with leukemia have high serum levels of sCR1 may indicate Complement receptor type 1 (CR1) is an integral memhigh synthetic and shedding rates of this receptor. 7 brane protein of many hematopoietic cells and is foundIn a preliminary study on a small group of patients with in a soluble form in plasma. Preliminary data have indicirrhosis, sCR1 levels were found to be above the normal cated that soluble complement receptor 1 (sCR1) levels range. 7 This observation cannot be attributed to an increased in serum were increased in patients with cirrhosis. In synthesis of sCR1 by hepatocytes, because these cells are this study, sCR1 was measured in patients with various known not to produce it. 9 The concentration of many plasma liver diseases with a newly established enzyme-linked proteins decreases in liver failure because of diminished liver immunosorbent assay (ELISA). sCR1 level was elevated synthesis. The drop in the concentration of these proteins is in chronic active hepatitis C (24 patients, 62.6 { 31 ng/ an accepted index of liver failure. The concentration of only mL; 31 normal controls, 31.4 { 7.8 ng/mL, P õ .001), and few large glycoproteins e.g., complement C7 increases in liver in cirrhosis (35 patients, 143.7 { 61 ng/mL, P õ .001).failure. 9a Thus, the present study was undertaken to define The levels increased transiently in 3 patients who had whether elevated serum sCR1 might be related to specific Amanita phalloides intoxication. Complement receptor type 1 (CR1) (CD35, C3b/C4b recep-other diseases. Of these 35 patients, 25 were fully evaluated for liver tor) is an integral membrane glycoprotein found on erythro-transplantation. cytes and most white blood cells. 1,2 On phagocytes, CR1 is (2) Twenty-four patients who had chronic hepatitis C proven by mainly involved in the initial binding of C3b-coated particles, serology and histology. which are subsequently ingested. 3 In addition, CR1 serves as showed that a recombinant soluble form of CR1 was 100-11 patients, serial samples after transplantation were analyzed in fold more efficient than factor H, the physiological cofactor relation to the patient's clinical progress assessed independently by for the inactivation of C3b in plasma. 5 the transplant surgeons. In this group, the immunosuppressive ther-A soluble form of CR1 (sCR1) is present in plasma. 6,7 In apy for the prevention of rejection included cyclosporine, azathiovitro, leukocytes that express CR1 on their surface release prine, and steroids. Antithymocytes globulin (monoclonal or polysCR1 by proteolytic cleavage. sCR1 comprises most of the clonal) was used in some patients for corticosteroid-resistant rejection. Rejection was defined clinically and by the therapeutic extracellular domain of membrane-bound CR1. 8 Since CR1 measures undertaken, i.e., antirejection therapy.is mostly expressed by hematopoietic cells, plasma sCR1 is ELISA for sCR1. Soluble CR1 levels were determined in serum likely to derive from them. Observations that many patients with a sandwich ELISA using two anti-CR1 monoc...