Human genetic basis of severe or critical illness in COVID-19

Genetic Predictors of Paxlovid Treatment Response: The Role of IFNAR2, OAS1, OAS3, and ACE2 in COVID-19 Clinical Course

Background: This study investigated the role of genetic polymorphisms in IFNAR2, OAS1, OAS3, and ACE2 as predictors of Paxlovid treatment response, specifically examining their influence on the clinical course and laboratory parameters of COVID-19 patients. Methods: We analyzed the impact of polymorphisms in genes associated with the interferon pathway (IFNAR2 rs2236757), antiviral response (OAS1 rs10774671, OAS3 rs10735079), and viral entry (ACE2 rs2074192) in individuals treated with Paxlovid. Results: Our findings suggest that genetic variations in these genes may modulate the immune response and coagulation pathways in the context of Paxlovid treatment during COVID-19 infection. Specifically, the IFNAR2 rs2236757 G allele was associated with alterations in inflammatory and coagulation markers, while polymorphisms in OAS1 and OAS3 influenced coagulation parameters. Furthermore, specific genotypes were linked to changes in clinical parameters such as oxygen saturation, leukocyte count, and liver function markers in Paxlovid-treated patients. Conclusions: These results highlight the potential of considering genetic factors in understanding individual responses to COVID-19 treatment with Paxlovid and informing future personalized approaches.

Critical illness-based chronic disease: a new framework for intensive metabolic support

PURPOSE OF REVIEW

This review addresses the novel concept of critical illness as a potential chronic disease. The high clinical and economic burdens of chronic critical illness and post-ICU syndromes are mainly due to refractoriness to therapy and consequently lead to significant complications. Interventions need to be preventive in nature and therefore a robust disease model is warranted.

RECENT FINDINGS

There are three paradigms that are leveraged to create a new critical illness-based chronic disease (CIBCD) model: metabolic model of critical illness, intensive metabolic support (IMS; insulinization and nutrition support), and driver-based chronic disease modeling. The CIBCD model consists of four stages: risk, predisease, (chronic) disease, and complications. The principal goal of the CIBCD model is to expose early opportunities to prevent disease progression, particularly further morbidity, complications, and mortality. IMS is used to target seminal pathophysiological events such as immune-neuroendocrine axis (INA) activation and failure to downregulate INA activation because of preexisting chronic diseases and recurrent pathological insults.

SUMMARY

The CIBCD model complements our understanding of critical illness and provides needed structure to preventive actions that can improve clinical outcomes. Many research, knowledge, and practice gaps exist, which will need to be addressed to optimize and validate this model.

Association of Endothelial Nitric Oxide Synthase Polymorphisms with Clinical Severity in Patients with COVID-19

Background/Objectives: To elucidate the factors that contribute to individual variability in the progression of COVID-19, experiments on endothelial nitric oxide synthase polymorphisms have been reported. Nitric oxide synthase (NOS3) is located in the endothelium and is involved in the regulation of inflammation and vascular homeostasis. In this study, we investigated the association between COVID-19 severity and NOS3 G894T and NOS3 27-bp VNTR 4b/a genetic polymorphisms. Methods: Patients with COVID-19 (n = 178) were divided into Group 1 (mild disease) and Group 2 (severe disease) based on oxygen saturation levels in room air (Group 1, SpO2 ≥ 93%, n = 107; and Group 2, SpO2 < 93%, n = 73) and hospitalization requirements. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism analysis. Results: Overall, genotype and allele frequencies of the NOS3 genetic polymorphisms were similar across the two study groups (p > 0.05). However, the subgroup analysis showed a notable trend for the 4b/4a allele distribution between Groups 1 and 2. In the younger subgroup of patients (≤50 years old) without chronic obstructive pulmonary disease, Group 2 tended to have a higher frequency of the 4b allele than Group 1 (97.4% vs. 85.4% p = 0.06) and a higher occurrence of 4b/4b genotype (94.7% vs. 74.0%, p = 0.05). Additionally, a rarely observed 4c allele was detected only in two subjects within Group 2 but not in Group 1. Conclusions: These findings suggest a trend of association between COVID-19 severity and NOS3 27-bp VNTR 4b/a genetic polymorphism. Genetic analysis may reveal patient susceptibility to disease, prognosis risk factors, and drug responsiveness.

