[1] Queens Univ, Div Rheumatol, Dept Med, Kingston, ON, Canada
[2] Univ Toronto, Lupus Clin, Toronto Western Hosp, Ctr Prognosis Studies Rheumat Dis, 399 Bathurst St, Toronto, ON, Canada
[3] Dalhousie Univ, Nova Scotia Hlth Author, Div Rheumatol, Halifax, NS, Canada
[4] Stanford Univ, Div Immunol Rheumatol, Palo Alto, CA 94304 USA