Consumers Can Now Buy a Blood Test to Evaluate Their Alzheimer Disease Risk, but Should They?

This Medical News feature discusses a Quest Diagnostics blood biomarkers test that is supposed to help consumers assess their Alzheimer disease risk.

Serum lysophospholipidome of dietary origin as a suitable susceptibility/risk biomarker of human hypercholesterolemia: A cross-sectional study.

BACKGROUND & AIMS: Whether bioactive lysophospholipids (lyso-PLs) and trimethylamine-N-oxide (TMAO) serve as non-invasive biomarkers in early human hypercholesterolemia (HC) is unknown. This study aimed to assess whether serum lyso-PLs and plasma TMAO may be suitable susceptibility/risk biomarkers of HC in humans. Secondarily, we aimed to evaluate the relationships between targeted metabolites, diet composition and circulating liver transaminases, and verify these results in hamsters. METHODS: A targeted metabolomics and lipidomics approach determined plasma TMAO and serum lysophosphatidylcholines (lyso-PCs) and lysophosphatidylethanolamines (lyso-PEs) in low (L-LDL-c) and moderate to high (MH-LDL-c) LDL-cholesterol subjects. Additionally, the relationships between targeted metabolites, liver transaminases and diet, particularly fatty acid intake, were tested. In parallel, plasma and liver lyso-PL profiles were studied in 16 hamsters fed a moderate high-fat (HFD) or low-fat (LFD) diet for 30 days. RESULTS: Predictive models identified lyso-PC15:0 and lyso-PE18:2 as the most discriminant lyso-PLs among groups. In MH-LDL-c (n = 48), LDL-cholesterol and saturated FAs were positively associated with lyso-PC15:0, whereas in L-LDL-c (n = 70), LDL-cholesterol and polyunsaturated fatty acids (PUFAs) were negatively and positively related to lyso-PE18:2, respectively. Interestingly, in MH-LDL-c, the lower lyso-PE 18:2 concentrations were indicative of higher LDL-cholesterol levels. Intrahepatic accumulation of lyso-PLs-containing essential n-6 PUFAs, including lyso-PE18:2, were higher in HFD-fed hamsters than LFD-fed hamsters. CONCLUSIONS: Overall, results revealed a possible hepatic adaptive mechanism to counteract diet-induced steatosis in animal and hypercholesterolemia progression in humans. In particular, low serum lyso-PE18:2 suggests a suitable susceptibility/risk biomarker of HC in humans.

Is there an association between ABO blood types and depressive symptoms among Japanese healthcare workers during the COVID-19 pandemic?

ABO blood types could be a biological predisposition for depression. The present cross-sectional analysis was conducted amid the second wave of COVID-19 in Japan during July 2020. We wanted to investigate the association between ABO blood types and depressive symptoms among workers (352 men and 864 women, aged 21-73 years) of a medical institution in Tokyo, Japan, which took a leading role in the response to COVID-19 in the country. A Poisson regression model with a robust variance estimator was used to estimate the prevalence ratio (PR) and 95% confidence interval (CI) for depressive symptoms associated with ABO blood types. Overall, the prevalence of depressive symptoms (using two questions employed from a Two-question case-finding instrument) was 22.0%. The adjusted PRs (95% CI) for depressive symptoms, comparing the carriers of blood type O, A, and AB with those of type B, were 0.88 (0.66, 1.18), 0.81 (0.62, 1.07), and 1.07 (0.74, 1.53), respectively. There was no difference in the prevalence of depressive symptoms between non-B and B carriers. The present study did not support the association of ABO blood types with depressive symptoms.

Gastrin and the Moderate Hypergastrinemias.

