CLU and systemic lupus erythematosus: Systemic lupus erythematosus (SLE) patients with high circulating clusterin and vitronectin greatly demonstrate renal involvement (82). Increased clusterin and vitronectin levels have also been reported in lenses of patients with exfoliation glaucoma (83). Thus, clusterin may not be physiological complement regulator, as it has failed to protect against complement attack under normal or pathological conditions (84).