Weight Loss With Knee and Ankle Pain and Swelling

History  A 47-year-old man was seen for pain in both knees. For the past year, he had noted swelling of both ankles and pain and swelling of both knees. He had been seen by another physician six months previously, and a diagnosis of rheumatoid arthritis was made on the basis of the clinical symptoms. A regimen of indomethacin (Indocin) and aspirin was begun, but there was no clinical improvement. During the past year he had lost 6.7 kg. The patient denied pulmonary or gastrointestinal symptoms.Results of a physical examination were normal except for the findings in the extremities. Effusions of both knees and ankles were present. The knees were warm and tender, and there was limitation of motion of both knees due to pain. There was no evidence of clubbing, rash, or subcutaneous nodules.Pertinent laboratory data included the following: erythrocyte sedimentation rate, 51 mm/hr; lupus erythematosus (LE) preparation,