Blood group AB is associated with severe forms of dengue virus infection

The Investigation of the Distribution of ABO/Rh Blood Group in Hospitalized COVID-19 Patients and Its Association With Disease Severity, Clinical Outcomes, Lab Tests, and Radiologic Findings

Background and Aims

it is important to identify patients at higher risk for severity and poor outcomes of COVID-19 infection, to have better disease management and pandemic control. In this study, we aimed to assess the distribution of ABO and Rh blood groups in hospitalized COVID-19 infected patients and demonstrate its association with severity and outcomes of the disease.

Methods

This is a cross-sectional study at Ziaeian Specialist Hospital, in Tehran, Iran. Of all confirmed COVID-19 infected patients who were admitted to this hospital, 273 patients were enrolled in this study and categorized based on their disease severity or clinical outcomes including intensive care unit (ICU) admission, need for mechanical ventilation and mortality. The distribution of ABO and Rh blood groups was assessed and compared between different groups, to investigate the association of blood group types with disease severity or outcomes. Also, the study population was categorized based on their blood group types to demonstrate the association of laboratory parameters, radiologic findings, and length of hospitalization with blood groups. Sex, age and underlying disease were adjusted in the final model by multivariate regression analysis.

Results

This study showed that Blood group A (35.9%) was the most prevalent among hospitalized COVID-19 patients followed by O (34.8%), B (21.6%), and AB (7.7%) (A > O > B > AB). ABO and Rh blood group was not associated with disease severity, need for mechanical ventilation, or ICU admission, while blood group B was associated with an increased risk of death in comparison with type O, in hospitalized COVID-19 patients (p = 0.02). The number of patients with severe levels of C-reactive protein (CRP) test results was lower in O blood group patients in comparison with non-O blood groups (p = 0.01).

Conclusion

No significant association was found between blood groups and other lab tests, radiologic findings, and length of hospitalization.

Investigating the Association Between ABO Blood Groups and Rhesus Factors with Dengue and Chikungunya Virus Infections During the 2017 Outbreak in Bangladesh

This retrospective study was conducted in 2017 during the dual dengue and chikungunya outbreak in Bangladesh. Febrile participants underwent blood tests for chikungunya, dengue, and ABO groups and rhesus (Rh) factors. Blood grouping information was gathered from healthy donors. Males and those aged between 18 and 49 years had a higher risk of contracting dengue and chikungunya. Blood group O exhibited the highest infection rates at ∼50%, whereas group AB had the lowest at ∼9% among the participants in the study. Yet, when considering the general population's blood group distribution, the combined odds of infection were 2.0, 3.5, and 1.4 times higher in groups B, O, and AB, respectively, than in group A. Infection rates were greater in Rh-negative people. Blood groups B, O, and AB showed higher susceptibility than blood group A according to adjusted odds ratios. Blood groups ABO and Rh factor hold significance in disease susceptibility and vaccine effectiveness. Keeping these implications in mind, further investigations are necessary to understand the mechanisms underlying these connections and their effects on the efficacy of dengue and chikungunya vaccines.

Host genetic regulation of human gut microbial structural variation

Although the impact of host genetics on gut microbial diversity and the abundance of specific taxa is well established1-6, little is known about how host genetics regulates the genetic diversity of gut microorganisms. Here we conducted a meta-analysis of associations between human genetic variation and gut microbial structural variation in 9,015 individuals from four Dutch cohorts. Strikingly, the presence rate of a structural variation segment in Faecalibacterium prausnitzii that harbours an N-acetylgalactosamine (GalNAc) utilization gene cluster is higher in individuals who secrete the type A oligosaccharide antigen terminating in GalNAc, a feature that is jointly determined by human ABO and FUT2 genotypes, and we could replicate this association in a Tanzanian cohort. In vitro experiments demonstrated that GalNAc can be used as the sole carbohydrate source for F. prausnitzii strains that carry the GalNAc-metabolizing pathway. Further in silico and in vitro studies demonstrated that other ABO-associated species can also utilize GalNAc, particularly Collinsella aerofaciens. The GalNAc utilization genes are also associated with the host's cardiometabolic health, particularly in individuals with mucosal A-antigen. Together, the findings of our study demonstrate that genetic associations across the human genome and bacterial metagenome can provide functional insights into the reciprocal host-microbiome relationship.

