The host's angiotensin-converting enzyme polymorphism may explain epidemiological findings in COVID-19 infections

Accuracy study of Angiotensin 1-7 composite index test to predict pulmonary fibrosis and guide treatment

BACKGROUND

Pulmonary fibrosis can develop after acute respiratory distress syndrome (ARDS). The hypothesis is we are able to measure phenotypes that lie at the origin of ARDS severity and fibrosis development. The aim is an accuracy study of prognostic circulating biomarkers.

METHODS

A longitudinal study followed COVID-related ARDS patients with medical imaging, pulmonary function tests and biomarker analysis, generating 444 laboratory data. Comparison to controls used non-parametrical statistics; p < 0·05 was considered significant. Cut-offs were obtained through receiver operating curve. Contingency tables revealed predictive values. Odds ratio was calculated through logistic regression.

RESULTS

Angiotensin 1-7 beneath 138 pg/mL defined Angiotensin imbalance phenotype. Hyper-inflammatory phenotype showed a composite index test above 34, based on high Angiotensin 1-7, C-Reactive Protein, Ferritin and Transforming Growth Factor-β. Analytical study showed conformity to predefined goals. Clinical performance gave a positive predictive value of 95 % (95 % confidence interval, 82 %-99 %), and a negative predictive value of 100 % (95 % confidence interval, 65 %-100 %). Those severe ARDS phenotypes represented 34 (Odds 95 % confidence interval, 3-355) times higher risk for pulmonary fibrosis development (p < 0·001).

CONCLUSIONS

Angiotensin 1-7 composite index is an early and objective predictor of ARDS evolving to pulmonary fibrosis. It may guide therapeutic decisions in targeted phenotypes.

Gene variants rs5182, rs2074192, and rs4343 in the renin-angiotensin-aldosterone system are associated with symptom severity, higher odds of hospitalization, and death in COVID-19

OBJECTIVES

To analyze the gene variants of the renin-angiotensin-aldosterone system and determine their association with the severity and outcome of COVID-19.

METHODS

A total of 104 patients were included in the study: 34 asymptomatic patients with COVID-19 as controls and 70 symptomatic patients as cases. The genetic variants ACE rs4343, ACE2 rs2074192, AGTR1 rs5182, and AGT rs4762 were identified using TaqMan genotyping tests.

RESULTS

Patients with the T/T genotype of AGTR1 rs5182 have a higher probability of developing symptomatic COVID-19 (odds ratio [OR] 12.25, 95% confidence interval [CI] 1.34-111.9, P ≤0.001) and a higher risk of hospitalization because of disease (OR 14.00, 95% CI 1.53-128.49, P = 0.012). The haplotype CTG (AGTR1 rs5182, ACE2 rs2074192, ACE rs4343) decreased the odds of death related to COVID-19 in the study population (OR 0.03, 95% CI 0.0-0.06, P = 0.026).

CONCLUSIONS

The T/T genotype of the AGTR1 rs5182 variant increased the probability of symptomatic COVID-19 and hospitalization, whereas the haplotype CTG (consisting of AGTR1 rs5182, ACE2 rs2074192, and ACE rs4343) decreased the odds of death related to COVID-19 by 97% in the hospitalized patients with COVID-19. These results support the participation of renin-angiotensin-aldosterone system gene variants as modifiers of the severity of symptoms associated with SARS-CoV-2 infection and the outcome of COVID-19.

More evidence for widespread antagonistic pleiotropy in polymorphic disease alleles

Introduction

Many loci segregate alleles classified as "genetic diseases" due to their deleterious effects on health. However, some disease alleles have been reported to show beneficial effects under certain conditions or in certain populations. The beneficial effects of these antagonistically pleiotropic alleles may explain their continued prevalence, but the degree to which antagonistic pleiotropy is common or rare is unresolved. We surveyed the medical literature to identify examples of antagonistic pleiotropy to help determine whether antagonistic pleiotropy appears to be rare or common.

Results

We identified ten examples of loci with polymorphisms for which the presence of antagonistic pleiotropy is well supported by detailed genetic or epidemiological information in humans. One additional locus was identified for which the supporting evidence comes from animal studies. These examples complement over 20 others reported in other reviews.

Discussion

The existence of more than 30 identified antagonistically pleiotropic human disease alleles suggests that this phenomenon may be widespread. This poses important implications for both our understanding of human evolutionary genetics and our approaches to clinical treatment and disease prevention, especially therapies based on genetic modification.

Evaluating direct amplification from viral transport medium for SARS-CoV-2 detection, strain typing, and angiotensin-converting enzyme genotyping and expression assays

OBJECTIVE

The aim of this study was to compare the performance of direct amplification of viral nucleic acid from transport medium to extracted nucleic acid for polymerase chain reaction (PCR), sequencing, and genotyping applications.

METHODS

XpressAmp lysate and extracted total nucleic acid from viral transport medium containing nasopharyngeal specimens were evaluated across different molecular applications to determine performance characteristics.

RESULTS

SARS-CoV-2 quantitative PCR and angiotensin-converting enzyme (ACE) genotyping assays worked well with XpressAmp lysate, almost equal with or better than extracted nucleic acid in some specimens. However, XpressAmp completely failed to perform in next-generation sequencing for strain typing. Both protocols failed to detect ACE2 expression in viral transport medium.

CONCLUSION

Direct amplification of viral nucleic acid from viral transport medium containing nasopharyngeal specimen works well for molecular assays with low thresholds of quality; however, it does have limitations with assays that require high quality nucleic acid for input. Use of the XpressAmp protocol significantly improves turnaround time and allows for easy ramp-up of PCR and genotyping assays.

Polymorphisms in the human angiotensin converting enzyme gene (ACE) linked to susceptibility of COVID-19 and malaria infections in the Ghanaian population

Genetic variations in the human angiotensin converting enzyme gene (ACE) influence ACE enzyme expression levels in humans and subsequently influence both communicable and non-communicable disease outcomes. More recently, polymorphisms in this gene have been linked to susceptibility and outcomes of infectious diseases such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and malaria infections. This study is the first to investigate the genetic diversity of ACE and ACE2 polymorphisms in the Ghanaian population. Archived filter blood blot samples from malaria patients aged ≤9 years were used. Molecular analysis for the detection of ACE rs4646994 (I/D), ACE2 rs2106809 (C/T) and rs2285666 (G/A) alleles as well as ACE2 exons 1-4 polymorphisms was conducted on 300 samples. The D allele (54%,162/300) was the most dominant polymorphism observed in the ACE rs4646994 gene whilst the G (68%, 204/300) and T alleles (59.3%,178/300) were the most frequent ACE2 rs2285666 and rs2106809 polymorphisms observed. For the 300 samples sequenced for ACE2 exons 1-4, analyses were done on 268, 282 and 137 quality sequences for exons 1, 2 and 3-4 respectively. For exon 1, the mutation D38N (2.2%; 6/268) was the most prevalent. The S19P and E37K mutations previously reported to influence COVID-19 infections were observed at low frequencies (0.4%, 1/268 each). No mutations were observed in exon 2. The N121K/T variants were the most seen in exons 3-4 at frequencies of 5.1% (K121, 7/137) and 2.9% (T121, 4/137) respectively. Most of the variants observed in the exons were novel compared to those reported in other populations in the world. This is the first study to investigate the genetic diversity of ACE and ACE2 genes in Ghanaians. The observation of novel mutations in the ACE2 gene is suggesting selection pressure. The importance of the mutations for communicable and non-communicable diseases (malaria and COVID-19) are further discussed.

[Genetic factors associated with long COVID]

INTRODUCTION

The variability in expression and evolution of COVID is not completely explained by clinical factors. In fact, genetic factors play an important role. Moreover, it is unknown whether the genetic factor that contribute to susceptibility and severity are also involved in the onset and evolution of long-COVID. The objective of this review is to gather information from literature to understand which genetic factors are involved in the onset of persistent COVID.

MATERIAL AND METHODS

Systematic review in PubMed and bioRxiv and medRxiv repositories based on MeSH-descriptors and MeSH-terms related to COVID and genetic factors. Using these terms 2715 articles were pooled. An initial screening performed by authors independently, selected 205 articles of interest. A final deeper screening a total of 85 articles were chosen for complete reading and summarized in this review.

RESULTS

Although ACE2 and TMPSS6 are involved in COVID susceptibility, their involvement in long-COVID has not been found. On the other hand, the severity of the disease and the onset of long-COVID has been associated with different genes involved in the inflammatory and immune response. Particularly interesting has been the association found with the FOXP4 locus.

CONCLUSIONS

Although studies on long-COVID are insufficient to fully comprehend the cause, it is clear that the current identified genetic factors do not fully explain the progression and onset of long-COVID. Other factors such as polygenic action, pleiotropic genes, the microbiota and epigenetic changes must be considered and studied.

Angiotensin-Converting Enzyme (ACE) level, but not ACE gene polymorphism, is associated with prognosis of COVID-19 infection: Implications for diabetes and hypertension

BACKGROUND

The renin-angiotensin-aldosterone system was shown to be activated in severe COVID-19 infection. We aimed to investigate the relationship between angiotensin converting enzyme (ACE) levels, ACE gene polymorphism, type 2 diabetes (T2DM), and hypertension (HT) and the prognosis of COVID-19 infection.

METHODS

This cross-sectional study analyzed the clinical features of adult patients with SARS-CoV-2 infection. ACE gene analysis and ACE level measurements were performed. The patients were grouped according to ACE gene polymorphism (DD, ID or II), disease severity (mild, moderate, or severe), and the use of dipeptidyl peptidase-4 enzyme inhibitor (DPP4i), ACE-inhibitor (ACEi) or angiotensin receptor blocker (ARB). Intensive care unit (ICU) admissions and mortality were also recorded.

