Final answer:
In type II hypersensitivity reactions, both hemoglobinuria and hemoglobinemia can be present. Two examples of these reactions are hemolytic transfusion reaction (HTR) and hemolytic disease of the newborn (HDN). To prevent HDN, Rh-negative mothers are given Rh(D) immune globulin (RhoGAM).
Step-by-step explanation:
In type II hypersensitivity reactions, both hemoglobinuria and hemoglobinemia can be present. These reactions occur when antibodies bind to cell-surface molecules, such as blood group antigens on red blood cells (RBCs). Two examples of type II hypersensitivity reactions involving RBCs are hemolytic transfusion reaction (HTR) and hemolytic disease of the newborn (HDN).
In HTR, when a person receives a transfusion of incompatible blood, their antibodies bind to the transfused RBCs, leading to complement-mediated lysis of the RBCs and the release of hemoglobin into the bloodstream. This results in hemoglobinemia (hemoglobin in the blood) and hemoglobinuria (hemoglobin in the urine).
To prevent HDN, Rh-negative mothers are given Rh(D) immune globulin (RhoGAM) during pregnancy and after delivery if the fetus is Rh-positive. This prevents the sensitization of the mother's immune system to Rh antigens and the production of anti-Rh antibodies, which can cause hemolytic reactions in subsequent pregnancies.