Ultrasensitive C-reactive protein, an acute time-phase reactive protein that reacts with S. pneumoniae C polysaccharide. Ultrasensitive C-reactive protein activates complement, promotes phagocytosis, and has immunomodulatory effects. Ultrasensitive C-reactive protein in excess of 70 (mg/L) is often seen in inflammatory conditions in the body, such as tonsillitis, bronchopneumonia or appendicitis or pyelonephritis. It can also be seen in tissue necrosis, such as myocardial infarction, severe trauma or burns. It can also be seen in cases of malignant tumors such as liver cancer and lung cancer. Of course, one of the most common conditions is rheumatic disease, in which ultrasensitive C-reactive protein may be significantly elevated, especially during the active phase.