| A | B |
| Paroxysmal nocturnal hemoglobinuria (PNH) | A disease characterized by complement-mediated hemolysis of erythrocytes resulting from a deficiency of decay-accelerating factor on the red blood cells (RBCs). |
| Hemolytic uremic syndrome (HUS) | A condition characterized by hemolytic anemia, low platelet count, and acute renal failure caused by either a Shiga toxin related to an infection or complement dysregulation |
| Hereditary angioedema (HAE) | A disease characterized by swelling of the extremities, the skin, the gastrointestinal tract, and other mucosal surfaces because of a deficiency in the complement inhibitor C1NH. |
| Atypical hemolytic uremic syndrome (aHUS) | A rare genetic disorder associated with defects in complement regulation that cause microvascular thrombosis and affect the kidneys. |
| Activation unit | The combination of complement components C1, C4b, and C2b that form the enzyme C3 convertase, whose substrate is C3. |
| C3 glomerulopathies (C3G) | Diseases involving the glomeruli of the kidneys. |
| Autocrine | Effect produced by a cell that stimulates the same cell. |
| Hemolytic titration (CH50) assay | An assay that measures complement-activating ability by determining the amount of patient serum required to lyse 50% of a standardized concentration of antibody-sensitized sheep erythrocytes. |
| ELISpot | A modified ELISA technique that detects the frequency of cultured cells that secrete a particular cytokine. |