APOH and lupus nephritis: A study among 796 SLE patients showed that positive IgM anti-β2GPI was associated with a 2.6-fold risk of ischemic attack, while it was associated with a reduced risk for hypertension (OR = 0.54) and renal damage, namely, lupus nephritis (OR = 0.54), persistent proteinuria (OR = 0.19), and renal SLE (OR = 0.58) with reference to negative IgM anti-β2GPI and regardless of the IgG status (46).