Lupus is an immune disease that often mimics other illnesses, according to experts. It can damage the heart, kidneys and other organs, and cause nerve pain, digestive problems and other symptoms. Today, it affects about 1.5 million Americans, 90 percent of them women.

Of course, the only way to be sure Alcott had it would be to examine her in person and run blood tests, Greaves admits. Without that, "we can do no more than speculate," he and Hirschhorn wrote in the spring issue of Perspectives in Biology and Medicine.

But lupus experts say they may be onto something.

"It certainly is possible that she had lupus," said Duane Peters, a spokesman for the Lupus Foundation in Washington. "Many of the pieces seem to fit."

Dr. David Karp, a specialist at the University of Texas Southwestern Medical Center in Dallas, agreed. "All I can say is that there isn't anything in this story to prove that she didn't have lupus," he said.

An Alcott biographer, too, was intrigued. "It's always valuable to get the story as close to the truth as possible," said Martha Saxton, author of "Louisa May Alcott: A Modern Biography" and an associate professor at Amherst College in Massachusetts.

Alcott died of a stroke in 1888 at age 55.Two months earlier, she wrote: "I look about 70, grey & wrinkled & bent & lame."

Ironically, mercury may have played a role after all, Greaves said. Some studies suggest it can trigger lupus. But that, too, is speculation.

Now the team is on to its next target: Robert Burns, the 18th-century Scottish poet. He, too, might have had mercury poisoning, Greaves said. History says the poet died of a heart infection, but Greaves is dubious.

"I'm not happy with that diagnosis at all," he said. "It wouldn't fly today."