CHICAGO — Chicago Police Superintendent Eddie Johnson’s kidney transplant was a success and he was already feeling well enough to check his emails just hours after the surgery, doctors said Thursday.

The 57-year-old Johnson will likely be released from the hospital this weekend, the doctors said at a news conference at Rush University Medical Center. His 25-year-old son, Daniel Johnson, who donated the kidney, was doing so well that he would likely be allowed to go home later Thursday, they said,

“The superintendent looks really good, he’s awake, he’s sitting up (and) he’s probably by now sitting in a chair,” said Dr. Edward Hollinger, Jr., who took part in the transplant surgery at Rush University Medical Center. “We are very pleased with the function of the kidney.”

Johnson disclosed in January that he had been battling a potentially life-threatening inflammation of the kidneys for decades and was on a waiting list for a new kidney — something doctors said on Thursday was becoming more and more urgent as his kidney function slipped to about 10 percent. They said he would have soon been forced to undergo dialysis if he did not receive a new kidney.

The doctors who performed the 6-hour surgery said Johnson will soon feel better than he has in the years his condition has been deteriorating, and that his energy will improve as his new kidney removes toxins from his body that his damaged kidneys were unable to completely remove.

They also said chances are slim that Johnson’s body will reject the kidney, and the odds of rejection are even less because the kidney he received was from his son. They said the chances of rejection fall after the first month and that if there are no problems in the next year it’s highly unlikely that Johnson’s body will reject the kidney.

Doctors said Johnson will be allowed to walk as much as he wants next week and they expect him to return to his office in three to five weeks.