THE ROLE OF C-REACTIVE PROTEIN AND ERYTHROCYTE SEDIMENTATION-RATE IN THE DIAGNOSIS OF INFECTED HYDRONEPHROSIS AND PYONEPHROSIS

Serum C-reactive protein levels and erythrocyte sedimentation rates we re prospectively evaluated in 38 patients with dilated pyelocaliceal s ystems in an attempt to distinguish simple hydronephrosis from infecte d hydronephrosis and pyonephrosis. The clinical presentations of infec ted hydronephrosis and pyonephrosis were extremely variable, ranging f rom no constitutional complaints to urosepsis. Renal sonography detect ed only 6 of 16 patients with pyonephrosis (specificity 96%, sensitivi ty 38%, accuracy 72.5%). Using a cutoff value of 3.0 mg./dl. for C-rea ctive protein and 100 mm. per hour for erythrocyte sedimentation rate, the diagnostic accuracy of detecting infected hydronephrosis and pyon ephrosis increased to 97%, with a specificity of 89% and sensitivity o f 100%. Based on our experience, we believe that the serum C-reactive protein and erythrocyte sedimentation rate levels can be used as scree ning tests to distinguish pyonephrosis and infected hydronephrosis fro m simple, uncomplicated hydronephrosis.