Calcineurin inhibitors revisited: A new paradigm for COVID-19?

Advances in attractive therapeutic approach for macrophage activation syndrome in COVID-19

Nowadays, people have relaxed their vigilance against COVID-19 due to its declining infection numbers and attenuated virulence. However, COVID-19 still needs to be concern due to its emerging variants, the relaxation of restrictions as well as breakthrough infections. During the period of the COVID-19 infection, the imbalanced and hyper-responsive immune system plays a critical role in its pathogenesis. Macrophage Activation Syndrome (MAS) is a fatal complication of immune system disease, which is caused by the excessive activation and proliferation of macrophages and cytotoxic T cells (CTL). COVID-19-related hyperinflammation shares common clinical features with the above MAS symptoms, such as hypercytokinemia, hyperferritinemia, and coagulopathy. In MAS, immune exhaustion or defective anti-viral responses leads to the inadequate cytolytic capacity of CTL which contributes to prolonged interaction between CTL, APCs and macrophages. It is possible that the same process also occurred in COVID-19 patients, and further led to a cytokine storm confined to the lungs. It is associated with the poor prognosis of severe patients such as multiple organ failure and even death. The main difference of cytokine storm is that in COVID-19 pneumonia is mainly the specific damage of the lung, while in MAS is easy to develop into a systemic. The attractive therapeutic approach to prevent MAS in COVID-19 mainly includes antiviral, antibiotics, convalescent plasma (CP) therapy and hemadsorption, extensive immunosuppressive agents, and cytokine-targeted therapies. Here, we discuss the role of the therapeutic approaches mentioned above in the two diseases. And we found that the treatment effect of the same therapeutic approach is different.

Liver Injury Associated with COVID-19 Infection: Pathogenesis, Histopathology, Prognosis, and Treatment

Liver injury occurs frequently as a consequence of SARS-CoV-2 infection. Direct infection of the liver leads to hepatic impairment with elevated transaminases. In addition, severe COVID-19 is characterized by cytokine release syndrome, which may initiate or exacerbate liver injury. In patients with cirrhosis, SARS-CoV-2 infection is associated with acute-on-chronic liver failure. The Middle East and North Africa (MENA) region is one of the world's regions characterized by a high prevalence of chronic liver diseases. Both parenchymal and vascular types of injury contribute to liver failure in COVID-19, with a myriad of pro-inflammatory cytokines playing a major role in perpetuating liver injury. Additionally, hypoxia and coagulopathy complicate such a condition. This review discusses the risk factors, and the underlying causes of impaired liver functions in COVID-19, with a focus on key players in the pathogenesis of liver injury. It also highlights the histopathological changes encountered in postmortem liver tissues as well as potential predictors and prognostic factors of such injury, in addition to the management strategies to ameliorate liver damage.

The Outcome of COVID-19 Infection on Kidney Transplantation Recipients in Southern Saudi Arabia: Single-Center Experience

BACKGROUND

To report the incidence, risk factors, and outcome of severe COVID-19 disease in kidney transplant recipients attending a Saudi hospital at a single center in the Kingdom of Saudi Arabia.

METHODS

A retrospective chart-based cohort study involving all kidney transplant recipients tested for COVID-19 in the Armed Forces Hospital Southern Region, KSA.

RESULTS

Of 532 kidney transplant recipients who reported to the center, from March 2020 to June 2022, 180 were tested for COVID-19. Of these recipients, 31 (17%) tested positive. Among the 31 positive recipients, 11 were treated at home, 15 were admitted to the noncritical isolation ward, and 5 were admitted to the intensive care unit (ICU). Older age (P = .0001), higher body mass index (P = .0001), and history of hypertension (P = .0023) were more frequent in the COVID-19-positive recipients. Admission to the ICU was more frequent in older recipients (P = .0322) with a history of ischemic heart disease (P = .06) and higher creatinine baseline (P = .08) presenting with dyspnea (P = .0174), and acute allograft dysfunction (P = .002). In the ICU group, 4 (80%) patients required hemodialysis, and 4 (80%) died.

CONCLUSIONS

Kidney transplant recipients with COVID-19 could have a higher risk for developing acute kidney injury, dialysis, and mortality than the general population. ICU admission and renal replacement therapy were more evident in older recipients with a history of ischemic heart disease, presenting with shortness of breath (P = .017) and a higher serum creatinine baseline. Acute allograft dysfunction was the independent predictor of mortality among patients admitted to the ICU.

