TO THE EDITOR
We read with great interest the article by Rao et al[1], “Ascites characteristics in acute pancreatitis: A prognostic indicator of organ failure and mortality” (World Journal of Gastroenterology). The authors provide valuable insights into the prognostic role of ascitic characteristics, particularly color depth, turbidity, elevated lactate dehydrogenase (LDH) levels are associated with organ failure, infected pancreatic necrosis, and mortality in acute pancreatitis (AP). This is a valuable contribution, as ascitic fluid characteristics have been relatively underexplored in AP. We commend the authors for their robust analysis of a large patient cohort; nonetheless, we would like to offer several critical perspectives and constructive suggestions for future investigations.
A central concern lies in the classification of ascitic fluid based solely on gross visual characteristics. While the stratification into yellow clear, yellow turbid, and red brown is intuitively understandable, both color and turbidity are inherently subjective and lack standardized criteria. Interobserver variability is likely, particularly in real-world settings where assessments may vary depending on operator experience or lighting conditions. To achieve objective and reproducible evaluation of ascitic fluid, future studies should adopt standardized analytic approaches such as digital colorimetry for quantifying color intensity, hemoglobin-related absorbance profiling to differentiate hemorrhagic discoloration from inflammatory turbidity, and turbidity measurement expressed as optical density or nephelometric units with prespecified cutoffs[2-4]. In addition, careful pre-analytic handling, including prompt sample processing and gentle centrifugation when hemolysis is suspected, should be implemented to ensure analytic reliability[5].
Moreover, the interpretation of turbid or discolored ascitic fluid warrants careful consideration, as such findings may not directly indicate the severity of AP but rather reflect secondary pathological processes. For example, the presence of turbid or hemorrhagic ascites may suggest concomitant conditions such as spontaneous bacterial peritonitis or intra-abdominal hemorrhage, both of which are independently associated with adverse clinical outcomes in patients with cirrhosis[6,7]. These associations may be extrapolated to patients with AP, in whom the pathophysiology of ascites is often heterogeneous and multifactorial. Accordingly, prognostic stratification based solely on the gross appearance of ascitic fluid may be insufficient. Instead, objective parameters such as a polymorphonuclear leukocyte count ≥ 250 cells/mm3, positive microbiological cultures, and biochemical indices may provide a more reliable assessment of underlying complications and their prognostic implications. Therefore, ascitic fluid evaluation should integrate cytologic and microbiologic markers including polymorphonuclear leukocyte counts, smear and culture results, and standard biochemical panels alongside objective measures of colorimetry and turbidity. This integrative approach would allow severity models to be anchored to reproducible and clinically meaningful criteria.
Additionally, this study evaluated ascitic fluid characteristics at a single time point within seven days of symptom onset. However, as noted by the authors, AP is a dynamic disease involving progressive local and systemic inflammation, increased capillary permeability, and fluid extravasation. Concurrent processes such as hypoalbuminemia, mechanical exudation, peripancreatic fat necrosis, and pancreatic ductal disruption can rapidly alter the volume and composition of ascitic fluid, particularly during the early phase of AP. Previous research, including the present study, has demonstrated that the presence of ascites alone is predictive of poorer clinical outcomes in AP[1,8,9]. Therefore, repeated evaluation of ascitic LDH, protein levels, and cellularity during the disease course may help better assess disease progression[10]. Such longitudinal assessment could facilitate timely therapeutic decision-making, including the consideration of peritoneal drainage or lavage, and enhance prognostic modeling and clinical risk stratification. Consistent with previous reports highlighting the importance of sampling timing, scheduled assessments at admission, day 3, and days 5-7 represent a rational strategy to account for the dynamic course of AP, improve reproducibility, and more accurately capture disease progression. From a biochemical standpoint, the authors reported total protein and amylase levels in ascitic fluid but did not analyze the exudative or transudative nature of the effusion. Pancreatic ascites is typically exudative, characterized by elevated protein, low serum-ascites albumin gradient, and high amylase content. The use of serum-ascites albumin gradient and LDH may enhance the mechanistic insight and prognostic value of ascitic fluid analysis, enabling a more objective classification than visual appearance alone[10,11].
Notably, Rao et al[1] reported that ascitic LDH predicted abdominal compartment syndrome with an area under the curve of 0.79 (95% confidence interval: 0.70-0.88) and intra-abdominal hemorrhage with an area under the curve of 0.77 (95% confidence interval: 0.65-0.90), underscoring its moderate but clinically relevant prognostic performance. However, the predictive capacity of LDH was not analyzed in conjunction with established severity scores such as Bedside Index of Severity in Acute Pancreatitis, Acute Physiology and Chronic Health Evaluation II, or Ranson’s score[12,13]. Assessing the incremental value of ascitic LDH when incorporated into established prognostic models could help determine whether it provides predictive accuracy or enhances clinical decision-making. Moreover, while LDH reflects tissue damage, its prognostic utility may be enhanced by incorporating inflammatory markers such as interleukin-6, tumor necrosis factor-alpha, and procalcitonin, all of which are well-established indicators of disease severity and infection risk in AP[14,15]. The inclusion of these markers may enhance diagnostic precision and provide deeper mechanistic insight.
Finally, this study was conducted retrospectively at a single tertiary care center, which raises concerns regarding its generalizability. In addition, the study population was predominantly composed of patients with moderately severe to severe AP, which may have led to an overestimation of the association between ascitic abnormalities and adverse outcomes. Previous studies have also indicated that the ascites formation is independently associated with an increased risk of organ failure in AP[9]. Accordingly, prospective multicenter cohort studies that include a wider spectrum of disease severity are necessary to confirm these findings and support their integration into broader clinical practice.
