A Novel Combination of C-Reactive Protein and Vascular Endothelial Growth Factor in Differential Diagnosis of Ascites

Ascites with unknown cause remains a diagnostic challenge, which needs novel noninvasive biomarkers for the precise diagnosis. We aimed to evaluate the ascitic fluid and serum C-reactive protein (CRP) and vascular endothelial growth factor (VEGF) as diagnostic markers in the differential diagnosis of malignant and benign ascites.

In this prospective work, 315 consecutive patients with ascites were studied. Ascitic fluid and serum levels of CRP and VEGF were evaluated by using an enzyme-linked immunosorbent assay.

Patients were divided into a benign ascites group (group 1) (n = 256) and a malignant ascites group (group 2) (n = 59). Ascitic and serum CRP were significantly elevated in malignant ascites than benign ascites group [5.08 (3.62-6.58) vs. 1.82 (0.64-3.86) ng/ml; P < 0.001 and 12.7 (8.55-17.05) vs. 5.94 (2.57-10.64) ng/ml; P < 0.001], respectively. Ascitic and serum VEGF were significantly increased in malignant ascites than benign ascites patients [0.68 (0.39-0.96) vs. 0.41 (0.25-0.83) ng/ml; P < 0.001 and 0.74 (0.41-1.08) vs. 0.54 (0.23-0.86) ng/ml; P < 0.001], respectively. At a cutoff value of 7.3 and 0.63 ng/ml, serum CRP and VEGF had specificity (77.3 and 89.5 %) and sensitivity (83.1 and 94.9 %) for detecting malignant ascites [area under the curve (AUC) 0.821, 0.921], respectively. At a cutoff value of 2.5 and 0.57 ng/ml, ascitic CRP and VEGF had specificity (81.6 and 85.5 %) and sensitivity (84.7 and 91.5 %) for detecting malignant ascites (AUC 0.842, 0.894), respectively.

Elevated ascitic fluid and serum CRP and VEGF values were related to the malignant ascites.