With Russian president Vladimir Putin saber-rattling with tactical nuclear weapons as a warning to the Ukraine and free world, US president Joe Biden comparing the current nuclear risk to the Cuban Missile Crisis, it is worth contemplating what to do to treat acute radiation syndrome (ARS).
Just as Israel’s Rafael Advanced Defense Systems Israel Aerospace Industries developed the Iron Dome to shoot down missiles and rockets hurled at the country from across its borders, a Haifa company named Pluri Inc, has been researching ARS for years and found a way to cope.
Acute radiation syndrome
This leading regenerative medicine firm recently announced that a clinical study conducted by the US Department of Defense’s (DoD) Armed Forces Radiobiology Research Institute at the Uniformed Services University of the Health Sciences of its novel placenta-based cell therapy product called PLX-R18. The studies were designed to evaluate PLX-R18 as a potential prophylactic countermeasure against ARS administered prior to radiation exposure.
These animal studies demonstrate that PLX-R18, administered 24 hours before radiation exposure, and again 72 hours after exposure, resulted in a significant increase in survival rates, from a four percent survival rate in the placebo group to 74% in the treated group.
In addition, the data show an increase in recovery of blood lineages (platelets, neutrophils, white blood cells and lymphocytes) and a favorable safety profile. Furthermore, it showed a significant increase in bone marrow cell numbers and improved regenerative capability into all blood lineages.
“We are very pleased with the positive results from the studies showing that PLX-R18 can potentially be used prophylactically, before exposure to radiation. We believe that this outcome is an important contribution to protect the armed and medical forces that may need to enter contaminated areas,” said Yaky Yanay, president and CEI of Pluristem. “It is Pluristem’s goal to provide the different federal agencies access to PLX-R18 that it may be used as a countermeasure both before and after radiation exposure in order to minimize hematological and other organ damage. We look forward to the continued development of this unique agent as an off-the-shelf product.”
The animal studies were conducted following guidance from the US Food and Drug Administration (FDA), as efficacy studies are not yet permitted in humans for this indication.
PLX-R18, which was granted an FDA designation for the treatment of ARS, is also being evaluated by the US National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), as a treatment following radiation exposure (ARS).
ARS results from exposure to high levels of radiation, as in the case of a nuclear accident or attack, and it may cause severe or fatal systemic effects such as injuries that hinder the bone marrow’s ability to produce blood cells and platelets, as well as other organs and systems within the body, increasing patients’ susceptibility to life-threatening hemorrhage, infection, and anemia.
Pluristem has also entered into a collaboration agreement with Fukushima Medical University in Japan to examine PLX-R18 cells for the treatment of hematological ARS and gastrointestinal effects.
Pluristem was founded in 2003 as a 3D cell manufacturing company. It is a clinical-stage biotherapy company focused on using placental cells and its 3D technology platform to develop cell therapies for conditions such as inflammation, ischemia and hematological disorders.
Several years ago, its chairman and CEO, Yaky Yanay, realized the company’s technology could also be relevant to victims of radioactive catastrophes.
The first experiments were done on small animals, in collaboration with Prof. Raphael Gorodetsky, head of Biotechnology and Radiobiology Laboratories at the Sharett Institute of Oncology, Hadassah-University Medical Center in Jerusalem.
How do you know if you're suffering from radiation poisoning?
According to the Mayo Clinic, when a person has experienced known or probable exposure to a high dose of radiation from an accident or attack, medical personnel take a number of steps to determine the absorbed radiation dose. This information is essential for determining how severe the illness is likely to be, which treatments to use and whether a person is likely to survive.
Details about the distance from the source of radiation and duration of exposure can help provide a rough estimate of the severity of radiation sickness.
The time between radiation exposure and the onset of vomiting is a fairly accurate screening tool to estimate absorbed radiation dose. The shorter the time before the onset of this sign, the higher the dose. The severity and timing of other signs and symptoms also may help medical personnel determine the absorbed dose.
Frequent blood tests over several days enable medical personnel to look for drops in disease-fighting white blood cells and abnormal changes in the DNA of blood cells. These factors indicate the degree of bone marrow damage, which is determined by the level of an absorbed dose.
A device called a dosimeter can measure the absorbed dose of radiation but only if it was exposed to the same radiation event as the affected person. A device such as a Geiger counter can be used to survey people to determine the body location of radioactive particles. A part of the larger emergency response to a radioactive accident or attack would include identifying the type of radiation exposure. This information would guide some decisions for treating people with radiation sickness.
The treatment goals for radiation sickness are to prevent further radioactive contamination; treat life-threatening injuries, such as from burns and trauma; reduce symptoms; and manage pain. Decontamination involves removing external radioactive particles. Removing clothing and shoes eliminates about 90% of external contamination. Gently washing with water and soap removes additional radiation particles from the skin.
Decontamination prevents radioactive materials from spreading more. It also lowers the risk of internal contamination from inhalation, ingestion or open wounds. If there was severe damage to bone marrow, the victim may also receive transfusions of red blood cells or blood platelets. After a significant radiation event, a person will require further evaluation at a hospital or with a healthcare provider to determine the extent of their injuries.
The thyroid gland is most susceptible to injury after radiation exposure. Potassium iodide is a salt tablet that helps block radioactive iodine from being absorbed by the thyroid gland. Most nuclear accidents release radioactive iodine, which is absorbed into the body. Since the thyroid regularly uses iodine to balance the body's metabolism, the thyroid is very susceptible to radioactive material.