RT Journal Article SR Electronic T1 Anemia of chronic disease in patients with rheumatoid arthritis--use of zinc protoporphyrin (ZPP) levels. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 446 OP 446 VO 34 IS 2 A1 Shanmugam Saravana A1 Ashok Rai YR 2007 UL http://www.jrheum.org/content/34/2/446.abstract AB