Blood group antigen expression on vaginal and buccal epithelial cells and mucus in secretor and nonsecretor women

The relationship between blood groups and risk of infection with SARS-CoV-2 or development of severe outcomes: A review

The outbreak of coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is considered a global catastrophe that has overwhelmed health care systems. Since initiation of the pandemic, identification of characteristics that might influence risk of infection and poor disease outcomes have been of paramount interest. Blood group phenotypes are genetically inherited characteristics whose association with certain infectious diseases have long been debated. The aim of this review is to identify whether a certain type of blood group may influence an individual’s susceptibility to SARS‐CoV‐2 infection and developing severe outcomes. Our review shows that blood group O protects individuals against SARS‐CoV‐2, whereas blood group A predisposes them to being infected. Although the association between blood groups and outcomes of COVID‐19 is not consistent, it is speculated that non‐O blood group carriers with COVID‐19 are at higher risk of developing severe outcomes in comparison to O blood group. The interaction between blood groups and SARS‐CoV‐2 infection is hypothesized to be as result of natural antibodies against blood group antigens that may act as a part of innate immune response to neutralize viral particles. Alternatively, blood group antigens could serve as additional receptors for the virus and individuals who are capable of expressing these antigens on epithelial cells, which are known as secretors, would then have a high propensity to be affected by SARS‐CoV‐2.

ABO blood groups and risk of human immunodeficiency virus infection: A systematic review and meta-analysis

The last few decades have seen a pandemic of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), which continues to cause substantial morbidity and mortality. ABO blood groups are anthropological and genetic characteristics of a population whose associations with HIV infection are still controversial. This systematic review with meta-analysis was undertaken to investigate whether certain blood groups may have associations with HIV infection. PubMed, Scopus and Web of Science databases were systematically searched as of 6 September 2021. Grey literature was identified through screening Google Scholar, and reference lists of relevant studies. All observational studies providing data on ABO blood group distribution among HIV-infected and uninfected participants were included. Using a random effect model, risk ratios (RR) and 95% confidence intervals (CIs) were pooled to quantify this relationship. Fifty eligible studies with a total of 3,068,244 participants and 6508 HIV-infected cases were included. The overall analysis found that blood group AB increased the risk of HIV infection by 19% as compared with non-AB blood groups (RR = 1.19, 95% CI: 1.03-1.39, p = 0.02). Pooled estimates for other blood groups failed to reach statistical significance. Subgroup analyses identified a positive relationship between AB blood group and HIV infection within Asia, patient populations (as opposed to blood donors and general populations), studies with lower sample sizes, high-income countries and studies with a moderate quality score. The sequential omission and re-analysis of studies within sensitivity analyses produced no change in the overall pooled effect. In conclusion, this study identified that blood group AB carriers were more susceptible to HIV infection. Future investigations should be directed toward clarification of the exact role of ABO blood groups in HIV infection and the possible underlying mechanisms.

Maternal H-antigen secretor status is an early biomarker for potential preterm delivery

OBJECTIVE

Pre-pregnancy or first trimester biomarkers predicting preterm delivery are lacking. The purpose of this study was to determine whether maternal H-antigen (secretor status) is a potential biomarker for preterm delivery.

METHODS

This cohort study examined maternal saliva samples and birth data gathered by the National Children's Study Vanguard pilot phase (2009-2014) and included 300 women who were ≥18 years old and provided birth data and saliva samples. The maternal secretor status phenotype was determined by quantifying H-antigen in saliva using enzyme-linked immunoassay. Mothers were stratified by secretor status and multivariable analysis estimated adjusted associations with preterm delivery.

RESULTS

Maternal lack of H-antigen production was an independent risk factor for preterm delivery after adjusting for known confounders (aOR 4.53; 95% CI: 1.74, 11.81; P = 0.002).

CONCLUSIONS

Maternal H-antigen may be a biomarker identifying women at-risk for preterm delivery. Prospective cohort studies validating these findings are needed.

Donor fecal microbiota transplantation ameliorates intestinal graft-versus-host disease in allogeneic hematopoietic cell transplant recipients

Disruption of the intestinal microbiota occurs frequently in allogeneic hematopoietic cell transplantation (allo-HCT) recipients and predisposes them to development of graft-versus-host disease (GvHD). In a prospective, single-center, single-arm study, we investigated the effect of donor fecal microbiota transplantation (FMT) on symptoms of steroid-refractory or steroid-dependent, acute or late-onset acute intestinal GvHD in 15 individuals who had undergone allo-HCT. Study participants received a fecal suspension from an unrelated healthy donor via nasoduodenal infusion. Donor FMT was well tolerated, and infection-related adverse events did not seem to be related to the FMT procedure. In 10 of 15 study participants, a complete clinical response was observed within 1 month after FMT, without additional interventions to alleviate GvHD symptoms. This response was accompanied by an increase in gut microbial α-diversity, a partial engraftment of donor bacterial species, and increased abundance of butyrate-producing bacteria, including Clostridiales and Blautia species. In 6 of the 10 responding donor FMT recipients, immunosuppressant drug therapy was successfully tapered. Durable remission of steroid-refractory or steroid-dependent GvHD after donor FMT was associated with improved survival at 24 weeks after donor FMT. This study highlights the potential of donor FMT as a treatment for steroid-refractory or steroid-dependent GvHD, but larger clinical trials are needed to confirm the safety and efficacy of this procedure.

