Immunobiology of Hemoglobin
Hemoglobin (Hb), an inflammatory molecule, is being studied as an antigenic and immunogenic agent in lupus in the lab. Under physiological conditions, hemoglobin binds to haptoglobin (Hp), and the complex is cleared via CD163-mediated endocytosis. In lupus, Hb concentrations can overwhelm available Hp levels (and other clearance mechanisms), leading to the presence of free Hb. Hb, as well as free heme, have well-documented inflammatory and toxic effects.
The lab has previously described the preferential Hb-mediated release of lupus-associated cytokines from splenocytes derived from aging, lupus-prone mice. Anti-Hb autoantibodies have been observed in such mice and in SLE patients.
Keywords: Autoimmunity, Systemic Lupus Erythematosus, Hemoglobin.