(CNN) - Harold Ramis, the actor, writer and director whose films include "Stripes," "Ghostbusters," "Groundhog Day" and "Analyze This," has died. He was 69.
His death was caused by complications related to autoimmune inflammatory vasculitis, a condition Ramis battled for four years, according to United Talent Agency, which represented Ramis for many years.
For more than 40 years, Ramis was a leading figure in comedy. A veteran of the Second City troupe in his hometown of Chicago, he was a writer for "SCTV" and wrote or co-wrote the scripts for "National Lampoon's Animal House" (1978), "Caddyshack" (1980), "Stripes" (1981), "Ghostbusters" (1984), "Groundhog Day" (1993) and "Analyze This" (1999).
The films often featured members of his generation of comedy talents -- veterans of the National Lampoon's recordings, "Saturday Night Live" and "Second City TV" -- most notably Ramis' old comedy colleague and fellow Chicagoan Bill Murray.
His directing credits include "Caddyshack," "National Lampoon's Vacation" (1983), "Groundhog Day," "Analyze This" and -- in a change from his usual comedies -- the dark 2005 film "The Ice Harvest." He occasionally acted as well, most notably playing Murray's friend in "Stripes," Dr. Egon Spengler in "Ghostbusters" and a doctor in "As Good as It Gets" (1997).
Ramis' films were some of the most influential -- and highest-grossing -- comedies of recent decades. "Animal House" remains a model for knockabout laughs and gross-out moments. "Caddyshack" is eminently quotable. "Ghostbusters" was the second-biggest box office hit of 1984, just behind "Beverly Hills Cop."
But though the movies were full of silly moments, Ramis often tried to tap into larger themes. Perhaps most successful was "Groundhog Day" in which Bill Murray's cynical weatherman is forced to relive the same day over and over again until he finally comes to terms with his life. The film has been used as the subject of philosophical and religious discussions.
That intellectual bent didn't always go over well with studio bosses, Ramis observed.
In an interview with the Onion A.V. Club, he mentioned the studio for his 2009 film "Year One" was uncertain how to pitch it.
"When the studio said, 'Well, what is the movie about?' I said, 'The movie tracks the psycho-social development of civilization.' And they said, 'Uh, that's not going to be too good on a poster.' "
Ramis was also a mentor to several current comedy writers and directors, the Chicago Tribune noted in its obituary. Judd Apatow, a fan, cast him as Seth Rogen's father in "Knocked Up." Jake Kasdan put him in "Walk Hard: The Dewey Cox Story" (which was co-produced and co-written by Apatow).
Ramis was usually a good-natured presence, playing understanding characters -- often doctors, of one sort or another. It was true to his personality, the late Second City founder Bernie Sahlins told the Chicago Tribune in 1999.
"He's the least changed by success of anyone I know in terms of sense of humor, of humility, sense of self," Sahlins told the paper. "He's the same Harold he was 30 years ago. He's had enormous success relatively, but none of it has gone to his head in any way."
Indeed, Ramis always seemed to find a way to laugh.
Asked by The New York Times about the existential questions raised by "Groundhog Day" -- and competing interpretations of the film's meaning -- he mentioned that he didn't practice any religion himself.
''Although I am wearing meditation beads on my wrist,'' he noted. ''But that's because I'm on a Buddhist diet. They're supposed to remind me not to eat, but actually just get in the way when I'm cutting my steak.''
Ramis is survived by his wife, Erica Mann Ramis, three children and two grandchildren.