Ramis has been battling complications from the illness, known formally as autoimmune inflammatory vasculitis, for the past four years.
It has no known cause and is incurable, but can be treated with medications. The disease causes swelling of the blood vessels and can affect the function of internal organs.
His wife, Erica Mann Ramis, said he died peacefully at 12:53 a.m. today, surrounded by family, according to reports. An infection triggered the autoimmune disease, crippling him and forcing him to learn how to walk again. He suffered a relapse in 2011,
Ramis grew up in Chicago and honed his comedic skills with the Second City comedy troupe’s television series “Second City Television, better known as SCTV.”
While there, he worked with fellow comedians Bill Murray, John Belushi and Dan Aykroyd, all of whom became the core of “Saturday Night Live” when the show launched.
He set a new comedy standard co-writing the film “National Lampoon’s Animal House,” which was cerebral, silly and also biting social satire. They same style marked other film collaborations like “Stripes” (1981) and “Ghostbusters” “National Lampoon’s Vacation” (1983), “Analyze This,” and “Groundhog Day.”
Ramis and Belushi developed a close rapport during their time at Second City and both headed to New York together around the same time. Murray and Ramis worked together on “The National Lampoon Radio Hour” before venturing into films.