RESULTS

A total of 266 patients were enrolled. Gene analysis detected DD polymorphism in the ACE 1 gene in 32.7% (n = 87), ID in 51.5% (n = 137), and II in 15.8% (n = 42) of the patients. ACE gene polymorphisms were not associated with disease severity, ICU admission, or mortality. ACE levels were higher in patients who died (p = 0.004) or were admitted to the ICU (p<0.001) and in those with severe disease compared to cases with mild (p = 0.023) or moderate (p<0.001) disease. HT, T2DM, and ACEi/ARB or DPP4i use were not associated with mortality or ICU admission. ACE levels were similar in patients with or without HT (p = 0.374) and with HT using or not using ACEi/ARB (p = 0.999). They were also similar in patients with and without T2DM (p = 0.062) and in those with and without DPP4i treatment (p = 0.427). ACE level was a weak predictor of mortality but an important predictor of ICU admission. It predicted ICU admission in total (cutoff value >37.092 ng/mL, AUC: 0.775, p<0.001).

CONCLUSION

Our findings suggest that higher ACE levels, but not ACE gene polymorphism, ACEi/ARB or DPP4i use, were associated with the prognosis of COVID-19 infection. The presence of HT and T2DM and ACEi/ARB or DPP4i use were not associated with mortality or ICU admission.

The dynamics of SARS-CoV-2 infection in unvaccinated and vaccinated populations in Mumbai, India, between 28 December 2020 and 30 August 2021

The emergence and evolution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants that could compromise vaccine efficacy (VE) with re-infections in immunized individuals have necessitated continuous surveillance of VE. Here, the occurrence and dynamics of SARS-CoV-2 infections in the context of vaccination during the second wave of infection in Mumbai were evaluated. RT-PCR cycle threshold (Ct) values of the open reading frame (ORF)/envelope (E)/nucleocapsid (N) genes obtained from a total of 42415 samples, comprising unvaccinated (96.88%) and vaccinated cases (3.12%) were analyzed between December 28, 2020, and August 30, 2021. A lower incidence of SARS-CoV-2 infection in fully vaccinated cases (5.07%) compared to partially vaccinated cases (6.5%) and unvaccinated cases (13.453%) was recorded. VE was significant after the first dose of vaccination (ORF gene p-value = 0.003429, and E/N gene p-value = 0.000866). Furthermore, VE was observed to be significant when the post-immunization (first dose) period was stratified to within 30 days (ORF gene p-value = 0.0094 and E/N gene p-value = 0.0023) and to 60 days following the second dose of vaccination (ORF gene p-value = 0.0238). Also, significantly higher efficacy was observed within individuals receiving two doses compared to a single dose (ORF gene p-value = 0.0132 and E/N gene p-value = 0.0387). The emergence of breakthrough infections was also evident (odds ratio= 0.34; 95% confidence interval= 0.27-0.43). Interestingly, viral loads trended towards being higher in some groups of partially vaccinated individuals compared to completely vaccinated and unvaccinated populations. Finally, our results delineated a significantly higher incidence of SARS-CoV-2 acquisition in males, asymptomatic individuals, individuals with comorbidities, and those who were unvaccinated.

The impact of ACE2 polymorphisms (rs1978124, rs2285666, and rs2074192) and ACE1 rs1799752 in the mortality rate of COVID-19 in different SARS-CoV-2 variants

BACKGROUND

Clinical severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outcomes could be influenced by genetic polymorphisms in angiotensin I-converting enzyme (ACE1) and ACE2. This study aims to examine three polymorphisms (rs1978124, rs2285666, and rs2074192) on the ACE2 gene and ACE1 rs1799752 (I/D) in patients who have coronavirus disease 2019 (COVID-19) with various SARS-CoV-2 variants.

METHODS

Based on polymerase chain reaction-based genotyping, four polymorphisms in the ACE1 and ACE2 genes have been identified in 2023 deceased patients and 2307 recovered patients.

RESULTS

The ACE2 rs2074192 TT genotype was associated with the COVID-19 mortality in all three variants, whereas the CT genotype was associated with the Omicron BA.5 and Delta variants. ACE2 rs1978124 TC genotypes were related to COVID-19 mortality in the Omicron BA.5 and Alpha variants, but TT genotypes were related to COVID-19 mortality in the Delta variant. It was found that ACE2 rs2285666 CC genotypes were associated with COVID-19 mortality in Delta and Alpha variants, and CT genotypes in Delta variants. There was an association between ACE1 rs1799752 DD and ID genotypes in the Delta variant and COVID-19 mortality, whereas there was no association in the Alpha or Omicron BA.5 variants. In all variants of SARS-CoV-2, CDCT and TDCT haplotypes were more common. In Omicron BA.5 and Delta, CDCC and TDCC haplotypes were linked with COVID-19 mortality. In addition to COVID-19 mortality, the CICT, TICT, and TICC were significantly correlated.

CONCLUSION

The ACE1/ACE2 polymorphisms had an impact on COVID-19 infection, and these polymorphisms had different effects in various SARS-CoV-2 variants. To confirm these results, however, more research needs to be conducted.

Association of the ACE and AGT gene polymorphisms with global disparities in COVID-19-related deaths

OBJECTIVE

The aim of the study was to investigate the gene polymorphisms of angiotensin-converting enzyme (ACE), angiotensinogen (AGT), and angiotensin type 1 receptor (AT1R) in association with coronavirus disease 2019 (COVID-19) mortality rates worldwide.

METHODS

The prevalence of ACE I/D, AGT M235T, and AT1R A1166C alleles' frequencies in different populations was assessed. Data on COVID-19-related cases and deaths were acquired from the European Center for Disease Prevention and Control, which included weekly reports by country and continent. An Excel tool was developed to visualize the acquired data of mortality and incidence by classifying them by continent/country across specific periods of time. Spearman's nonparametric correlation was used to evaluate the association between country-based frequencies in RAS gene polymorphisms and COVID-19-related deaths.

RESULTS

While China constituted the initial reservoir of COVID-19, incidence/mortality rates in Europe and America outnumbered the figures in the former. A clear association was identified between death rates and ACE D/I ( r  = 0.3659; P  = 0.033), as well as AGT A/G variants ( r  = 0.7576; P  = 0.015). Data on AT1R polymorphisms suggested no correlation with mortality rates.

CONCLUSION

Our results demonstrated a significant disparity in COVID-19-related susceptibility and mortality among different populations and corroborate the importance of gene polymorphisms in predicting and consequently improving patients' outcomes.

Clinical determinants of oxygen saturation and length of hospitalisation of COVID-19 patients: A cross-sectional study in Indonesia

Aims

Indonesia was one of the countries with the highest COVID-19 positive cases. Understanding the length of hospitalisation is critical for anticipating bed demand and resource allocation, such as oxygen. This study aims to examine the determinants of oxygen saturation and the length of hospitalisation in Hermina Mekarsari Hospital, West Java, Indonesia.

Methods

This cross-sectional study uses medical records from June to August 2021. The inclusion criteria were: COVID-19 patients aged between18 and 65, fully conscious, and not using mechanical ventilation. Participants who passed away during hospital stay were excluded. We used demographic information, laboratory data, and the clinician's assessments of the patients admitted to the hospital. Linear regression was performed for oxygen saturation on day seven, while logistic regression analysis was conducted to predict the length of hospital stay.

Results

In total, 371 participants with an average age of 47.2 (standard deviation 15.8) years were included. Most participants were female (57.7%) and smoking (78.4%). The results indicated that decreasing oxygen saturation was reported in vomiting patients (β = 1.63, p-value = .001), hypertensive patients (β 1.18 with, p-value = .034), and patients with the increased respiratory rate (β = 0.28, p-value = .000). In the logistic regression, we found that respondents who experienced dyspnoea, headache, fever, an increasing number of D-Dimer and blood glucose, and those with diabetes mellitus were more likely to stay more than 14 days.

Conclusions

Oxygen saturation was influenced by vomiting, hypertension, and increasing respiratory rate. Length of hospitalisation of more than 14 days was influenced by dyspnoea, headache, fever, increased number of D-Dimer, blood glucose, and diabetes mellitus. Identifying the determinants of oxygen saturation and length of stay can inform health professionals in designing a suitable intervention to reduce mortality and length of stay among COVID-19 patients in Indonesia.

Targeted genetic analysis unveils novel associations between ACE I/D and APO T158C polymorphisms with D-dimer levels in severe COVID-19 patients with pulmonary embolism

Only a percentage of COVID-19 patients develop thrombotic complications. We hypothesized that genetic profiles may explain part of the inter-individual differences. Our goal was to evaluate the genotypic distribution of targeted DNA polymorphisms in COVID-19 patients complicated (PE+) or not (PE-) by pulmonary embolism. We designed a retrospective observational study enrolling N = 94 consecutive patients suffering severe COVID-19 with pulmonary embolism (PE+, N = 47) or not (PE-, N = 47) during hospitalization. A panel of N = 13 prothrombotic DNA polymorphisms (FV R506Q and H1299R, FII G20210A, MTHFR C677T and A1298C, CBS 844ins68, PAI-1 4G/5G, GPIIIa HPA-1 a/b, ACE I/D, AGT T9543C, ATR-1 A1166C, FGB - 455G > A, FXIII103G > T) and N = 2 lipid metabolism-related DNA polymorphisms (APOE T 112C and T158C) were investigated using Reverse Dot Blot technique. Then, we investigated possible associations between genotypic subclasses and demographic, clinical, and laboratory parameters including age, obesity, smoking, pro-inflammatory cytokines, drug therapy, and biomarkers of thrombotic risk such as D-dimer (DD). We found that 58.7% of PE+ had homozygous mutant D/D genotype at ACE I/D locus vs. PE- (40.4%) and 87% of PE+ had homozygous mutant C/C genotype at APOE T158C locus vs. PE- (68.1%). In PE+ group, DD levels were significantly higher in D/D and I/D genotypes at ACE I/D locus (P = 0.00066 and P = 0.00023, respectively) and in C/C and T/C genotypes at APOE T158C locus (P = 1.6e-06 and P = 0.0012, respectively) than PE- group. For the first time, we showed significant associations between higher DD levels and ACE I/D and APOE T158C polymorphisms in PE+ vs. PE- patients suggesting potential useful biomarkers of poor clinical outcome.

