What Is C-Reactive Protein (CRP)?CRP, C-reactive protein, is a blood test which indicates inflammation and is a marker for some diseases.C-reactive protein, Indicator Of Arthritis & Heart DiseaseC-Reactive Protein: Indicator of Arthritis & Heart Disease. When the body has any sort of inflammation, levels of C-reactive protein in the ...C-reactive Protein Levels In Rheumatoid Arthritis | LIVESTRONG.COMC-reactive Protein Levels In Rheumatoid Arthritis. Rheumatoid arthritis is a chronic autoimmune disorder characterized by inflammation of the joints and often other ...