Pathophysiology of acute respiratory syndrome coronavirus 2 infection: a systematic literature review to inform EULAR points to consider

Acute Respiratory Failure in Autoimmune Rheumatic Diseases: A Review

This review examines respiratory complications in autoimmune rheumatic diseases within intensive care units (ICUs). The respiratory system, primarily affected in diseases like rheumatoid arthritis, systemic lupus erythematosus, and scleroderma, often leads to respiratory failure. Common manifestations include alveolar hemorrhage, interstitial fibrosis, and acute respiratory distress syndrome. Early recognition and treatment of non-malignant conditions are crucial to prevent rapid disease progression, with ICU mortality rates ranging from 30% to 60%. Delayed immunosuppressive or antimicrobial therapy may result in organ system failure. Collaboration with rheumatic specialists is vital for accurate diagnosis and immediate intervention. Mortality rates for rheumatic diseases in the ICU surpass those of other conditions, underscoring the need for specialized care and proactive management. The review emphasizes comprehensive assessments, distinguishing disease-related complications from underlying issues, and the importance of vigilant monitoring to enhance patient outcomes.

Antiplatelet agents for the treatment of adults with COVID-19

BACKGROUND

Severe coronavirus disease 2019 (COVID-19) can cause thrombotic events that lead to severe complications or death. Antiplatelet agents, such as acetylsalicylic acid, have been shown to effectively reduce thrombotic events in other diseases: they could influence the course of COVID-19 in general.

OBJECTIVES

To assess the efficacy and safety of antiplatelets given with standard care compared to no treatment or standard care (with/without placebo) for adults with COVID-19.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register (which comprises MEDLINE (PubMed), Embase, ClinicalTrials.gov, WHO ICTRP, medRxiv, CENTRAL), Web of Science, WHO COVID-19 Global literature on coronavirus disease and the Epistemonikos COVID-19 L*OVE Platform to identify completed and ongoing studies without language restrictions to December 2022.

SELECTION CRITERIA

We followed standard Cochrane methodology. We included randomised controlled trials (RCTs) evaluating antiplatelet agents for the treatment of COVID-19 in adults with COVID-19, irrespective of disease severity, gender or ethnicity.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. To assess bias in included studies, we used the Cochrane risk of bias tool (RoB 2) for RCTs. We rated the certainty of evidence using the GRADE approach for the outcomes.

MAIN RESULTS

Antiplatelets plus standard care versus standard care (with/without placebo) Adults with a confirmed diagnosis of moderate to severe COVID-19 We included four studies (17,541 participants) that recruited hospitalised people with a confirmed diagnosis of moderate to severe COVID-19. A total of 8964 participants were analysed in the antiplatelet arm (either with cyclooxygenase inhibitors or P2Y12 inhibitors) and 8577 participants in the control arm. Most people were older than 50 years and had comorbidities such as hypertension, lung disease or diabetes. The studies were conducted in high- to lower middle-income countries prior to wide-scale vaccination programmes. Antiplatelets compared to standard care: - probably result in little to no difference in 28-day mortality (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.85 to 1.05; 3 studies, 17,249 participants; moderate-certainty evidence). In absolute terms, this means that for every 177 deaths per 1000 people not receiving antiplatelets, there were 168 deaths per 1000 people who did receive the intervention (95% CI 151 to 186 per 1000 people); - probably result in little to no difference in worsening (new need for invasive mechanical ventilation or death up to day 28) (RR 0.95, 95% CI 0.90 to 1.01; 2 studies, 15,266 participants; moderate-certainty evidence); - probably result in little to no difference in improvement (participants discharged alive up to day 28) (RR 1.00, 95% CI 0.96 to 1.04; 2 studies, 15,454 participants; moderate-certainty evidence); - probably result in a slight reduction of thrombotic events at longest follow-up (RR 0.90, 95% CI 0.80 to 1.02; 4 studies, 17,518 participants; moderate-certainty evidence); - may result in a slight increase in serious adverse events at longest follow-up (Peto odds ratio (OR) 1.57, 95% CI 0.48 to 5.14; 1 study, 1815 participants; low-certainty evidence), but non-serious adverse events during study treatment were not reported; - probably increase the occurrence of major bleeding events at longest follow-up (Peto OR 1.68, 95% CI 1.29 to 2.19; 4 studies, 17,527 participants; moderate-certainty evidence). Adults with a confirmed diagnosis of asymptomatic SARS-CoV-2 infection or mild COVID-19 We included two RCTs allocating participants, of whom 4209 had confirmed mild COVID-19 and were not hospitalised. A total of 2109 participants were analysed in the antiplatelet arm (treated with acetylsalicylic acid) and 2100 participants in the control arm. No study included people with asymptomatic SARS-CoV-2 infection. Antiplatelets compared to standard care: - may result in little to no difference in all-cause mortality at day 45 (Peto OR 1.00, 95% CI 0.45 to 2.22; 2 studies, 4209 participants; low-certainty evidence); - may slightly decrease the incidence of new thrombotic events up to day 45 (Peto OR 0.37, 95% CI 0.09 to 1.46; 2 studies, 4209 participants; low-certainty evidence); - may make little or no difference to the incidence of serious adverse events up to day 45 (Peto OR 1.00, 95% CI 0.60 to 1.64; 1 study, 3881 participants; low-certainty evidence), but non-serious adverse events were not reported. The evidence is very uncertain about the effect of antiplatelets on the following outcomes (compared to standard care plus placebo): - admission to hospital or death up to day 45 (Peto OR 0.79, 95% CI 0.57 to 1.10; 2 studies, 4209 participants; very low-certainty evidence); - major bleeding events up to longest follow-up (no event occurred in 328 participants; very low-certainty evidence). Quality of life and adverse events during study treatment were not reported.