Tick-borne encephalitis: Acute clinical manifestations and severity in 581 cases from Germany, 2018-2020

OBJECTIVES

Tick-borne encephalitis (TBE) is a growing public health problem with an average of 361 cases notified annually to Germany's passive surveillance system since 2001. We aimed to assess clinical manifestations and identify covariates associated with severity.

METHODS

We included cases notified 2018-2020 in a prospective cohort study and collected data with telephone interviews, questionnaires to general practitioners, and hospital discharge summaries. Covariates' causal associations with severity were evaluated with multivariable logistic regression, adjusted for variables identified via directed acyclic graphs.

RESULTS

Of 1220 eligible cases, 581 (48%) participated. Of these, 97.1% were not (fully) vaccinated. TBE was severe in 20.3% of cases (children: 9.1%, ≥70-year-olds: 48.6%). Routine surveillance data underreported the proportion of cases with central nervous system involvement (56% vs. 84%). Ninety percent required hospitalization, 13.8% intensive care, and 33.4% rehabilitation. Severity was most notably associated with age (odds ratio (OR): 1.04, 95% confidence interval (CI): 1.02-1.05), hypertension (OR: 2.27, 95%CI: 1.37-3.75), and monophasic disease course (OR: 1.67, 95%CI: 1.08-2.58).

CONCLUSIONS

We observed substantial TBE burden and health service utilization, suggesting that awareness of TBE severity and vaccine preventability should be increased. Knowledge of severity-associated factors may help inform patients' decision to get vaccinated.

ASSOCIATION OF BLOOD TYPE AND MORTALITY OF COVID-19: A HOSPITAL-BASED STUDY IN NATIONAL REFERRAL HOSPITAL, INDONESIA

Background

The ABO blood type is crucial in a number of illnesses, including cancer, cardiovascular disease, and some communicable and non-communicable illnesses. However, there is currently little clear evidence between COVID-19 with ABO blood types. This study was, therefore, aimed to assess the association between ABO blood type and the mortality of patients infected with COVID-19 in a national referral hospital in Indonesia.

Materials and Methods

This study used a retrospective cohort design. The research sample was COVID-19 patients who were in Dr. M. Djamil Hospital Padang. The number of samples in this study was 93 subjects. The Chi-square test was used in the data analysis. The data were analyzed using the SPSS version 21.0 program, and p<0.05 was considered significant.

Results

The results of this study found the percentage of mortality of COVID-19 patients was higher for blood group O (46.2%), followed by AB (41.7%), B (26.3%), and A (13.9%). There was a relationship between blood type and mortality in hospitalized COVID-19 patients (p <0.05), where blood type O had the highest risk (OR = 5.31, 95% CI 1.57-17.98) followed by blood type AB (OR = 4.43, 95% CI 1.01-19.58).

Conclusion

This study confirmed there was a relationship between blood type and mortality in hospitalized COVID-19 patients, where blood type O had the highest risk followed by blood type AB.

Alterations in clinical characteristics of blood donors post COVID-19 recovery

BACKGROUND

Corona Virus Disease-19 (COVID-19), a current worldwide pandemic is a cuase of concern. Risk-adjusted differences in outcomes of the patients are not well characterized. Susceptibility to infection with respect to blood group, blood pressure, pulse rate, hemoglobin, age and BMI were analyzed.

METHODS

Blood donors, of all the ages and gender, who recovered from COVID-19 infection, were selected for the study Samples from Regional laboratory and the Central blood bank of Hafr al Batin, Saudi Arabia were collected. Out of 1508 healthy blood donor 134 had recovered from corona without any preexisting diseases.