A haemochromatosis-causing HFE mutation is associated with SARS-CoV-2 susceptibility in the Czech population

BACKGROUND

Coronavirus disease (COVID-19), which is caused by the SARS-CoV-2 virus, has become a global pandemic. While susceptibility to COVID-19 is subject to several external factors, including hypertension, BMI, and the presence of diabetes, it is also genetically determined to a significant extent. Infectious agents require iron (Fe) for proper functioning. Carriers of mutations resulting in increased iron concentrations are understood to be at increased risk of COVID-19.

METHODS

We examined HFE genotypes associated with hereditary haemochromatosis (rs1800562 and rs1799945 SNPs) in 617 COVID-19 patients (166 asymptomatic, 246 symptomatic and 205 hospitalised survivors) and 2 559 population-based controls.

RESULTS

We found a higher frequency of the minor allele (Tyr282) of the rs1800562 polymorphism (P < 0.002) in patients compared to controls (8.5 % vs 5.5 %). Non-carriers of the minor allele were protected against SARS-Cov-2 infection (OR, 95 %CI; 0.59, 0.42-0.82). The frequency of minor allele carriers was almost identical across asymptomatic, symptomatic, and hospitalised survivors. The rs1799945 variant did not affect disease severity and its occurrence was almost identical in patients and controls (P between 0.58 and 0.84).

CONCLUSIONS

In conclusion, our results indicate that presence of the rs1800562 minor allele, which is associated with hereditary haemochromatosis (thus increased levels of plasma Fe), increases susceptibility to SARS-CoV-2.

Association investigations between ACE1 and ACE2 polymorphisms and severity of COVID-19 disease

Due to the unique affinity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the angiotensin-converting enzyme 2 (ACE2) receptor in patients, the foremost recent evidence indicated that ACE1 and ACE2 polymorphisms could affect the susceptibility of individuals to SARS-CoV-2 infection and also the disease outcome. Here, we aimed to assess the possible association between two polymorphisms and the severity of disease in patients. In the present study, 146 patients with COVID-19 who were admitted to the Mazandaran University of Medical Sciences hospitals between March 2020 and July 2020 were enrolled in this case-control study. The patients were divided into four groups based on clinical symptoms and severity of the diseases (mild, moderate, severe, and critical). After DNA extraction, the ACE gene I/D polymorphism (rs4646994) and ACE2 gene polymorphism (rs2285666) were genotyped using Gap-PCR and PCR-RFLP techniques, respectively. Then, five samples from each obtained genotype were confirmed by Sanger sequencing technique. Data were analyzed with SAS software version 9.1 using appropriate statistical procedures. The ACE gene I/D polymorphism (rs4646994) genotypes were classified into three types: I/I, I/D, and D/D. Our finding indicated that the prevalence of ACE1 D/D genotype was significantly higher in severe and critical COVID-19 patients (P = 0.0016). Additionally, the analysis revealed a remarkable association between rs4646994 SNP and the HB and ESRI levels in patients (P < 0.05). Although the ACE2 rs2285666 SNP was not related to the severity of disease, this variant was significantly associated with ALT, ESRI, and P. These results provide preliminary evidence of a genetic association between the ACE-D/D genotype and the D allele of ACE1 genotype and the disease severity. Therefore, our findings might be useful for identifying the susceptible population groups for COVID-19 therapy.

Polymorphisms in ACE1, TMPRSS2, IFIH1, IFNAR2, and TYK2 Genes Are Associated with Worse Clinical Outcomes in COVID-19

Although advanced age, male sex, and some comorbidities impact the clinical course of COVID-19, these factors only partially explain the inter-individual variability in disease severity. Some studies have shown that genetic polymorphisms contribute to COVID-19 severity; however, the results are inconclusive. Thus, we investigated the association between polymorphisms in ACE1, ACE2, DPP9, IFIH1, IFNAR2, IFNL4, TLR3, TMPRSS2, and TYK2 and the clinical course of COVID-19. A total of 694 patients with COVID-19 were categorized as: (1) ward inpatients (moderate symptoms) or patients admitted at the intensive care unit (ICU; severe symptoms); and (2) survivors or non-survivors. In females, the rs1990760/IFIH1 T/T genotype was associated with risk of ICU admission and death. Moreover, the rs1799752/ACE1 Ins and rs12329760/TMPRSS2 T alleles were associated with risk of ICU admission. In non-white patients, the rs2236757/IFNAR2 A/A genotype was associated with risk of ICU admission, while the rs1799752/ACE1 Ins/Ins genotype, rs2236757/IFNAR2 A/A genotype, and rs12329760/TMPRSS2 T allele were associated with risk of death. Moreover, some of the analyzed polymorphisms interact in the risk of worse COVID-19 outcomes. In conclusion, this study shows an association of rs1799752/ACE1, rs1990760/IFIH1, rs2236757/IFNAR2, rs12329760/TMPRSS2, and rs2304256/TYK2 polymorphisms with worse COVID-19 outcomes, especially among female and non-white patients.

Genetic Variants and Protective Immunity against SARS-CoV-2

The novel coronavirus-19 (SARS-CoV-2), has infected numerous individuals worldwide, resulting in millions of fatalities. The pandemic spread with high mortality rates in multiple waves, leaving others with moderate to severe symptoms. Co-morbidity variables, including hypertension, diabetes, and immunosuppression, have exacerbated the severity of COVID-19. In addition, numerous efforts have been made to comprehend the pathogenic and host variables that contribute to COVID-19 susceptibility and pathogenesis. One of these endeavours is understanding the host genetic factors predisposing an individual to COVID-19. Genome-Wide Association Studies (GWAS) have demonstrated the host predisposition factors in different populations. These factors are involved in the appropriate immune response, their imbalance influences susceptibility or resistance to viral infection. This review investigated the host genetic components implicated at the various stages of viral pathogenesis, including viral entry, pathophysiological alterations, and immunological responses. In addition, the recent and most updated genetic variations associated with multiple host factors affecting COVID-19 pathogenesis are described in the study.

Systematic review and meta-analysis of human genetic variants contributing to COVID-19 susceptibility and severity

The COVID-19 pandemic has spawned global health crisis of unprecedented magnitude, claiming millions of lives and pushing healthcare systems in many countries to the brink. Among several factors that contribute to an increased risk of COVID-19 and progression to exacerbated manifestations, host genetic landscape is increasingly being recognized as a critical determinant of susceptibility/resistance to infection and a prognosticator of clinical outcomes in infected individuals. Recently, several case-control association studies investigated the influence of human gene variants on COVID-19 susceptibility and severity to identify the culpable mutations. However, a comprehensive synthesis of the recent advances in COVID-19 host genetics research was lacking, and the inconsistent findings of the association studies required reliable evaluation of the strength of association with greater statistical power. In this study, we embarked on a systematic search of all possible reports of genetic association with COVID-19 till April 07, 2022, and performed meta-analyses of all the genetic polymorphisms that were examined in at least three studies. After identifying a total of 84 studies that investigated the association of 130 polymorphisms in 61 genes, we performed meta-analyses of all the eligible studies. Seven genetic polymorphisms involving 15,550 cases and 444,007 controls were explored for association with COVID-19 susceptibility, of which, ACE1 I/D rs4646994/rs1799752, APOE rs429358, CCR5 rs333, and IFITM3 rs12252 showed increased risk of infection. Meta-analyses of 11 gene variants involving 6702 patients with severe COVID-19 and 8640 infected individuals with non-severe manifestations revealed statistically significant association of ACE2 rs2285666, ACE2 rs2106809, ACE2 rs2074192, AGTR1 rs5186, and TNFA rs1800629 with COVID-19 severity. Overall, our study presents a synthesis of evidence on all the genetic determinants implicated in COVID-19 to date, and provides evidence of correlation between the above polymorphisms with COVID-19 susceptibility and severity.

Protozoan co-infections and parasite influence on the efficacy of vaccines against bacterial and viral pathogens

A wide range of protozoan pathogens either transmitted by vectors (Plasmodium, Babesia, Leishmania and Trypanosoma), by contaminated food or water (Entamoeba and Giardia), or by sexual contact (Trichomonas) invade various organs in the body and cause prominent human diseases, such as malaria, babesiosis, leishmaniasis, trypanosomiasis, diarrhea, and trichomoniasis. Humans are frequently exposed to multiple pathogens simultaneously, or sequentially in the high-incidence regions to result in co-infections. Consequently, synergistic or antagonistic pathogenic effects could occur between microbes that also influences overall host responses and severity of diseases. The co-infecting organisms can also follow independent trajectory. In either case, co-infections change host and pathogen metabolic microenvironments, compromise the host immune status, and affect microbial pathogenicity to influence tissue colonization. Immunomodulation by protozoa often adversely affects cellular and humoral immune responses against co-infecting bacterial pathogens and promotes bacterial persistence, and result in more severe disease symptoms. Although co-infections by protozoa and viruses also occur in humans, extensive studies are not yet conducted probably because of limited animal model systems available that can be used for both groups of pathogens. Immunosuppressive effects of protozoan infections can also attenuate vaccines efficacy, weaken immunological memory development, and thus attenuate protection against co-infecting pathogens. Due to increasing occurrence of parasitic infections, roles of acute to chronic protozoan infection on immunological changes need extensive investigations to improve understanding of the mechanistic details of specific immune responses alteration. In fact, this phenomenon should be seriously considered as one cause of breakthrough infections after vaccination against both bacterial and viral pathogens, and for the emergence of drug-resistant bacterial strains. Such studies would facilitate development and implementation of effective vaccination and treatment regimens to prevent or significantly reduce breakthrough infections.

