In March of 2020, the Coronavirus disease (Covid-19) took over the world from Wuhan, China. One of the first known effects of this virus was that it was attacking our respiratory system with breathing and chest pain being two of the more serious symptoms. Covid-19 has become a fatal virus with inevitably no known cure; however, many patients have recovered from this virus, but long lasting effects are still unknown.
During the early stages of COVID-19, it was originally reported that 36% of patients hospitalized with covid had effects to their Central Nervous System (CNS). The involvement of the CNS was previously a described symptom of hospitalized patients with severe acute respiratory syndrome. The CNS was also linked to the 2003-2004 SARS outbreak, it was a reasonable hypothesis to believe that patients infected with COVID-19 may also be experiencing damage to their CNS. It is not yet known the extent of how SARS-Cov-2 can affect the CNS or if it does, how is it affecting the brain. Direct CNS infection from SARS-CoV2 has been already shown in mice, but its response in humans is still unknown.
The study done by Kanberg et al., (2020) looked at the effect COVID-19 possibly has on patients who are infected or recovered from the virus. The study primarily looked at how the virus can reach the brain. In this study, Kanberg used plasma biomarkers in CNS injuries. Plasma biomarkers can measure biochemical changes, the two biomarkers used in this study were GFAp and NfL. The biomarker GFAp (glial fibrillary acidic protein) refers to the neurofilament light chain protein used as a marker of astrocytic activation. Astrocytes are an important part of the CNS functions such as blood flow. The second biomarker NfL is a neurofilament light chain protein and is a biomarker of neuronal injury, otherwise known as damage to our nervous tissue. To diagnose COVID-19 in the early stages and now, a PCR analysis of both the nose and throat were done. Forty-seven patients with confirmed COVID-19 were divided into 3 groups which were divided by disease severity, mild, moderate, and severe.
In the results section, SARS-CoV-2 patients were placed into three categories, mild, moderate and severe. Patients in the mild group were healthier and younger in general. The patients in moderate and severe groups were mostly men that were older and had underlying conditions. It was found that both GFAp and NfL levels were correlated with age of the patients. Patients who had severe COVID-19 has much higher levels of GFAp and NfL. Levlels of GFAp were also increased in patients with moderate COVID-19. The plasma levels of both GFAp and NfL did not change signifigantly from the initial to follow up of the COVID-19 patients.
Within this paper, the results showed astrocyclic activation (GFAp measurements) may be a common feature in patients with moderate and severe COVID-19. Neuronal injury (NfL). May show up later in the process of the disease. Further studies must be done to help understand the nature of the CNS and the effect of biomarkers
Kanberg, Nelly, et al. “Neurochemical evidence of astrocytic and neuronal injury commonly found in COVID-19.” Neurology95.12 (2020): e1754-e1759.
