Antigen binding proteins that activate LCAT are provided. Nucleic acids encoding the antigen binding proteins and vectors and cells containing such nucleic acids are also provided. The antigen binding proteins have value in therapeutic methods in which it is useful to modulate HDL particle size, increase plasma levels of HDL-C, and increase reverse cholesterol transport. Accordingly, the antigen binding proteins have utility in the treatment and prevention of atherosclerosis, various cardiovascular diseases and cholesterol-related disorders, inflammatory conditions, thrombosis-related conditions, metabolic syndrome, diabetes and insulin-resistance. The LCAT antigen binding proteins are also useful in treating the consequences, symptoms, and/or pathology associated with either genetic or acquired LCAT deficiency, including chronic kidney disease (CKD).
