Increased liver stiffness is considered a marker of possible long-term liver injury. And it is precisely what a recent study has detected, presented at the last annual meeting of the Radiological Society of North America (RSNA, for its acronym in English). Specific, …
Increased liver stiffness is considered a marker of possible long-term liver injury. And it is precisely what a recent study has detected, presented at the last annual meeting of the Radiological Society of North America (RSNA, for its acronym in English).
Specifically, the liver stiffness is closely related to fibrosis in patients with chronic liver disease, but is also increased in those with acute hepatitis, acute liver failure, and cholestasis. Fibrosis is the buildup of scar tissue in the liver. Over time, healthy liver tissue decreases and the liver can no longer function properly. Progressive fibrosis can lead to liver cancer and liver failure.
Evidence on the effects of COVID-19
“Our study is part of the emerging evidence that COVID-19 infection can cause liver injury that lasts long after the acute illness.”as stated by the Dra. Firouzeh Heidari, Postdoctoral Researcher at Massachusetts General Hospital in Boston (USA).
For the study, the researchers compared the liver stiffness of patients with a history of COVID-19 infection with two control groups. All patients underwent ultrasound transverse wave elastography between 2019 and 2022 at Massachusetts General Hospital. Shear wave elastography is a specialized technique that uses sound waves to measure tissue stiffness.
The patients were classified into one of three groups based on when they underwent elastography and whether they tested positive for COVID-19. The COVID-19 positive pool contained 31 patients who had a positive COVID-19 PCR test result at least 12 weeks prior to elastography examination. The pandemic control group consisted of a random sample of 50 patients who underwent elastography during the COVID-19 pandemic and had a history of only negative COVID-19 PCR test results. The pre-pandemic control group consisted of a random sample of 50 patients who underwent elastography examination prior to the COVID-19 pandemic.
The mean age was 53.1 years for COVID-positive patients, 55.2 years for the pandemic control group, and 58.2 years for the pre-pandemic control group. Of the total cohort, 67 were women. In the COVID-positive group, elastography examinations were performed an average of 44 weeks after a positive PCR test result.
After controlling for age, sex, and time period, a statistical analysis of the elastography results revealed that the COVID-positive patients had higher liver stiffness statistically significant than control patients. COVID-positive patients had higher median live stiffness (7.68 kPa) than pandemic control patients (5.99 kPa).
The research found that the pre-pandemic control group also had a higher mean stiffness (7.01) compared to the pandemic control group. The reason for this finding is not yet understood, but it is believed to be the result of changes in referral patterns during the pandemic. Furthermore, it was observed that patients referred for elastography before the pandemic were older than patients referred after the onset of the pandemic.
“We do not yet know if the elevated liver stiffness seen after COVID-19 infection will lead to adverse patient outcomes.” noted Dr. Heidari. “We are currently investigating whether the severity of acute COVID-related symptoms predicts the severity of long-term liver injury. We hope to enrich our existing database with additional patient data and a broader range of covariates to better understand post-mortem effects. -acute COVID-19 within the liver”.