What influences the progression of Covid-19?

New findings from fundamental research into SARS-CoV2

February 19, 2021

Some people who contract Covid-19 hardly even notice that they have it. Others become seriously ill and have to be admitted to hospital. The working group ‘Cellular immunity in inflammation and cancer’ at Universitätsklinikum Erlangen has now identified the immune messenger substance interleukin-3 as a significant early indicator for whether the virus infection will remain mild or develop into a severe case. Their results have been published in the journal ‘Nature Communications’.

The researchers led by PD Dr. med. Georg Weber, deputy head of the Department of Surgery at Universitätsklinikum Erlangen and Dr. Alan Bénard, physician at the Department of Surgery, focus on immunological mechanisms in inflammatory and malignant diseases at the cellular level. In a study, they have now proven that a low level of interleukin-3 in the blood plasma is often linked to a severe case of Covid-19.

The cytokine interleukin-3 has a major role to play in regulating the body’s immune response. It stimulates the production of the protein CXCL12 by cells at the site of an inflammation, for example a lung infection caused by SARS-CoV-2. This protein communicates with plasmacytoid dendritic cells, non-specialised immune cells which normally circulate in the bloodstream. Basically, CXCL12 ‘lures’ these cells into the inflamed lung, where they curb the reproduction of the viruses causing the inflammation,’ explains Dr. Weber.

More precise evaluation of risk

Levels of interleukin 3 are therefore a good indicator of whether a person who has contracted Covid-19 is likely to suffer a severe form of the disease. Until now, medical staff have only had much vaguer criteria to go on, such as the age of the patient or whether they suffer from certain underlying conditions. ‘It is possible, however, that people who do not belong to a risk group have low levels of interleukin-3 in their blood. These are the cases where until now a severe progression of the disease has tended to come as a surprise and adequate medical care has perhaps been provided too late as a result,’ explains Dr. Weber.

The results of this study can now help important decisions about the treatment of Covid-19 patients be taken at an earlier stage. Looking to the future, researchers may develop an immune therapy approach, where patients are given interleukin-3 in an inhalant in order to specifically protect their lungs from the viral attack.

Further information:

PD Dr. Georg Weber
Department of Surgery at Universitätsklinikum Erlangen
Phone: + 49 9131 8533296
E-mail: georg.weber@uk-erlangen.de

Dr. Alan Bénard
Department of Surgery at Universitätsklinikum Erlangen
Tel. 09131/85-42055
E-mail: alan.benard@uk-erlangen.de