ASSOCIATION OF CRYOGLOBULINEMIA WITH NODULES, VASCULITIS AND FIBROSING ALVEOLITIS IN RHEUMATOID-ARTHRITIS AND THEIR RELATIONSHIP TO SERUM CLQ BINDING-ACTIVITY AND RHEUMATOID-FACTOR

  • 1 January 1979
    • journal article
    • research article
    • Vol. 38  (3) , 405-413
Abstract
Two measurements of serum immune complexes, cryoglobulinemia and 125I-Clq [q fraction of complement component 1] binding, were performed in patients with severe rheumatoid arthritis (RA) and compared with normal levels. Cryoglobulinemia was present in 20 of 28 patients (71%) with extra-articular disease (mean level 17 .mu.g/ml) including nodules, digital vasculitis, cutaneous ulcers, rash, neuropathy, lung disease and scleritis, but in none of 32 patients with joint disease alone (uncomplicated RA) (mean level 3 .mu.g/ml). Cryoglobulinemia correlates with, but probably does not antedate, extra-articular disease and may be useful in predicting morbidity and mortality in this group of patients. Serum 125I-Clq binding was raised in patients with uncomplicated RA and those with extra-articular disease although levels were higher in the latter group. Both tests showed a negative correlation withth serum hemolytic C and a positive correlation with Ig[immunoglobulin]M rheumatoid factor although there were some sera with raised levels of rheumatoid factor without cryoglobulinemia. Cryoglobulinemia is a better test than Clq-binding for demonstrating the presence of circulating immune complexes involved in the pathogenesis of extra-articular lesions.