It has been estimated that 20% of people diagnosed with COVID-19 go on to experience severe respiratory distress symptoms – in some cases, requiring urgent and specialised medical care. Disease stage significantly affects COVID-19 treatment and survival rates: the overall mortality rate for hospitalised patients varies between 2.3% for patients diagnosed at an early stage of COVID-19 to 11% for advanced stage.
Understandably, improving early detection of COVID-19, along with predictions around which patients are likely to develop severe symptoms, is a high priority. In this study published in Urine, researchers from the China and the US used urine proteomic profiling to distinguish a healthy control group from COVID-19 patients. In addition, they were able to identify specific proteome features in the urine of patients that indicated whether they had mild or severe COVID-19.
According to lead investigator Ping Xu, this is the first study to establish a link between the urine proteome and understanding of COVID-19 development. He explains: "Urine is one of the most frequently studied biomaterials for biomarkers of human diseases in proteomics because of its accessibility.
“In the case of COVID-19 infections, multiple pathways are compromised; for example, the behaviour of platelets and oxygen levels in the blood. This study demonstrates that these molecular alterations can be detected in urine. Our findings could potentially be used to support diagnosis of COVID-19, as well as predictions around the progression from mild to severe COVID-19. They may also shed light on our understanding of the COVID-19 pathogenesis.”
According to Xu, solutions like these are urgently needed. “COVID-19 patients with severe symptoms often face very limited treatment options. Imaging technology, such as CT scans has been widely used to diagnose the virus, but the cost is high and technical expertise is required. We need low-cost and reliable diagnostic techniques to estimate and predict the transition of mild COVID-19 cases to severe ones.”
He adds: “Though the number of samples collected in this study was small, the results show that the urine proteome is an important source of information on COVID-19, which definitely warrants further investigation."
The study included 32 healthy control subjects, six COVID-19 patients and two people who had recovered from the virus. All six COVID-19 patients developed either a fever or a cough. Three patients displayed severe symptoms (fatigue and dyspnea) and the other three mild symptoms. All six had comorbities.