Value of acute-phase proteins in the differential diagnosis of acute scrotum

Abstract

Objectives: The evaluation of patients with an acute scrotum is primarily based on physical examination, imaging studies, as well as blood and urine tests. However, the differential diagnosis may be difficult in some cases. In a retrospective study, we investigated the value of acutephase proteins in serum and plasma from patients with an acute scrotum.

Methods: A total of 104 patients (epididymitis n=52, testicular tumor n=17, testicular torsion n = 11, other conditions n = 24) with an acute scrotum were included in this study. In all patients the acute-phase proteins C-reactive protein (CRP), haptoglobin, alpha1-acid glycoprotein and transferrin in serum as well as fibrinogen in plasma were determined by turbidimetric analysis. The results were compared to the clinical findings, routine blood and urine tests and ultrasound.

Results: Patients with an epididymitis showed at least a 4-fold elevation of CRP except for 2 cases (median 63.2 mg/l). In these patients, the sensitivity of CRP was 96.2%, the specificity 94.2%, the negative predictive value 94.2% and the positive predictive value 94.3%. Patients with a testicular tumor had no significant elevation of CRP (median 9 mg/l) as well as those with a testicular torsion (median 5 mg/l) except for 1 patient. The difference between patients with epididymitis and those with noninflammatory conditions was statistically significant (p<0.001, Kruskal-Wallis test and Tukey-Kramer test). The remaining parameters (haptoglobin, fibrinogen, a1-acid glycoprotein, transferrin, white blood count, body temperature and ultrasound) were less sensitive and specific.

Conclusions: Acute-phase proteins (especially C-reactive protein) are helpful in differentiating epididymitis from noninflammatory conditions like testicular torsion or tumor. Turbidimetric analysis of these proteins is rapid, easy and inexpensive.