RESULTS

Major donors were male (85.1%). 28% donors in age range of 26-35 years. O+(32.8%) were the highest donors. Systolic and diastolic blood pressure and pulse rate elevated significantly of age group 46-55 (p<0.05) and 56-65 (p<0.001). Systolic blood pressure in males (134.13 ± 9.57) was significantly higher (p<0.05) than those of females (129.35 ± 10.61). Donors with Rh+ significantly higher systolic (p<0.05) and pulse rate (p<0.05) as compared to Rh-.

DISCUSSION

O+ donors were highly susceptible. Blood pressure, pulse rate and Hb alter with age. Males exhibit higher variation in systolic blood pressure, with Rh+ factor playing a predominant role. Donors above 45-years of age and a high BMI have significantly elevated blood pressure and pulse. These results are challenging or contradictory from the results of Turkish and Chinese studies where blood group A+ was more predominantly affected by the SARS-CoV-2 with minimum infection rate on females and Rh- donors.

CONCLUSION

Factors like blood group V-2 treatment especially with the age group of 45 years and above.

Uncovering the Burden of Dengue in Africa: Considerations on Magnitude, Misdiagnosis, and Ancestry

Dengue is a re-emerging neglected disease of major public health importance. This review highlights important considerations for dengue disease in Africa, including epidemiology and underestimation of disease burden in African countries, issues with malaria misdiagnosis and co-infections, and potential evidence of genetic protection from severe dengue disease in populations of African descent. The findings indicate that dengue virus prevalence in African countries and populations may be more widespread than reported data suggests, and that the Aedes mosquito vectors appear to be increasing in dissemination and number. Changes in climate, population, and plastic pollution are expected to worsen the dengue situation in Africa. Dengue misdiagnosis is also a problem in Africa, especially due to the typical non-specific clinical presentation of dengue leading to misdiagnosis as malaria. Finally, research suggests that a protective genetic component against severe dengue exists in African descent populations, but further studies should be conducted to strengthen this association in various populations, taking into consideration socioeconomic factors that may contribute to these findings. The main takeaway is that Africa should not be overlooked when it comes to dengue, and more attention and resources should be devoted to this disease in Africa.

Susceptibility of ABO blood group to COVID-19 infections: clinico-hematological, radiological, and complications analysis

In the wake of the COVID-19 pandemic, research indicates that the COVID-19 disease susceptibility varies among individuals depending on their ABO blood groups. Researchers globally commenced investigating potential methods to stratify cases according to prognosis depending on several clinical parameters. Since there is evidence of a link between ABO blood groups and disease susceptibility, it could be argued that there is a link between blood groups and disease manifestation and progression. The current study investigates whether clinical manifestation, laboratory, and imaging findings vary among ABO blood groups of hospitalized confirmed COVID-19 patients.This retrospective cohort study was conducted between March 1, 2020 and March 31, 2021 in King Faisal Specialist Hospital and Research Centre Riyadh and Jeddah, Saudi Arabia. Demographic information, clinical information, laboratory findings, and imaging investigations were extracted from the data warehouse for all confirmed COVID-19 patients.A total of 285 admitted patients were included in the study. Of these, 81 (28.4%) were blood group A, 43 (15.1%) were blood group B, 11 (3.9%) were blood group AB, and 150 (52.6%) were blood group O. This was almost consistent with the distribution of blood groups among the Saudi Arabia community. The majority of the study participants (79.6% [n = 227]) were asymptomatic. The upper respiratory tract infection (P = .014) and shortness of breath showed statistically significant differences between the ABO blood group (P = .009). Moreover, the incidence of the symptoms was highly observed in blood group O followed by A then B except for pharyngeal exudate observed in blood group A. The one-way ANOVA test indicated that among the studied hematological parameters, glucose (P = .004), absolute lymphocyte count (P = .001), and IgA (P = .036) showed statistically significant differences between the means of the ABO blood group. The differences in both X-ray and computed tomography scan findings were statistically nonsignificant among the ABO age group. Only 86 (30.3%) patients were admitted to an intensive care unit, and the majority of them were blood groups O 28.7% (n = 43) and A 37.0% (n = 30). However, the differences in complications' outcomes were statistically nonsignificant among the ABO age group.ABO blood groups among hospitalized COVID-19 patients are not associated with clinical, hematological, radiological, and complications abnormality.

