PHILADELPHIA -- Talk show host Oprah Winfrey is expected to spend two weeks in Philadelphia defending a defamation case linked to a sex-abuse scandal at her South African girls' school.

The trial is set to start March 29.

Winfrey's lawyers say in recent filings she must attend as a named defendant and has rearranged her TV production schedule to do so. She also appears likely to testify.

The case centers on remarks Winfrey made in suspending a headmistress amid the 2007 abuse complaints.

Winfrey had said she "lost confidence" in Nomvuyo Mzamane and was "cleaning house from top to bottom."

A judge this week refused to drop Mzamane's defamation suit.

A dorm matron was later charged with abusing six students.