Scleroderma, polymyositis, and dermatomyositis elicit little or no CRP response. CRP levels also tend not to be elevated in systemic lupus erythematosus (SLE) unless serositis or synovitis is present. Elevations of CRP in the absence of clinically significant inflammation can occur in kidney failure. CRP level is an independent risk factor for atherosclerotic disease. Patients with high CRP concentrations are more likely to develop stroke, myocardial infarction, and severe peripheral vascular disease. Elevated level of CRP can also be observed in inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis.
High levels of CRP has been associated to point mutation Cys130Arg in the APOE gene, coding for apolipoprotein E, establishing a link between lipid values and inflammatory markers modulation.