SOLUBLE TUMOR-NECROSIS-FACTOR RECEPTOR LEVELS REFLECT COAGULATION ABNORMALITIES IN SYSTEMIC JUVENILE CHRONIC ARTHRITIS

The objective was to evaluate tumour necrosis factor (TNF) status in p atients with systemic juvenile chronic arthritis (s-JCA). Plasma level s of TNF-alpha, and serum levels of soluble TNF receptor 1 and 2 (sTNF R1 and sTNFR2) were measured using specific immunoassays in 20 patient s with s-JCA, 10 with polyarticular JCA and 15 with pauciarticular JCA , and in 20 controls comparable for age. In patients with active s-JCA , circulating levels of TNF-alpha: sTNFR1 and sTNFR2 were significantl y (P < 0.001) higher than those of controls. The levels of sTNFR1 and sTNFR2, but not those of TNF-alpha, were associated with the persisten ce and severity of systemic symptoms and were significantly correlated with prolongation of partial thromboplastin time and decrease in prot hrombin activity. In two patients evaluated during a s-JCA-associated macrophage activation syndrome, a marked increase in sTNFR1 and sTNFR2 was found. Our results suggest that in s-JCA, TNF is involved in syst emic manifestations, in the subclinical coagulation abnormalities, and in the development of the macrophage activation syndrome.