Application of intravenous immunoglobulin (IVIG) to modulate inflammation in critical COVID-19 - A theoretical perspective

Immunopathology of and potential therapeutics for secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome: a translational perspective

Secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (sHLH/MAS) is a life-threatening immune disorder triggered by rheumatic disease, infections, malignancies, or medications. Characterized by the presence of hemophagocytic macrophages and a fulminant cytokine storm, sHLH/MAS leads to hyperferritinemia and multiorgan failure and rapidly progresses to death. The high mortality rate and the lack of specific treatments necessitate the development of a new drug. However, the complex and largely unknown immunopathologic mechanisms of sHLH/MAS, which involve dysfunction of various immune cells, diverse etiologies, and different clinical contexts make this effort challenging. This review introduces the terminology, diagnosis, and clinical features of sHLH/MAS. From a translational perspective, this review focuses on the immunopathological mechanisms linked to various etiologies, emphasizing potential drug targets, including key molecules and signaling pathways. We also discuss immunomodulatory biologics, existing drugs under clinical evaluation, and novel therapies in clinical trials. This systematic review aims to provide insights and highlight opportunities for the development of novel sHLH/MAS therapeutics.

Intravenous immunoglobulin for treatment of hospitalized COVID-19 patients: an evidence mapping and meta-analysis

BACKGROUND

The clinical efficacy and safety of intravenous immunoglobulin (IVIg) treatment for COVID-19 remain controversial. This study aimed to map the current status and gaps of available evidence, and conduct a meta-analysis to further investigate the benefit of IVIg in COVID-19 patients.

METHODS

Electronic databases were searched for systematic reviews/meta-analyses (SR/MAs), primary studies with control groups, reporting on the use of IVIg in patients with COVID-19. A random-effects meta-analysis with subgroup analyses regarding study design and patient disease severity was performed. Our outcomes of interest determined by the evidence mapping, were mortality, length of hospitalization (days), length of intensive care unit (ICU) stay (days), number of patients requiring mechanical ventilation, and adverse events.

RESULTS

We included 34 studies (12 SR/MAs, 8 prospective and 14 retrospective studies). A total of 5571 hospitalized patients were involved in 22 primary studies. Random-effects meta-analyses of very low to moderate evidence showed that there was little or no difference between IVIg and standard care or placebo in reducing mortality (relative risk [RR] 0.91; 95% CI 0.78-1.06; risk difference [RD] 3.3% fewer), length of hospital (mean difference [MD] 0.37; 95% CI - 2.56, 3.31) and ICU (MD 0.36; 95% CI - 0.81, 1.53) stays, mechanical ventilation use (RR 0.92; 95% CI 0.68-1.24; RD 2.8% fewer), and adverse events (RR 0.98; 95% CI 0.84-1.14; RD 0.5% fewer) of patients with COVID-19. Sensitivity analysis using a fixed-effects model indicated that IVIg may reduce mortality (RR 0.76; 95% CI 0.60-0.97), and increase length of hospital stay (MD 0.68; 95% CI 0.09-1.28).

CONCLUSION

Very low to moderate certainty of evidence indicated IVIg may not improve the clinical outcomes of hospitalized patients with COVID-19. Given the discrepancy between the random- and fixed-effects model results, further large-scale and well-designed RCTs are warranted.

Targeting intracellular pathways in idiopathic inflammatory myopathies: A narrative review

In recent decades, several pieces of evidence have drawn greater attention to the topic of innate immunity, in particular, interferon (IFN) and Interleukin 6 in the pathogenesis of idiopathic inflammatory myopathies (IIM). Both of these molecules transduce their signal through a receptor coupled with Janus kinases (JAK)/signal transducer and activator of transcription proteins (STAT). In this review, we discuss the role of the JAK/STAT pathway in IIM, evaluate a possible therapeutic role for JAK inhibitors in this group of diseases, focusing on those with the strongest IFN signature (dermatomyositis and antisynthetase syndrome).

