RT Journal Article SR Electronic T1 Immunoglobulin A and C reactive protein levels in ankylosing spondylitis. JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 719 OP 720 DO 10.1136/ard.46.9.719 VO 46 IS 9 A1 A Collado A1 R Sanmarti A1 M A Brancós A1 E Kanterewicz A1 T Gallart A1 J Rotés-Querol A1 A Cobos YR 1987 UL http://ard.bmj.com/content/46/9/719.abstract AB