The Relevance of Ascitic Lactate Dehydrogenase (LDH) and Serum Ascites Albumin Gradient (SAAG) in the Differential Diagnosis of Ascites among Patients in a Nigerian Hospital.

Aim: The study aimed to determine the diagnostic values for lactate dehydrogenase (LDH) and serum ascites albumin gradient (SAAG) with maximum sensitivity and minimum false positivity so as to differentiate malignancy-related ascites from non-malignant ascites in South West region of Nigeria. Study Design: This is a cross sectional study to determine the correlation between ascitic fluid LDH and SAAG and malignant and non-malignant ascites. Place and Duration of Study: This study was carried out at the clinics of gastroenterology, surgery, and obstetrics/gynecology at the Lagos University Teaching Hospital (LUTH), between August 2011 and July 2013. Methods: A total of 75 patients with ascites admitted into Lagos University Teaching Hospital (LUTH) from 2011 to 2013 were enrolled for the study. Thirty seven (7males, 30 females) had malignancy-related ascites while 38(18 males, 20 females) had non-malignant ascites. Levels of LDH and SAAG were determined in all patients with ascites. Statistical analysis was performed using SPSS software application (version 15.0) and p˂0.05 was considered statistically significant and results expressed as mean ± standard deviation. Results: A total of 75 patients were recruited for the study. Twenty-five of them (33.3%) were males while 50(66.7%) were females. The mean age for both sexes was 59.03±13.54 years. Using Receiver Operator Characteristic (ROC) curve, cut-off levels were 11.5 for SAAG and 310 IU/l for LDH. These cut-offs divided the malignant from the non-malignant group. Higher levels of ascitic LDH were seen in the malignant group (900.67±918.45 IU/l) when compared to the non-malignant group (199.29±194.53 IU/l). This was statistically significant (P<0.05). The diagnostic accuracy of LDH was 90.7%. SAAG was lower in the malignant (6.74±4.84 g/L) group when compared to the non-malignant (13.56±7.50 g/L). This was also statistically significant (P<0.05). The diagnostic accuracy of SAAG was 73.3%. Conclusion: It was concluded that measurement of ascitic fluid LDH and SAAG were relevant in differentiating malignant from non-malignant ascites. The determined cut-off values for LDH and SAAG in this study provides the distinctive differential diagnosis between malignant and nonmalignant ascites. Routine analysis of serum and ascitic fluid albumin and LDH will resolve the problem of malignant and non-malignant ascites especially in low-resource areas or in the developing world.