[1] Virginia Commonwealth Univ, Richmond, VA USA
[2] Northwestern Univ, Chicago, IL 60611 USA
[3] Washington Univ, Dept Med, Div Rheumatol, St Louis, MO USA
[4] Washington Univ, Dept Genet, Div Rheumatol, St Louis, MO 63110 USA
[5] Washington Univ, Sch Med, Med Rheumatol, St Louis, MO USA