Association of ABO and Rh Blood Group in Susceptibility, Severity, and Mortality of Coronavirus Disease 2019: A Hospital-Based Study From Delhi, India

Background

ABO and Rh blood group systems are associated with many diseases including cancerous, infectious, non-infectious, bacterial and viral diseases. Studies have shown association of blood groups A and O with higher and lower odds for coronavirus disease 2019 positivity, respectively.

Methods

This is a single-center, retrospective study conducted at Sir Ganga Ram Hospital, Delhi. We investigated the association of ABO and Rh blood groups with susceptibility to coronavirus disease 2019 infection, severity of disease, recovery period, and mortality of patients. Patients were enrolled from April 8, 2020 to October 4, 2020. A total of 2,586 real-time PCR (RT-PCR)-confirmed coronavirus disease 2019 (COVID-19) patients were recruited. Data was analyzed using chi-square test, odds ratio, and Mann–Whitney test to determine the association of blood groups.

Results

In the 2,586 COVID-19-infected patients, the frequencies of A, B, O, and AB were 29.93%, 41.80%, 21.19%, and 7.98%, respectively. Of the patients, 98.07% were Rh positive. Blood group A (odds ratio, 1.53; CI, 1.40–1.66; p < 0.001) and B (odds ratio, 1.15; CI, 1.06–1.24; p < 0.001) is observed to be significantly associated with COVID-19 susceptibility, whereas blood group O (odds ratio, 0.65; CI, 0.59–0.71; p < 0.001) and AB (odds ratio, 0.66; CI, 0.59–0.71; p < 0.001) have low risk of COVID-19 infection.

Conclusion

A, B, and Rh+ are found to be more susceptible to COVID-19 infection, whereas blood groups O, AB, and Rh− are at a lower risk of COVID-19 infection. No association was found between blood groups and susceptibility to severity of disease and mortality.

ABO and Rhesus Blood Groups in Acute Puumala Hantavirus Infection

Puumala hantavirus (PUUV) causes hemorrhagic fever with renal syndrome. We aimed to evaluate whether ABO and rhesus blood groups associate with the susceptibility or the severity of PUUV infection. We analyzed blood groups in 289 adult patients treated in Tampere University hospital due to PUUV infection during the years 1982–2017. Patients’ blood group distribution was compared to that of healthy, voluntary blood donors living in the Tampere University Hospital responsibility area (n = 21,833). The severity of PUUV infection, as judged by the severity of acute kidney injury (AKI), thrombocytopenia, inflammation, capillary leakage, and the length of hospital care, was analyzed across the groups. The ABO and rhesus blood group distributions did not differ between the patients and blood donors. Patients with non-O blood groups had lower systolic blood pressure compared to patients with blood group O, but there was no difference in other markers of capillary leakage or in the severity of AKI. Minor deviations in the number of platelets and leukocytes were detected between the O and non-O blood groups. To conclude, patients with blood group O may be less susceptible to hypotension, but otherwise blood groups have no major influences on disease susceptibility or severity during acute PUUV infection.

"Mysterious veil" between the blood group system and pathogens

As a stable genetic marker of human, blood group is expressed in a polymorphic system in the population. Blood group and pathogens mainly produce effects through the interaction between antigens and antibodies. On the one hand, they can promote pathogen colonization, invasion or evasion of host clearance mechanism, and on the other hand, they can make some hosts less susceptible to corresponding pathogens. By exploring the molecular mechanism between the blood group system and pathogenic microorganisms, it can provide a scientific basis for the treatment of human related diseases and the development of vaccines.

