Response protein, or C-reactive protein, is an acute phase protein that is synthesized by human hepatocytes. It is traditionally considered an inflammatory marker and is usually required in conjunction with changes in blood cells in routine blood work to determine what type of infection is present and to determine whether antibiotic treatment is needed. Also, in cardiovascular and connective tissue diseases, such as the acute phase of rheumatoid arthritis, c-reactive protein can be elevated. Therefore, the specific symptoms and manifestations need to be taken into account for symptomatic treatment.