CRP and systemic lupus erythematosus: Among the 31 SLE patients with co-existing FM, 15 (48.4%) had either ESR above the laboratory reference range of 30.0 mm/h or CRP above the reference range of 10.0 mg/L, whereas 18 (43.9%) of the 41 SLE patients without co-existing FM had ESR or CRP above the reference range.