Analyses of ABO blood groups with susceptibility and symptomatic variations of COVID-19 infection, a questionnaire-based survey

Coronavirus disease 2019 (COVID-19) is a novel respiratory disease that has led to a global pandemic and created a havoc. The COVID-19 disease severity varies among individuals, depending on fluctuating symptoms. Many infectious diseases such as hepatitis B and dengue hemorrhagic fever have been associated with ABO blood groups. The aim of this study was to explore whether ABO blood groups might serve as a risk or a protective factor for COVID-19 infection. Moreover, the symptomatic variations of COVID-19 infection among the individuals with different blood groups were also analyzed. An online questionnaire-based survey was conducted in which 305 partakers were included, who had successfully recovered from coronavirus infection. The ABO blood groups of 1294 healthy individuals were also taken as a control. The results of the current study demonstrated that antibody A containing blood groups (blood group B, p-value: 0.049 and blood group O, p-value: 0.289) had a protective role against COVID-19 infection. The comparison of symptomatic variations among COVID-19-infected subjects showed that blood group O subjects had lower chances of experiencing severe symptoms relating to respiratory distress, while subjects with AB blood group were more prone to develop symptoms, but the differences in both groups were found to be statistically non-significant. In conclusion, subjects who do not have anti-A antibodies in their serum (i.e., subjects with group A and AB) are more likely to be infected with COVID-19. The current data showed that there was no significant association of signs and symptoms variations of COVID-19 infection among individuals with different blood groups.

ABO Blood Group and Outcomes in Patients with COVID-19 Admitted in the Intensive Care Unit (ICU): A Retrospective Study in a Tertiary-Level Hospital in Bangladesh

PURPOSE

The world is heavily suffering from the COVID-19 pandemic for more than a year, with over 191 million confirmed cases and more than 4.1 million deaths to date. Previous studies have explored several risk factors for coronavirus disease 2019 (COVID-19), but there is still a lack of association with ABO blood type. This study aimed to find out the relationship between the ABO blood group and COVID-19 outcomes in Bangladesh.

SUBJECTS AND METHODS

This retrospective cross-sectional study was conducted in the intensive care unit (ICU) of a tertiary-level COVID-dedicated hospital in Dhaka city, Bangladesh, between April 2020 and November 2020. Records from 771 critically ill patients were extracted who were confirmed for COVID-19 by reverse transcriptase-polymerase chain reaction (RT-PCR) assay, and blood grouping records were available in the health records.

RESULTS

The blood groups were 37.35%, 17.38%, 26.46%, and 18.81% for A, B, AB, and O type, respectively. Clinical symptoms were significantly more common in patients with blood type A (p < 0.05). Patients with blood type A had higher WBC counts and peak serum ferritin levels and both were statistically significant (p < 0.001). Patients with blood type A had a greater need for supplemental oxygen, and they were more likely to die in comparison to the patients with other blood types (p < 0.05). In multivariable analysis, our primary outcome death was significantly associated with blood type A (AOR: 3.49, 95% CI: 1.57-7.73) while adjusting for age, male gender, and non-communicable diseases.

CONCLUSION

Based on this study results, it can be concluded that the COVID-19 patients with blood type A have a higher chance of death and other complications. The authors recommend blood grouping before treating the COVID-19 patients, and healthcare workers should prioritize treating the patients based on that result.

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.

Association of dengue disease severity and blood group: A systematic review and meta-analysis

