[1] Univ Calif Davis, Sch Med, Div Rheumatol Allergy & Clin Immunol, Davis, CA 95616 USA
[2] Emory Univ, Sch Med, Dept Pathol, Atlanta, GA 30322 USA
[3] Univ Pittsburgh, Sch Med, Dept Med, Pittsburgh, PA USA
[4] Monash Univ, Dept Microbiol, Melbourne, Vic 3004, Australia