IE = infective endocarditis; PWID = people who inject drugs; CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; CK-MB = MB isoenzyme of creatine kinase; GPT/ALT = glutamate-pyruvate transaminase/alanine aminotransferase; GOT/AST = glutamic oxaloacetic transaminase/aspartate aminotransferase; LDH = lactate dehydrogenase. Here, CRP is linked to infective endocarditis.