Problems with iron levels in the blood and the body's ability to regulate this important nutrient as a result of SARS-CoV-2 infection could be a key trigger for long COVID, new research has discovered.
University of Cambridge
Summary
Research suggests that iron dysregulation in the blood, caused by SARS-CoV-2 infection, could be a key factor in triggering long COVID
Long COVID symptoms include fatigue, shortness of breath, muscle aches, and brain fog. As many as 30% of people infected with SARS-CoV-2 could develop long COVID.
Researchers from the University of Cambridge and Oxford analysed blood samples from 214 individuals, finding that 45% experienced long COVID symptoms months later.
Low iron levels and ongoing inflammation were detected early post-COVID-19, even in mild cases, contributing to anaemia and disrupting red blood cell production
The study revealed that iron dysregulation was linked to persistent symptoms of long COVID, independent of age, sex, or initial COVID-19 severity.
Research was funded by Wellcome, the Medical Research Council, NIHR, and the European Union Horizon 2020 Programme.
Extracts
Shortly after the start of the COVID-19 pandemic, researchers at the University of Cambridge began recruiting people who had tested positive for the virus to the COVID-19 cohort of the National Institute for Health and Care Research (NIHR) BioResource. These included asymptomatic healthcare staff identified via routine screening through to patients admitted to Cambridge University Hospitals NHS Foundation Trust, some to its intensive care unit.
Over the course of a year, participants provided blood samples, allowing researchers to monitor changes in the blood post-infection. As it became clear that a significant number of patients would go on to have symptoms that persisted – long COVID – researchers were able to track back through these samples to see whether any changes in the blood correlated with their later condition.
In findings published in Nature Immunology, researchers at the Cambridge Institute of Therapeutic Immunology and Infectious Disease (CITIID), University of Cambridge, together with colleagues at Oxford, analyzed blood samples from 214 individuals. Approximately 45% of those questioned about their recovery reported symptoms of long COVID between three and ten months later.
When the body has an infection, it responds by removing iron from the bloodstream. This protects us from potentially lethal bacteria that capture the iron in the bloodstream and grow rapidly. It's an evolutionary response that redistributes iron in the body, and the blood plasma becomes an iron desert.
However, if this goes on for a long time, there is less iron for red blood cells, so oxygen is transported less efficiently affecting metabolism and energy production, and for white blood cells, which need iron to work properly. The protective mechanism ends up becoming a problem.
Co-author Professor Hal Drakesmith, from the MRC Weatherall Institute of Molecular Medicine at the University of Oxford
MEA Comment
The ME Association originally reported on this research at the University of Cambridge, which is looking at the way in which inflammation caused by Covid-19 infection may be causing a deficiency of iron, last year. This research has now been published in Nature.
Please note that this is NOT a recommendation for people with either Long Covid or ME/CFS to start self treatment with iron supplements.
Taking iron supplements when you don't have iron deficiency anaemia can cause what is called iron overload and serious side effects.
Dr Charles Shepherd,
Trustee and Hon. Medical Adviser to the ME Association,
Member of the 2018-2021 NICE guideline on ME/CFS committee,
Member of the 2002 Chief Medical Officer's Working Group on ME/CFS
Charles Shepherd
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