α-Gal, present in all pigs/bovines close to the human B-antigen; and AH-histo-blood-group antigen, identical to human AH-antigen and present only in some animals. We investigate the possible impact of patients' ABO blood group on bioprosthesis structural valve degeneration (SVD) through calcification/pannus/tears/perforations for patients ≤60 years at implantation. Methods and Results This was a single-center study (Paris, France) that included all degenerative bioprostheses explanted between 1985 and 1998, mostly porcine bioprostheses (Carpentier-Edwards second/third porcine bioprostheses) and some bovine bioprostheses. For the period 1998 to 2014, only porcine bioprostheses with longevity ≥13 years were included (total follow-up ≥29 years). Except for blood groups, important predictive factors for SVD were prospectively collected (age at implantation/longevity/number/site/sex/SVD types) and analyzed using logistic regression. All variables were available for 500 explanted porcine bioprostheses. By multivariate analyses, the A group was associated with an increased risk of: tears (odds ratio[OR], 1.61; P=0.026); pannus (OR, 1.5; P=0.054), pannus with tears (OR, 1.73; P=0.037), and tendency for lower risk of: calcifications (OR, 0.63; P=0.087) or isolated calcification (OR, 0.67; P=0.17). A-antigen was associated with lower risk of perforations (OR 0.56; P=0.087). B-group patients had an increased risk of: perforations (OR, 1.73; P=0.043); having a pannus that was calcified (OR, 3.0, P=0.025). B-antigen was associated with a propensity for calcifications in general (OR, 1.34; P=0.25). Conclusions Patient's ABO blood group is associated with specific SVD types. We hypothesize that carbohydrate antigens, which may or may not be common to patient and animal bioprosthetic tissue, will determine a patient's specific immunoreactivity with respect to xenograft tissue and thus bioprosthesis outcome in terms of SVD.

Postmortem examination of COVID-19 patients reveals diffuse alveolar damage with severe capillary congestion and variegated findings in lungs and other organs suggesting vascular dysfunction

AIMS

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly evolved into a sweeping pandemic. Its major manifestation is in the respiratory tract, and the general extent of organ involvement and the microscopic changes in the lungs remain insufficiently characterised. Autopsies are essential to elucidate COVID-19-associated organ alterations.

METHODS AND RESULTS

This article reports the autopsy findings of 21 COVID-19 patients hospitalised at the University Hospital Basel and at the Cantonal Hospital Baselland, Switzerland. An in-corpore technique was performed to ensure optimal staff safety. The primary cause of death was respiratory failure with exudative diffuse alveolar damage and massive capillary congestion, often accompanied by microthrombi despite anticoagulation. Ten cases showed superimposed bronchopneumonia. Further findings included pulmonary embolism (n = 4), alveolar haemorrhage (n = 3), and vasculitis (n = 1). Pathologies in other organ systems were predominantly attributable to shock; three patients showed signs of generalised and five of pulmonary thrombotic microangiopathy. Six patients were diagnosed with senile cardiac amyloidosis upon autopsy. Most patients suffered from one or more comorbidities (hypertension, obesity, cardiovascular diseases, and diabetes mellitus). Additionally, there was an overall predominance of males and individuals with blood group A (81% and 65%, respectively). All relevant histological slides are linked as open-source scans in supplementary files.

CONCLUSIONS

This study provides an overview of postmortem findings in COVID-19 cases, implying that hypertensive, elderly, obese, male individuals with severe cardiovascular comorbidities as well as those with blood group A may have a lower threshold of tolerance for COVID-19. This provides a pathophysiological explanation for higher mortality rates among these patients.

Hypercoagulopathy and Adipose Tissue Exacerbated Inflammation May Explain Higher Mortality in COVID-19 Patients With Obesity

