Serum CRP in the diagnosis and treatment of pelvic inflammatory disease.

The usefulness of serum C-reactive protein (CRP) measurement was studied in a population of 152 patients admitted to a gynaecological emergency unit. Fifty-one of 55 patients with PID had raised (over 10 mg/l) (13-270 mg/l) CRP levels with a mean of 76.1 mg/l. CRP was elevated (12-40 mg/l) in 2 of 18 patients with threatened abortion with successful outcome, in 8 of 28 patients with incomplete abortion, and in 2 of 16 patients with ectopic pregnancy. Furthermore, 6 of 35 patients with noninfectious disorders (ovarian cyst, uterine fibroid, unexplained pelvic pains) had slightly elevated (12-59 mg/l) CRP levels. Thus, in this series a CRP greater than 10 mg/l had good sensitivity (93%) and specificity (83%) in the diagnosis of PID. Furthermore, CRP levels became normal much sooner than did erythrocyte sedimentation rate following effective antibiotic therapy, suggesting that it is useful in monitoring therapeutic response.