Immunomodulatory therapy for the management of critically ill patients with COVID-19: A narrative review

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Understanding the physiological and immunological processes underlying the clinical manifestations of COVID-19 is vital for the identification and rational design of effective therapies.

AIM

To describe the interaction of SARS-CoV-2 with the immune system and the subsequent contribution of hyperinflammation and abnormal immune responses to disease progression together with a complete narrative review of the different immunoadjuvant treatments used so far in COVID-19 and their indication in severe and life-threatening subsets.

METHODS

A comprehensive literature search was developed. Authors reviewed the selected manuscripts following the PRISMA recommendations for systematic review and meta-analysis documents and selected the most appropriate. Finally, a recommendation of the use of each treatment was established based on the level of evidence of the articles and documents reviewed. This recommendation was made based on the consensus of all the authors.

RESULTS

A brief rationale on the SARS-CoV-2 pathogenesis, immune response, and inflammation was developed. The usefulness of 10 different families of treatments related to inflammation and immunopathogenesis of COVID-19 was reviewed and discussed. Finally, based on the level of scientific evidence, a recommendation was established for each of them.

CONCLUSION

Although several promising therapies exist, only the use of corticosteroids and tocilizumab (or sarilumab in absence of this) have demonstrated evidence enough to recommend its use in critically ill patients with COVID-19. Endotypes including both, clinical and biological characteristics can constitute specific targets for better select certain therapies based on an individualized approach to treatment.

Identification of host transcriptome-guided repurposable drugs for SARS-CoV-1 infections and their validation with SARS-CoV-2 infections by using the integrated bioinformatics approaches

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is one of the most severe global pandemic due to its high pathogenicity and death rate starting from the end of 2019. Though there are some vaccines available against SAER-CoV-2 infections, we are worried about their effectiveness, due to its unstable sequence patterns. Therefore, beside vaccines, globally effective supporting drugs are also required for the treatment against SARS-CoV-2 infection. To explore commonly effective repurposable drugs for the treatment against different variants of coronavirus infections, in this article, an attempt was made to explore host genomic biomarkers guided repurposable drugs for SARS-CoV-1 infections and their validation with SARS-CoV-2 infections by using the integrated bioinformatics approaches. At first, we identified 138 differentially expressed genes (DEGs) between SARS-CoV-1 infected and control samples by analyzing high throughput gene-expression profiles to select drug target key receptors. Then we identified top-ranked 11 key DEGs (SMAD4, GSK3B, SIRT1, ATM, RIPK1, PRKACB, MED17, CCT2, BIRC3, ETS1 and TXN) as hub genes (HubGs) by protein-protein interaction (PPI) network analysis of DEGs highlighting their functions, pathways, regulators and linkage with other disease risks that may influence SARS-CoV-1 infections. The DEGs-set enrichment analysis significantly detected some crucial biological processes (immune response, regulation of angiogenesis, apoptotic process, cytokine production and programmed cell death, response to hypoxia and oxidative stress), molecular functions (transcription factor binding and oxidoreductase activity) and pathways (transcriptional mis-regulation in cancer, pathways in cancer, chemokine signaling pathway) that are associated with SARS-CoV-1 infections as well as SARS-CoV-2 infections by involving HubGs. The gene regulatory network (GRN) analysis detected some transcription factors (FOXC1, GATA2, YY1, FOXL1, TP53 and SRF) and micro-RNAs (hsa-mir-92a-3p, hsa-mir-155-5p, hsa-mir-106b-5p, hsa-mir-34a-5p and hsa-mir-19b-3p) as the key transcriptional and post- transcriptional regulators of HubGs, respectively. We also detected some chemicals (Valproic Acid, Cyclosporine, Copper Sulfate and arsenic trioxide) that may regulates HubGs. The disease-HubGs interaction analysis showed that our predicted HubGs are also associated with several other diseases including different types of lung diseases. Then we considered 11 HubGs mediated proteins and their regulatory 6 key TFs proteins as the drug target proteins (receptors) and performed their docking analysis with the SARS-CoV-2 3CL protease-guided top listed 90 anti-viral drugs out of 3410. We found Rapamycin, Tacrolimus, Torin-2, Radotinib, Danoprevir, Ivermectin and Daclatasvir as the top-ranked 7 candidate-drugs with respect to our proposed target proteins for the treatment against SARS-CoV-1 infections. Then, we validated these 7 candidate-drugs against the already published top-ranked 11 target proteins associated with SARS-CoV-2 infections by molecular docking simulation and found their significant binding affinity scores with our proposed candidate-drugs. Finally, we validated all of our findings by the literature review. Therefore, the proposed candidate-drugs might play a vital role for the treatment against different variants of SARS-CoV-2 infections with comorbidities, since the proposed HubGs are also associated with several comorbidities.

