Corrigendum to “Haptoglobin Genotype and Outcome after Subarachnoid Haemorrhage: New Insights from a Meta-Analysis”
Reported differences between Hp types, relevant to SAH.
No difference between Hp types
Difference between Hp types
Serum Hp1-1 is higher than Hp2-2, with Hp2-1 intermediate, in many populations tested, including European (Belgian [37–39], Iceland ), East Asian (Japanese , Koreans ), and African (Black Zimbabweans , Gabonese , Papuans ).
Haemoglobin binding: capacity per Hp monomer
(1) Ultrafiltration assay of uncomplexed Hb  (2) Mass spectrometry 
Haemoglobin binding: affinity
(1) Surface plasmon resonance  (2) Surface plasmon resonance  (3) Spectrophotometric signal of Hp-Hp interaction 
Inhibition of Hb-mediated oxidation
(1) Reduction in low-density lipoprotein oxidation  (2) Reduction in Hb intrinsic redox potential  (3) Reduction in Hb autooxidation 
(1) Hp1-1 is better than Hp2-2 at inhibiting protein and lipid oxidation . (2) Hp1-1 is better than Hp2-2 at inhibiting oxidation of linolenic acid and low-density lipoprotein . (3) Hp1-1 is better than Hp2-2 at inhibiting lipid peroxidation .
Interaction with CD163: affinity
(1) Hp2-2 is better than Hp1-1, by surface plasmon resonance and binding of radioiodinated Hp-Hb complexes in vitro . (2) Hp2-2 is better than Hp1-1, by binding of radioiodinated Hp-Hb complexes in vitro .
Interaction with CD163: uptake of Hp-Hb complexes
Plasma half-life of Hp-Hb complexes after injection in guinea pigs 
(1) Hp2-2 is better than Hp1-1, by measurement of free Hb in humans . (2) Hp1-1 is better than Hp2-2, by uptake of radioiodinated Hp-Hb complexes in human cells in vitro .
Effects on inflammation
Binding of Hp1-1-Hb complexes to CD163 results in secretion of the anti-inflammatory cytokine IL-10 [19, 20].