In vivo leukocyte migration in arthritis

Rheumatoid arthritis (RA) is a joint disease characterized by inflammation of the joints, stiffness, swelling, overgrowth of the cartilage tissue, and pain. The extent of inflammation in an arthritic joint can be indicated by the degree of swelling and warmth. Because these sensations tend to be subjective, the relation between pain perceived by the patient and inflammation is poorly defined. In rheumatoid arthritis, the synovial fluid in the joint contains increased numbers of neutrophils, a type of white blood cell. Studies suggest that neutrophils may release highly reactive elements, such as enzymes and oxygen radicals, that are capable of destroying joint tissue. In addition, neutrophils may release substances, such as prostaglandins and bradykinin, that may cause pain. Studies have shown a correlation between the movement of neutrophils and the degree of pain. The migration of neutrophils in the knees of patients with RA and osteoarthritis, a chronic joint disease, was assessed by labeling the neutrophils with a radioactive marker. Patients with RA exhibited significant neutrophil migration, which was reduced by 60 percent after injection of anti-inflammatory steroids into the joint. The decrease in neutrophil migration coincided with a reduction in pain. The migration of leukocytes (white blood cells) was also detected in patients with osteoarthritis but not patients with RA. The findings show that radioactive labeling of neutrophils is a sensitive method for assessing neutrophil-induced inflammation in the joints of patients with RA. (Consumer Summary produced by Reliance Medical Information, Inc.)