Severe Corona course now predictable

01.12.2023 12:15

Researchers have managed to use the number and structure of blood platelets to predict whether a severe course of the corona virus can occur. They have thus identified a prognostic biomarker for the severity of Covid-19. This means the therapy can now be adjusted at an early stage. Methodologically, the researchers used imaging flow cytometry, which makes it possible to analyze interactions between blood cells quickly and in large numbers.

As soon as the body becomes infected with Sars-CoV-2, a series of immune reactions take place. One of these reactions is that the blood platelets, also called thrombocytes, attach to the immune cells and this causes cell aggregates, i.e. clumps, to form in the bloodstream. A study by the team led by Oliver Hayden, Professor of Biomedical Electronics, used imaging flow cytometry to show that the concentration of blood platelet aggregates increases significantly in intensive care patients with a severe course of corona.

The research team has thus succeeded in identifying a prognostic biomarker for the severity of Covid-19. This result was made possible by the optimal interdisciplinary conditions that the central institute TranslaTUM offers TUM engineers for collaboration with doctors at the Munich Rechts der Isar Hospital.

Patient-friendly and uncomplicated measurement

For the analysis, blood was first taken from the test subjects. A few drops of blood are enough to count thousands of blood cells within seconds and analyze their aggregation using imaging flow cytometry. The head of the study, Prof. Hayden, says: “In addition, this method has the great advantage that we neither have to prepare nor mark the samples, but can examine them directly and in a standardized manner without losing the aggregates due to the effects of high shear forces. In the future, this cost-effective method could help to quantify interactions between the coagulation system and the immune system.” The near-patient measurement allows an immediate examination after blood collection in order to rule out aging effects of the blood samples, which themselves lead to aggregates.

Two thirds of the blood platelets of those affected are affected

In total, the research team examined the blood of 36 intensive care patients between the ages of 32 and 83 who had been admitted to hospital with a corona infection and had a moderate to severe course. The results of the study show that the number of bound platelets was significantly higher in severely ill patients than in moderately ill patients and even more so in comparison to healthy blood donors.

With regard to the composition of the cell aggregates, the researchers were able to show that, depending on the severity of the Covid-19 disease, the number of cell aggregates and their composition change gradually and early before a complication occurs. The clumps were typically composed of fewer than ten platelets. In extreme cases, it was observed that up to two thirds of all patient platelets were aggregated.

Better management of patients

The high concentration of cell aggregates was detected in all test subjects suffering from Covid-19 who were admitted to the intensive care unit. This simple diagnosis of platelet aggregates has the potential to identify high-risk patients at an early stage and thus improve care.

The interdisciplinary team of engineers and doctors now wants to transfer the knowledge they have collected to other diseases. The researchers assume that the method described here could also work, for example, in cardiovascular or cancer diseases.

publication

Klenk, C., Erber, J., Fresacher, D., Röhrl, S., Lengl, M., Heim, D., Irl, H., Schlegel, M., Haller, B., Lahmer, T., Diepold, K., Rasch, S. and Hayden, O. Platelet aggregates detected using quantitative phase imaging associated with COVID-19 severity. Commun Med 3, 161 (2023). doi.org/10.1038/s43856-023-00395-6.