Rheumatoid arthritis, Pyrexia of Unknown Origin

A 61-yr-old previously fit lorry driver was referred by his general practitioner in October 1999 to an orthopaedic clinic with a 6-month history of painful hands, shoulders and feet. His general practitioner had treated him with ibuprofen without much improvement. He admitted to a recent history of loss of appetite with loss of two stones (12.7 kg) in weight. His joint pains had been increasing in severity with visible swelling of his fingers and knees. He had no relevant family history. He was an ex-smoker and drank little alcohol. Physical examination revealed a healthy-looking man with signs of synovitis in the symptomatic joints. The orthopaedic surgeon referred him to the rheumatologist (K.C.). The preliminary blood tests showed haemoglobin of 10.4 g/dl with normal haematocrit, leucocyte and platelet counts and normal serum vitamin B12 and red-cell folate levels. His serum ferriti