RT Journal Article SR Electronic T1 Serum histidine in rheumatoid arthritis: a family study JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 501 OP 502 DO 10.1136/ard.40.5.501 VO 40 IS 5 A1 Kirkham, J. A1 Lowe, J. A1 Bird, H. A. A1 Wright, V. YR 1981 UL http://ard.bmj.com/content/40/5/501.abstract AB We have compared free serum histidine in patients with rheumatoid arthritis, their blood relatives, and their non-blood relatives. The hypohistidinaemia of rheumatoid arthritis is acquired with the disease and does not provide a biochemical marker of those at risk.