It has been found those with the most severe form of the disease have extremely low numbers of an immune cell called a T-cell.

T-cells clear infection from the body.

The clinical trial will evaluate if a drug called interleukin 7, known to boost T-cell numbers, can aid patients’ recovery.

It involves scientists from the Francis Crick Institute, King’s College London and Guy’s and St Thomas’ Hospital.

They have looked at immune cells in the blood of 60 Covid-19 patients and found an apparent crash in the numbers of T-cells.

Prof Adrian Hayday from the Crick Institute said it was a “great surprise” to see what was happening with the immune cells.

“They’re trying to protect us, but the virus seems to be doing something that’s pulling the rug from under them, because their numbers have declined dramatically.

In a microlitre (0.001ml) drop of blood, normal healthy adults have between 2,000 and 4,000 T-cells, also called T lymphocytes.

The Covid patients the team tested had between 200-1,200.

‘Extremely encouraging’

The researchers say these findings pave the way for them to develop a “fingerprint test” to check the levels of T-cells in the blood which could provide early indications of who might go on to develop more severe disease.

But it also provides the possibility for a specific treatment to reverse that immune cell decline.

Manu Shankar-Hari, a critical care consultant at Guy’s and St Thomas’ Hospital, said that around 70% of patients that he sees in intensive care with Covid-19 arrive with between 400-800 lymphocytes per microlitre. “When they start to recover, their lymphocyte level also starts to go back up,” he added.

LEAVE A REPLY

Please enter your comment!
Please enter your name here