Therapeutic role of immunomodulators during the COVID-19 pandemic- a narrative review

The emergency state caused by COVID-19 saw the use of immunomodulators despite the absence of robust research. To date, the results of relatively few randomized controlled trials have been published, and methodological approaches are riddled with bias and heterogeneity. Anti-SARS-CoV-2 antibodies, convalescent plasma and the JAK inhibitor baricitinib have gained Emergency Use Authorizations and tentative recommendations for their use in clinical practice alone or in combination with other therapies. Anti-SARS-CoV-2 antibodies are predominating the management of non-hospitalized patients, while the inpatient setting is seeing the use of convalescent plasma, baricitinib, tofacitinib, tocilizumab, sarilumab, and corticosteroids, as applicable. Available clinical data also suggest the potential clinical benefit of the early administration of blood-derived products (e.g. convalescent plasma, non-SARS-CoV-2-specific immunoglobins) and the blockade of factors implicated in the hyperinflammatory state of severe COVID-19 (Interleukin 1 and 6; Janus Kinase). Immune therapies seem to have a protective effect and using immunomodulators alone or in combination with viral replication inhibitors and other treatment modalities might prevent progression into severe COVID-19 disease, cytokine storm and death. Future trials should address existing gaps and reshape the landscape of COVID-19 management.

Scientific premise for the involvement of neutrophil extracellular traps (NETs) in vaccine-induced thrombotic thrombocytopenia (VITT)

Following on from the devastating spread of COVID-19, a major global priority has been the production, procurement, and distribution of effective vaccines to ensure that the global pandemic reaches an end. However, concerns were raised about worrying side effects, particularly the occurrence of thrombosis and thrombocytopenia after administration of the Oxford/AstraZeneca and Johnson & Johnson's Janssen COVID-19 vaccine, in a phenomenon being termed vaccine-induced thrombotic thrombocytopenia (VITT). Similar to heparin-induced thrombocytopenia (HIT), this condition has been associated with the development of anti-platelet factor 4 antibodies, purportedly leading to neutrophil-platelet aggregate formation. Although thrombosis has also been a common association with COVID-19, the precise molecular mechanisms governing its occurrence are yet to be established. Recently, increasing evidence highlights the NLRP3 (NOD-like, leucine-rich repeat domains, and pyrin domain-containing protein) inflammasome complex along with IL-1β and effete neutrophils producing neutrophil extracellular traps (NETs) through NETosis. Herein, we propose and discuss that perhaps the incidence of VITT may be due to inflammatory reactions mediated via IL-1β/NLRP3 inflammasome activation and consequent overproduction of NETs, where similar autoimmune mechanisms are observed in HIT. We also discuss avenues by which such modalities could be treated to prevent the occurrence of adverse events and ensure vaccine rollouts remain safe and on target to end the current pandemic.

Efficacy of High-Dose Polyclonal Intravenous Immunoglobulin in COVID-19: A Systematic Review

BACKGROUND

Although several therapeutic strategies have been investigated, the optimal treatment approach for patients with coronavirus disease (COVID-19) remains to be elucidated. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of polyclonal intravenous immunoglobulin (IVIG) therapy in COVID-19.

METHODS

A systematic literature search using appropriate medical subject heading (MeSH) terms was performed through Medline (PubMed), EMBASE, SCOPUS, OVID and Cochrane Library electronic databases. The main outcomes considered were mortality and safety of IVIG versus placebo/standard of care. This review was carried out in accordance with Cochrane methodology including the risk bias assessment and grading of the quality of evidence. Measures of treatment effect were mean differences (MD) together with 95% confidence intervals (CIs) for continuous outcome measures and risk ratio (RR) or MD for binary outcomes. Two reviewers independently extracted data from individual studies, and disagreements were resolved by a third reviewer.