The COVID-19 Pandemic and Explaining Outcomes in Africa: Could Genomic Variation Add to the Debate?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, emanated from the Wuhan Province in China and rapidly spread across the globe causing extensive morbidity and mortality rate, and affecting the global economy and livelihoods. Contrary to early predictions of "body bags" across Africa, the African COVID-19 pandemic was marked by apparent low case numbers and an overall mortality rate when compared with the other geographical regions. Factors used to describe this unexpected pattern included a younger population, a swifter and more effective national health policy, limited testing capacities, and the possibility of inadequate reporting of the cases, among others. However, despite genomics contributing to interindividual variations in many diseases across the world, there are inadequate genomic and multiomics data on COVID-19 in Africa that prevent richer transdisciplinary discussions on the contribution of genomics to the spread of COVID-19 pandemic. To invite future debates on comparative studies of COVID-19 genomics and the pandemic spread around the world regions, this expert review evaluates the reported frequency distribution of genetic variants in candidate genes that are likely to affect COVID-19 infection dynamics/disease outcomes. We propose here that genomic variation should be considered among the many factors determining the COVID-19 infection and its outcomes in African populations and across the world.

Host genetic diversity and genetic variations of SARS-CoV-2 in COVID-19 pathogenesis and the effectiveness of vaccination

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), responsible for the outbreak of coronavirus disease 2019 (COVID-19), has shown a vast range of clinical manifestations from asymptomatic to life-threatening symptoms. To figure out the cause of this heterogeneity, studies demonstrated the trace of genetic diversities whether in the hosts or the virus itself. With this regard, this review provides a comprehensive overview of how host genetic such as those related to the entry of the virus, the immune-related genes, gender-related genes, disease-related genes, and also host epigenetic could influence the severity of COVID-19. Besides, the mutations in the genome of SARS-CoV-2 __leading to emerging of new variants__ per se affect the affinity of the virus to the host cells and enhance the immune escape capacity. The current review discusses these variants and also the latest data about vaccination effectiveness facing the most important variants.

Angiotensin-converting enzyme 1 and voltage-gated potassium channel-interacting protein 4 gene polymorphisms in COVID-19 patients from east of Iran

Background

Coronavirus disease 2019 (COVID-19), the infectious respiratory disease caused by a newly discovered pathogen (severe acute respiratory syndrome coronavirus 2), is a pandemic that places a burden on the health care system. Recently, most research on COVID-19 has emphasized its profound impact on specific regions and ethnic groups. A possible explanation for these variations in disease presentation and severity might be differences in the gene pool of populations. This study therefore attempted to clarify possible involvements of genetic factors affecting COVID-19 pathogenesis with a focus on voltage-gated potassium channel-interacting protein 4 (KCNIP4) and angiotensin-converting enzyme 1 (ACE1) gene polymorphisms.

Materials and methods

In this case-control study, the polymorphisms were genotyped using PCR in 194 COVID-19 patients and 194 healthy controls.

Results

COVID-19 susceptibility and severity appeared to be unaffected by these polymorphisms. However, this study supported the relevance of ACE1 II genotype frequency to a decreased number of deaths due to the infection. We found that COVID-19 patients with the ACE1 II genotype have a statistically significant better chance of survival (p = 0.008).

Conclusion

This study strengthens the idea that the ACE1 I/D polymorphism can be a novel prognostic factor indicating the outcome of COVID-19.

Control of aging by the renin–angiotensin system: a review of C. elegans, Drosophila, and mammals

The free-living, non-parasitic nematode Caenorhabditis elegans is a premier model organism for the study of aging and longevity due to its short lifespan, powerful genetic tools, and conservation of fundamental mechanisms with mammals. Approximately 70 percent of human genes have homologs in C. elegans, including many that encode proteins in pathways that influence aging. Numerous genetic pathways have been identified in C. elegans that affect lifespan, including the dietary restriction pathway, the insulin/insulin-like growth factor (IGF) signaling pathway, and the disruption of components of the mitochondrial electron transport chain. C. elegans is also a powerful system for performing drug screens, and many lifespan-extending compounds have been reported; notably, several FDA-approved medications extend the lifespan in C. elegans, raising the possibility that they can also extend the lifespan in humans. The renin–angiotensin system (RAS) in mammals is an endocrine system that regulates blood pressure and a paracrine system that acts in a wide range of tissues to control physiological processes; it is a popular target for drugs that reduce blood pressure, including angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs). Emerging evidence indicates that this system influences aging. In C. elegans, decreasing the activity of the ACE homolog acn-1 or treatment with the ACE-inhibitor Captopril significantly extends the lifespan. In Drosophila, treatment with ACE inhibitors extends the lifespan. In rodents, manipulating the RAS with genetic or pharmacological interventions can extend the lifespan. In humans, polymorphisms in the ACE gene are associated with extreme longevity. These results suggest the RAS plays a conserved role in controlling longevity. Here, we review studies of the RAS and aging, emphasizing the potential of C. elegans as a model for understanding the mechanism of lifespan control.

The role of ACE1 I/D and ACE2 polymorphism in the outcome of Iranian COVID-19 patients: A case-control study

Background: Since the beginning of the pandemic of coronavirus disease 2019 (COVID-19), many countries have experienced a considerable number of COVID-19 cases and deaths. The etiology of a broad spectrum of symptoms is still debated. Host genetic variants might also significantly influence the outcome of the disease. This study aimed to evaluate the association of angiotensin-converting enzyme (ACE1) gene Insertion/Deletion (I/D) polymorphism (rs1799752) and ACE2 gene rs1978124 single nucleotide polymorphism with the COVID-19 severity.

Methods: This study was conducted on 470 COVID-19 patients and a control group of 56 healthy individuals across several major cities in Iran. The blood sample and clinical data were collected from the participants, and their ACE1 I/D and ACE2 rs1978124 polymorphisms were determined using polymerase chain reaction and PCR-RFLP, respectively. Serum levels of C-reactive protein (CRP), interleukin 6 (IL-6), and ACE1 were measured in the blood samples.

Results: We found that the ACE1 DD genotype frequency was inversely correlated with the risk of intubation (p = 0.017) and mortality in COVID-19 patients (p = 0.049). Even after adjustment, logistic regression demonstrated that this significant inverse association remained constant for the above variables at odds ratios of (OR) = 0.35 and Odds Ratio = 0.49, respectively. Also, in the expired (p = 0.042) and intubated (p = 0.048) groups with II + ID genotypes, the mean level of CRP was significantly higher than in the DD genotype group. Furthermore, in both intubated and expired groups, the mean serum level of ACE1 was higher compared with non-intubated and survived groups with II or II + ID genotypes. The results also indicated that ACE2 rs1978124 TT + CT genotypes in females have a significant positive role in susceptibility to COVID-19; however, in females, the TT + CT genotypes had a protective effect (OR = 0.098) against the severity of COVID-19.

Conclusion: These findings suggest that ACE1 I/D and ACE2 rs1978124 polymorphism could potentially influence the outcome of COVID-19 in the Iranian population.

Analysis of post COVID-19 condition and its overlap with myalgic encephalomyelitis/chronic fatigue syndrome

BACKGROUND

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disease (COVID-19) triggers the development of numerous pathologies and infection-linked complications and exacerbates existing pathologies in nearly all body systems. Aside from the primarily targeted respiratory organs, adverse SARS-CoV-2 effects were observed in nervous, cardiovascular, gastrointestinal/metabolic, immune, and other systems in COVID-19 survivors. Long-term effects of this viral infection have been recently observed and represent distressing sequelae recognised by the World Health Organisation (WHO) as a distinct clinical entity defined as post-COVID-19 condition. Considering the pandemic is still ongoing, more time is required to confirm post COVID-19 condition diagnosis in the COVID-19 infected cohorts, although many reported post COVID-19 symptoms overlap with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

AIMS OF REVIEW

In this study, COVID-19 clinical presentation and associated post-infection sequelae (post-COVID-19 condition) were reviewed and compared with ME/CFS symptomatology.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The onset, progression, and symptom profile of post COVID-19 condition patients have considerable overlap with ME/CFS. Considering the large scope and range of pro-inflammatory effects of this virus, it is reasonable to expect development of post COVID-19 clinical complications in a proportion of the affected population. There are reports of a later debilitating syndrome onset three months post COVID-19 infection (often described as long-COVID-19), marked by the presence of fatigue, headache, cognitive dysfunction, post-exertional malaise, orthostatic intolerance, and dyspnoea. Acute inflammation, oxidative stress, and increased levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNFα), have been reported in SARS-CoV-2 infected patients. Longitudinal monitoring of post COVID-19 patients is warranted to understand the long-term effects of SARS-CoV-2 infection and the pathomechanism of post COVID-19 condition.

