COVID-19: Mechanisms, risk factors, genetics, non-coding RNAs and neurologic impairments

Quantitative IgG response to SARS-CoV-2 membrane protein in infected individuals strongly correlates with lung injury

The clinical manifestations of SARS-CoV-2 infection may range from asymptomatic or minor conditions to severe and life-threatening outcomes. The respiratory system is a principal target of the virus and in the majority of cases of severe disease, an acute form of pneumonia develops. Despite concerted global efforts to elucidate the pathogenic mechanisms of COVID-19, the progression of the infection leading to pulmonary damage remains poorly understood. The present study aimed to analyse the immunological profile of subjects with a previous SARS-CoV-2 infection and predisposition to lung injury. The results showed a strong correlation between IgG anti-membrane antibodies and lung injury.

Clinical characteristics and prognostic factors of COVID-19 in rheumatic patients and their family members: a retrospective study

Background

Patients with rheumatic diseases who receive long-term treatment with steroids, immunosuppressants, or biologics are more susceptible to infection with pathogens than the general population. In order to explore the differences in clinical features and prognosis of Corona Virus Disease 2019 (COVID-19) infection between patients with rheumatic diseases and the general population (family members), a retrospective investigative study was used to analyze the differences between the two populations.

Methods

The study was conducted in 13 Grade A Tertiary hospitals in China to investigate the clinical symptoms and prognostic factors of patients with rheumatic diseases who were infected with COVID-19 for the first time and their families.

Results

A total of 2,889 participants were included in this study, including 1,530 patients with rheumatic diseases and 1,359 family members. In terms of clinical symptoms, the complete recovery time from COVID-19 for patients with rheumatic disease patients was 13 days (8.00, 18.00), which was shorter than that of family members (16 days, 11.00, 20.00). The risk of developing moderate to severe cases of COVID-19 was lower in patients with rheumatic disease than in their family members (OR=0.511, P=0.0026). Compared with non-use of non-steroidal anti-inflammatory drugs (NSAIDs), the risk of developing mild cases of COVID-19 was 0.595 times greater with pre-infection use of NSAIDs (P = 0.0003). The use of glucocorticoids and Chinese herbal decoctions before infection increased the probability of developing mild cases of COVID-19 (OR=1.537, 1.773, P<0.05). The risk of developing moderate to severe cases with disease-modifying anti-rheumatic drugs (DMARDs) used before infection was 0.350 times that without such drugs (P<0.001). In terms of prognosis, compared with family members, the complete recovery time of patients with rheumatic diseases was reduced by 2.241 days on average (P<0.001), and the complete recovery time of patients with mild rheumatism was reduced by 4.178 days on average (P<0.001). There was no significant difference in the complete recovery time from COVID-19 in patients with severe rheumatism compared with their family members (P=0.1672). The use of NSAIDs, glucocorticoids, DMARDs, biologics, Chinese patent medicine, and Chinese herbal decoctions during the infection period could shorten the recovery time of COVID-19 symptoms (P<0.05).

Conclusions

Compared with their family members, patients with rheumatic diseases had milder symptoms after infection with COVID-19, which was related to the use of glucocorticoids, DMARDs, and Chinese herbal decoctions before infection. During the COVID-19 infection phase, the use of NSAIDs, glucocorticoids, DMARDs, biologics, Chinese patent medicine, and Chinese herbal decoctions might shorten the recovery time from symptoms of COVID-19.

Chinese clinical trial registry

ChiCTR2300072679.

SARS-CoV-2 Vaccine Improved Hemostasis of a Patient with Protein S Deficiency: A Case Report

A 16-year-old patient, while an infant, incurred right-sided hemiparesis and had difficulty breast feeding. She was later diagnosed with a neonatal stroke and her genetic testing showed a missense mutation in her PROS1 (Protein S) gene. Both her grandfather and father, but not her mother, had hereditary Protein S (PS) deficiency. The patient was not prescribed any mediation due to her young age but was frequently checked by her physician. The patient's plasma was first collected at the age of 13, and the isolated plasma from the patient and her father were analyzed by aPTT, thrombin generation, and enzyme-linked immunosorbent assays. These analyses showed low PS activity and clotting time associated with the missense mutation in the PROS1 gene. During the COVID-19 pandemic, the patient received her first Pfizer vaccination dose in 2021, followed by a booster dose in 2022. The plasma samples were collected 8 weeks post-immunization, after which her clotting parameters had improved for up to 6 months following vaccination. The patient's plasma showed a significant reduction in thrombin generation and an improved aPTT clotting time. Mass spectrometry analysis revealed that her antithrombin-III level was significantly higher post-vaccination, and both thrombin and FXII levels were significantly lowered compared with her father. To our knowledge, this is the first report to document that COVID-19 vaccination can lower the risk of thrombosis in a patient with inherited thrombophilia. Although the effect was observed on a single mutation, it would be interesting to investigate the effect of COVID-19 vaccinations on other thrombophilia.

