There are reasons to be “optimistic” about the possibility of creating simple tests to determine if someone has long COVID, an expert has said.

Long COVID is a term which refers to a condition where people experience persistent systems of COVID-19 that can last for weeks, months or over a year after an infection has gone.

A wide range of persistent symptoms have been associated with the condition, such as fatigue, shortness of breath, chest pain and problems with memory and concentration.

Professor Danny Altmann, from Imperial College London’s Department of Immunology and Inflammation, is one of the leading researchers working on understanding why some people have persistent symptoms of COVID-19, while others recover fully from the infection.

His team is developing tests to look at antiviral immunity, white blood cell subsets and patterns of autoimmune antibodies in people with long COVID compared to those who have recovered from COVID-19, with hopes that the research will help to find potential treatments for the condition.

Diagnosing long COVID

Professor Altmann told a recent Imperial College Academic Health Science Centre (AHSC) online seminar that he was confident that researchers would be able to create tests to diagnose long COVID in the future.

He said: “I’m optimistic about a test (or tests) for long COVID, even if the disease process encompasses more than one mechanistic pathway.

“We and many other groups around the world are working hard to characterise serum biomarkers – that is, a signature of changes that could be definitively tested in a small blood test.

“In our approach, this is based upon analysis of differential immune responses, especially autoimmunity, that is, antibodies that attack the body’s own cells.”

He was joined for the seminar by Professor Helen Ward, Clinical Professor of Public Health and Director of the Patient Experience Research Centre at Imperial, who talked about leading a study to better understand why some people who are infected with the coronavirus have long COVID while others do not.

Earlier this year, Professor Altmann and Professor Rosemary Boyton, from Imperial’s Department of Infectious Disease, received funding from the National Institute of Health Research (NIHR) to study the mechanisms for long COVID and its symptoms.

The Imperial research team is hoping to use blood samples from non-hospitalised long Covid patients and those who fully recovered from the virus to analyse the different patterns of immune response and what may be causing the different outcomes from infection.

Professor Altmann noted that it was important for researchers to understand how to diagnose long COVID in order to allow people to get access to healthcare services for the condition. These diagnostic clues should also help to inform choice of new treatments.

He added that if between 10-20 per cent of COVID-19 cases were to lead to persistent symptoms, this could mean there were already up to 40 million long-term cases globally, posing a significant challenge for healthcare planning and provision.