The striking mimics between COVID-19 and malaria: A review

Objectives

COVID-19 is a transmissible illness triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since its onset in late 2019 in Wuhan city of China, it continues to spread universally, leading to an ongoing pandemic that shattered all efforts to restrain it. On the other hand, in Africa, the COVID-19 infection may be influenced by malaria coinfection. Hence, in this review article, we aimed to give a comprehensive account of the similarities between COVID-19 and malaria in terms of symptoms, clinical, immunological, and molecular perspectives.

Methodology

In this article, we reviewed over 50 research papers to highlight the multilayered similarities between COVID-19 and malaria infections that might influence the ontology of COVID-19.

Results

Despite the poor health and fragile medical system of many sub-Saharan African countries, they persisted with a statistically significantly low number of COVID-19 cases. This was attributed to many factors such as the young population age, the warm weather, the lack of proper diagnosis, previous infection with malaria, the use of antimalarial drugs, etc. Additionally, population genetics appears to play a significant role in shaping the COVID-19 dynamics. This is evident as recent genomic screening analyses of the angiotensin-converting enzyme 2 (ACE2) and malaria-associated-variants identified 6 candidate genes that might play a role in malaria and COVID-19 incidence and severity. Moreover, the clinical and pathological resemblances between the two diseases have made considerable confusion in the diagnosis and thereafter curb the disease in Africa. Therefore, possible similarities between the diseases in regards to the clinical, pathological, immunological, and genetical ascription were discussed.

Conclusion

Understanding the dynamics of COVID-19 infection in Sub-Saharan Africa and how it is shaped by another endemic disease like malaria can provide insights into how to tailor a successful diagnostic, intervention, and control plans that lower both disease morbidity and mortality.

[Comparative study of patients hospitalized for SARS-CoV-2 infection in two consecutive waves in Tunisia]

Introduction

Since December 2019, a novel coronavirus (SARS-CoV-2) has triggered a global pandemic with a heavy medical and societal-economic toll. The health consequences were not similar during the successive waves that affected several countries. The aim of our study was to compare the sociodemographic, clinical and evolutionary features of COVID-19 patients hospitalized at the Military Hospital of Tunis (HMPIT) during the 2^nd and 3^rd waves that affected the country.

Patients and methods

Observational prospective study involving 1,527 COVID-19 patients hospitalized at HMPIT over 11 months, divided into two periods: from July 2020 to December 2020 called the second wave (V2) and from January 2021 to May 2021 called the third wave (V3). We compared the epidemiological data, the clinical form and the evolution of the patients for each period.

Results

The number of hospitalized patients was 636 during V2 compared to 891 during V3. Average age was 63.5 ± 15.3 years during V2 versus 65.8 ± 17.8 years during V3 (P = not significant [NS]). The percentage of young adults [18-40 years] was 6.5% during V2 compared to 6.7% during V3 (P = NS). The gender ratio (M/F) was 1.59 for V2 and 1.42 for V3 (P = NS). Comorbidities were present in 65% of V2 patients and 66.3% of V3 patients (P = NS), with hypertension being the most prevalent one in both groups (47.2% for V2 versus 44.9% for V3; P = NS), followed by overweight, dyslipidemia and diabetes (33% for V2 versus 39.3% for V3; P = 0.012). The median duration between symptoms onset and hospitalization was 7 days [5-10] during V2 versus 8.5 days during V3 [5-12] (P = 0.0004). The severe clinical form was present in 49% of patients admitted during V2 compared to 34.8% during V3 (P < 10^-3). The critical form represented 18.6% of cases during V2 against 16.8% during V3 (P = NS). The average hospital length of stay in COVID units (outside of intensive care unit) was 8.4 ± 5.4 days during V2 and 9.8 ± 5.7 days during V3. The average length of stay was significantly longer for the intensive care unit (11.3 ± 3.4 days for V2 versus 13.8 ± 3.9 days for V3; P = 0.01). The case fatality rate was 24.5% during V2 and 20.7% during V3 (P = NS). Median age of death was 70.2 years [42-88] during V2 and 70.4 years [22-96] during V3 with 2 patients less than 40 years of age (1%) for the latter period. The gender ratio (M/F) of deceased patients was 3.21 for V2 and 1.5 for V3 (P = 0.001). The case fatality rate was higher in the intensive care unit (65.4% for V2 versus 69.7% for V3; P = NS). Causes of death were dominated by ARDS (acute respiratory distress syndrome) for both periods (55.1% for V2 versus 70.8% for V3; P = 0.002), followed by septic shock (12.8% for V2 versus 10.8% for V3; P = NS) and multi-organ failure (9.6% for V2 versus 7.0% for V3; P = NS).

Conclusion

This study revealed a decrease in severe and critical clinical forms during the 3rd wave, as well as a decrease in the case fatality rate compared to the previous wave, due to improved management and vaccination. On the other hand, the percentage of ARDS was significantly higher during this wave probably related to the beginning of circulation in our country of the Delta variant causing more severe clinical cases.

Genetic polymorphisms associated with susceptibility to COVID-19 disease and severity: A systematic review and meta-analysis

Although advanced age and presence of comorbidities significantly impact the variation observed in the clinical symptoms of COVID-19, it has been suggested that genetic variants may also be involved in the disease. Thus, the aim of this study was to perform a systematic review with meta-analysis of the literature to identify genetic polymorphisms that are likely to contribute to COVID-19 pathogenesis. Pubmed, Embase and GWAS Catalog repositories were systematically searched to retrieve articles that investigated associations between polymorphisms and COVID-19. For polymorphisms analyzed in 3 or more studies, pooled OR with 95% CI were calculated using random or fixed effect models in the Stata Software. Sixty-four eligible articles were included in this review. In total, 8 polymorphisms in 7 candidate genes and 74 alleles of the HLA loci were analyzed in 3 or more studies. The HLA-A*30 and CCR5 rs333Del alleles were associated with protection against COVID-19 infection, while the APOE rs429358C allele was associated with risk for this disease. Regarding COVID-19 severity, the HLA-A*33, ACE1 Ins, and TMPRSS2 rs12329760T alleles were associated with protection against severe forms, while the HLA-B*38, HLA-C*6, and ApoE rs429358C alleles were associated with risk for severe forms of COVID-19. In conclusion, polymorphisms in the ApoE, ACE1, TMPRSS2, CCR5, and HLA loci appear to be involved in the susceptibility to and/or severity of COVID-19.

Potential long-term effects of SARS-CoV-2 infection on the pulmonary vasculature: a global perspective

The lungs are the primary target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, with severe hypoxia being the cause of death in the most critical cases. Coronavirus disease 2019 (COVID-19) is extremely heterogeneous in terms of severity, clinical phenotype and, importantly, global distribution. Although the majority of affected patients recover from the acute infection, many continue to suffer from late sequelae affecting various organs, including the lungs. The role of the pulmonary vascular system during the acute and chronic stages of COVID-19 has not been adequately studied. A thorough understanding of the origins and dynamic behaviour of the SARS-CoV-2 virus and the potential causes of heterogeneity in COVID-19 is essential for anticipating and treating the disease, in both the acute and the chronic stages, including the development of chronic pulmonary hypertension. Both COVID-19 and chronic pulmonary hypertension have assumed global dimensions, with potential complex interactions. In this Review, we present an update on the origins and behaviour of the SARS-CoV-2 virus and discuss the potential causes of the heterogeneity of COVID-19. In addition, we summarize the pathobiology of COVID-19, with an emphasis on the role of the pulmonary vasculature, both in the acute stage and in terms of the potential for developing chronic pulmonary hypertension. We hope that the information presented in this Review will help in the development of strategies for the prevention and treatment of the continuing COVID-19 pandemic.

IFITM3, FURIN, ACE1, and TNF-α Genetic Association With COVID-19 Outcomes: Systematic Review and Meta-Analysis

Human polymorphisms may contribute to SARS-CoV-2 infection susceptibility and COVID-19 outcomes (asymptomatic presentation, severe COVID-19, death). We aimed to evaluate the association of IFITM3, FURIN, ACE1, and TNF-α genetic variants with both phenotypes using meta-analysis. The bibliographic search was conducted on the PubMed and Scielo databases covering reports published until February 8, 2022. Two independent researchers examined the study quality using the Q-Genie tool. Using the Mantel–Haenszel weighted means method, odds ratios were combined under both fixed- and random-effect models. Twenty-seven studies were included in the systematic review (five with IFITM3, two with Furin, three with TNF-α, and 17 with ACE1) and 22 in the meta-analysis (IFITM3 n = 3, TNF-α, and ACE1 n = 16). Meta-analysis indicated no association of 1) ACE1 rs4646994 and susceptibility, 2) ACE1 rs4646994 and asymptomatic COVID-19, 3) IFITM3 rs12252 and ICU hospitalization, and 4) TNF-α rs1800629 and death. On the other hand, significant results were found for ACE1 rs4646994 association with COVID-19 severity (11 studies, 692 severe cases, and 1,433 nonsevere controls). The ACE1 rs4646994 deletion allele showed increased odds for severe manifestation (OR: 1.45; 95% CI: 1.26–1.66). The homozygous deletion was a risk factor (OR: 1.49, 95% CI: 1.22–1.83), while homozygous insertion presented a protective effect (OR: 0.57, 95% CI: 0.45–0.74). Further reports are needed to verify this effect on populations with different ethnic backgrounds.

