Almost a year in space, astronaut Scott Kelly's immune system was on alert and altered the activity of some of his genes compared to his Earth-bound, identical twin, which researchers have found.
Scientists do not know if the changes were good or bad, but the results of a unique Nasa twin study raise new questions for physicians as the space agency wants to send people to Mars.
Genetic duplicate testing gave scientists the first opportunity to explore human biology in detail, as how astronaut genes turn on and off differently in space. An enigmatic change announced at a science conference: Kelly's immune system was hyperactivated.
"It's as if the body reacts to this alien environment as if you had a mysterious organism in it," said geneticist Christopher Mason Weill Cornell Medicine of New York, who led the study. He said the doctors looked for it in other astronauts.
Since the beginning of space exploration, Nasa has studied the load on the bodies of astronauts, such as bone resorption, which requires physical exertion. Usually they are in space for about six months. Kelly, who lived on the International Space Station, spent 340 days in space and set a US record.
"I have never felt completely normal in outer space," said the now-retired Kelly in an email to AP, in which she noted the usual congestion due to fluid migration, headaches and difficulty concentrating with additional carbon dioxide and digestive problems from weightlessness.
However, this study was a unique entry into the molecular plane, with former astronaut Mark Kelly, Scott's twin, standing for comparison. Full results have not yet been published, but the researchers presented some results at a meeting of the American Association for the Advancement of Science.
A number of genes linked to the immune system have become hyperactive, Mason said. Mason also discovered a spike in the blood of another marker that stimulated the immune system. However, Kelly's blood showed less of another cell type, which is an early defense against viruses.
It is no surprise that the activity of gene activity in space is changing ̵
"You can see how the body adapts to the change in its environment," Mason said.
The good news: Shortly after Kelly was back on Earth in March 2016, everything returned to normal. However, these immune gene genes seemed to have that memory or that need "almost six weeks later," Mason said. "All in all, it's encouraging," said Craig Kundrot, who heads NASA's space life and science research. "There are no important new warning signs, we are seeing changes we did not necessarily expect, but we do not know if those changes matter."
Of four Russians who have been living in space for more than a year, Nasa already knew they were staying for extended periods of time outside the earth, said Kundrot, adding, "We are also striving for more than just possible "We want our astronauts to do more than survive."
The immune problems are more familiar to Jerry Linenger, a US astronaut who spent more than four months on the Russian space station Mir. He said he had never been ill in orbit, but once on earth, "I was probably sicker than I was in my life."
Astronauts were exposed to the germs of their crewmates, and after a week there was nothing new In the sterile environment of a space station, "your immune system really is not challenged," Linenger said.