The antral hormone gastrin potently regulates gastric acid secretion and fundic mucosal growth. Consequently, appropriate gastrin secretion and plasma concentrations are important for the early phases of digestion. This review describes as the first premise the normal biogenesis of gastrin in the antral mucosa, but also mentions the extraantral expression. Subsequently, the molecular nature and concentration levels of gastrin in serum or plasma are overviewed. Third, assays for accurate measurements of plasma or serum concentrations are commented. Finally, the problem of moderate hypergastrinemia due to Helicobacter pylori infections and/or treatment with proton-pump inhibitors (PPI) is discussed. The review concludes that accurate measurement of the true concentrations of bioactive gastrins in plasma is important. Moreover, it suggests that moderate hypergastrinemias are also essential health issues that require serious attention.

Blood system ABO antigens as risk factor for severity of SARS-CoV-2 infection.

INTRODUCTION: Whether there is an influence of the ABO blood system on SARS-CoV-2 infection is unknown. OBJECTIVE: To analyze if there is an association between the ABO system antigens and susceptibility to and severity of SARS-CoV-2 infection. MATERIAL AND METHODS: The frequency of ABO system antigens was compared in 73 confirmed cases of SARS-CoV-2 infection and 52 clinically healthy donors. Infection severity was assessed by comparing the frequency of antigens by disease severity and mortality. RESULTS: The risk of suffering from SARS-CoV-2 infection increases in subjects with A vs. non-A antigen (OR = 1.45; 95 % CI: 1.061-1.921). Blood phenotype O reduces the risk of SARS-CoV-2 infection (OR = 0.686; 95 % CI: 0.522-0.903). No differences were found regarding disease severity. In critically ill patients, the risk of mortality increased in subjects with A vs. non-A antigen (OR = 3.34; 95 % CI: 1.417-8.159). CONCLUSION: Blood group A is a risk factor for SARS-CoV-2 infection, but not for disease severity, although in critically ill patients it is a risk factor for mortality.

INTRODUCCIÓN: Se desconoce si existe una influencia del sistema sanguíneo ABO en susceptibilidad y gravedad de la enfermedad. OBJETIVO: Analizar si existe una asociación entre los antígenos del sistema ABO y la susceptibilidad y gravedad de la infección por SARS-CoV-2. MATERIAL Y MÉTODOS: Se compararon las frecuencias de los antígenos del sistema ABO en 73 casos confirmados de infección por SARS-CoV-2 y 52 donadores clínicamente sanos. La gravedad de la infección se evaluó comparando la frecuencia de los antígenos por gravedad de la enfermedad y la mortalidad. RESULTADOS: El riesgo de padecer infección por SARS-CoV-2 se incrementa en sujetos con antígeno A vs los no-A (OR=1.45; IC95 %:1.061-1.921). El fenotipo sanguíneo O disminuye el riesgo de padecer infección por SARS-CoV-2 (OR=0.686; IC95 %: 0.522-0.903). No se encontraron diferencias entre la gravedad de la enfermedad. En los pacientes graves, el riesgo de mortalidad se incrementó en sujetos con antígeno A vs los no-A (OR= 3.34; IC95 %: 1.417-8.159). CONCLUSIÓN: El grupo sanguíneo A es un factor de riesgo para padecer infección por SARS-CoV-2, no así en la gravedad de la enfermedad, pero en los pacientes graves fue un factor de riesgo para la mortalidad.

Alcohol-related Liver Disease and sepsis.

OBJECTIVE: Sepsis is one of the most common complications and causes of death in patients with Alcohol-related Liver Disease. This narrative review will focus on several aspects of sepsis in the context of Alcohol-related Liver Disease. The pathophysiology of the increased susceptibility to infections consists mainly of impaired innate and adaptive immunity, changes in gut microbiota with consequent gut translocation of bacteria due to both alcohol abuse and the underlying liver disease. The diagnosis of sepsis in the context of Alcohol-related Liver Disease is challenging. Moreover, the use of classical acute-phase serum proteins (e.g., C-reactive protein and procalcitonin) has several limitations in this setting. The early administration of an adequate antibiotic treatment is pivotal. Finally, measures of infection control and prevention are needed because the prognosis of sepsis in patients affected by Alcohol-related Liver Disease is poor.