HLA-DQ2/8 and COVID-19 in Celiac Disease: Boon or Bane

The SARS-CoV-2 pandemic continues to pose a global threat. While its virulence has subsided, it has persisted due to the continual emergence of new mutations. Although many high-risk conditions related to COVID-19 have been identified, the understanding of protective factors remains limited. Intriguingly, epidemiological evidence suggests a low incidence of COVID-19-infected CD patients. The present study explores whether their genetic background, namely, the associated HLA-DQs, offers protection against severe COVID-19 outcomes. We hypothesize that the HLA-DQ2/8 alleles may shield CD patients from SARS-CoV-2 and its subsequent effects, possibly due to memory CD4 T cells primed by previous exposure to human-associated common cold coronaviruses (CCC) and higher affinity to those allele's groove. In this context, we examined potential cross-reactivity between SARS-CoV-2 epitopes and human-associated CCC and assessed the binding affinity (BA) of these epitopes to HLA-DQ2/8. Using computational methods, we analyzed sequence similarity between SARS-CoV-2 and four distinct CCC. Of 924 unique immunodominant 15-mer epitopes with at least 67% identity, 37 exhibited significant BA to HLA-DQ2/8, suggesting a protective effect. We present various mechanisms that might explain the protective role of HLA-DQ2/8 in COVID-19-afflicted CD patients. If substantiated, these insights could enhance our understanding of the gene-environment enigma and viral-host relationship, guiding potential therapeutic innovations against the ongoing SARS-CoV-2 pandemic.

COVID-19 as a polymorphic inflammatory spectrum of diseases: a review with focus on the brain

There appear to be huge variations and aberrations in the reported data in COVID-19 2 years now into the pandemic. Conflicting data exist at almost every level and also in the reported epidemiological statistics across different regions. It is becoming clear that COVID-19 is a polymorphic inflammatory spectrum of diseases, and there is a wide range of inflammation-related pathology and symptoms in those infected with the virus. The host's inflammatory response to COVID-19 appears to be determined by genetics, age, immune status, health status and stage of disease. The interplay of these factors may decide the magnitude, duration, types of pathology, symptoms and prognosis in the spectrum of COVID-19 disorders, and whether neuropsychiatric disorders continue to be significant. Early and successful management of inflammation reduces morbidity and mortality in all stages of COVID-19.

A review of the main genetic factors influencing the course of COVID-19 in Sardinia: the role of human leukocyte antigen-G

INTRODUCTION

A large number of risk and protective factors have been identified during the SARS-CoV-2 pandemic which may influence the outcome of COVID-19. Among these, recent studies have explored the role of HLA-G molecules and their immunomodulatory effects in COVID-19, but there are very few reports exploring the genetic basis of these manifestations. The present study aims to investigate how host genetic factors, including HLA-G gene polymorphisms and sHLA-G, can affect SARS-CoV-2 infection.

MATERIALS AND METHODS

We compared the immune-genetic and phenotypic characteristics between COVID-19 patients (n = 381) with varying degrees of severity of the disease and 420 healthy controls from Sardinia (Italy).

