Association Between Haptoglobin Genotype and the Development of Perihematomal Edema After Spontaneous Intracerebral Hemorrhage

Intracerebral hemorrhage is bleeding into the brain parenchyma. It is a major cause of stroke, and is associated with significant morbidity and mortality. Brain injury from intracerebral hemorrhage occurs in two phases. The early phase involves the mechanical compression of brain tissue by the expanding hematoma. In a later phase, brain edema, especially perihematomal edema, develops causing further compression that may lead to brain herniation and death. Several factors are implicated in the development of brain edema, including inflammation resulting from the oxidative stress caused by iron-rich hemoglobin released from lysed erythrocytes in brain tissue. This study investigates the neuroprotective role of an acute phase reactant, haptoglobin, in minimizing the development of perihematomal edema following intracerebral hemorrhage. This protein protects brain tissue from hemoglobin degradation products by forming haptoglobin-hemoglobin complexes that are subsequently cleared by the spleen. Notably, different alleles of haptoglobin exist in humans, with varying affinities for hemoglobin. Investigating the association between the different alleles and the degree of perihematomal edema formation is the primary goal of this study. The investigators will also look at a marker of inflammation, matrix metalloproteinases, and analyze its level of expression in subjects with different alleles of haptoglobin.