Jakarta, June 9 : Critically ill Covid-19 patients treated with non-altered stem cells from umbilical cord connective tissue were more than twice as likely to survive as those who did not have the treatment, according to a small study. The clinical trial, carried out at four hospitals in Jakarta, Indonesia, also showed that administering the treatment to Covid-19 patients with an added chronic health condition such as diabetes, hypertension or kidney disease increased their survival more than fourfold. The findings were published in the STEM CELLS Translational Medicine. All 40 patients who took part in the double-blind, controlled, randomised study were adults in intensive care who had been intubated due to Covid-19-induced pneumonia. Half were given intravenous infusions containing umbilical mesenchymal stromal cells, or stem cells derived from the connective tissue of a human birth cord, and half were given infusions without them. "The survival rate of those receiving the stem cells was 2.5 times higher and climbed even more -- 4.5 times -- in the Covid-19 patients who had other chronic health conditions," said Ismail Hadisoebroto Dilogo, Professor at Cipto Mangunkusumo Central Hospital-Universitas in Indonesia. The stem cell infusion also was found to be safe and well-tolerated with no life-threatening complications or acute allergic reactions in seven days of post-infusion monitoring, he said. Previous clinical trials have shown that treating Covid-19 pneumonia patients with stem cells from umbilical cord connective tissue may help them survive and recover more quickly, but the Indonesian study is the first to treat intubated, critically ill Covid-19 pneumonia patients with a naive, or non-genetically manipulated, form of the stem cells. "Unlike other studies, our trial used stem cells obtained through explants from actual umbilical cord tissue and we did not manipulate them to exclude ACE2, a cellular protein thought to be an entry point for Covid-19," Dilogo said. Some research suggests that one of the main causes of acute respiratory distress in Covid-19 patients is "cytokine storm," a condition in which infection prompts the body's immune system to flood the bloodstream with inflammatory proteins. "Although our study focused on a small number of patients, we think this experimental treatment could potentially lead to an effective adjuvant therapy for Covid-19 patients in intensive care who do not respond to conventional supportive treatment," Dilogo said. /IANS