C-reactive protein and insulin-like growth factor-1 in differential diagnosis of ascites.

Abstract

Insulin-like growth factor-1 (IGF-1) and C-reactive protein (CRP) are produced mainly by the liver; the output of these markers in response to inflammatory processes may be affected in patients with hepatic dysfunction. This may explain the differences in IGF-1 and CRP values in patients with non-portal and portal hypertension ascites. We aimed to evaluate serum and ascitic fluid IGF-1 and CRP as diagnostic markers in the differential diagnosis of benign and malignant ascites. In this prospective study, 398 consecutive patients with ascites were included. Serum and ascitic fluid levels of IGF-1 and CRP were measured using an enzyme-linked immunosorbent assay. Patients were divided into group 1, due to benign ascites (n = 324), and group 2, due to malignant ascites (n = 74). Serum and ascitic IGF-1 were significantly increased in malignant ascites than benign ascites group [305 ± 65.7 ng/mL vs 95 ± 53.8 ng/mL; P < 0.001 and 288 ± 54.7 ng/mL vs 83.2 ± 36.7 ng/mL; P < 0.001], respectively. Serum and ascitic CRP were significantly higher in malignant ascites than benign ascites patients [12.8 ± 6.3 mg/mL vs 6.1 ± 4.9 mg/mL; P < 0.001 and 5.1 ± 2.2 mg/mL vs 1.6 ± 1.3 mg/mL; P < 0.001], respectively. At a cutoff value of 309.4 ng/mL and 7.8 mg/mL, serum IGF-1 and CRP had (95.1%, 81%) sensitivity and (88.6%, 75.5%) specificity for detecting malignant ascites [area under the curve: 0.932, 0.845], respectively. At a cutoff value of 291.6 ng/mL and 2.6 mg/mL, ascitic IGF-1 and CRP had (94.6%, 84%) sensitivity and (83.2%, 80.3%) specificity for detecting malignant ascites (area under the curve: 0.911, 0.893) correspondingly. Elevated serum and ascitic fluid IGF-1 and CRP levels were associated with malignant ascites.