Similar results were observed in a guinea pig model exposed to transfusions of senile erythrocytes: in the absence of treatment with purified haptoglobin, the animals rapidly developed (24 h) a combination of intravascular hemolysis, hypertension, vascular lesions (necrosis/coagulation), hemoglobinuria, and acute renal failure [185]. The gene discussed is HP; the disease is Hypertension.