ACTA FAC. MED. NAISS. 2003; 20 (4): 209-212

Original article
 

THE VALUE OF SERUM-ASCITES ALBUMIN GRADIENT IN DIFFERENTIAL DIAGNOSIS OF ASCITES AND THE PROPOSAL FOR THE NEW CUT-OFF VALUE
 

Goran Bjelaković, Aleksandar Nagorni , Ivanka Stamenković , Daniela Benedeto-Stojanov, Vesna Brzački, Suzana Raičević, Biljana Radovanović¹, Marija Bjelaković², Vuka Katić, Vesna Živković³, Dragomir Vučetić⁴

¹Clinic of Gastroenterology and Hepatology, Clinical Centre Niš,
²Institute of Anatomy,
³Institute of Pathology,
⁴Medical Faculty, University of Niš, Clinic of Gynecology and Obstetrics, Clinical Center Niš
 

SUMMARY
Serum ascites albumin gradient (SAAG) has long been recognized as a reliable biochemical marker that can help in differential diagnosis of ascites. Values under 11 g/L indicate that patient with ascites has portal hypertension and vise versa. Because of poor sensitivity (Se) and specificity (Sp) of SAAG in some of the previous studies and possibilities owing to new statistical methods like Receiver Operating Characteristic (ROC) analysis, it is interesting to define new cut-off value with maximal Se and Sp. The investigation included 171 patients, 130 with cirrhotic, mean age 60 years, and 41 with malignant ascites, mean age 63 years. In the group with malignant ascites 6 patients. (14.63%) had liver metastasis, but only two of them (4.88%), were recorded with massive liver metastasis that caused portal hypertension. The mean value of SAAG (- SD) in the group of patients with cirrhotic ascites was 21.89 - 8.34 g/L and was statistically significant, higher than SAAG in group with malignant ascites of 11.17 - 7.13 g/L, (p < 0.001). A cut-off value for SAAG of 11 g/L had high sensitivity (97.56%) but low specificity (46.34%), so we decide to determine new cut-off value using ROC analysis. With the probability of p < 0.05, the interval of reliability was 11.2-19.7 g/L with a cut-off value of 15.86 g/L. We concluded that a cut-off value for the SAAG had to be corrected to a higher level to achieve the maximal sensitivity and specificity, and thus help in differential diagnosis of ascites.

Key words: serum ascites albumin gradient, ascites