New proposal for the serum ascites albumin gradient cut-off value in Chinese ascitic patients

BACKGROUND: Serum ascites albumin gradient (SAAG) has been recognized as a reliable marker in the differential diagnosis of ascites. The etiological background of cirrhosis is rather different between western countries and eastern countries. The threshold of SAAG in Chinese ascitic patients has not been evaluated yet. The aim of this study was to define a new reasonable threshold of SAAG in Chinese ascitic patients. METHODS: Adult patients with ascites admitted to the Shanghai Changzheng Hospital from Jan 2004 to Jun 2010 were retrospectively analyzed. The diagnostic criteria for cirrhotic ascites are clinical manifestations, radiological features and esophageal-gastric varicosis, or histopathology. Serum was detected by chemical method using a commercial kit. We used receiver operating characteristic (ROC) analysis to achieve maximal sensitivity and specificity of SAAG. RESULTS: The mean value of SAAG in portal-hypertension-related ascites was significantly higher than that in the non-portal-hypertension-related ascites (21.15 ± 4.38 g/L vs 7.48 ± 3.64 g/L, P = 0.002). The SAAG cut-off value under 12.50 g/L predicted portal hypertension ascites with the sensitivity of 99.20%, specificity of 95.10% and accuracy of 97.65%. CONCLUSIONS: SAAG is useful to distinguish portal-hypertension-related ascites and non-portal-hypertension-related ascites, and 12.50 g/L might present as a more reasonable threshold in Chinese ascitic patients. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1602582638991860.