• Of a small number of patients, 15% died compared with the 85% expected
• Overall 70% of patients who were on the brink of death saw improvements
• The researchers admitted they did not expect such positive results
• The treatment works by injecting patients with cells taken from fat tissue
• The stem cells are known to bolster the immune system, which was shown here

A stem cell therapy boosted Covid-19 survival rates five-fold for patients hooked up to ventilators, Spanish scientists have claimed.

Two out of the 13 patients in the small study died, with the remainder returning from the brink of death after doctors assumed at least 11 of them would succumb to the disease.

Overall 70 per cent of patients saw improvements despite being in the most critical category of illness.

The researchers admitted they did not expect such positive results but cautioned their research was only on a small number of patients.

The treatment works by injecting patients with cells taken from the fat tissue of liposuction patients – typically women under 50 years old and with no other health conditions.

These cells are thought to bolster the immune system, providing vital support for Covid-19 patients who are fighting the virus, most of whom are elderly and frail.

The stem cells also managed to tone down inflammation, which is internal swelling that has been found to be extreme and damaging in some Covid-19 patients, and can lead to organ failure.

However, chances of the treatment making it into hospitals during the pandemic are slim because scientists have faced barriers to getting stem cell treatments approved for other diseases in the past.

The treatment, called ‘AT-MSC’, uses a type of stem cell called mesenchymal stem cells (MSCs) which have been investigated for various diseases caused by inflammation, such as Crohn’s disease.

This is the first time the results of using MSCs for Covid-19 patients has been reported.

The therapy was used in Spain by a number of universities, led by Professor Bernat Soria from the Miguel Hernández University (UMH).

WHAT IS THE STEM CELL THERAPY?
The treatment, called ‘AT-MSC’, uses a type of stem cell called mesenchymal stem cells (MSCs).

Everybody naturally grows these cells. But as Professor Bernat Soria from the Miguel Hernández University (UMH) puts it, ‘the younger, the better’.

The cells are harvested from the fat tissue of liposuction donors, usually women under 50 who have no underlying health conditions.

Scientists mechanically separate the fat tissue on plastic. The mesenchymal stromal cells inside the tissue float up and bind to the plastic.

They are easy to culture, Professor Soria said. ‘In six to eight weeks you have 100million cells and the dose [of AT-MSC] is approximately 1million cells per kilogram.’

MSCs have the ability to differentiate into a variety of cell types, including bone, cartilage and muscle cells, and so are known to have tissue repairing abilities.

They are typically investigated for the treatment of various inflammatory diseases such as Crohn’s because they help have an anti-inflammatory effect. However, clinical studies investigating the efficacy of MSCs in treating diseases are in preliminary development.

In the study, 13 critical coronavirus patients were enrolled. They were all white, aged between 47 and 73 years old, and only one patient was a woman.

On a scale of clinical severity designed by the World Health Organization, they scored 6-7. Grade 8 is death.

The patients were given the treatment AT-MSC having not got any better when given various medicines, including experimental Covid-19 drugs lopinavir/ritonavir, hydroxychloroquine and tocilizumab.

Each received a dose of one million cells per kilo of their body weight and monitored closely. If their condition was not improving, they were given one or more doses.

The results of AT-MSC in coronavirus patients admitted in ICUs were compared with the clinical evolution and mortality of similar cases.

Therefore it is not the highest standard of drug evaluation – a randomised controlled trial – when two groups either receiving a specific drug or not, are compared.

According to the results, the stem cell therapy improved outcomes without causing any serious side effects.

Nine of the 13 patients showed improvements, and seven were taken off ventilation after an average of 16 days.

Two of the patients given the stem cell treatment died (15 per cent) compared with 70-85 per cent in a group of ‘similar cases’.

Professor Soria told MailOnline he did not expect such staggering results – which were published today in The Lancet eClinicalMedicine.

He said: ‘In summary it has been much better that what I expected.’

Professor Soria began his research on the use of cellular therapy during the Asian epidemic of SARS-1 in 2003.

Unlike SARS, the new coronavirus (SARS-CoV-2) doesn’t just cause damage to the lungs. In Covid-19 patients, there are a number of complications that lead to the demise of organs other than the lungs.

SARS-CoV-2 typically causes a depression of the immune system, coupled with a widespread extreme inflammatory response.

The hyper activation of the immune response is called a cytokine storm, and scientists are eager to find treatments to halt its damage to otherwise healthy tissues.

AT-MSC managed to decrease patients’ inflammation markers, called C-reactive protein and ferritin, five days after the first dose.

Professor Soria expected AT-MSC to help curb the damage caused by the cytokine storm, but also found it ‘restores partially the immune system’.

It boosted the presence of T cells, which directly attack the virus, and B cells, which trigger antibodies into action.

This is beneficial because it means the therapy can not only mitigate the complications of the virus, but help to eliminate it from the body at the same time.

MSCs have tissue repair properties because they have the ability to differentiate into a variety of cell types, including bone, cartilage and muscle cells.

The researchers also found evidence the MSCs repaired lung tissue, with chest X-rays, in as little as 48 hours.

This was evident further with a drop in D-dimer, a tissue damage and blood clotting biomarker.

Professor Soria said: ‘Preliminary data suggest efficacy, but this need a controlled randomized double blind clinical trial to be done.’

The paper said there were 17 clinical trials registered to look at MSCs, which have peaked in interest as a potential Covid-19 treatment.

Only one other severe Covid-19 patient has ever been reported to have been given MSCs, ‘with favourable outcome’.

Professor Soria and colleagues wrote: ‘Pre-clinical evidence of the potential for MSCs in viral lung infections is still scarce and, in some cases, controversial.

‘It is true that there are no preclinical studies in animal models of SARS-CoV-2 infection and that most preclinical evidence comes from influenza virus infection models.

‘Nevertheless, although results of these studies are not uniformly positive, no adverse events related to cell therapy in this setting has been reported.

‘These results are a proof of concept… These results support conducting a phase 2 randomized controlled trial already under way.