Elevated Plasma Free Fatty Acid Susceptible to Early Cognitive Impairment in Type 2 Diabetes Mellitus.

BACKGROUND: Elevated free fatty acid (FFA) induces lipotoxicity, attributed to diabetes and cognitive decline. Sterol regulatory element-binding protein-1c (SREBP-1c) regulates lipid metabolism. OBJECTIVE: We investigated the roles of FFA in mild cognitive impairment (MCI) of type 2 diabetes mellitus (T2DM) patients and determine its association with rs11868035 polymorphism. METHODS: We recruited 191 Chinese T2DM patients into two groups through Montreal Cognitive Assessment. Demographic and clinical data were collected, multiple domain cognitive functions were tested, plasma FFA levels were measured through ELISA, and SREBP-1c rs11868035 genotype was detected using the Seqnome method. RESULTS: In comparison with the healthy-cognition group (n = 128), the MCI group (n = 63) displayed lower glucose control (p = 0.012) and higher plasma FFA level (p = 0.021), which were independent risk factors of MCI in T2DM patients in multivariate regression analysis (OR = 1.270, p = 0.003; OR = 1.005, p = 0.036). Additionally, the plasma FFA levels of MCI patients were positively correlated with Stroop color word test-C time scores (r = 0.303, p = 0.021) and negatively related to apolipoprotein A1 levels (r = -0.311, p = 0.017), which are associated positively with verbal fluency test scores (r = 0.281, p = 0.033). Both scores reflected attention ability and executive function. Moreover, the G allele carriers of rs11868035 showed higher digit span test scores than non-carriers in T2DM patients (p = 0.019) but without correlation with plasma FFA levels. CONCLUSION: In T2DM, elevated plasma level of FFA, when combined with lower apolipoprotein A1 level portends abnormal cholesterol transport, were susceptible to early cognitive impairment, especially for attention and execution deficits. The G allele of SREBP-1c rs11868035 may be a protective factor for memory.

Potential benefit of vitamin D supplementation in people with respiratory illnesses, during the COVID-19 pandemic.

This review describes the evidence for the potential benefit of vitamin D supplementation in people with respiratory diseases who may have a higher susceptibility to coronavirus disease 2019 (COVID-19) infection and its consequences. Clinical evidence indicates that vitamin D may reduce the risk of both upper and lower respiratory tract infections and offers benefit particularly in people with vitamin D deficiency. Some evidence exists for a higher incidence of active tuberculosis (TB) in patients who are deficient in vitamin D. An association between low levels of 25(OH)D (the active form of vitamin D) and COVID-19 severity of illness and mortality has also been reported. In addition, low 25(OH)D levels are associated with poor outcomes in acute respiratory distress syndrome (ARDS). The cytokine storm experienced in severe COVID-19 infections results from excessive release of pro-inflammatory cytokines. Due to its immunomodulatory effects, adequate vitamin D levels may cause a decrease in the pro-inflammatory cytokines and an increase in the anti-inflammatory cytokines during COVID-19 infections. Vitamin D deficiency was found in 82.2% of hospitalized COVID-19 cases and 47.2% of population-based controls (p < 0.0001). The available evidence warrants an evaluation of vitamin D supplementation in susceptible populations with respiratory diseases, such as TB, and particularly in those who are deficient in vitamin D. This may mitigate against serious complications of COVID-19 infections or reduce the impact of ARDS in those who have been infected.

Systems analysis and controlled malaria infection in Europeans and Africans elucidate naturally acquired immunity.

Controlled human infections provide opportunities to study the interaction between the immune system and malaria parasites, which is essential for vaccine development. Here, we compared immune signatures of malaria-naive Europeans and of Africans with lifelong malaria exposure using mass cytometry, RNA sequencing and data integration, before and 5 and 11 days after venous inoculation with Plasmodium falciparum sporozoites. We observed differences in immune cell populations, antigen-specific responses and gene expression profiles between Europeans and Africans and among Africans with differing degrees of immunity. Before inoculation, an activated/differentiated state of both innate and adaptive cells, including elevated CD161+CD4+ T cells and interferon-γ production, predicted Africans capable of controlling parasitemia. After inoculation, the rapidity of the transcriptional response and clusters of CD4+ T cells, plasmacytoid dendritic cells and innate T cells were among the features distinguishing Africans capable of controlling parasitemia from susceptible individuals. These findings can guide the development of a vaccine effective in malaria-endemic regions.

