C-REACTIVE PROTEIN - This blood test is used as an indicator of acute inflammation. C-reactive protein is produced by the liver during periods of inflammation. C-reactive protein plays a role in stimulating the body's complement system. Normally C-reactive protein should be negative in the bloodstream. Conditions which can cause a positive C-reactive protein include: rheumatoid arthritis, lupus, pneumococcal pneumonia, rheumatic fever, cancer, tuberculosis, and myocardial infarction. A positive C-reactive protein may also be seen in the later half of pregnancy and in some who are taking birth control pills. This test is performed on a venipuncture specimen.