Dengue disease encompasses various clinical manifestations including dengue fever (DF) and dengue hemorrhagic fever (DHF). In this article, we aimed to systematically review and analyze the association between different blood groups and severity of dengue. We searched nine databases for eligible papers reporting prevalence, distribution, and frequency of blood group type among dengue patients. Network meta-analysis using R software was used to analyze the data. Of a total of 63 reports screened, we included 10 studies with total sample size 1977 patients (1382 DF and 595 DHF). Blood group O was found to have the worst outcome with the highest risk of developing DF (P-score = 0.01) followed by group B (P-score = 0.34), group A (P-score = 0.64), and group AB (P-score = 1), respectively. Blood group O also had the worst outcome with highest risk of developing DHF (P-score = 0.1) followed by group B (P-score = 0.29), group A (P-score = 0.61), and group AB (P-score = 1), respectively. There was a significant increase (P-value <.001) in the overall odds risk of dengue infection among patients with Rhesus-positive blood groups [OR = 540.03; (95% CI = 151.48-1925.18)]. However, there was no significant difference in the odds risk of DF when compared to DHF according to Rhesus status (P-value = .954). This study identified the O blood group as a potential risk factor in predicting clinical severity in dengue patients which may be helpful in evaluating patients for their likely need for critical care.

Association Between ABO Blood Group System and COVID-19 Susceptibility in Wuhan

Background: The ABO blood group system has been associated with multiple infectious diseases, including hepatitis B, dengue haemorrhagic fever and so on. Coronavirus disease 2019 (COVID-19) is a new respiratory infectious disease and the relationship between COVID-19 and ABO blood group system needs to be explored urgently.

Methods: A hospital-based case-control study was conducted at Zhongnan Hospital of Wuhan University from 1 January 2020 to 5 March 2020. A total of 105 COVID-19 cases and 103 controls were included. The blood group frequency was tested with the chi-square statistic, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated between cases and controls. In addition, according to gender, the studied population was divided into two subgroups, and we assessed the association between cases and controls by gender. Finally, considering lymphopenia as a feature of COVID-19, the relationship between the ABO blood group and the lymphocyte count was determined in case samples.

Results: The frequencies of blood types A, B, AB, and O were 42.8, 26.7, 8.57, and 21.9%, respectively, in the case group. Association analysis between the ABO blood group and COVID-19 indicated that there was a statistically significant difference for blood type A (P = 0.04, OR = 1.33, 95% CI = 1.02–1.73) but not for blood types B, AB or O (P = 0.48, OR = 0.90, 95% CI = 0.66–1.23; P = 0.61, OR = 0.88, 95% CI = 0.53–1.46; and P = 0.23, OR = 0.82, 95% CI = 0.58–1.15, respectively). An analysis stratified by gender revealed that the association was highly significant between blood type A in the female subgroup (P = 0.02, OR = 1.56, 95% CI = 1.08–2.27) but not in the male subgroup (P = 0.51, OR = 1.14, 95% CI = 0.78–1.67). The average level of lymphocyte count was the lowest with blood type A in patients, however, compared with other blood types, there was still no significant statistical difference.

Conclusions: Our findings provide epidemiological evidence that females with blood type A are susceptible to COVID-19. However, these research results need to be validated in future studies.

Association of ABO blood groups with dengue fever and its complications in a tertiary care hospital

CONTEXT:

Dengue fever (DF) has been steadily increasing in India with outbreaks in certain areas taking the proportion of epidemics. Along with secondary dengue, several risk factors predispose to dengue hemorrhagic fever and dengue shock syndrome. Very few studies associating the relationship between dengue and its severity with ABO blood group have been documented.

AIMS:

The aim of this study was to determine the association between distribution of ABO Rh blood groups and DF and DF with thrombocytopenia.

SETTINGS AND DESIGN:

This was a retrospective descriptive study conducted at the clinical laboratory of the department of microbiology.

MATERIALS AND METHODS:

Dengue patients whose case record contained information on blood group were screened for details of blood group and confirmed dengue diagnosis. Randomly 384 case records were selected. These were divided into two groups; Group 1 included DF cases (platelet count >20,000) and Group 2 included DF cases with thrombocytopenia (platelet count <20,000). Control group consisted of patients other than dengue, whose blood grouping had been done; randomly 390 were selected and analyzed.

STATISTICAL ANALYSIS USED:

P value was calculated using the Chi-square test. Odds ratio were calculated using the Fisher's exact test.

