IMMUNE-COMPLEXES IN EARLY ARTHRITIS .1. DETECTION OF IMMUNE-COMPLEXES BEFORE RHEUMATOID-ARTHRITIS IS DEFINITE

  • 1 January 1981
    • journal article
    • research article
    • Vol. 44  (3) , 512-521
Abstract
Patients (53) with early arthritis were studied longitudinally for up to 3 yr. During this time, 24 developed sufficient features for definite rheumatoid arthritis (RA) to be diagnosed. The others (arthralgia patients) differed from the RA patients as, in the majority. C-reactive protein and erythrocyte sedimentation rate were normal and antinuclear antibodies or rheumatoid factors were rarely found. In time their signs and symptoms improved or disappeared. Circulating immune complexes [IC] were detected in both groups of patients by the platelet aggregation test, whereas IC detected by abnormal CIq[complement component Iq]-binding activity were found mainly in the RA patients. Platelet-aggregating complexes [PAC] were usually present in the 1st samples studied and disappeared in the arthralgia patients with recovery from their symptoms. In the RA patients, CIq-binding complexes appeared simultaneously or later than PAC, but both tests were positive several months before RA could be diagnosed. Apparently IC are one of the first immunological abnormalities to appear in patients with arthritis. Although the constituent antigen and antibody of complexes detected by either test are unknown, their possible nature is discussed.