Parvovirus B19 & Anemia

Parvovirus B19 can stimulate a temporary infection of the bone marrow and so has an obvious tropism for erythroid progenitor cells, finally due to a reticulocytopenia, rapid decline of anemia, and transient capture in erythropoiesis in the bone marrow, which characterizes by a transient aplasia crisis. In patients with underlying immunodeficiency status, persistent B19 infection may occur. It is thought that these patients fail to mount a neutralizing antibody response to the virus due to a persistent bone marrow insufficiency. Therefore, they usually lack the immune complex mediated symptoms of erythema infectiosum and arthropathy . Chronic anemia and pure red cell aplasia due to chronic B19 infection have been documented in congenital immunodeficiency, children with lymphoblastic leukemia, patients with acquired immunodeficiency syndrome (AIDS), and recipients of solid organ transplants.In chronically infected patients, the anemia may be intermittent, with periods of relapse (associated with viremia) and remission (associated with spontaneous disappearance of the virus from the circulation). Clinically, the degree of anemia may be severe.