Quantitation of ( @entity19459 )2 C1r-C1s complexes in XXXX as an indicator of C1 activation.

@entity1 @entity1310 @entity8 @entity6300 @entity19459 @entity1252 @entity631
C1 activation was assessed in several forms of @entity631 by radioimmunoassay quantitation of circulating ( @entity19459 )2 C1r-C1s complexes (INC). Eight @entity1 with active @entity1252 ( @entity1252 ) and @entity1310 had elevated serum INC (mean = 15.3 vs control = 5.8, P less than 0.01). Their INC levels were normal during remission. Serum INC had a weak inverse correlation with serum @entity6300 greater than 3 mg/dl (r = 0.42, P = 0.02). In longitudinal studies, serum INC also had a weak inverse correlation with serum C3 and C4. Only 1 of 10 @entity1 with type I and 1 of 15 with type III @entity631 ( @entity631 ) had elevated serum INC. No @entity1 with type II @entity631 had elevated levels. Two of 10 @entity1 with poststreptococcal @entity631 (P-SGN) had elevated serum INC, but all normalized with convalescence. @entity1 with @entity8 had normal serum INC. The data demonstrate the importance of C1 activation in @entity1252 and P-SGN. The mechanism of complement activation in types @entity631 remains unclear; the data suggest, but do not prove, that C1-independent complement activation may occur in these @entity1 .
