Clinical Features and Liver Injury in Patients with COVID-19 in the Japanese Population

Liver injury associated with the severity of COVID-19: A meta-analysis

Background

The current 2019 novel coronavirus disease (COVID-19) pandemic is a major threat to global health. It is currently uncertain whether and how liver injury affects the severity of COVID-19. Therefore, we conducted a meta-analysis to determine the association between liver injury and the severity of COVID-19.

Methods

A systematic search of the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2022, was performed to analyse the reported liver chemistry data for patients diagnosed with COVID-19. The pooled odds ratio (OR), weighted mean difference (WMD) and 95% confidence interval (95% CI) were assessed using a random-effects model. Furthermore, publication bias and sensitivity were analyzed.

Results

Forty-six studies with 28,663 patients were included. The pooled WMDs of alanine aminotransferase (WMD = 12.87 U/L, 95% CI: 10.52-15.23, I ² = 99.2%), aspartate aminotransferase (WMD = 13.98 U/L, 95% CI: 12.13-15.83, I ² = 98.2%), gamma-glutamyl transpeptidase (WMD = 20.67 U/L, 95% CI: 14.24-27.10, I ² = 98.8%), total bilirubin (WMD = 2.98 μmol/L, 95% CI: 1.98-3.99, I ² = 99.4%), and prothrombin time (WMD = 0.84 s, 95% CI: 0.46-1.23, I ² = 99.4%) were significantly higher and that of albumin was lower (WMD = -4.52 g/L, 95% CI: -6.28 to -2.75, I ² = 99.9%) in severe cases. Moreover, the pooled OR of mortality was higher in patients with liver injury (OR = 2.72, 95% CI: 1.18-6.27, I ² = 71.6%).

Conclusions

Hepatocellular injury, liver metabolic, and synthetic function abnormality were observed in severe COVID-19. From a clinical perspective, liver injury has potential as a prognostic biomarker for screening severely affected patients at early disease stages.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, Identifier: CRD42022325206.

Involvement of the Liver in COVID-19: A Systematic Review

COVID-19, a respiratory viral infection, has affected 388 million individuals worldwide as of the February 4, 2022. In this review, we have outlined the important liver manifestations of COVID-19 and discussed the possible underlying pathophysiological mechanisms and their diagnosis and management. Factors that may contribute to hepatic involvement in COVID-19 include direct viral cytopathic effects, exaggerated immune responses/systemic inflammatory response syndrome, hypoxia-induced changes, vascular changes due to coagulopathy, endothelitis, cardiac congestion from right heart failure, and drug-induced liver injury. The majority of COVID-19-associated liver symptoms are mild and self-limiting. Thus management is generally supportive. Liver function tests and abdominal imaging are the primary investigations done in relation to liver involvement in COVID-19 patients. However, imaging findings are nonspecific. Severe acute respiratory syndrome coronavirus 2 RNA has been found in liver biopsies. However, there is limited place for liver biopsy in the clinical context, as it does not influence management. Although, the management is supportive in the majority of patients without previous liver disease, special emphasis is needed in those with nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, hepatitis B and C infections, and alcoholic liver disease, and in liver transplant recipients.

Clinical relevance of serum Krebs von den Lungen-6 levels in patients with coronavirus disease 2019

The clinical relevance of Krebs von den Lungen-6 (KL-6) levels in patients with coronavirus disease 2019 (COVID-19) is unclear. This study aimed to evaluate the correlation between KL-6 levels, laboratory parameters, and clinical outcomes. We enrolled 364 patients with confirmed COVID-19 who were hospitalized within 1 week of symptom onset. Their serum KL-6 level was measured on admission. Demographic data, symptoms, comorbidities, and laboratory parameters were recorded at the time of admission. Days to nucleic acid conversion and days of hospitalization were defined as clinical outcomes for evaluating the clinical relevance of serum KL-6 levels in COVID-19. Patients with elevated KL-6 levels were significantly older; had more reported instances of fever, cough, fatigue, and wheezing; and a longer hospital stays than those with normal KL-6 levels; the difference was statistically significant (p < 0.001). Furthermore, KL-6 levels was associated with the days of hospitalization and various laboratory parameters that influence the severity and prognosis of COVID-19. Elevated KL-6 levels have also been shown to be an independent risk factor for prolonged hospitalization. Our data suggest that serum KL-6 levels on admission can serve as an indicator for assessing the clinical outcomes of COVID-19.

Dysregulated liver function in SARS-CoV-2 infection: Current understanding and perspectives

Since it was first reported in December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread rapidly around the world to cause the ongoing pandemic. Although the clinical manifestations of SARS-CoV-2 infection are predominantly in the respiratory system, liver enzyme abnormalities exist in around half of the cases, which indicate liver injury, and raise clinical concern. At present, there is no consensus whether the liver injury is directly caused by viral replication in the liver tissue or indirectly by the systemic inflammatory response. This review aims to summarize the clinical manifestations and to explore the underlying mechanisms of liver dysfunction in patients with SARS-CoV-2 infection.

Laboratory hematologic features of COVID-19 associated liver injury: A systematic review

BACKGROUND

Liver injury is a common complication of infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The utility of laboratory hematology data in the diagnosis and risk stratification of patients with coronavirus disease 2019 (COVID-19) has not been comprehensively examined.

AIM

To address the following. (1) Are the abnormalities in hematologic parameters seen in the general population of patients with COVID-19 also seen in those patients with associated liver injury? (2) Is liver injury in COVID-19 a sign of severe disease and does liver injury correlate with hematologic markers of severe disease? And (3) What is the quality of this evidence?

METHODS

To address these questions, a comprehensive systematic review was performed. We searched the peer reviewed medical literature using MEDLINE (PubMed interface), Web of Science, and EMBASE for cohort studies that specifically addressed liver injury and COVID-19 without limitation of date of publication or language. A quality assessment of the studies was performed using the Newcastle-Ottawa Scale.

RESULTS

Thirty-two articles were suitable for inclusion in our systematic review. These included 22 articles with a cohort of COVID-19 patients with liver injury, 5 comparing non-severe vs severe COVID-19 populations in which liver injury was addressed, and 5 other cohort studies with a focus on liver injury. White blood cell count, absolute neutrophil count, absolute lymphocyte count (ALC), and hemoglobin were the parameters most helpful in distinguishing COVID-19 with liver injury from COVID-19 without liver injury. ALC and d-dimer were identified as being potentially useful in distinguishing non-severe from severe COVID-19. Liver injury was more frequently seen in cohorts with severe disease. Most studies were of high quality (24/48, 86%) with 4/28 (14%) of moderate quality and 0 of low quality.

CONCLUSION

Our study supports the use of select hematologic parameters in diagnosis and risk stratification of liver injury in COVID-19 patients. Although of overall high quality, the current medical literature is limited by the small number of studies with high statistical power and the variable definition of COVID-19 liver injury in the literature.