Impact of COVID-19 Infection on Liver Transplant Recipients: Does It Make Any Difference?

The first case of coronavirus disease 2019 (COVID-19) was diagnosed in December 2019 in Wuhan, China. Since then, this novel infectious disease, caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), has grown into a pandemic with over 330 million infected individuals worldwide, many of them with innate or acquired immunosuppression.

Liver transplantation (LT) is offered as a curative therapy for end-stage liver disease as well as for acute liver failure cases. Advances in immunosuppressive therapy decreased the rates of acute and chronic graft rejection, significantly improving the quality of life.

Liver transplant recipients are considered at particularly high risk for developing critical COVID-19 infection because of their chronic immunosuppressed state. Available data are heterogeneous, and the mortality rate is variably reported in the literature. There is controversy regarding whether their immunosuppressive status is a risk or a protective factor for developing severe respiratory disease. Moreover, the mechanism of action is still unclear.

We report the clinical outcome of three liver transplant recipients who had COVID-19 pneumonia at different moments following liver transplantation. All patients received a standard immunosuppression regimen and specific antiviral therapy, requiring no invasive mechanical ventilation. They were discharged from the hospital with no long-term COVID-19 complications.

Cyclosporine A Inhibits Viral Infection and Release as Well as Cytokine Production in Lung Cells by Three SARS-CoV-2 Variants

In December 2019, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started spreading worldwide causing the coronavirus disease 2019 (COVID-19) pandemic. The hyperactivation of the immune system has been proposed to account for disease severity and death in COVID-19 patients. Despite several approaches having been tested, no therapeutic protocol has been approved. Given that Cyclosporine A (CsA) is well-known to exert a strong antiviral activity on several viral strains and an anti-inflammatory role in different organs with relevant benefits in diverse pathological contexts, we tested its effects on SARS-CoV-2 infection of lung cells. We found that treatment with CsA either before or after infection of CaLu3 cells by three SARS-CoV-2 variants: (i) reduces the expression of both viral RNA and proteins in infected cells; (ii) decreases the number of progeny virions released by infected cells; (iii) dampens the virus-triggered synthesis of cytokines (including IL-6, IL-8, IL1α and TNF-α) that are involved in cytokine storm in patients. Altogether, these data provide a rationale for CsA repositioning for the treatment of severe COVID-19 patients.

IMPORTANCE SARS-CoV-2 is the most recently identified member of the betacoronavirus genus responsible for the COVID-19 pandemic. Repurposing of available drugs has been a “quick and dirty” approach to try to reduce mortality and severe symptoms in affected patients initially, and can still represent an undeniable and valuable approach to face COVID-19 as the continuous appearance and rapid diffusion of more “aggressive”/transmissible variants, capable of eluding antibody neutralization, challenges the effectiveness of some anti-SARS-CoV-2 vaccines. Here, we tested a known antiviral and anti-inflammatory drug, Cyclosporine A (CsA), and found that it dampens viral infection and cytokine release from lung cells upon exposure to three different SARS-CoV-2 variants. Knock down of the main intracellular target of CsA, Cyclophilin A, does not phenocopy the drug inhibition of viral infection. Altogether, these findings shed new light on the cellular mechanisms of SARS-CoV-2 infection and provide the rationale for CsA repositioning to treat severe COVID-19 patients.

Immunosuppression in kidney transplant recipients with COVID-19 infection - where do we stand and where are we heading?

The appropriate immunosuppressive regimen in kidney transplant recipients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2/COVID-19) infection remains unclear. The impact of direct virus injury complicated by dysregulated hyperimmune response with overwhelming release of various cytokines in COVID-19 infected subjects contributes to the complexity of management. The largest concern of the practicing clinicians at current time is how to tailor maintenance immune-modulating therapy during active viral infection and the efficacy of the soon-to-be upcoming immunization for COVID-19. This targeted review aims to cover most of the current evidence on the effect of key maintenance immunosuppressive agents in COVID-19 infection and proposes a line of management to specific scenarios on this very rapidly evolving subject.