AUTHORS' CONCLUSIONS

In people with confirmed or suspected COVID-19 and moderate to severe disease, we found moderate-certainty evidence that antiplatelets probably result in little to no difference in 28-day mortality, clinical worsening or improvement, but probably result in a slight reduction in thrombotic events. They probably increase the occurrence of major bleeding events. Low-certainty evidence suggests that antiplatelets may result in a slight increase in serious adverse events. In people with confirmed COVID-19 and mild symptoms, we found low-certainty evidence that antiplatelets may result in little to no difference in 45-day mortality and serious adverse events, and may slightly reduce thrombotic events. The effects on the combined outcome admission to hospital or death up to day 45 and major bleeding events are very uncertain. Quality of life was not reported. Included studies were conducted in high- to lower middle-income settings using antiplatelets prior to vaccination roll-outs. We identified a lack of evidence concerning quality of life assessments, adverse events and people with asymptomatic infection. The 14 ongoing and three completed, unpublished RCTs that we identified in trial registries address similar settings and research questions as in the current body of evidence. We expect to incorporate the findings of these studies in future versions of this review.

Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases

Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.

Characteristics associated with poor COVID-19 outcomes in people with psoriasis, psoriatic arthritis and axial spondyloarthritis: data from the COVID-19 PsoProtect and Global Rheumatology Alliance physician-reported registries

OBJECTIVES

To investigate factors associated with severe COVID-19 in people with psoriasis (PsO), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA).

METHODS

Demographic data, clinical characteristics and COVID-19 outcome severity of adults with PsO, PsA and axSpA were obtained from two international physician-reported registries. A three-point ordinal COVID-19 severity scale was defined: no hospitalisation, hospitalisation (and no death) and death. ORs were estimated using multivariable ordinal logistic regression.

RESULTS

Of 5045 cases, 18.3% had PsO, 45.5% PsA and 36.3% axSpA. Most (83.6%) were not hospitalised, 14.6% were hospitalised and 1.8% died. Older age was non-linearly associated with COVID-19 severity. Male sex (OR 1.54, 95% CI 1.30 to 1.83), cardiovascular, respiratory, renal, metabolic and cancer comorbidities (ORs 1.25-2.89), moderate/high disease activity and/or glucocorticoid use (ORs 1.39-2.23, vs remission/low disease activity and no glucocorticoids) were associated with increased odds of severe COVID-19. Later pandemic time periods (ORs 0.42-0.52, vs until 15 June 2020), PsO (OR 0.49, 95% CI 0.37 to 0.65, vs PsA) and baseline exposure to TNFi, IL17i and IL-23i/IL-12+23i (OR 0.57, 95% CI 0.44 to 0.73; OR 0.62, 95% CI 0.45 to 0.87; OR 0.67, 95% CI 0.45 to 0.98; respectively; vs no disease-modifying antirheumatic drug) were associated with reduced odds of severe COVID-19.

CONCLUSION

Older age, male sex, comorbidity burden, higher disease activity and glucocorticoid intake were associated with more severe COVID-19. Later pandemic time periods, PsO and exposure to TNFi, IL17i and IL-23i/IL-12+23i were associated with less severe COVID-19. These findings will enable risk stratification and inform management decisions for patients with PsO, PsA and axSpA during COVID-19 waves or similar future respiratory pandemics.

Nineteen months into the pandemic, what have we learned about COVID-19-related outcomes in patients with psoriasis?