Systematic Review Registration: https://www.crd.york.ac.uk/prosperodisplay_record.php?ID=CRD42021268578, identifier CRD42021268578

The mechanism underlying extrapulmonary complications of the coronavirus disease 2019 and its therapeutic implication

The coronavirus disease 2019 (COVID-19) is a highly transmissible disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that poses a major threat to global public health. Although COVID-19 primarily affects the respiratory system, causing severe pneumonia and acute respiratory distress syndrome in severe cases, it can also result in multiple extrapulmonary complications. The pathogenesis of extrapulmonary damage in patients with COVID-19 is probably multifactorial, involving both the direct effects of SARS-CoV-2 and the indirect mechanisms associated with the host inflammatory response. Recognition of features and pathogenesis of extrapulmonary complications has clinical implications for identifying disease progression and designing therapeutic strategies. This review provides an overview of the extrapulmonary complications of COVID-19 from immunological and pathophysiologic perspectives and focuses on the pathogenesis and potential therapeutic targets for the management of COVID-19.

The role of angiotensin-converting enzyme 2 in the pathogenesis of COVID-19: the villain or the hero?

Angiotensin-converting enzyme 2 (ACE 2) is the entry receptor for the novel coronavirus SARS-CoV-2, the aetiological agent of COVID-19. At the same time, ACE 2 expression decreases during COVID-19. Two seemingly contradictory relationships between the expression of ACE 2 and COVID-19 have been reported. Increased level of expression of ACE 2 may be a risk factor for the development of COVID-19 infection, while reduced ACE 2 expression during COVID-19 leads to acute respiratory distress syndrome. This article provides a comprehensive overview of available scientific knowledge about the role of ACE 2 in the pathogenesis of COVID-19, which is available up to current day. Also, it discusses unknown factors that we will have to reveal in order to understand the whole role of ACE 2 in the pathogenesis of COVID-19.

Role of Genetic Variants and Host Polymorphisms on COVID‐19: From Viral Entrance Mechanisms to Immunological Reactions

Coronavirus disease 2019 (COVID‐19), caused by a highly pathogenic emerging virus, is called severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). Knowledge regarding the pathogenesis of this virus is in infancy; however, investigation on the pathogenic mechanisms of the SARS‐CoV‐2 is underway. In COVID‐19, one of the most remarkable characteristics is the wide range of disease manifestation and severity seen across individuals of different ethnic backgrounds and geographical locations. To effectively manage COVID‐19 in the populations, beyond SARS‐CoV‐2 detection, serological response assessment, and analytic techniques, it is critical to obtain knowledge about at‐risk individuals and comprehend the identified variations in the disease's severity in general and also in the populations' levels. Several factors can contribute to variation in disease presentation, including population density, gender and age differences, and comorbid circumstances including diabetes mellitus, hypertension, and obesity. Genetic factors presumably influence SARS‐CoV‐2 infection susceptibility. Besides this, COVID‐19 has also been linked with a higher risk of mortality in men and certain ethnic groups, revealing that host genetic characteristics may affect the individual risk of death. Also, genetic variants involved in pathologic processes, including virus entrance into cells, antiviral immunity, and inflammatory response, are not entirely understood. Regarding SARS‐CoV‐2 infection characteristics, the present review suggests that various genetic polymorphisms influence virus pathogenicity and host immunity, which might have significant implications for understanding and interpreting the matter of genetics in SARS‐CoV‐2 pathogenicity and customized integrative medical care based on population investigation.

Genetic factors presumably influence SARS‐CoV‐2 infection susceptibility.

Genetic variants were involved in the pathologic processes of SARS‐CoV‐2 infection.

Various genetic polymorphisms influence virus pathogenicity and host immunity.

Human leukocyte antigens (HLAs) may play a vital role in SARS‐CoV‐2 susceptibility.

Polymorphisms in several genes such as IL‐6, TMPRSS2, IFITM3, CD26, ACE, and DBP were associated with the COVID‐19 severity.

Low incidence of COVID-19 case severity and mortality in Africa; Could malaria co-infection provide the missing link?

Background

Despite reports of malaria and coronavirus diseases 2019 (COVID-19) co-infection, malaria-endemic regions have so far recorded fewer cases of COVID-19 and deaths from COVID-19, indicating a probable protection from the poor outcome of COVID-19 by malaria. On the contrary, other evidence suggests that malaria might contribute to the death caused by COVID-19. Hence, this paper reviewed existing evidence hypothesizing poor outcome or protection of COVID-19 patients when co-infected with malaria.

Methods

PRISMA guidelines for systematic review were employed in this study. Published articles from December 2019 to May 2021on COVID-19 and malaria co-infection and outcome were systematically searched in relevant and accessible databases following a pre-defined strategy. Studies involving human, in vivo animal studies, and in vitro studies were included.

Results

Twenty three (23) studies were included in the review out of the 3866 records identified in the selected scientific databases. Nine (9) papers reported on co-infection of COVID-19 and malaria. Five (5) papers provided information about synergism of malaria and COVID-19 poor prognosis, 2 papers reported on syndemic of COVID-19 and malaria intervention, and 7 studies indicated that malaria protects individuals from COVID-19.

Conclusions

Low incidence of COVID-19 in malaria-endemic regions supports the hypothesis that COVID-19 poor prognosis is prevented by malaria. Although further studies are required to ascertain this hypothesis, cross-immunity and common immunodominant isotopes provide strong evidence to support this hypothesis. Also, increase in co-inhibitory receptors and atypical memory B cells indicate synergy between COVID-19 and malaria outcome, though, more studies are required to make a definite conclusion.

Low incidence and mortality rate of COVID-19 in malaria endemic regions

There have been reports of malaria and COVID-19 co-infection

Malaria could be the link for the reported low incidence of COVID-19 in Africa

Cross immunity and common immunodominant epitopes between Malaria and COVID-19, and antimalaria drugs could be the reason for observed low fatality and incidence rate of COVID-19 in malaria endemic regions.

Malaria infection and deaths could increase amid the COVID-19 pandemic due to interrupted malaria control interventions.

The Role of Angiotensin Converting Enzyme 1 Insertion/Deletion Genetic Polymorphism in the Risk and Severity of COVID-19 Infection

Background: Individuals infected with the COVID-19 virus present with different symptoms of varying severity. In addition, not all individuals are infected despite exposure. Risk factors such as age, sex, and comorbidities play a major role in this variability; however, genetics may also be important in driving the differences in the incidence and prognosis of the disease. An Insertion/Deletion (I/D) polymorphism in the ACE1 gene (rs1799752) may explain these genetic differences. The aims of this study were to determine the potential role of ACE1 I/D genetic polymorphism in the risk of contracting COVID-19 as well as predicting the severity of COVID-19 infection.

Methods: Three-hundred and eighty-seven non-related Lebanese subjects, 155 controls and 232 cases, who presented to the American University of Beirut Medical Center (AUBMC) for COVID-19 PCR testing were recruited. Clinical data were collected via filling a questionnaire and accessing the medical records. Peripheral blood was withdrawn for DNA isolation, and genotyping performed with standard PCR followed by band visualization on agarose gel.

Results: In our study population, previously described risk factors such as gender, age, and comorbidities were associated with increase in disease susceptibility and severity. ACE1 I was the least common allele, and there was a positive association between ACE1 I and the risk of contracting the COVID-19 disease. More specifically, the frequency of II genotype was significantly higher among cases when compared to controls (P = 0.035) with individuals with the II genotype having greater risk for contracting the COVID-19 disease: OR = 2.074, P = 0.048 in the multivariate analysis. As for disease severity, the DD genotype and D allele were associated with increased risk for developing severe symptoms (OR = 2.845, P = 0.026 and OR = 2.359, P = 0.014, respectively), and the DD genotype with necessitating hospitalization (OR = 2.307, P = 0.042). In parallel, D allele carriers showed a significantly increased risk for developing hypoxia: OR = 4.374, P = 0.045.

Conclusion: We found a positive association between ACE1 I and the risk of contracting the COVID-19 disease, and between ACE1 D and a worse outcome of the COVID-19 infection. Therefore, genotyping for ACE1 I/D polymorphism could be used to assess risk and predict severity for better prognosis and management of the disease.

Kidneys in SARS-CoV-2 Era; a challenge of multiple faces

INTRODUCTION

With the evolution of SARS-CoV-2 pandemic, it was believed to be a direct respiratory virus. But, its deleterious effects were observed on different body systems, including kidneys.

AIM OF WORK

In this review, we tried as much as we can to summarize what has been discussed in the literature about the relation between SARS-CoV-2 infection and kidneys since December, 2019.

METHODS

Each part of the review was assigned to one or two authors to search for relevant articles in three databases (Pubmed, Scopus and Google scholar) and collected data were summarized and revised by two independent researchers.

CONCLUSION

The complexity of COVID-19 pandemic and kidney could be attributed to the direct effect of SARS-CoV-2 infection on the kidneys, different clinical presentation, difficulties confronting dialysis patients, restrictions of the organ transplant programs, poor outcomes and bad prognosis in patients with known history of kidney diseases who got infected with SARS-CoV-2. This article is protected by copyright. All rights reserved.

Religion, social interactions, and COVID-19 incidence in Western Germany

This paper investigates how social interactions, as shaped by religious denomination, are related to COVID-19 incidence and associated mortality in Western Germany. We observe that the number of infections and deaths during the early pandemic phase were much higher in predominantly Catholic counties with arguably stronger family and social ties. The relationship was confirmed at the county level through numerous robustness checks, and after controlling for a series of characteristics and county fixed effects. At the individual level, we confirmed that Catholics, relative to non-Catholics, have tighter and more frequent interactions with their family and friends. Moreover, the intensity of social interaction was able to partially explain the relationship between COVID-19 incidence and share of Catholics at the county level. Our results highlight the number of dimensions that have to be taken into account when designing and implementing mitigation measures in the early stages of disease outbreaks.

