Researchers have identified two blood biomarkers that may predict cognitive deficits, including “brain fog,” up to a year after a COVID-19 diagnosis. The study, published in Nature Medicine, analyzed data from over 1,800 hospitalized patients and found high levels of fibrinogen and d-dimer, proteins linked to blood coagulation, to be highly correlated with cognitive issues.
These findings were further validated in an independent dataset of nearly 18,000 U.S. patients. The study offers a promising direction for managing the long-term cognitive effects of COVID-19.
Post-COVID-19 cognitive deficits, commonly referred to as “brain fog,” can have a significant impact on an individual’s daily life. The diagnosis of these deficits includes both objective measures assessed by clinicians and subjective measures reported by patients. However, the development of these cognitive deficits remains unknown.
In this study, Maxime Taquet and colleagues analyzed data from 1,837 U.K. patients hospitalized for COVID-19 between January 2020 and November 2021. Blood samples were collected during hospital admission, and measurements of cognition were obtained six and twelve months later, both from clinicians and patients.
Through statistical analysis, the researchers identified two blood biomarker profiles highly correlated with post-acute COVID-19 cognitive deficits. The first profile showed elevated levels of fibrinogen, a protein associated with blood coagulation, which corresponded to both objective and subjective cognitive deficits.
The second profile revealed elevated levels of d-dimer, another blood-coagulation protein, which correlated with subjective cognitive deficits, including “brain fog,” as well as fatigue and shortness of breath.
These findings were replicated in a separate study involving the health records of 17,911 U.S. patients. The comparison of pre-pandemic and post-pandemic cohorts reinforced the specificity of d-dimer for COVID-19 cognitive issues.
The authors suggest that these findings could contribute to the development of models for predicting and managing post-COVID-19 cognitive deficits. However, they emphasize the need for further research in larger cohorts.
Post-COVID cognitive deficits can have a significant impact on individuals’ lives, affecting their ability to work and function normally. Understanding the biological underpinnings of these deficits is crucial for the development of effective management strategies. The identification of these two blood biomarkers provides valuable insights into the complex biology of post-COVID cognitive deficits.
Further research in larger populations is necessary to better understand the relationship between these biomarkers and cognitive deficits and to develop targeted interventions to help individuals experiencing long-term cognitive effects after a COVID-19 diagnosis.
This study adds to the growing body of research focused on understanding the long-term effects of COVID-19 and highlights the urgent need to address the cognitive sequelae that many individuals face even after recovering from the initial infection.