New concepts in the pathogenesis of urinary tract infections

Random amplified polymorphic DNA fingerprinting was used to distinguish among Escherichia coli bacterial strains creating urinary tract infections (UTIs) in women. Bacteria bound more avidly to cells from postmenopausal donors with history of UTIs (PK) compared with cells from women without history of UTIs (AO). Nonpiliated bacterial strains did not adhere to the cell lines. Increasing S-IgA concentrations has no effect on AO cell bacterial binding, whereas bacterial adhesion to PK cell epithelium increased with increasing S-IgA concentration.

Relatedness of Escherichia coli colonizing women longitudinally

PURPOSE

The longitudinal colonization patterns by Escherichia coli of the vaginal introitus and urinary tract were investigated.

MATERIALS AND METHODS

Cultures of the vaginal introitus and midstream urine were collected once a week for 12 consecutive weeks from five women with (patients) and five without (controls) a history of urinary tract infection (UTI).

RESULTS

A total of 63 E. coli isolates was obtained from the 10 women, 26 from controls and 37 from patients. The bacterial counts of E. coli present in control individuals were uniformly low, < or = 200 E. coli/mL. The numbers in patients were higher and more variable, reaching > 10(5)/mL in urine and vaginal specimens. In 16 instances, E. coli was present in the urine and the vaginal introitus concurrently (matched isolates). Random amplified polymorphic DNA (RAPD) fingerprinting was used to characterize all matched E. coli isolates. Concurrent vaginal and urinary tract colonization was more common in the patient population, and usually, the same E. coli strain was present at both sites; only 15% of the matched isolates represented different strains. The RAPD fingerprinting was also carried out on selected isolates recovered from four patients and three control individuals over the 12-week study period. Colonization of the vaginal introitus and urinary tract in these individuals varied over time. Generally, however, a predominant E. coli strain was present in the vaginal milieu, urinary tract, or both, either continuously (for as long as 9 consecutive weeks in one patient) or intermittently.

CONCLUSION

The results support the concept that the vaginal mucosa acts as reservoir of E. coli which may enter the urinary tract.

Evaluation and management of pediatric urinary tract infections

Urinary tract infections (UTIs) are relatively common in children. We describe the evaluation and management of children with UTIs, as well as the risks and consequences related to the UTI. This article describes a rational approach to the evaluation and management of childhood UTIs with the relation to the natural history and risk factors.

Pathogenesis of urinary tract infection. Role of host defenses

In the last decade, there have been modest strides made in our understanding of the pathogenesis of urinary tract infections (UTIs). Matching the advances achieved in unraveling the complexities of bacterial virulence factors using molecular-genetic techniques has been a parallel increase in knowledge of host defense mechanisms. Host susceptibility to UTI in the past has been predominantly studied in patients with structural (obstruction) or functional abnormalities (diabetes mellitus); however, most patients with UTIs have no such demonstrable abnormalities, hence attention has now focused on host behavioral factors in addition to genetically determined cellular mechanisms that predispose to sporadic and recurrent UTI.

Binding of type 1-piliated Escherichia coli to vaginal mucus

To better understand the interactions involved in bacterial adherence and the role of mucus in the pathogenesis of urinary tract infections, we developed a system to study the binding of a recombinant Escherichia coli strain, HB101/pWRS1-17, expressing type 1 pili, to vaginal mucus collected from 28 women. Bacteria bound to differing extents to all specimens examined, and preincubation of bacteria with mannose inhibited binding by 50 to 89%. Additionally, all mucus samples showed reactivity with anti-mannose antibody, and the levels of reactivity correlated with the levels of bacterial binding, suggesting that the mannose-terminal saccharides present on these glycoproteins are the receptors for the binding of type 1-piliated bacteria. Mucus specimens collected over periods of 5 days and 12 weeks exhibited significant variation in bacterial binding, indicating temporal differences in the ability of vaginal mucus to act as a receptor for type 1-piliated E. coli. The results show that vaginal mucus can bind bacteria and may thus influence the initial attachment and subsequent colonization of the vaginal and urinary tract epithelium by E. coli.