The Impact of SARS-CoV-2 Infection, and Application of Immunosuppressive Agents in Kidney Transplant Recipients Suffering from COVID-19

In December 2019, the COVID-19 pandemic began to ravage the world quickly, causing unprecedented losses in human life and the economy. A statistical study revealed that the proportion of solid organ transplant (SOT) recipients with severe symptoms and deaths after being infected by SARS-CoV-2 is considerably higher than that of non-SOT recipients, and the prognosis is relatively poor. In addition, the clinical manifestation of SOT recipients suffering from COVID-19 is different from that of general COVID-19 patients. Acute kidney injury (AKI) is a common complication in COVID-19 patients, and it is likely more common among SOT recipients infected with SARS-CoV-2. Clinical experts consider that SOT recipients have long-term treatment with immunosuppressants, and the comorbidities are driven by a high rate of severe symptoms and mortality. Orthotopic kidney allograft transplantation is an effective treatment for patients suffering from end-stage kidney disease/kidney failure through which they can easily extend their life. Indeed, kidney transplant recipients have suffered significant damage during this pandemic. To effectively reduce the severity of symptoms and mortality of kidney transplant recipients suffering from COVID-19, precise application of various drugs, particularly immunosuppressants, is necessary. Therefore, herein, we will collate the current clinical experience of treating COVID-19 infection in kidney transplant recipients and discuss the adjustment of patients using immunosuppressive agents in the face of COVID-19.

Kidney Transplant Recipients Infected With Coronavirus Disease 2019: Retrospective Qatar Experience

BACKGROUND

This study aimed to evaluate the incidence of coronavirus disease 2019 (COVID-19) infection on kidney transplant, mortality, and risk factors associated with infection acquisition and severe illness in kidney transplant recipients with COVID-19.

METHODS

Of 693 kidney transplant recipients who reported to our center, 249 were tested for COVID-19 by throat and nasal swab reverse transcription polymerase chain reaction. Of these, 43 recipients tested positive and 206 recipients tested negative. Among the 43 positive recipients, 9 were treated within an isolation facility, 25 were admitted to the hospital, and 9 were admitted to the intensive care unit (ICU). Risk factors associated with positive results and ICU admission were evaluated.

RESULTS

COVID-19 was found in 6% of transplant recipients. Asian ethnicity (p = .003), history of hypertensive nephropathy (p = .01), AB blood group (P = .04), and higher tacrolimus trough levels (P = .007) were more frequent in the COVID-19 positive than in the COVID-19 negative group. ICU admission was more frequent in recipients presenting with fever, shortness of breath, and acute allograft dysfunction. Renal replacement therapy was required in 3 (7%) of 43 recipients, and mortality was reported in 1 (2.3%) recipient. Acute allograft dysfunction was an independent risk factor for severe COVID-19 (odds ratio, 93.7; 95% confidence interval, 2.37-3710.94; P = .02).

CONCLUSIONS

Higher tacrolimus targets may be associated with COVID-19 development. Acute kidney injury during the COVID-19 course may be a sign of severe disease. Prognostication of COVID-19 severity in kidney transplant recipients is crucial for early recognition of critical illness and may ensure early intervention.

Combined Therapy of Ciclosporin Plus Favipiravir in the Management of Patients with Severe COVID-19, not Responding to Dexamethasone: A non-Controlled Prospective Trial

BACKGROUND

Regarding the COVID-19 pandemic, potential therapeutic agents are being evaluated almost every day. Ciclosporin, a calcineurin inhibitor, is characterized by beneficial antiviral and immunomodulatory effects. The present study aimed to evaluate the efficacy of ciclosporin in managing COVID-19.

METHODS

This study was a prospective non-controlled clinical trial carried out on 20 patients. Confirmed COVID-19 patients received two doses of ciclosporin (10 mg/kg and 5 mg/kg injections) 24 h apart. Mortality rate and the lengths of intensive care unit (ICU) and hospital stays were assessed for all 20 patients.

RESULTS

The mortality rate and the need for mechanical ventilation were calculated as 50%. The percentage of ICU admission was 70%. The lengths of ICU and hospital stays were 8.13 ± 6.81 and 14.25 ± 8.55 days, respectively. The levels of ferritin and white blood cells were significantly higher after injecting the second dose of ciclosporin. Seven patients (35%) had radiologically improved lungs after ciclosporin therapy.