RESULTS

A total of 2401 COVID-19 patients from 10 studies (four randomized controlled trials (RCT) and six non-randomized controlled trials (non-RCTs)) were included in the analysis. Participants received IVIG or placebo/standard of care. The use of IVIG was not associated with a significantly reduced risk of death (RR 0.50, 95% CIs 0.18-1.36, p = 0.17 for RCTs; RR 0.95, 95% CIs 0.61-1.58, p = 0.94 for non-RCTs; low certainty of evidence). IVIG significantly reduced the length of hospital stay (MD -2.24, 95% CIs -3.20/-1.27; p = 0.00001; low certainty of evidence), although this difference was significant only for studies evaluating moderate COVID-19 patients. No significant difference was observed in the incidence of overall and serious adverse events between IVIG recipients and controls (very low certainty of evidence).

CONCLUSIONS

The current evidence from the literature does not support the use of IVIG in COVID-19 patients.

DW-UNet: Loss Balance under Local-Patch for 3D Infection Segmentation from COVID-19 CT Images

(1) Background: COVID-19 has been global epidemic. This work aims to extract 3D infection from COVID-19 CT images; (2) Methods: Firstly, COVID-19 CT images are processed with lung region extraction and data enhancement. In this strategy, gradient changes of voxels in different directions respond to geometric characteristics. Due to the complexity of tubular tissues in lung region, they are clustered to the lung parenchyma center based on their filtered possibility. Thus, infection is improved after data enhancement. Then, deep weighted UNet is established to refining 3D infection texture, and weighted loss function is introduced. It changes cost calculation of different samples, causing target samples to dominate convergence direction. Finally, the trained network effectively extracts 3D infection from CT images by adjusting driving strategy of different samples. (3) Results: Using Accuracy, Precision, Recall and Coincidence rate, 20 subjects from a private dataset and eight subjects from Kaggle Competition COVID-19 CT dataset tested this method in hold-out validation framework. This work achieved good performance both in the private dataset (99.94-00.02%, 60.42-11.25%, 70.79-09.35% and 63.15-08.35%) and public dataset (99.73-00.12%, 77.02-06.06%, 41.23-08.61% and 52.50-08.18%). We also applied some extra indicators to test data augmentation and different models. The statistical tests have verified the significant difference of different models. (4) Conclusions: This study provides a COVID-19 infection segmentation technology, which provides an important prerequisite for the quantitative analysis of COVID-19 CT images.

Rationale for Polyclonal Intravenous Immunoglobulin Adjunctive Therapy in COVID-19 Patients: Report of a Structured Multidisciplinary Consensus

Introduction: Adjunctive therapy with polyclonal intravenous immunoglobins (IVIg) is currently used for preventing or managing infections and sepsis, especially in immunocompromised patients. The pathobiology of COVID-19 and the mechanisms of action of Ig led to the consideration of this adjunctive therapy, including in patients with respiratory failure due to the SARS-CoV-2 infection. This manuscript reports the rationale, the available data and the results of a structured consensus on intravenous Ig therapy in patients with severe COVID-19. Methods: A panel of multidisciplinary experts defined the clinical phenotypes of COVID-19 patients with severe respiratory failure and, after literature review, voted for the agreement on the rationale and the potential role of IVIg therapy for each phenotype. Due to the scarce evidence available, a modified RAND/UCLA appropriateness method was used. Results: Three different phenotypes of COVID-19 patients with severe respiratory failure were identified: patients with an abrupt and dysregulated hyperinflammatory response (early phase), patients with suspected immune paralysis (late phase) and patients with sepsis due to a hospital-acquired superinfection (sepsis by bacterial superinfection). The rationale for intravenous Ig therapy in the early phase was considered uncertain whereas the panelists considered its use in the late phase and patients with sepsis/septic shock by bacterial superinfection appropriate. Conclusion: As with other immunotherapies, IVIg adjunctive therapy may have a potential role in the management of COVID-19 patients. The ongoing trials will clarify the appropriate target population and the true effectiveness.