Atypical HUS triggered by COVID-19: A case report

We hereby present a case of an atypical hemolytic uremic syndrome (aHUS) precipitated by coronavirus disease 2019 (COVID-19). A 26-year-old male was diagnosed with COVID-19 and acute kidney injury. His kidney biopsy was suggestive of thrombotic microangiopathy. Five sessions of plasmapheresis were done but were discontinued in view of nonrecovery of kidney function. He was then referred for a kidney transplant. On genetic analysis, he was found to have mutations in the complement system (CFHR1 and CFHR3), which suggested this was a case of aHUS precipitated by COVID-19. In view of the high risk of recurrence of the primary disease in live-related kidney donor transplantation, he was advised for simultaneous liver and kidney transplants.

Effects of selected inherited factors on susceptibility to SARS-CoV-2 infection and COVID-19 progression

Genetic predispositions may influence geographical and interethnic differences in COVID-19 prevalence and mortality in affected populations. Of the many genes implicated in COVID-19 progression, a substantial number have no direct functional link on virus transfer/viability or on the host immune system. To address this knowledge deficit, a large number of in silico studies have recently been published. However, the results of these studies often contradict the findings of studies involving real patients. For example, the ACE2 has been shown to play an important role in regulating coronavirus entry into cells, but none of its variations have been directly associated with COVID-19 susceptibility or severity. Consistently was reported that increased risk of COVID-19 is associated with blood group A and with the APOE4 allele. Among other genes with potential impacts are the genes for CCR5, IL-10, CD14, TMPRSS2 and angiotensin-converting enzyme. Variants within the protein-coding genes OAS1 and LZTFL1 (transferred to the human genome from Neanderthals) are understood to be among the strongest predictors of disease severity. The intensive research efforts have helped to identify the genes and polymorphisms that contribute to SARS-CoV-2 infection and COVID-19 severity.

Association between angiotensinogen (AGT), angiotensin-converting enzyme (ACE) and angiotensin-II receptor 1 (AGTR1) polymorphisms and COVID-19 infection in the southeast of Iran: a preliminary case-control study

BACKGROUND

The COVID-19 pandemic remains an emerging public health crisis with serious adverse effects. The disease is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV--2) infection, targeting angiotensin-converting enzyme-2 (ACE2) receptor for cell entry. However, changes in the renin-angiotensin system (RAS) balance alter an individual's susceptibility to COVID-19 infection. We aimed to evaluate the association between AGT rs699 C > T, ACE rs4646994 I/D, and AGTR1 rs5186 C > A variants and the risk of COVID-19 infection and the severity in a sample of the southeast Iranian population.

METHODS

A total of 504 subjects, including 258 COVID-19 positives, and 246 healthy controls, were recruited. Genotyping of the ACE gene rs4646994, and AGT rs699, and AGTR1 rs5186 polymorphisms was performed by polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP), respectively.

RESULTS

Our results showed that the II genotype of ACE rs4646994 and the I allele decreased the risk of COVID-19 infection. Moreover, we found that the TC genotype and C allele of AGT rs699 increased the risk of COVID-19 infection. The AGTR1 rs5186 was not associated with COVID-19 infection. Also, we did not find any association between these polymorphisms and the severity of the disease. However, we found a significantly higher age and prevalence of diabetes and hypertension in patients with severe disease than a non-severe disease.

CONCLUSIONS

These findings suggest that ACE rs4646994 and AGT rs699 polymorphisms increase the risk of COVID-19 infection in a southeast Iranian population.

Angiotensin-converting-enzyme insertion/deletion polymorphism, ACE activity, and COVID-19: A rather controversial hypothesis. A case-control study

Accumulating data has shown a contribution of the renin‐angiotensin system in COVID‐19 pathogenesis. The role of angiotensin‐converting enzyme (ACE) insertion (I)/deletion (D) polymorphism as a risk factor in developing COVID‐19 disease comes from epidemiological data and is controversially discussed. We conducted a retrospective case‐control study and assessed the impact of ACE I/D genotype in COVID‐19 disease prevalence and severity. In 81 COVID‐19 patients explicitly characterized and 316 controls, recruited during the first wave of COVID‐19 pandemic, ACE I/D genotype, and ACE activity were determined. A generalized linear model was used and Poisson regression analysis estimated the risk ratios (RRs) of alleles and genotypes for disease severity. DD patients had almost 2.0‐fold increased risk (RR: 1.886, confidence limit [CL] 95%: 1.266–2.810, p = 0.0018) of developing a more severe disease when contrasted to ID and II individuals, as did D allele carriers compared to I carriers (RR: 1.372; CL 95%: 1.051–1.791; p = 0.0201). ACE activity (expressed as arbitrary units, AU/L) was lower in patients (3.62 ± 0.26) than in controls (4.65 ± 0.13) (p < 0.0001), and this reduction was observed mainly among DD patients compared to DD controls (3.97 ± 0.29 vs. 5.38 ± 0.21; p = 0.0014). Our results demonstrate that ACE DD genotype may predispose to COVID‐19 increased disease severity via a mechanism associated, at least in part, with the significant fall in their ACE activity. Our findings suggest a more complex pattern of synergy between this polymorphism and ACE activity in COVID‐19 patients compared to healthy individuals and set the grounds for large‐scale studies assessing ACE genotype‐based optimized therapies with ACE inhibitors and angiotensin receptor blockers.

Age and genotype dependent erythropoietin protection in COVID-19

Erythropoietin (EPO) is the main mediator of erythropoiesis and an important tissue protective hormone that appears to mediate an ancestral neuroprotective innate immune response mechanism at an early age. When the young brain is threatened-prematurity, neonatal hyperbilirubinemia, malaria- EPO is hyper-secreted disproportionately to any concurrent anemic stimuli. Under eons of severe malarial selection pressure, neuroprotective EPO augmenting genetic determinants such as the various hemoglobinopathies, and the angiotensin converting enzyme (ACE) I/D polymorphism, have been positively selected. When malarial and other cerebral threats abate and the young child survives to adulthood, EPO subsides. Sustained high ACE and angiotensin II (Ang II) levels through the ACE D allele in adulthood may then become detrimental as witnessed by epidemiological studies. The ubiquitous renin angiotensin system (RAS) influences the α-klotho/fibroblast growth factor 23 (FGF23) circuitry, and both are interconnected with EPO. Here we propose that at a young age, EPO augmenting genetic determinants through ACE D allele elevated Ang II levels in some or HbE/beta thalassemia in others would increase EPO levels and shield against coronavirus disease 2019, akin to protection from malaria and dengue fever. Human evolution may use ACE2 as a “bait” for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) to gain cellular entry in order to trigger an ACE/ACE2 imbalance and stimulate EPO hypersecretion using tissue RAS, uncoupled from hemoglobin levels. In subjects without EPO augmenting genetic determinants at any age, ACE2 binding and internalization upon SARS-CoV-2 entry would trigger an ACE/ACE2 imbalance, and Ang II oversecretion leading to protective EPO stimulation. In children, low nasal ACE2 Levels would beneficially augment this imbalance, especially for those without protective genetic determinants. On the other hand, in predisposed adults with the ACE D allele, ACE/ACE2 imbalance, may lead to uncontrolled RAS overactivity and an Ang II induced proinflammatory state and immune dysregulation, with interleukin 6 (IL-6), plasminogen activator inhibitor, and FGF23 elevations. IL-6 induced EPO suppression, aggravated through co-morbidities such as hypertension, diabetes, obesity, and RAS pharmacological interventions may potentially lead to acute respiratory distress syndrome, cytokine storm and/or autoimmunity. HbE/beta thalassemia carriers would enjoy protection at any age as their EPO stimulation is uncoupled from the RAS system. The timely use of rhEPO, EPO analogs, acetylsalicylic acid, bioactive lipids, or FGF23 antagonists in genetically predisposed individuals may counteract those detrimental effects.

Human Ace D/I Polymorphism Could Affect the Clinicobiological Course of COVID-19

Introduction

The coronavirus disease 2019 (COVID-19), that is caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), has spread rapidly worldwide since December 2019. The SARS-CoV-2 virus has a great affinity for the angiotensin-converting enzyme-2 (ACE-2) receptor, which is an essential element of the renin-angiotensin system (RAS). This study is aimed at assessing the impact of the angiotensin-converting enzyme (ACE) gene insertion (I)/deletion (D) polymorphisms, on the susceptibility and clinical outcomes of the COVID-19 immunoinflammatory syndrome. Patients and Methods. A total of 112 patients diagnosed with COVID-19 between 1 and 15 May 2020 were enrolled in the study. ACE gene allele frequencies were compared to the previously reported Turkish population comprised of 300 people.

Results

The most common genotype in the patients and control group was DI with 53% and II with 42%, respectively. The difference in the presence of the D allele between the patient and control groups was statistically significant (67% vs. 42%, respectively, p < 0.0001). Severe pneumonia was observed more in patients with DI allele (31%) than DD (8%) and II (0%) (p = 0.021). The mortality rate, time to defervescence, and the hospitalization duration were not different between the genotype groups.

Conclusion

Genotype DI of ACE I/D polymorphism is associated with the infectious rate particularly severe pneumonia in this study conducted in the Turkish population. Therefore, ACE D/I polymorphism could affect the clinical course of COVID-19.

