Immune system study could help sickest COVID-19 patients

Researchers have found a common 'immune signature' in many of the sickest COVID-19 patients which could help guide treatment.

As part of an ongoing study called COVID-IP, patients at Guy’s and St Thomas' who have agreed to donate to an infectious disease biobank provide regular blood samples during their treatment for COVID-19. These are processed at the Trust and analysed in the team’s laboratories at King's College London and at the Francis Crick Institute.

The research analysed blood samples from 60 Guy’s and St Thomas’ patients with COVID-19 to understand why some patients get very ill with the disease. Working with researchers from the Crick and King's College London, they found that many of the sickest patients had low numbers of immune system cells called T Cells that help to fight disease.

When patients can't mount an effective T cell response, there aren’t enough immune cells to clear the body of virus-infected cells. As this situation persists and worsens, the remaining immune cells can become misguided, themselves causing damage to the lungs and other vital organs.

Project lead Adrian Hayday, who heads the Crick’s Immunosurveillance Laboratory and is Professor of Immunobiology at King’s College London, said: “The changes we've observed in the blood are not subtle and patients with these features seem more likely to experience severe disease, requiring intensive management.

“There's a lot we still don’t know about this virus, but we have seen that it doesn’t simply discriminate according to age and underlying condition. Although in smaller numbers, younger, healthy individuals can also be struck down with severe symptoms.

“The dedication of scientists and medical professionals, drawn from many different countries, who have come together to tackle this issue is incredible, and the speed that they have been able to gather these results is unprecedented.

“We need to be at a point where clinical treatment decisions can be guided by the state-of-the-art knowledge of the immune system. Indeed, this is why we’re making our data rapidly and freely available so that it can be used across the world by those investigating new avenues for treatment.”

Dr Manu Shankar-Hari, consultant in intensive care medicine at Guy’s and St Thomas’ NHS Foundation Trust, and NIHR Clinician Scientist said: “We routinely measure white blood cell counts, including lymphocyte and basophil counts in all hospitalised patients. Clearly, our new COVID-IP study highlights the enormous potential to measure the status of very specific types of immune cell involved in fighting the virus.

“Moreover, the study’s identification of detailed T cell deficits offers strong support for an international clinical trial in which we provide patients with recombinant IL-7, a natural drug that promotes T cell function.  The trial has been designated an Urgent Public Health COVID-19 Trial by the Chief Medical Officer.”

The COVID-IP study could be used to identify the patients most likely to do worse and require additional treatment. A trial of an immune treatment called interleukin-7 (IL-7) which boosts numbers of T Cells has also started at Guy’s and St Thomas'. At the moment no treatment is known to treat COVID-19, so the study offers hope that this treatment could help very ill patients recover from the disease.

The trial has recruited its first patient at Guy’s and St Thomas’. You can find more details about this study on the NIHR website.

The COVID-IP study, which is analysing the immune response of patients with COVID-19 is supported by King's Together and is ongoing.

Information about COVID-19 studies currently running at the Trust can be found on our studies page. Patients being treated in our ICU and COVID wards will be asked by their clinicians about taking part in these studies. We can only recruit patients currently being treated for COVID-19 at the Trust.