Table 1: Major reported cytoprotective and antiinflammatory effects of the Hp-CD163-HO-1 pathway.

Intravascular HpHb complex formation:
 Protects against oxidative “hot spot” in Hb
 Protects against heme release from Hb
 Facilitates CD163-mediated clearance
 Prevents renal filtration of Hb and uptake in proximal tubules
 Prevents NO scavenging
Cellular response on CD163-mediated Hb endocytosis:
 Cellular differentiation
 HO-1 upregulation
 Nrf-2 activation
 IL-10 synthesis
Other effects of heme metabolites generated by HO-1 activity:
 Antagonism of proinflammatory cytokines
 ROS scavenging
 Inhibition of platelet aggregation