Antígenos del sistema sanguíneo ABO como factor de riesgo para la gravedad de la infección por SARS-CoV-2 / Blood system ABO antigens as risk factor for severity of SARS-CoV-2 infection

Resumen Introducción: Se desconoce si existe una influencia del sistema sanguíneo ABO en susceptibilidad y gravedad de la enfermedad. Objetivo: Analizar si existe una asociación entre los antígenos del sistema ABO y la susceptibilidad y gravedad de la infección por SARS-CoV-2. Material y métodos: Se compararon las frecuencias de los antígenos del sistema ABO en 73 casos confirmados de infección por SARS-CoV-2 y 52 donadores clínicamente sanos. La gravedad de la infección se evaluó comparando la frecuencia de los antígenos por gravedad de la enfermedad y la mortalidad. Resultados: El riesgo de padecer infección por SARS-CoV-2 se incrementa en sujetos con antígeno A vs los no-A (OR=1.45; IC95 %:1.061-1.921). El fenotipo sanguíneo O disminuye el riesgo de padecer infección por SARS-CoV-2 (OR=0.686; IC95 %: 0.522-0.903). No se encontraron diferencias entre la gravedad de la enfermedad. En los pacientes graves, el riesgo de mortalidad se incrementó en sujetos con antígeno A vs los no-A (OR= 3.34; IC95 %: 1.417-8.159). Conclusión: El grupo sanguíneo A es un factor de riesgo para padecer infección por SARS-CoV-2, no así en la gravedad de la enfermedad, pero en los pacientes graves fue un factor de riesgo para la mortalidad.

Abstract Introduction: Whether there is an influence of the ABO blood system on susceptibility to the disease and its severity is unknown. Objective: To analyze if there is an association between the ABO blood system phenotypes and susceptibility to SARS-CoV-2 infection and its severity. Material and methods: The frequency of ABO antigens was compared in 73 confirmed cases of SARS-CoV-2 infection and 52 clinically healthy donors. The severity of the infection was evaluated by comparing the frequency of antigens by severity of the disease and mortality. Results: The risk of SARS-CoV-2 infection is increased in subjects with antigen A vs non-A subjects (OR=1.45; 95 %: 1.061-1.921). Blood phenotype O decreases the risk of SARS-CoV-2 infection (OR= 0.686; 95 % CI: 0.522-0.903). No differences were found regarding disease severity. The mortality risk is increased in subjects antigen A vs non-A (OR= 3.34; 95% IC: 1.417-8.159). Conclusion: Blood group A is a risk factor for SARS-CoV-2 infection, but not for disease severity, although in critically ill patients it is a risk factor for mortality.

Modelling suggests ABO histo-incompatibility may substantially reduce SARS-CoV-2 transmission.

Several independent datasets suggest blood type A is over-represented and type O under-represented among COVID-19 patients. However, blood group antigens appear not to be conventional susceptibility factors in that they do not affect disease severity, and the relative risk to non-O individuals is attenuated when population prevalence is high. Here, I model a scenario in which ABO transfusion incompatibility reduces the chance of a patient transmitting the virus to an incompatible recipient - thus in Western populations type A and AB individuals are "super-recipients" while type O individuals are "super-spreaders". This results in an offset in the timing of the epidemic among individuals of different blood types, and an increased relative risk to type A/AB patients that is most pronounced during early stages of the epidemic. However, once the majority of any given population is infected, the relative risk to each blood type approaches unity. Published data on COVID-19 prevalence from regions in the early stages of the SARS-CoV-2 epidemic suggests that if this model holds true, ABO incompatibility reduces virus transmissibility by at least 60 %. Exploring the implications of this model for vaccination strategies shows that paradoxically, targeted vaccination of either high-susceptibility type A/AB or "super-spreader" type O individuals is less effective than random vaccination at blocking community spread of the virus. Instead, the key is to maintain blood type diversity among the remaining susceptible individuals. Given the good agreement between this model and observational data on disease prevalence, the underlying biochemistry urgently requires experimental investigation.

