Association between COVID-19 and chronic liver disease: Mechanism, diagnosis, damage, and treatment

Impact of chronic ethanol consumption and SARS-COV-2 on the liver and intestine: A pilot dose-response study in mice

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, there was a marked increase in alcohol consumption. COVID-19 superimposed on underlying liver disease notably worsens the outcome of many forms of liver injury. The goal of a current pilot study was to test the dual exposure of alcohol and COVID-19 infection in an experimental animal model of alcohol-associated liver disease (ALD).

METHODS

After 4 weeks of ethanol (EtOH) feeding, C57BL/6 male mice received SARS-CoV-2 (SARS2-N501YMA30) intranasally at 3 × 102, 1 × 103, 3 × 103, and 1 × 104 plaque-forming units (PFU). Mice were then weighed/monitored daily for morbidity/mortality for 10 days while continuing EtOH consumption. Markers of liver inflammation, injury, and intestinal barrier integrity were evaluated.

RESULTS

A similar gradual weight loss was observed in all inoculated mice (slightly less in the 3 × 102 group) up to post-infection day 4. Greater mortality was observed in mice receiving the highest viral dose at days 3 and 4 post-infection. The majority of the surviving mice subjected to EtOH and inoculated with 3 × 103 or 1 × 104 PFU rapidly lost 25% of their body weight and were euthanized on post-infection day 4. Analysis of liver health in animals that survived to the end of the experiment exhibited no significant changes in hepatic steatosis but had a limited increase in plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels at all viral doses versus EtOH alone. However, the 1 × 104 PFU viral dose exacerbated EtOH-induced hepatic inflammation characterized by elevated levels of several pro-inflammatory cytokines, including Il-6 and Tnf-α. There was limited effect of viral infection on the intestine.

CONCLUSIONS

SARS-CoV-2 infection caused a dose-dependent negative impact on body weight and survival in mice fed EtOH. This pilot study suggests that early mortality observed after high-dose SARS-CoV-2 challenge could be due, in part, to hepatic dysfunction following chronic EtOH feeding.

Association between alcohol-associated cirrhosis and inpatient complications among COVID-19 patients: A propensity-matched analysis from the United States

BACKGROUND

Alcohol-associated cirrhosis (AC) contributes to significant liver-related mortality in the United States. It is known to cause immune dysfunction and coagulation abnormalities. Patients with comorbid conditions like AC are at risk of worse clinical outcomes from coronavirus disease 2019 (COVID-19). The specific association between AC and COVID-19 mortality remains inconclusive, given the lack of robust clinical evidence from prior studies.

AIM

To study the predictors of mortality and the outcomes of AC in patients hospitalized with COVID-19 in the United States.

METHODS

We conducted a retrospective cohort study using the National Inpatient Sample (NIS) database 2020. Patients were identified with primary COVID-19 hospitalizations based on an underlying diagnosis of AC. A matched comparison cohort of COVID-19 patients without AC was identified after 1:N propensity score matching based on baseline sociodemographic characteristics and Elixhauser comorbidities. Primary outcomes included median length of stay, median inpatient charges, and in-hospital mortality. Secondary outcomes included a prevalence of systemic complications.

RESULTS

A total of 1325 COVID-19 patients with AC were matched to 1135 patients without AC. There was no difference in median length of stay and hospital charges in COVID-19 patients with AC compared to non-AC (P > 0.05). There was an increased prevalence of septic shock (5.7% vs 4.1%), ventricular fibrillation/ventricular flutter (0.4% vs 0%), atrial fibrillation (13.2% vs 8.8%), atrial flutter (8.7% vs 4.4%), first-degree atrioventricular nodal block (0.8% vs 0%), upper extremity venous thromboembolism (1.5% vs 0%), and variceal bleeding (3.8% vs 0%) in the AC cohort compared to the non-AC cohort (P < 0.05). There was no difference in inpatient mortality in COVID-19 patients with non-AC compared to AC, with an odds ratio of 0.97 (95% confidence interval: 0.78-1.22, P = 0.85). Predictors of mortality included advanced age, cardiac arrhythmias, coagulopathy, protein-calorie malnutrition, fluid and electrolyte disorders, septic shock, and upper extremity venous thromboembolism.

CONCLUSION

AC does not increase mortality in patients hospitalized with COVID-19. There is an increased association between inpatient complications among COVID-19 patients with AC compared to non-AC.

Treatment of liver fibrosis: Past, current, and future

Liver fibrosis accompanies the progression of chronic liver diseases independent of etiologies, such as hepatitis viral infection, alcohol consumption, and metabolic-associated fatty liver disease. It is commonly associated with liver injury, inflammation, and cell death. Liver fibrosis is characterized by abnormal accumulation of extracellular matrix components that are expressed by liver myofibroblasts such as collagens and alpha-smooth actin proteins. Activated hepatic stellate cells contribute to the major population of myofibroblasts. Many treatments for liver fibrosis have been investigated in clinical trials, including dietary supplementation (e.g., vitamin C), biological treatment (e.g., simtuzumab), drug (e.g., pegbelfermin and natural herbs), genetic regulation (e.g., non-coding RNAs), and transplantation of stem cells (e.g., hematopoietic stem cells). However, none of these treatments has been approved by Food and Drug Administration. The treatment efficacy can be evaluated by histological staining methods, imaging methods, and serum biomarkers, as well as fibrosis scoring systems, such as fibrosis-4 index, aspartate aminotransferase to platelet ratio, and non-alcoholic fatty liver disease fibrosis score. Furthermore, the reverse of liver fibrosis is slowly and frequently impossible for advanced fibrosis or cirrhosis. To avoid the life-threatening stage of liver fibrosis, anti-fibrotic treatments, especially for combined behavior prevention, biological treatment, drugs or herb medicines, and dietary regulation are needed. This review summarizes the past studies and current and future treatments for liver fibrosis.

The pathophysiology of postacute sequelae of COVID-19 (PASC): Possible role for persistent inflammation

As the SARS-CoV-2-induced pandemic wanes, a substantial number of patients with acute Corona Virus-induced disease (COVID-19 continue to have symptoms for a prolonged time after initial infection. These patients are said to have postacute sequelae of COVID (PASC) or "long COVID". The underlying pathophysiology of this syndrome is poorly understood and likely quite heterogeneous. The role of persistent, possibly deviant inflammation as a major factor in comorbidity is suspected.

Objective

To review data that address the relative importance of inflammation in the pathophysiology spectrum of PASC and to address how this would impact diagnosis and approach to therapy in patients identified as having such inflammatory abnormalities.

Methods

A review of public databases, including PubMed, MeSH, NLM catalog, and clinical trial databases such as clinicaltrials.gov.

Results

The literature supports a prominent role for various forms and types of inflammation in the pathophysiologic spectrum of PASC. Such inflammation can be persistent ant CoV-2-specific responses, new onset autoimmune responses, or a loss of normal immunoregulation resulting in widespread, sustained inflammatory pathologies that can affect both broad constitutional symptoms (such as fatigue, neurocognitive dysfunction, and anxiety/depression) and organ-specific dysfunction and/or failure.

Conclusions

PASC is a significant clinical entity with similarities to and differences from other postviral syndromes. Significant research efforts are ongoing to better understand specific aberrant inflammatory pathways present in individual patients for the purpose of developing and implementing effective therapies and ultimately prophylaxis strategies to prevent the progression of COVID-19 as well as likely future viral illnesses and pandemics.