COVID-19, caused by SARS-CoV-2, is characterized by pneumonia, lymphopenia, exhausted lymphocytes and a cytokine storm. Several reports from around the world have identified obesity and severe obesity as one of the strongest risk factors for COVID-19 hospitalization and mechanical ventilation. Moreover, countries with greater obesity prevalence have a higher morbidity and mortality risk of developing serious outcomes from COVID-19. The understanding of how this increased susceptibility of the people with obesity to develop severe forms of the SARS-CoV-2 infection occurs is crucial for implementing appropriate public health and therapeutic strategies to avoid COVID-19 severe symptoms and complications in people living with obesity. We hypothesize here that increased ACE2 expression in adipose tissue displayed by people with obesity may increase SARS-CoV-2 infection and accessibility to this tissue. Individuals with obesity have increased white adipose tissue, which may act as a reservoir for a more extensive viral spread with increased shedding, immune activation and pro-inflammatory cytokine amplification. Here we discuss how obesity is related to a pro-inflammatory and metabolic dysregulation, increased SARS-CoV-2 host cell entry in adipose tissue and induction of hypercoagulopathy, leading people with obesity to develop severe forms of COVID-19 and also death. Taken together, it may be crucial to better explore the role of visceral adipose tissue in the inflammatory response to SARS-CoV-2 infection and investigate the potential therapeutic effect of using specific target anti-inflammatories (canakinumab or anakinra for IL-1β inhibition; anti-IL-6 antibodies for IL-6 inhibition), anticoagulant or anti-diabetic drugs in COVID-19 treatment of people with obesity. Defining the immunopathological changes in COVID-19 patients with obesity can provide prominent targets for drug discovery and clinical management improvement.

Role of prothrombin 19911 A>G polymorphism, blood group and male gender in patients with venous thromboembolism: Results of a German cohort study

The role of the A>G polymorphism at position 19911 in the prothrombin gene (factor [F] 2 at rs3136516) as a risk factor for venous thromboembolism [VTE] is still unclear. To evaluate the presence of the F2 polymorphism in VTE patients compared to healthy blood donors and to adjust the results for common inherited thrombophilias [IT], age at onset and blood group [BG], and to calculate the risk of VTE recurrence. We investigated 1012 Caucasian patients with a diagnosis of VTE for the presence of the F2 rs3136516 polymorphism and compared these with 902 healthy blood donors. Odds ratios [OR] together with their 95% confidence intervals were calculated adjusted for F5 at rs6025, F2 at rs1799963, blood group, age and gender. In addition, we evaluated the risk of recurrent VTE during patient follow-up calculating hazard ratios [HR] together with their 95% CI. Compared with the AA wildtype, the F2 GG and AG genotypes (rs3136516) were associated with VTE (OR 1.48 and 1.45). The OR in F5 carriers compared to controls was 5.68 and 2.38 in patients with F2 (rs1799963). BG "non-O" was significantly more often diagnosed in patients compared to BG "O" (OR 2.74). VTE recurrence more often occurred in males (HR 2.3) and in carriers with combined thrombophilia (HR 2.11). Noteworthy, the rs3136516 polymorphism alone was not associated significantly with recurrence. In Caucasian patients with VTE the F2 GG/GA genotypes (rs3136516) were moderate risk factors for VTE. Recurrence was associated with male gender and combined thrombophilia.

The Effect of Autophagic Activity on the Function of Apheresis Platelets and on the Efficacy of Clinical Platelet Transfusion

Platelet activation and survival jointly determine the efficacy of clinical platelet transfusion. This study aimed to discuss the effect of autophagic activity on activation and aggregation of apheresis platelets and on the efficacy of clinical platelet transfusion. In this study, we investigated the effects of autophagic activity of apheresis platelets for different blood types and after different storage durations on platelet activation and aggregation functions. By Western blot, immunofluorescence, and RT-qPCR detection, we found that with the prolongation of the storage duration, the expressions of both autophagy-related proteins and genes were upregulated in apheresis platelets and their expressions were insignificantly higher in the apheresis platelets of type A and O blood than in those of type B and type AB blood. After RAPA/IGF-1 pretreatment, there was a significant increase/reduction in autophagic activity. After RAPA and IGF-1 pretreatment, an opposite variation trend was observed with platelet activation and aggregation. Autophagic activity of platelets correlated negatively with the efficacy of clinical platelet transfusion. These research findings provide a theoretical basis for effective clinical platelet transfusion.

Association of ABO blood groups with the severity of coronary artery disease: a cross-sectional study

Objective

To investigate whether ABO blood groups is associated with the severity of coronary artery disease (CAD).

