Long COVID biomarkers could predict patient risk, new study suggests
A clinical study examining immune system proteins in long COVID patients has identified potential biomarkers that researchers believe could help predict risk and guide treatment.
The research analysed DNA and blood samples from 175 participants who had previously contracted COVID-19, measuring levels of immune proteins and genetic variants to understand their connection to persistent symptoms.
Cardiff Metropolitan University conducted the study in collaboration with Cwm Taf Morgannwg University Health Board, examining the role of Interleukin-6 (IL-6) proteins in long COVID development.
Long COVID affects people who have previously had COVID-19, with symptoms including heart disease, muscle and joint pain, extreme tiredness, coughing, shortness of breath and memory difficulties.
The study measured levels of two proteins – IL-6 and IL-6 Receptor (IL-6R) – which are produced by the immune system to fight infection. Researchers also examined genetic variants of the IL-6R gene to determine potential risk factors.
Results showed that long COVID sufferers had elevated levels of IL-6 compared to those who had fully recovered. The study also found that patients with a particular IL-6R genetic variant, known as the ‘AA’ genotype, appeared to have an increased risk of developing long COVID.
Craig Greenstock, 63, from Pontypridd, participated in the study after being hospitalised with COVID pneumonitis in December 2020. He spent nine weeks in hospital, including time on a ventilator, and was subsequently diagnosed with long COVID.
“I can safely say that when I was first admitted to hospital and what then developed was the scariest time of my life, both physically and mentally,” said Greenstock. “I was extremely unwell for some time, with my family being given 24 hours for my condition to improve. My symptoms following the virus have been so significant it has resulted in me having to retire from work.”
Greenstock continues to experience fatigue, breathlessness, brain fog, PTSD, and night terrors, requiring daily treatment for asthma-related symptoms.
Participants completed questionnaires about their long COVID symptoms at different times throughout the year to assess whether seasonal changes affected the condition.
Dr Richard Webb, a principal lecturer in biomedical sciences in the Centre for Cardiovascular Research, Innovation and Development at Cardiff Metropolitan University, led the study.
“While interpretation is complicated by seasonal variations, the findings from the study point towards possible future use of IL-6 and IL-6R genotype as biomarkers predictive of long COVID risk, which may bring advantages regarding the management and treatment of the illness,” said Webb.
Dr Ceri Lynch, a consultant in anaesthetics and intensive care medicine at Cwm Taf Morgannwg University Health Board, collaborated on the research.
“This collaborative research between Cwm Taf Morgannwg and Cardiff Metropolitan University has shown some interesting and exciting findings with regard to the risk factors for developing long Covid,” said Lynch. “We would like to continue this work, with the ultimate aim of identifying an effective drug treatment for the condition.”
The study was funded through The Cwm Taf Morgannwg University Health Board Collaborative Research Fund.
Researchers plan to integrate their findings into the Post-hospitalisation COVID-19 study (PHOSP-COVID), which includes researchers and clinicians from across the UK working to understand long-term health outcomes for hospitalised COVID-19 patients.
“I would be prepared to try any medicine that could improve my standard of life back to anywhere near where it was before I fell ill,” added Greenstock.
The full study is published in ScienceDirect under the title ‘Seasonal variation in the associations between self-reported long-COVID symptoms and IL-6 signalling-related factors (particularly the rs2228145 variant of the IL-6R gene)’.