BACKGROUND

The impact of psoriasis on the outcomes of Coronavirus disease 2019 (COVID-19) is yet to be precisely delineated.

OBJECTIVES

To assess the risk of COVID-19, COVID-19-associated hospitalization, and mortality among patients with psoriasis as compared with age-, sex-, and ethnicity-matched control subjects. In addition, we aim to delineate determinants of COVID-19-associated hospitalization and mortality in patients with psoriasis.

METHODS

A population-based retrospective cohort study was performed to longitudinally follow patients with psoriasis and their matched controls with regard to COVID-19-related outcomes. The risk of COVID-19 infection, COVID-19-associated hospitalization, and mortality were assessed using uni- and multi-variable Cox regression analyses. Determinants of COVID-19-associated hospitalization and mortality were evaluated using multivariable logistic regression analysis.

RESULTS

The study population included 144 304 patients with psoriasis and 144 304 age- and sex-matched control individuals. Patients with psoriasis displayed a slightly elevated risk of SARS-CoV-2 infection (fully-adjusted HR, 1.05; 95% CI, 1.03-1.08; p < 0.001). Relative to controls, patients with psoriasis had comparable multivariate risk of COVID-19-associated hospitalization (fully-adjusted HR, 1.08; 95% CI, 0.99-1.18; p = 0.065) and COVID-19-associated mortality (fully-adjusted HR, 0.88; 95% CI, 0.73-1.05; p = 0.162). When evaluating individuals hospitalized due to COVID-19, patients with psoriasis were more likely to have type-2 diabetes mellitus (adjusted OR, 1.24; 95% CI, 1.03-1.50; p = 0.027) and obesity (adjusted OR, 1.37; 95% CI, 1.13-1.65; p = 0.001) relative to controls.

CONCLUSIONS

While patients with psoriasis are at a higher risk of contracting SARS-CoV-2 infection, they are not more susceptible to the complications of COVID-19.

A randomised, double-blind, placebo-controlled, multicentre clinical trial of AZD1656 in diabetic patients hospitalised with COVID-19: The ARCADIA Trial - implications for therapeutic immune modulation

BACKGROUND

A potential immunotherapeutic role for AZD1656 (a glucokinase activator) in the treatment of COVID-19 was hypothesized. The ARCADIA trial investigated the safety and efficacy of AZD1656 in diabetic patients admitted to hospital with COVID-19.

METHODS

The ARCADIA trial was a Phase II randomised, double-blind, placebo-controlled clinical trial. Adult diabetic patients, admitted with COVID-19, were recruited at 28 hospitals in the UK, Romania and Czech Republic and randomly assigned (1:1) to receive AZD1656 tablets (100mg twice a day), or matched placebo, for up to 21 days, in addition to usual care. All involved were masked to treatment allocation. The primary endpoint was clinical improvement measured at Day 14. The Full Analysis Set (FAS) included all patients who received at least one dose of assigned treatment. ARCADIA is complete and registered with ClinicalTrials.gov (NCT04516759).

FINDINGS

Between 29 September 2020 to 16 April 2021, 170 patients were screened and 156 patients were randomised, three of whom did not commence treatment. Of the remaining 153, 80 were assigned to AZD1656 and 73 were assigned to placebo and included in the Full Analysis Set (FAS). The primary analysis showed no statistically significant difference between groups (AZD1656: 76·3%; Placebo: 69·9%, p=0·19). There was no difference in the number of adverse events between groups (AZD1656: 35·7%; Placebo: 33·3%). Mortality was lower in the AZD1656 group compared to the placebo group (AZD1656: four (5%); Placebo: nine (12·3%), p=0·090)). At Day 7 there were zero deaths in the AZD1656 group compared to six deaths in the placebo group (p=0·011, post hoc). A difference between groups in time to hospital discharge was also seen (p=0·16). Immunophenotyping data suggested that AZD1656-treated patients had a less pro-inflammatory immune response and a better adaptive immune response than those treated with placebo.

INTERPRETATION

Although the trial did not achieve its primary endpoint, AZD1656 was associated with a decrease in deaths and a reduction in the duration of hospitalisation, as compared to Placebo. Immunophenotyping and immunochemistry indicated an immunomodulatory effect of AZD1656. The trial suggests a beneficial therapeutic effect of AZD1656 and identifies a new therapeutic concept: small molecule activation of endogenous homeostatic immune cells which themselves become the therapeutic agent within the body. Phase 2 trials of this size carry the risk of false positive results and confirmation of these results in a larger clinical trial is now required.

FUNDING

UK Research and Innovation (UKRI) 'Innovate UK' programme and Excalibur Medicines Ltd.

