A filtration medium is sealed within a housing. The filtration medium is sized and configured to define multiple filtration regions within the housing, through which independent, though concurrent, blood filtration can occur. Each filtration region is served by its own inlet path, which conveys blood into the filtration region. The filtration medium in each filtration region passes the blood to remove at least one undesired component, such as, e.g., leukocytes. After filtration, the multiple filter regions convey the blood into a single, centrally located manifold. A single outlet path communicates with the manifold.