Ascitic Fluid Total Protein, a useful marker in non‐portal hypertensive ascites

BACKGROUND AND AIMS: Diagnostic performance of ascitic fluid total protein (AFTP) concentration remained unsettled. Our aim was to determine diagnostic value of AFTP in differential diagnosis of causes of ascites. METHODS: Seven hundred four consecutive patients with new-onset ascites were prospectively enrolled in this study. RESULTS: In the training cohort, diagnostic performance of quantitative AFTP assay was superior to that of Rivalta test in differential diagnosis of ascites. At the predetermined cut-off value of 25 g/L, quantitative AFTP assay was more useful in the differentiation of non-portal hypertensive ascites from portal hypertensive ascites compared with the exudate-transudate classification, area under curve of receiver operating characteristic curve was 0.958. Quantitative AFTP assay was superior to serum-ascites albumin gradient in the detection of non-portal hypertensive ascites, especially malignant ascites and tuberculous peritonitis. In mixed ascites, AFTP was useful in identifying peritoneal lesions. CONCLUSIONS: Ascitic fluid total protein is a useful marker in non-portal hypertensive ascites; thus, it should be determined in diagnostic work-up of the patients with ascites.