Perforin, COVID-19 and a possible pathogenic auto-inflammatory feedback loop

During COVID‐19 infection, reduced function of natural killer (NK) cells can lead to both compromised viral clearance and dysregulation of the immune response. Such dysregulation leads to overproduction of cytokines, a raised neutrophil/lymphocyte ratio and monocytosis. This in turn increases IL‐6 expression, which promotes scar and thrombus formation. Excess IL‐6 also leads to a further reduction in NK function through downregulation of perforin expression, therefore forming a pathogenic auto‐inflammatory feedback loop. The perforin/granzyme system of cytotoxicity is the main mechanism through which NK cells and cytotoxic T lymphocytes eliminate virally infected host cells, as well as being central to their role in regulating immune responses to microbial infection. Here, we present epidemiological evidence suggesting an association between perforin expression and resistance to COVID‐19. In addition, we outline the manner in which a pathogenic auto‐inflammatory feedback loop could operate and the relationship of this loop to genes associated with severe COVID‐19. Such an auto‐inflammatory loop may be amenable to synergistic multimodal therapy.

SARS-CoV-2 Serology Testing in an Asymptomatic, At-Risk Population: Methods, Results, Pitfalls

The primary aim of this study was to determine the seroprevalence of SARS-CoV-2 antibodies in a population of pediatric healthcare workers (HCWs). This study was conducted 14 May-13 July 2020. Study participants included pediatric HCWs at a pediatric hospital with either direct patient contact or close proximity to patient-care areas. SARS-CoV-2 antibodies were assessed via the Wytcote Superbio SARS-CoV-2 IgM/IgG Antibody Fast Detection Kit and the Abbott Architect SARS-CoV-2 IgG assay. Participants underwent RT-PCR testing upon entry to the study and following rapid IgM+/IgG+ results; respiratory panel PCR (RP-PCR) was performed following IgM+ results. A total of 57 of 289 (19.7%) of participants demonstrated positive serology as assessed by the Wytcote rapid kit (12 on Day 1 and 45 throughout the study). However, only one of these participants demonstrated IgG+ serology via the Abbott assay. Two participants tested SARS-CoV-2+ via RT-PCR testing. One individual was adenovirus+ and enterovirus/rhinovirus+. In our study population, we observed a seroprevalence of SARS-CoV-2 antibodies of 0.35%. The lack of concordance between antibody tests suggests that the Wytcote rapid test kit may not be of use as a screening tool. However, the feasibility of the overall process indicates that a similar methodology may have potential for future epidemiologic surveillance.

COVID-19 and immune-mediated inflammatory diseases: effect of disease and treatment on COVID-19 outcomes and vaccine responses

At the beginning of the COVID-19 pandemic, patients with immune-mediated inflammatory diseases were considered to be at high risk for SARS-CoV-2 infection and the development of severe COVID-19. Data collected over the past year, however, suggest that a diagnosis of inflammatory arthritis, psoriasis, or inflammatory bowel diseases does not increase risk for SARS-CoV-2 infection or severe COVID-19 compared with people without these diseases. Furthermore, substantial data suggest that certain medications frequently used in patients with immune-mediated inflammatory diseases, in particular cytokine inhibitors, might even lower the risk for severe COVID-19. Conversely, glucocorticoids and potentially B-cell-depleting treatments seem to worsen COVID-19 outcomes. Additionally, the first data on SARS-CoV-2 vaccination in patients with these diseases suggest that tolerability of vaccination in patients with immune-mediated inflammatory diseases is good, although the immune response to vaccination can be somewhat reduced in this patient group, particularly those taking methotrexate or CD20-targeted treatment.

Involvement of Interleukin-1 Receptor-Associated Kinase 4 and Interferon Regulatory Factor 5 in the Immunopathogenesis of SARS-CoV-2 Infection: Implications for the Treatment of COVID-19

Interleukin-1 receptor-associated kinase 4 (IRAK4) and interferon regulatory factor 5 (IRF5) lie sequentially on a signaling pathway activated by ligands of the IL-1 receptor and/or multiple TLRs located either on plasma or endosomal membranes. Activated IRF5, in conjunction with other synergistic transcription factors, notably NF-κB, is crucially required for the production of proinflammatory cytokines in the innate immune response to microbial infection. The IRAK4-IRF5 axis could therefore have a major role in the induction of the signature cytokines and chemokines of the hyperinflammatory state associated with severe morbidity and mortality in COVID-19. Here a case is made for considering IRAK4 or IRF5 inhibitors as potential therapies for the "cytokine storm" of COVID-19.