RESULTS

HLA-G locus analysis showed that the extended haplotype HLA-G*01:01:01:01/UTR-1 was more prevalent in both COVID-19 patients and controls. In particular, this extended haplotype was more common among patients with mild symptoms than those with severe symptoms [22.7% vs 15.7%, OR = 0.634 (95% CI 0.440 - 0.913); P = 0.016]. Furthermore, the most significant HLA-G 3'UTR polymorphism (rs371194629) shows that the HLA-G 3'UTR Del/Del genotype frequency decreases gradually from 27.6% in paucisymptomatic patients to 15.9% in patients with severe symptoms (X2 = 7.095, P = 0.029), reaching the lowest frequency (7.0%) in ICU patients (X2 = 11.257, P = 0.004). However, no significant differences were observed for the soluble HLA-G levels in patients and controls. Finally, we showed that SARS-CoV-2 infection in the Sardinian population is also influenced by other genetic factors such as β-thalassemia trait (rs11549407C>T in the HBB gene), KIR2DS2/HLA-C C1+ group combination and the HLA-B*58:01, C*07:01, DRB1*03:01 haplotype which exert a protective effect [P = 0.005, P = 0.001 and P = 0.026 respectively]. Conversely, the Neanderthal LZTFL1 gene variant (rs35044562A>G) shows a detrimental consequence on the disease course [P = 0.001]. However, by using a logistic regression model, HLA-G 3'UTR Del/Del genotype was independent from the other significant variables [ORM = 0.4 (95% CI 0.2 - 0.7), PM = 6.5 x 10-4].

CONCLUSION

Our results reveal novel genetic variants which could potentially serve as biomarkers for disease prognosis and treatment, highlighting the importance of considering genetic factors in the management of COVID-19 patients.

Nonlinear interdependence of the results of measuring anti-SARS-CoV-2 IgG levels using Abbott and Euroimmun test systems

BACKGROUND

There are significant number of tests used to determine the level of antibodies to SARS-CoV-2 which differ both in the methods underlying testing and in the antigenic targets used and classes of measured immunoglobulins. Comparison of the results obtained using various tests reveals their significant discrepancy when converted to the WHO recommended standard unit for measuring the level of specific immunoglobulins BAU/mL. The aim of this study is a comparison of anty-SARS-CoV-2 IgG levels, measured using test systems based on different methodological platforms - EuroImmun assay and Abbott assay.

METHOD

Abbott uses the immunochemiluminescence method CLIA, EuroImmun uses the enzyme immunoassay method ELISA. The dependences of the measurement error on the level of antibodies for the two test systems were approximated by power functions using the least squares method. The nonlinear relation of antibody levels values measured by Abbott assay and Euroimmun assay was approximated by an asymptotic function.

RESULTS

The study involved 112 people. Our results confirm the fallacy of using a single conversion coefficient in BAU/mL for anti-SARS-CoV-2 IgG levels measured by Abbott and EuroImmun. To describe the interdependence of anti-SARS-CoV-2 IgG Abbott and EuroImmun levels, we offer the function y = 18/π arctan(0.0009x) and a calculator that allows to easily recalculate the results obtained using these tests.

CONCLUSION

The non-linear nature of the interdependence of the measured anti-SARS-CoV-2 antibodies levels on the levels magnitude is one of the main reasons for the discrepancy between the tests results when converted to BAU/mL using a single conversion coefficient.

Cellular and Molecular Mechanisms of Pathogenic and Protective Immune Responses to SARS-CoV-2 and Implications of COVID-19 Vaccines

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has devastated the world with coronavirus disease 2019 (COVID-19), which has imparted a toll of at least 631 million reported cases with 6.57 million reported deaths. In order to handle this pandemic, vaccines against SARS-CoV-2 have been developed and billions of doses of various vaccines have been administered. In the meantime, several antiviral drugs and other treatment modalities have been developed to treat COVID-19 patients. At the end of the day, it seems that anti-SARS-CoV-2 vaccines and newly developed antiviral drugs may be improved based on various new developments. COVID-19 represents a virus-induced, immune-mediated pathological process. The severity of the disease is related to the nature and properties of the host immune responses. In addition, host immunity plays a dominant role in regulating the extent of COVID-19. The present reality regarding the role of anti-SARS-CoV-2 vaccines, persistence of SARS-CoV-2 infection even three years after the initiation of the pandemic, and divergent faces of COVID-19 have initiated several queries among huge populations, policy makers, general physicians, and scientific communities. The present review aims to provide some information regarding the molecular and cellular mechanisms underlying SARS-CoV-2 infection.