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

Background and Aims: 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. Methods: 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. Results: 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. Conclusion: Elevated ascitic fluid and serum CRP and VEGF values were related to the malignant ascites.