title: Authors' reply.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA; Division of Rheumatology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand, .
authors.forename: Patompong
authors.initials: P
authors.lastname: Ungprasert
authors.affiliation: Department of Medicine, Bassett Medical Center, Cooperstown, NY 13326, USA.
authors.forename: Karn
authors.initials: K
authors.lastname: Wijarnpreecha
authors.affiliation: Department of Medicine, Bassett Medical Center, Cooperstown, NY 13326, USA.
authors.forename: Charat
authors.initials: C
authors.lastname: Thongprayoon