Anhaptoglobinemia refers to absence of the serum glycoprotein haptoglobin, a hemoglobin-binding acute-phase protein (summary by Teye et al., 2004). Serum levels of haptoglobin vary among normal persons: levels are low in the neonatal period and in the elderly, differ by population, and can be influenced by environmental factors, such as infection. Secondary hypohaptoglobinemia can occur as a consequence of hemolysis, during which haptoglobin binds to free hemoglobin (summary by Delanghe et al., 1998). [from
OMIM]