title: Red blood cell-bound C3d in normal subjects and in random hospital patients.
abstract: Red blood cells (RBC) drawn into EDTA from 103 normal adults, 26 newborn infants, and 203 randomly selected hospital patients, and into citrate-phosphate-dextrose (CPD) from 87 Red Cross donors, were evaluated for RBC-bound C3d by agglutination with anti-C3d and by a radiolabeled anti-antiglobulin technique. Positive agglutination reactions were observed only with RBC from 26 hospital patients; however, by the radiolabeled antiglobulin method, C3d was demonstrable on all RBC, but its amount varied widely among different subjects. A normal range for RBC-bound C3d was established. RBC-bound C3d levels were not related to the age (18-88 years) or sex of the subjects and remained unchanged over 9 months. Red blood cells taken into CPD had more RBC-bound C3d than cells taken into EDTA; cord RBC had less than adult RBC. In 39 percent of the hospital patients (excluding those with autoimmune hemolytic anemia) RBC-bound C3d was above the normal range and a good correlation was found between values obtained by the radiolabeled anti-antiglobulin method and by agglutination titration scores. There was a threshold level of RBC-bound C3d below which agglutination reactions were negative. Evaluation of RBC-bound C3d in health and disease is important for determining optimal characteristics of anticomplement antiglobulin reagents.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000918:Antibody Specificity; D003167:Complement Activation; D003298:Coombs Test; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006386:Hemagglutination Tests; D006801:Humans; D007106:Immune Sera; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D011951:Receptors, Complement / Q000097:blood*; D017464:Receptors, Complement 3d
chemical_list: D007106:Immune Sera; D011951:Receptors, Complement; D017464:Receptors, Complement 3d