ABO Blood Types and COVID-19: Spurious, Anecdotal, or Truly Important Relationships? A Reasoned Review of Available Data.

Since the emergence of COVID-19, many publications have reported associations with ABO blood types. Despite between-study discrepancies, an overall consensus has emerged whereby blood group O appears associated with a lower risk of COVID-19, while non-O blood types appear detrimental. Two major hypotheses may explain these findings: First, natural anti-A and anti-B antibodies could be partially protective against SARS-CoV-2 virions carrying blood group antigens originating from non-O individuals. Second, O individuals are less prone to thrombosis and vascular dysfunction than non-O individuals and therefore could be at a lesser risk in case of severe lung dysfunction. Here, we review the literature on the topic in light of these hypotheses. We find that between-study variation may be explained by differences in study settings and that both mechanisms are likely at play. Moreover, as frequencies of ABO phenotypes are highly variable between populations or geographical areas, the ABO coefficient of variation, rather than the frequency of each individual phenotype is expected to determine impact of the ABO system on virus transmission. Accordingly, the ABO coefficient of variation correlates with COVID-19 prevalence. Overall, despite modest apparent risk differences between ABO subtypes, the ABO blood group system might play a major role in the COVID-19 pandemic when considered at the population level.

The histo-blood group antigens of the host cell may determine the binding of different viruses such as SARS-CoV-2.

Viruses have caused the death of millions of people worldwide. Specifically, human viruses are grouped into 21 families, including the family of coronaviruses (CoVs). In December 2019, in Wuhan, China, a new human CoV was identified, SARS-CoV-2. The first step of the infection mechanism of the SARS-CoV-2 in the human host is adhesion, which occurs through the S glycoprotein that is found in diverse human organs. Another way through which SARS-CoV-2 could possibly attach to the host's cells is by means of the histo-blood group antigens. In this work, we have reviewed the mechanisms by which some viruses bind to the histo-blood group antigens, which could be related to the susceptibility of the individual and are dependent on the histo-blood group.

The Impact of ABO Blood Grouping on COVID-19 Vulnerability and Seriousness: A Retrospective Cross-Sectional Controlled Study among the Arab Community.

Background and Objectives: Studies have noted that some ABO blood types are more susceptible to COVID-19 virus infection. This study aimed to further confirm the relationship between different blood groups on the vulnerability, symptoms, cure period, and severity among COVID-19 recovered patients. Subjects and Methods: This cross-sectional study approached the participants from the Arab community via social media (mainly Facebook and WhatsApp). The data were collected through two Google Form questionnaires, one for COVID-19 recovered patients (COVID-19 group, n = 726), and the other for the healthy people (Control group, n = 707). Results: The subjects with blood group O were the least likely to be infected with the COVID-19 virus, while those with blood group A were not likely to be the most susceptible. There were significant differences among different ABO blood groups regarding the distribution of oxygen saturation percentage, myalgia, and recovery time after COVID-19 infection (p < 0.01, 0.01, and 0.05, respectively). The blood group A showed the highest percentage of patients who experienced an oxygen saturation range of 90-100%, whereas the blood group O showed the highest percentage of patients who experienced an oxygen saturation range of 70-80%. The blood group A showed the lowest percentage of patients who required artificial respiration, whereas the blood group O showed the highest percentage of patients who required artificial respiration. The blood group B showed the lowest percentage of patients who experienced myalgia and exhibited the lowest percentage of patients who needed 3 weeks or more to recover. Conclusion: The people of blood group O may be the least likely to be infected with COVID-19, however, they may be the more in need of treatment in hospital and artificial respiration compared to the other blood groups.