Lewis phenotype in women with preterm labor and premature rupture of the membranes

Objective: The purpose of this study was to evaluate the possible association between Lewis phenotype status in pregnant women and preterm labor (PTL) or preterm rupture of the membranes (PROM).

Methods: Red blood cell (RBC) Lewis phenotype was determined in 113 pregnant women admitted for PTL or PROM and in 121 controls. The results were controlled for the influence of race on Lewis phenotype.

Results: Pregnancy was associated with a higher frequency in women with the a–b– phenotype. There was no association between RBC Lewis phenotype and the occurrence of PTL or PROM.

Conclusions: A susceptibility to PTL or PROM is not due to a lack of Lewis antigen expression on the plasma membrane of the vaginal mucosa.

Variation of blood group antigen expression on vaginal cells and mucus in secretor and nonsecretor women

The expression of blood group antigens on the surface of urothelial cells and in mucus is controlled partly by the blood type and secretor status of the individual. To our knowledge, the possibility that the levels of these antigens vary with time has not been previously assessed. We determine if the pattern and/or intensity of blood group antigen expression on vaginal epithelial cells and mucus changed with time. Cell and mucus specimens were collected weekly for 3 months from 10 women: 5 (2 secretors and 3 nonsecretors) with and 5 (3 secretors and 2 nonsecretors) without a history of urinary tract infections. In addition, samples were collected on 5 consecutive days from 5 of these individuals. The cell and mucus samples were assayed for ABH and Lewis blood group antigens using monoclonal antibodies in cell concentration immunofluorescence and enzyme-linked fluorogenic assays, respectively. Although the pattern of antigen expression in the vaginal cell and mucus samples was consistent with the blood type and secretor status of an individual, in all women the level of antigen expression changed significantly and rapidly during the 3-month and 5-day periods. The results show a previously unrecognized phenomenon and demonstrate that the expression of blood group antigens on vaginal cells and in mucus is a dynamic process.

Blood group antigen expression on vaginal cells and mucus in women with and without a history of urinary tract infections

Adherence of bacteria to carbohydrate receptors on the surface of vaginal epithelial cells is a critical event that precedes bacterial colonization of the vaginal mucosa and subsequent urinary tract infection. Blood group antigens, carbohydrate structures bound to lipids or proteins, constitute an important component of the uroepithelial cell membrane and may affect susceptibility to urinary tract infections. To determine if the ABH and Lewis antigen expression in women with a history of urinary tract infections differed from that of women without such a history, vaginal specimens from 87 women (42 patients and 45 controls) were analyzed for the detection of these antigenic determinants using monoclonal antibodies in quantitative immunoassays. The profile of ABH antigen expression was generally consistent with the ABO phenotype of the individual and appeared to be influenced by the secretor status. Secretors expressed higher levels of A, B and H determinants than nonsecretors. In addition, Lewis antigens were detected on vaginal cells and in mucus. Samples from nonsecretors expressed higher levels of Le(a) and Le(x) antigens, whereas secretors expressed higher levels of Le(b) and Le(y) antigens. The levels of antigen expression varied widely among individuals with the same blood type and secretor status. Comparisons between patient and control groups showed no significant differences in ABH or Lewis antigen expression overall, or when controlling for ABO or secretor phenotypes, respectively. These findings confirm our previous observations on healthy women, and document the heterogeneity of blood group antigen expression on vaginal epithelial cells and mucus from women with a history of urinary tract infections.

Effect of Lewis blood group antigen expression on bacterial adherence to COS-1 cells

Epithelial cells from secretor individuals demonstrate decreased bacterial adherence compared with cells from nonsecretors. Lewis blood group antigen expression is one component of the secretor/nonsecretor phenotype and several epidemiologic studies have suggested a link between Lewis blood group antigen phenotype and susceptibility to urinary tract infections. In this study, we examined the possibility that the expression of the difucosylated Lewis blood group determinants, Leb and Ley (associated with the secretor phenotype), made cells less susceptible to Escherichia coli adherence by masking receptors for pili. COS-1 cells, which do not produce Lewis (Lea, Leb, Le(x), and Ley) blood group antigens, were used as target cells for bacterial adherence. The surface blood group antigen expression pattern of the cells was then modified by cotransfection with plasmids containing DNA inserts encoding alpha (1,2)-fucosyltransferase and alpha (1,3)- and alpha (1,4)-fucosyltransferases, resulting in the expression of Leb and Ley. E. coli HB101 expressing various adhesins (type 1, PapJ96, PapIA2, PapAD110, Prs, and S) from recombinant plasmids bound equally well to untransfected cells and transfected cells expressing Lea and Le(x) (nonsecretor phenotype) and Leb and Ley (secretor phenotype) antigens. We conclude that the presence of Leb and Ley antigens on cells from secretors does not alone mask receptors for E. coli pili or hinder bacterial adherence.