RT Journal Article SR Electronic T1 Biological and clinical markers of disease activity in ankylosing spondylitis. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 2729 OP 2732 VO 30 IS 12 A1 María Carmen Muñoz-Villanueva A1 Elisa Muñoz-Gomariz A1 Alejandro Escudero-Contreras A1 Verónica Pèrez-Guijo A1 Eduardo Collantes-Estévez YR 2003 UL http://www.jrheum.org/content/30/12/2729.2.abstract AB