ABO blood group influence COVID-19 infection: a meta-analysis.

INTRODUCTION: Previous studies have linked the relationship between ABO blood group and COVID-19 infection. However, existing evidence is preliminary and controversial. This meta-analysis sought to identify studies that describe COVID-19 and ABO blood group. METHODOLOGY: A literature search was conducted from PubMed, Web of Science, MedRxiv, BioRxiv and Google Scholar databases. Members of cases and controls were extracted from collected studies. Pooled Odds ratio (OR) and 95% confidence interval (95%CI) were calculated and interpreted from extracted data. Publication bias and sensitivity analysis were also applied to confirm our discovery. RESULTS: Total 13,600 patients and 3,445,047 controls were included in the study. Compared to other ABO blood group, blood group O was associated with a lower risk of COVID-19 infection (OR = 0.76, 95%CI 0.66-0.84), while blood group A and AB was associated with a higher risk (OR = 1.25, 95%CI 1.10-1.41; OR = 1.13, 95%CI 1.04-1.23, respectively). In the subgroup analysis, the relationship between blood group A, O and COVID-19 infection remained stable among Chinese, European and Eastern Mediterranean populations. In American population, blood groups B was linked with increased risk of COVID-19 infection (OR = 1.21, 95%CI 1.09-1.35). CONCLUSIONS: Our data suggested that individuals with blood types A and AB are more susceptible to COVID-19, while people with blood type O are less susceptible to infection. More research is needed to clarify the precise role of the ABO blood group in COVID-19 infection to address the global question.

Potential biomarker in serum for predicting susceptibility to type 2 diabetes mellitus: Free fatty acid 22:6.

AIMS/INTRODUCTION: Type 2 diabetes mellitus is closely linked to increased levels of free fatty acids (FFAs) in obese individuals, although which FFA is most associated with type 2 diabetes mellitus is unclear. This study aimed to identify the specific FFAs that best predict the occurrence of type 2 diabetes mellitus in obese individuals, and assess their potential application value. MATERIALS AND METHODS: Participants were divided into three groups: a normal weight group (n = 20), an obese group (n = 10) and a type 2 diabetes mellitus group (n = 10). FFAs in serum samples were determined by ultra-high-pressure liquid chromatography-mass spectrometry, and orthogonal partial least squares discriminant analysis models were used to study the FFA profile among the three groups. RESULTS: Compared with the normal weight group, 14 FFAs (C8:0/10:0/14:0/16:1/18:1/20:2/ 20:3 /20:4/ 20:5/ 22:6/7:0/9:0/11:0 and C13:0) were significantly increased in the obese group, and nine FFAs (C14:0, C18:1, C20:1, C 18:2, C20:2, C20:3, C18:3, C20:5 and C22:6) were significantly increased in the type 2 diabetes mellitus group. Subsequently, the Venn diagram results showed that six FFAs (C14:0, C18:1, C20:2, C20:3, C20:5 and C22:6) were significantly increased in both the obese and type 2 diabetes mellitus groups. Among these six, C22:6 was finally identified as an independent risk factor for type 2 diabetes mellitus, and had a great potential to predict the susceptibility to type 2 diabetes mellitus (area under the curve 0.803). CONCLUSIONS: C22:6 can be an independent risk factor for type 2 diabetes mellitus, and it has a great potential to predict the susceptibility to type 2 diabetes mellitus.

Seroprevalence of measles antibodies and factors associated with susceptibility: a national survey in Mexico using a plaque reduction neutralization test.