Acute respiratory distress syndrome: a life threatening associated complication of SARS-CoV-2 infection inducing COVID-19

Acute Respiratory Distress Syndrome (ARDS) is a form of respiratory failure in human. The number of deaths caused by SARS-CoV-2 infection inducing this severe pneumonia (ARDS) is relatively high. In fact, COVID-19 might get worsen in ARDS and provoke respiratory failure. A better understood of ARDS key features and the pathophysiological injuries of the pulmonary parenchyma are linked to lessons learned from previous severe diseases associated previous coronaviruses outbreaks (especially SARS-CoV and MERS-CoV) and more the ongoing SARS-CoV-2. The ARDS mechanism includes a diffuse alveolar damage associated disruption of alveolar capillary membrane, pulmonary edema, damaged endothelium and increased permeability. A diffuse inflammation, with acute onset, on the lung tissue accompanied by release of biochemical signal and inflammatory mediators (TNFα, IL-1 and IL-6) leading to hypoxemia, low PaO2/FiO2 ratio and the chest radiological expression of bilateral infiltrates in ARDS. The ongoing outbreak could lead to a better understood of ARDS pathophysiology and prognostic. An overview is also highlighted about the seven coronaviruses proved to infect human especially those having ability to cause severe disease SARS-CoV, MERS-CoV and SARS-CoV-2. In this review, we focused on the major pathological mechanisms leading to the ARDS development as a result of viral infection, severe COVID-19 worsening. Communicated by Ramaswamy H. Sarma.

In-hospital use of ACE inhibitors/angiotensin receptor blockers associates with COVID-19 outcomes in African American patients

BACKGROUNDThe angiotensin-converting enzyme (ACE) D allele is more prevalent among African Americans compared with other races and ethnicities and has previously been associated with severe coronavirus disease 2019 (COVID-19) pathogenesis through excessive ACE1 activity. ACE inhibitors/angiotensin receptor blockers (ACE-I/ARB) may counteract this mechanism, but their association with COVID-19 outcomes has not been specifically tested in the African American population.METHODSWe identified 6218 patients who were admitted into Mount Sinai hospitals with COVID-19 between February 24 and May 31, 2020, in New York City. We evaluated whether the outpatient and in-hospital use of ACE-I/ARB is associated with COVID-19 in-hospital mortality in an African American compared with non-African American population.RESULTSOf the 6218 patients with COVID-19, 1138 (18.3%) were ACE-I/ARB users. In a multivariate logistic regression model, ACE-I/ARB use was independently associated with a reduced risk of in-hospital mortality in the entire population (OR, 0.655; 95% CI, 0.505-0.850; P = 0.001), African American population (OR, 0.44; 95% CI, 0.249-0.779; P = 0.005), and non-African American population (OR, 0.748, 95% CI, 0.553-1.012, P = 0.06). In the African American population, in-hospital use of ACE-I/ARB was associated with improved mortality (OR, 0.378; 95% CI, 0.188-0.766; P = 0.006), whereas outpatient use was not (OR, 0.889; 95% CI, 0.375-2.158; P = 0.812). When analyzing each medication class separately, ARB in-hospital use was significantly associated with reduced in-hospital mortality in the African American population (OR, 0.196; 95% CI, 0.074-0.516; P = 0.001), whereas ACE-I use was not associated with impact on mortality in any population.CONCLUSIONIn-hospital use of ARB was associated with a significant reduction in in-hospital mortality among COVID-19-positive African American patients.FUNDINGNone.

Prevalence and mortality of COVID-19 are associated with the L55M functional polymorphism of Paraoxonase 1

Introduction

Accumulating evidence recommends that infectious diseases including coronavirus disease 2019 (COVID-19) are often associated with oxidative stress and inflammation. Paraoxonase 1 (PON1, OMIM: 168,820), a member of the paraoxonase gene family, has antioxidant properties. Enzyme activity of paraoxonase depends on a variety of influencing factors such as polymorphisms of PON1, ethnicity, gender, age, and a number of environmental variables. The PON1 has two common functional polymorphisms, namely, Q192R (rs662) and L55M (rs854560). The R192 and M55 alleles are associated with increase and decrease in enzyme activity, respectively.

Objective

The present study was conducted to investigate the possible association of rs662 and rs854560 polymorphisms with morbidity and mortality of COVID-19.

Methods

Data for the prevalence, mortality, and amount of accomplished diagnostic test (per 10⁶ people) on 25 November 2020 from 48 countries were included in the present study. The Human Development Index (HDI) was used as a potential confounding variable.

Results

The frequency of M55 was positively correlated with the prevalence (partial r = 0.487, df = 36, p = 0.002) and mortality of COVID-19 (partial r = 0.551, df = 36, p < 0.001), after adjustments for HDI and amount of the accomplished diagnostic test as possible confounders.

Conclusions

This means that countries with higher M55 frequency have higher prevalence and mortality of COVID-19.

Human genetic basis of coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in considerable morbidity and mortality worldwide. COVID-19 incidence, severity, and mortality rates differ greatly between populations, genders, ABO blood groups, human leukocyte antigen (HLA) genotypes, ethnic groups, and geographic backgrounds. This highly heterogeneous SARS-CoV-2 infection is multifactorial. Host genetic factors such as variants in the angiotensin-converting enzyme gene (ACE), the angiotensin-converting enzyme 2 gene (ACE2), the transmembrane protease serine 2 gene (TMPRSS2), along with HLA genotype, and ABO blood group help to explain individual susceptibility, severity, and outcomes of COVID-19. This review is focused on COVID-19 clinical and viral characteristics, pathogenesis, and genetic findings, with particular attention on genetic diversity and variants. The human genetic basis could provide scientific bases for disease prediction and targeted therapy to address the COVID-19 scourge.

Comparative Analysis of Susceptibility and Severity of COVID-19 in Countries from the Eastern and the Western World Till March '21

Majority of the world’s human population today is affected by Covid-19. The disease has not only exhibited differences in susceptibility among people of different countries, but also the mortality rate. In general, Western world has been reporting a greater number of infected cases than eastern countries. Even the mortality rates are quite high there. The aim of this study was to analyse the data available on the infectivity and mortality rates of Covid-19 in different countries till March’21 and then reviewed the literature to find reasons for the differences in susceptibility and severity in eastern and western countries. The reasons for the observed differences may be: (i) Eastern countries followed stricter modalities and got grace period to create better healthcare facilities to tackle COVID-19. This probably also slowed the transmission of virus and its evolution, (ii) Vaccination policies in the east may have provided some immunity due to cross reactivity, (iii) Frequent exposure to infections at young age in eastern countries might be helping in better immunity, (iv) Mutations in viral genome may be geography based and (v) Genetic differences in the immune system of the hosts with respect to ACE receptors and MHC may be playing an important role. In this article, an attempt has been made to put forth and discuss these plausible reasons along with suitable evidences. These findings may help in future research on the diagnosis, treatment and prevention of Covid-19.

Host variations in SARS-CoV-2 infection

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the zoonotic pathogen that causes the "Coronavirus Disease of 2019 (COVID-19)", and COVID-19 itself is yet to be thoroughly understood. Both the disease as well as the mechanisms by which the host interacts with the SARS-CoV-2 have not been fully enlightened. The epidemiological factors -e.g. age, sex, race-, the polymorphisms of the host proteins, the blood types and individual differences have all been in discussions about affecting the progression and the course of COVID-19 both individually and collectively, as their effects are mostly interwoven. We focused mainly on the effect of polymorphic variants of the host proteins that have been shown to take part in and/or affect the pathogenesis of COVID-19. Additionally, how the procedures of diagnosing and treating COVID-19 are affected by these variants and what possible changes can be implemented are the other questions, which are sought to be answered.

Infection outcome needs two to tango: human host and the pathogen

Infectious diseases are potential drivers for human evolution, through a complex, continuous and dynamic interaction between the host and the pathogen/s. It is this dynamic interaction that contributes toward the clinical outcome of a pathogenic disease. These are modulated by contributions from the human genetic variants, transcriptional response (including noncoding RNA) and the pathogen’s genome architecture. Modern genomic tools and techniques have been crucial for the detection and genomic characterization of pathogens with respect to the emerging infectious diseases. Aided by next-generation sequencing (NGS), risk stratification of host population/s allows for the identification of susceptible subgroups and better disease management. Nevertheless, many challenges to a general understanding of host–pathogen interactions remain. In this review, we elucidate how a better understanding of the human host-pathogen interplay can substantially enhance, and in turn benefit from, current and future applications of multi-omics based approaches in infectious and rare diseases. This includes the RNA-level response, which modulates the disease severity and outcome. The need to understand the role of human genetic variants in disease severity and clinical outcome has been further highlighted during the Coronavirus disease 2019 (COVID-19) pandemic. This would enhance and contribute toward our future pandemic preparedness.

ACE I/D polymorphism in Czech first-wave SARS-CoV-2-positive survivors

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread from China in 2019/2020 to all continents. Significant geographical and ethnic differences were described, and host genetic background seems to be important for the resistance to and mortality of COVID-19. Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism (rs4646994) is one of the candidates with the potential to affect infection symptoms and mortality.

METHODS

In our study, we successfully genotyped 408 SARS-CoV-2-positive COVID-19 survivors (163 asymptomatic and 245 symptomatic) and compared them with a population-based DNA bank of 2,559 subjects.

RESULTS

The frequency of ACE I/I homozygotes was significantly increased in COVID-19 patients compared with that in controls (26.2% vs. 21.2%; P = 0.02; OR [95% CI] = 1.55 [1.17-2.05]. Importantly, however, the difference was driven just by the symptomatic subjects (29.0% vs. 21.2% of the I/I homozygotes; P = 0.002; OR [95% CI] = 1.78 [1.22-2.60]). The genotype distribution of the ACE genotypes was almost identical in population controls and asymptomatic SARS-CoV-2-positive patients (P = 0.76).

CONCLUSIONS

We conclude that ACE I/D polymorphism could have the potential to predict the severity of COVID-19, with I/I homozygotes being at increased risk of symptomatic COVID-19.