Diagnostic Utility of Cytology, Ascitic Fluid Total Protein, and Serum Ascites Albumin Gradient in Ascitic Fluid Analysis

Abstract Introduction: Ascites, the pathological accumulation of fluid in the peritoneal cavity, poses a diagnostic challenge due to its diverse etiologies. The accurate classification of ascitic fluid is crucial for guiding appropriate management strategies. Traditional methods, such as ascitic fluid total protein (AFTP) analysis, have limitations, whereas the serum ascites albumin gradient (SAAG) is increasingly recognized as a more reliable diagnostic parameter. Aim: This study aims to (1) classify ascitic fluid samples into transudate, exudate, spontaneous bacterial peritonitis (SBP), and malignancy-positive cases based on cytological analysis and (2) evaluate the diagnostic accuracy of AFTP and SAAG in distinguishing between these categories. Materials and Methods: A cross-sectional study was conducted over 1 year at a tertiary care center in North Karnataka, analyzing 190 ascitic fluid samples. Cytological findings (cell count and morphology) were correlated with biochemical parameters (AFTP and SAAG), and statistical evaluation was performed. Results: The study cohort had a mean age of 48 ± 14 years, with a male-to-female ratio of 2.22:1. Among the 190 samples, 53.68% were classified as transudates, 17.37% as exudates, 17.37% as SBP, and 11.58% as malignancy-positive. AFTP demonstrated a diagnostic accuracy of 88.09% (sensitivity: 69.69%; specificity: 92.59%), whereas SAAG exhibited a superior accuracy of 92.26% (sensitivity: 87.87%; specificity: 93.33%). Conclusion: SAAG outperforms AFTP in accurately differentiating ascitic fluid types, particularly in distinguishing portal hypertension–related ascites. A combined approach integrating clinical data, cytology, and biochemical parameters enhances diagnostic precision and guides appropriate therapeutic interventions.