Monospecific Direct Coombs C3, Blood
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Complement, in conjunction with IgM antibody, may be present on patient or donor (transfused) RBCs and may cause hemolysis. The antibody may be directed against self-antigens (autoimmune hemolysis), maternal antigens (hemolytic disease of the newborn), donor antigens (eg, alloimmune transfusion reaction), or drugs.
The presence of in vivo coating of RBC with complement can be demonstrated by the direct antiglobulin (Coombs) test.
Detecting complement bound to RBC
Investigation of hemolytic anemia
The presence or absence of red cell-bound complement is used in conjunction with other testing and clinical data to aid in the characterization of hemolysis as immune-mediated. Possible causes include autoimmune hemolytic anemia, drug-induced hemolysis, hemolytic disease of the newborn, and alloimmune reactions to recently transfused RBC.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
If positive, reaction is graded (positive 1+ to 4+).