[1] UNMC, Dept Rheumatol, Omaha, NE USA
[2] Univ Nebraska Med Ctr, Omaha, NE USA
[3] Univ Penn, Dept Med, Perelman Sch Med, Philadelphia, PA USA
[4] Univ Penn, Philadelphia, PA USA
[5] Seattle VA, Mexico City, DF, Mexico
[6] Salt Lake City VA, Salt Lake City, UT USA
[7] Univ Utah, Salt Lake City, UT USA
[8] Univ Kansas, Kansas City, MO USA
[9] Univ Alabama Birmingham, Hoover, AL USA