Methods

Between January 2015 and December 2017, 1425 first diagnosed CAD patients confirmed by selective coronary angiography were recruited into this cross-sectional study, and their baseline characteristics, ABO blood groups, Gensini score were collected. Multiple linear regression analysis was performed to test the association between the severity of CAD and ABO blood groups.

Results

The Gensini score was significantly higher in the blood group A than in the non-A groups (41.2 ± 32 vs. 38 ± 27; P = 0.026). After adjusting for age, male, smoking, family history of CAD, hypertension, diabetes mellitus and hypercholesterolemia, multivariate linear regression indicated that blood group A was associated with the severity of CAD (β = 3.298, 95% CI: 0.91–6.505, P = 0.044). In diabetes group, A blood type was also associated with increased Gensini score (P = 0.02) after adjusting for age, male, family history of CAD, hypercholesterolemia, smoking and hypertension.

Conclusion

In this cross-sectional study, the data indicated that blood group A was an independent risk factor of severity of CAD in Chinese population and Chinese patients with type 2 diabetes.

Coronary Heart Disease and ABO Blood Group in Diabetic Women: A Case-Control Study

Numerous investigations conducted in general population have reported that certain ABO blood group may increase the risk of coronary heart disease (CHD). However, this association has not been yet well established and even is less clear in diabetic patients. Considering that women with type 2 diabetes mellitus (T2DM) are at greater risk to develop CHD and have higher cardiovascular mortality, this study aimed to evaluate the association between CHD and ABO blood group in women with T2DM. A case control study of eight hundred eighty-one (881) diabetic women was enrolled in this study. Among them, two hundred thirty eight (238) patients were identified to have CHD (CHD+) and two hundred eighty two (282) of them were identified without CHD but matched with the first group for other CHD risk factors (CHD-). ABO blood type (A, B, AB, O, and Rhesus factor) for both groups were determined. To compare the magnitude of the correlation between various blood groups with CHD development, odd ratios (OR) with 95% confidence intervals (CI) was calculated. Our results demonstrates that the percentage of AB blood group was significantly higher in the diabetic women with concurrent CHD than in those without CHD [30 (12.7%) vs. 13 (4.6%), Odd ratio: 2.9 (95%CI: 1.5-5.7), P = 0.001]. The results of the present study clearly demonstrate that the AB blood group has a higher odd ratio for the development of CHD and can be considered as a risk factor for the development of CHD in females with T2DM. More comprehensive studies are required to confirm these results.

Serum amylase activity altered by the ABO blood group system in Chinese subjects

Objective

The underlying interactions between ABO blood group antigens and pancreatic exocrine tissue have been demonstrated, and serum amylase was synthesized by pancreatic ductal cells. Thus, we investigated the link between ABO blood type and serum amylase activity in Chinese subjects.

Methods

Our study included 343 relatively healthy Chinese individuals, and the data were retrieved from electronic medical record database.

Results

A increased trend was observed for serum amylase activity in ABO blood type distribution, and we found that serum amylase activity was remarkable increased in subjects with O blood type compared to those with non‐O blood type (P = 0.013). Logistic regression analysis indicated that serum amylase was independently associated with individuals with O blood group (adjusted odds ratio 1.574; 95% CI, 1.022‐2.425, P = 0.039).

Conclusions

The present evidence suggests a significant link between serum amylase activity and ABO blood type in the study population, indicating ABO blood type may be associated with the susceptibility of pancreatic disease.

Recipients with blood group A associated with longer survival rates in cardiac valvular bioprostheses

Background

Pigs/bovines share with humans some of the antigens present on cardiac valves. Two such antigens are: the major xenogenic Ag, “Gal” present in all pig/bovine very close to human B-antigen of ABO-blood-group system; the minor Ag, pig histo-blood-group AH-antigen identical to human AH-antigen and present by some animals. We hypothesize that these antigens may modify the immunogenicity of the bioprosthesis and also its longevity. ABO distribution may vary between patients with low (<6 years) and high (≥15 years) bioprostheses longevity.

Methods

Single-centre registry study (Paris, France) including all degenerative porcine bioprostheses (mostly Carpentier-Edwards 2nd/3rd generation heart valves) explanted between 1985 and 1998 and some bovine bioprostheses. For period 1998–2014, all porcine bioprostheses with longevity ≥13 years (follow-up ≥29 years). Important predictive factors for bioprosthesis longevity: number, site of implantation, age were collected. Blood group and other variables were entered into an ordinal logistic regression analysis model predicting valve longevity, categorized as low (<6 years), medium (6–14.9 years), and high (≥15 years).