RESULTS:

DF was higher in 23% of individuals with AB blood group as compared to 8.5% of controls (P = 0.0004), whereas patients with blood group O were significantly less affected with DF (P = 0.0048). Disease severity was not associated with any of the blood groups.

CONCLUSIONS:

Individuals with AB blood group are more prone to DF, whereas individuals with blood group O are less prone.

FUT3 and FUT2 genotyping and glycoconjugate profile Lewisb as a protective factor to Toxoplasma gondii infection

The interaction between the ABO, FUT2 and FUT3 genes results in the synthesis of different glycoconjugates profiles expressed in gastrointestinal tract. Moreover, the protozoan Toxoplasma gondii, which causes toxoplasmosis, utilizes this organ as an infection route. We analyzed the frequencies of the different glycoconjugate profiles which were determined by phenotyping ABO and genotyping the status secretor (FUT2; substitution G428A) and Lewis (FUT3; substitution T202C and C314T) histo-blood systems, assessed by PCR-RFLP and PCR-SSP, respectively. A total of 244 pregnant women (G1: Seropositive; G2: Seronegative) for IgG T. gondii antibodies were enrolled. IgG anti-T. gondii antibodies were determined by ELISA. G1 was composed of 158 (64.8%) sample and G2 by 86 (36.2%). The glycoconjugate profile was accessed in 151 seropositive and 85 seronegative samples by the combination of ABO and Lewis phenotyping as well as FUT2 and FUT3 genotyping. In G1, 36 (22.8%) presented the glycoconjugate profile ALeb, 5 (3.3%) A, 13 (8.6) BLeb, 1 (0.6%) B, 41 (27.1%) Leb, 13(8.6%) H, 38(25.2%) Lea and 4 (2.6%) Lec. G2 was composed of 13 (15.3%) of ALeb, 15 (17.6%) BLeb, 1 (1.2%) B, 42 (49,4%) Leb and 14 (16.5) Lea. H and Lec glycoconjugate profiles were not found in G2. The frequencies of the glycoconjugates profiles Leb (p = 0.001) and H (p = 0.005) were significantly different compared between G1 and G2. The glycoconjugate profile H inferred from the ABO phenotyping and FUT3 and FUT2 genotyping is associated with infection by T. gondii in pregnant women and the Leb profile appears to protect the infection by this parasite.

Different Associations between DC-SIGN Promoter-336G/A (rs4804803) Polymorphism with Severe Dengue in Asians and South-Central Americans: a Meta-Analysis

Objective: This study was conducted to identify the association between rs4804803 polymorphism in DC-SIGN with the susceptibility of severe dengue. Methods: A comprehensive search was conducted to identify all eligible papers in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Google Scholar. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were used to assess the association. Subgroup analyses were performed by ethnicity. Sensitivity analyses were performed through employing different statistical models (fixed versus random effect model). Results: A total of nine papers and 12 studies, with 1520 severe dengue and 1496 clinical dengue infection were included. The overall meta-analysis revealed significant associations between rs4804803 and severe dengue under the recession (GG versus GA/AA: OR = 0.44, 95%CI, 0.23–0.82) and a codominant model (GG versus AA: OR = 0.43, 95%CI, 0.23–0.81), but sensitivity analysis indicated that the significant pooled ORs were not robust. The subgroup analysis suggested that the carrier of G in rs4804803 was a risk factor for severe dengue under dominant (GG/GA versus AA: OR = 1.86,95%CI, 1.01–3.45), superdominant (GA versus GG/AA: OR = 1.81,95%CI, 1.02–3.21) and a codominant (GA versus AA: OR=1.82,95%CI, 1.02–3.26) models in Asians, while it was a protective factor for severe dengue in South-central Americans under recessive (GG versus GA/AA: OR = 0.27,95%CI, 0.10–0.70) and codominant (GG versus AA: OR=0.24,95%CI, 0.09–0.64) models. The results from subgroup analysis were robust. Conclusions: Dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) promoter-336G/A (rs4804803) polymorphism is association with severe dengue, and it acts in different directions for Asians and South-central Americans.