Measles continues to be one of the leading causes of child mortality worldwide, even though a highly effective vaccine has existed for more than 40 years. We aimed to describe the seroprevalence of measles antibodies in Mexico in 2012 and the risk factors associated with susceptibility. A total of 7,785 serum samples were analyzed from the National Health and Nutrition Survey in Mexico. This national survey is representative of the general population, including noninstitutionalized adult, adolescent, and child populations. Antibody titers were classified into protective (> 120 mIU/mL) or susceptible (≤ 120 mIU/mL) levels. The weighted seroprevalence and susceptibility of the overall population were 99.37% (95% CI 99.07-99.58) and 0.63% (95% CI 0.42-0.93), respectively. Among 1-to-4-year-old children, 2.18% (95% CI 1.36-3.48) were susceptible to measles. Among adolescents and young adults, the prevalence of susceptibility was as follows: those 15-19 years of age had a prevalence of 0.22% (95% CI 0.09-0.57), and those 30-39 years of age had a prevalence of 1.17% (95% CI 0.47-2.85). Susceptibility was associated with young age, living in Mexico City, living in crowded households and unknown or nonvaccinated status among 1- to 5-year-old children. Although the overall sample population seroprevalence for measles is above 95%, increased susceptibility among younger children signals the importance of the timely administration of the first vaccine dose at 12 months of age. Furthermore, increased susceptibility among specific subgroups indicates the need to reinforce current vaccination policies, including the immunization of unvaccinated or incompletely vaccinated individuals from 10 to 39 years of age.

Evaluation of patients with primary immunodeficiency associated with Bacille Calmette-Guerin (BCG)-vaccine-derived complications.

BACKGROUND: Bacille Calmette-Guerin (BCG) vaccination has a great impact on the prevention of severe complications of tuberculosis. However, in patients with primary immunodeficiencies (PID), it can lead to severe complications such as severe combined immunodeficiency, chronic granulomatous disease, and Mendelian susceptibility to mycobacterial disease. This study highlights the demographics, clinical complications and laboratory parameters among PID patients associated with BCG vaccination side effects. METHODS: One hundred and thirty-seven PID patients with BCGosis were evaluated in this study, based on the complications following BCG vaccination. RESULTS: The mean age of the patients with BCG complications at the time of the first visit was five years. The within-group comparison of patients showed a highly significant incidence of pneumonia and hepatomegaly in severe combined immunodeficiency patients. Furthermore, the immunologic data showed an increase in the overall rates of lymphocytes such as CD3+, CD4+ and CD8 + T cells in Mendelian susceptibility to mycobacterial disease patients. The level of immunoglobulins has also increased in chronic granulomatous disease patients. CONCLUSION: The high rate of undiagnosed PIDs predisposes individuals to a high risk of severe side effects as a result of BCG vaccination, as well as infants that are less than one month of age. Therefore, there is a need for early screening and diagnosis of PIDs before exposing unknown PID status patients to BCG vaccination. The benefits of screening and early diagnosis of PID cannot be overemphasized, especially in patients with a previous family history of immunodeficiency.

Association between ABO blood groups and risk of coronavirus disease 2019: A protocol for systematic review and meta-analysis.

BACKGROUND: The 2019 Coronavirus Disease (COVID-19) pandemic has threatened millions of people worldwide. Growing evidence suggests that the ABO blood type contributed to the susceptibility of COVID-19, but the results are controversial. The major objective of this systematic review and meta-analysis study is to investigate the impact of ABO blood group on COVID-19 pneumonia. METHODS: Two independent reviewers searches the databases of the China Biology Medicine disc, China National Knowledge Infrastructure, China Science and Technology Periodical Database, Wanfang Database, PubMed, Embase, and Web of Science from the date of conception to June 30, 2020. We will manually search for gray literature, such as meeting records and dissertations. Two independent reviewers will screen studies that meet the criteria, extract data, statistical data, and assess the risk of bias. The dichotomous variable will calculate the odds ratio and the corresponding 95% confidence interval. Heterogeneity between included studies will be assessed by heterogeneity χ tests and I index. The forest plots will be used to describe the pooled results. The Begg rank correlation test or Egger linear regression test will be performed to quantize the publication bias. DISCUSSION: This study will provide high-quality evidence to evaluate the contribution of the ABO blood group in COVID-19 pneumonia infection. PROSPERO REGISTRATION NUMBER: CRD42020195615.