CONCLUSION

It seems that the protocol of two doses of ciclosporin in combination with favipiravir does not have favorable effects among COVID-19 patients that do not respond to dexamethasone. Controlled trials are needed to confirm the results.

Coronavirus disease 2019 and renal transplantation

Ever since the severe acute respiratory syndrome virus causing coronavirus disease 2019 (COVID-19) struck the world, global health strategies have changed significantly. According to the Centers for Disease Control and Prevention, kidney transplant recipients are stratified as being high risk of developing fatal illness from COVID-19 infection. Kidney transplant is the gold-standard treatment for end-stage kidney disease subjects. During the pandemic, significant concerns have emerged regarding continuation of kidney transplant surgeries and management of kidney transplant recipients post-transplant. The added risk of immunosuppression in this cohort was and remains a theoretical concern, posing a potential risk of transplantation rather than benefit. This comprehensive review aims to cover most of the faced challenges in kidney transplantation in different stages of the pandemic. In addition, it will elucidate the epidemiology, nature, course of the disease, surgical consideration in donors and recipients as well as role of immunosuppression and management of COVID-19 infected kidney transplant recipients during these extraordinary circumstances.

Liver transplantation during global COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory disease respiratory syndrome coronavirus-2 has significantly impacted the health care systems globally. Liver transplantation (LT) has faced an unequivocal challenge during this unprecedented time. This targeted review aims to cover most of the clinical issues, challenges and concerns about LT during the COVID-19 pandemic and discuss the most updated literature on this rapidly emerging subject.

A deep learning framework for high-throughput mechanism-driven phenotype compound screening and its application to COVID-19 drug repurposing

Phenotype-based compound screening has advantages over target-based drug discovery, but is unscalable and lacks understanding of mechanism. Chemical-induced gene expression profile provides a mechanistic signature of phenotypic response. However, the use of such data is limited by their sparseness, unreliability, and relatively low throughput. Few methods can perform phenotype-based de novo chemical compound screening. Here, we propose a mechanism-driven neural network-based method DeepCE, which utilizes graph neural network and multi-head attention mechanism to model chemical substructure-gene and gene-gene associations, for predicting the differential gene expression profile perturbed by de novo chemicals. Moreover, we propose a novel data augmentation method which extracts useful information from unreliable experiments in L1000 dataset. The experimental results show that DeepCE achieves superior performances to state-of-the-art methods. The effectiveness of gene expression profiles generated from DeepCE is further supported by comparing them with observed data for downstream classification tasks. To demonstrate the value of DeepCE, we apply it to drug repurposing of COVID-19, and generate novel lead compounds consistent with clinical evidence. Thus, DeepCE provides a potentially powerful framework for robust predictive modeling by utilizing noisy omics data and screening novel chemicals for the modulation of a systemic response to disease.

Transplant Drugs against SARS, MERS and COVID-19

There is an urgent need to develop drugs and vaccines to counteract the effects of the new coronavirus SARS-CoV-2 and adequately treat the corona virus disease (COVID-19). As these drugs are still under investigation, research also focuses on existing medication with proven effectiveness in other coronaviral diseases. The advantages of existing therapeutic drugs that are currently approved (for other indications) are the known safety profile, general availability and relatively lower costs involved in extending the purpose to a new disease. Calcineurin inhibitors (CNI) are drugs that have shown effectiveness in several coronaviral diseases, and are well-known and widely used drugs in transplant medicine. The aim of this narrative review is to present the current evidence of CNI in coronaviral diseases, the biophysiology of CNI and to suggest possible ways to study CNI as a new treatment option for COVID-19. We searched original papers, observational studies, case reports, and meta-analyses published between 2000 and 2020 in English in the PubMed database and Google Scholar using the keywords: (coronavirus), (treatment), (MERS), (SARS), (COVID-19), (tacrolimus), (ciclosporin), (cyclosporin) AND (calcineurin inhibitor). We excluded studies in patients with clear indications for immunosuppressive therapy. Additionally, we searched in the preprint servers and the World Health Organization bulletin. Ten studies were identified and included. Calcineurin inhibitor therapy has been suggested to be effective for coronaviral diseases in different settings. The results are summarized in a table. CNI should be investigated as a first treatment option based on evidence of direct antiviral effects and its properties preventing severe systemic hyperinflammation, as has been observed in COVID-19 with predominantly pulmonary immunopathological changes.