[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.

COVID-19 outcomes in patients with sickle cell disease and sickle cell trait compared with individuals without sickle cell disease or trait: a systematic review and meta-analysis

Background

Clinical manifestations and severity of SARS-CoV-2 infection in individuals with sickle cell disease (SCD) and sickle cell trait (SCT) are not well understood yet.

Methods

We performed a systematic review and meta-analysis to assess COVID-19 outcomes in individuals with SCD or SCT compared to individuals without sickle cell disease or trait. An electronic search on PubMed, Embase, and Cochrane Library was performed on August 3, 2023. Two authors (IFM and ISP) independently screened (IFM and ISP) and extracted data (IFM and ILC) from included studies. Main exclusion criterion was the absence of the non-SCD/SCT group. Exposure effects for binary endpoints were compared using pooled odds ratio (OR) with 95% confidence intervals (CI). I2 statistics was used to assess the heterogeneity and DerSimonian and Laird random-effects models were applied for all analyses to minimize the impact of differences in methods and outcomes definitions between studies. The overall quality of evidence was assessed using the GRADE system. Review Manager 5.4 and R software (v4.2.2) were used for statistical analyses. Registered with PROSPERO, CRD42022366015.

Findings

Overall, 22 studies were included, with a total of 1892 individuals with SCD, 8677 individuals with SCT, and 1,653,369 individuals without SCD/SCT. No difference in all-cause mortality was seen between SCD/SCT and non-SCD/SCT (OR 1.18; 95% CI 0.78-1.77; p = 0.429; I2 = 82%). When considering only studies adjusted for confounders (8 studies), patients with SCD/SCT were shown to be at increased risk of death (OR 1.86; 95% CI 1.30-2.66; p = 0.0007; I2 = 34%). No significant difference was seen between individuals with SCD and SCT (p = 0.863). The adjusted for confounders analysis for hospitalisation revealed higher rates for the SCD (OR 5.44; 95% CI 1.55-19.13; p = 0.008; I2 = 97%) and the SCT groups (OR 1.31; 95% CI 1.10-1.55; p = 0.002; I2 = 0) compared to the non-SCD/SCT population. Moreover, it was significantly higher for the SCD group (test for subgroup difference; p = 0.028).

Interpretation

Our findings suggest that patients with SCD or SCT may present with a higher mortality and hospitalisation rates due to COVID-19 infection.

Funding

None.

Differentially-regulated miRNAs in COVID-19: A systematic review

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for coronavirus disease of 2019 (COVID-19) that infected more than 760 million people worldwide with over 6.8 million deaths to date. COVID-19 is one of the most challenging diseases of our times due to the nature of its spread, its effect on multiple organs, and an inability to predict disease prognosis, ranging from being completely asymptomatic to death. Upon infection, SARS-CoV-2 alters the host immune response by changing host-transcriptional machinery. MicroRNAs (miRNAs) are regarded as post-transcriptional regulators of gene expression that can be perturbed by invading viruses. Several in vitro and in vivo studies have reported such dysregulation of host miRNA expression upon SARS-CoV-2 infection. Some of this could occur as an anti-viral response of the host to the viral infection. Viruses themselves can counteract that response by mounting their own pro-viral response that facilitates virus infection, an aspect which may cause pathogenesis. Thus, miRNAs could serve as possible disease biomarkers in infected people. In the current review, we have summarised and analysed the existing data about miRNA dysregulation in patients infected with SARS-CoV-2 to determine their concordance between studies, and identified those that could serve as potential biomarkers during infection, disease progression, and death, even in people with other co-morbidities. Having such biomarkers can be vital in not only predicting COVID-19 prognosis, but also the development of novel miRNA-based anti-virals and therapeutics which can become invaluable in case of the emergence of new viral variants with pandemic potential in the future.