Findings

Longevity and ABO-blood group were obtained for 483 explanted porcine bioprostheses. Mean longevity was 10.2 ± 3.9 years [0–28] and significantly higher for A-patients than others (P = 0.009). Using multivariate analysis, group A was a strong predictive factor of longevity (OR 2.09; P < 0.001). For the 64 explanted bovine bioprosthesis with low/medium longevity, the association, with A-group was even more significant.

Interpretation

Patients of A-group but not B have a higher longevity of their bioprostheses. Future graft-host phenotyping and matching may give rise to a new generation of long-lasting bioprosthesis for implantation in humans, especially for the younger population.

Fund

None.

The ABO locus is associated with increased platelet aggregation in patients with stable coronary artery disease

BACKGROUND

Genome-wide association studies of patients with coronary artery disease (CAD) suggest that several risk loci increase the risk of CAD and myocardial infarction (MI) equally. In contrast, the ABO locus is stronger associated with MI than with CAD, but the underlying mechanisms are unknown.

PURPOSE

To investigate the association between the ABO risk variant and platelet activation and aggregation. Moreover, to explore the effects of other CAD-associated risk variants.

METHODS

We included 879 stable CAD patients receiving low-dose aspirin. All patients were genotyped for 45 genome-wide significant CAD risk variants, including rs495828 at the ABO locus. A genetic risk score (GRS) was calculated to assess the combined risk of all genetic variants. Serum soluble P-selectin (sP-selectin) and thromboxane B₂ were used as measures of platelet activation, and platelet aggregation was assessed by multiple electrode aggregometry (MEA) using arachidonic acid and collagen as agonists and VerifyNow.

RESULTS

The rs495828 CAD risk allele was associated with higher MEA platelet aggregation; arachidonic acid: 14.9% (6.7-23.7%, p = 0.0002) higher AUC (Area Under aggregation Curve) per risk allele, and collagen: 13.1% (5.8%-20.9%, p = 0.0003). Conversely, sP-selectin levels were 7.5% (3.1%-11.7%, p = 0.001) lower per risk allele. Rs495828 genotypes were not associated with aggregation assessed by VerifyNow (p = 0.30) or S-thromboxane B₂ levels (p = 0.98). None of the remaining variants or the GRS were associated with platelet activation or aggregation.

CONCLUSIONS

The ABO risk allele was associated with increased platelet aggregation as assessed by MEA. This finding may contribute to explain the increased MI risk in ABO risk variant carriers.

Red blood cells: the forgotten player in hemostasis and thrombosis

New evidence has stirred up a long-standing but undeservedly forgotten interest in the role of erythrocytes, or red blood cells (RBCs), in blood clotting and its disorders. This review summarizes the most recent research that describes the involvement of RBCs in hemostasis and thrombosis. There are both quantitative and qualitative changes in RBCs that affect bleeding and thrombosis, as well as interactions of RBCs with cellular and molecular components of the hemostatic system. The changes in RBCs that affect hemostasis and thrombosis include RBC counts or hematocrit (modulating blood rheology through viscosity) and qualitative changes, such as deformability, aggregation, expression of adhesive proteins and phosphatidylserine, release of extracellular microvesicles, and hemolysis. The pathogenic mechanisms implicated in thrombotic and hemorrhagic risk include variable adherence of RBCs to the vessel wall, which depends on the functional state of RBCs and/or endothelium, modulation of platelet reactivity and platelet margination, alterations of fibrin structure and reduced susceptibility to fibrinolysis, modulation of nitric oxide availability, and the levels of von Willebrand factor and factor VIII in blood related to the ABO blood group system. RBCs are involved in platelet-driven contraction of clots and thrombi that results in formation of a tightly packed array of polyhedral erythrocytes, or polyhedrocytes, which comprises a nearly impermeable barrier that is important for hemostasis and wound healing. The revisited notion of the importance of RBCs is largely based on clinical and experimental associations between RBCs and thrombosis or bleeding, implying that RBCs are a prospective therapeutic target in hemostatic and thrombotic disorders.