Relative Ascites Polymorphonuclear Cell Count Indicates Bacterascites and Risk of Spontaneous Bacterial Peritonitis.

ABSTRACT

BACKGROUND AND AIMS: Absolute polymorphonuclear (PMN) counts in ascites define spontaneous bacterial peritonitis (SBP), a severe form of bacterial infection in liver cirrhosis. Bacterascites, another form of ascites infection, can progress to SBP or may resolve spontaneously but is not reflected by absolute PMN counts. We investigated whether the relative ascites PMN count (the absolute PMN count divided by the absolute leukocyte count) provides additional information to detect bacterascites or predict SBP. METHODS: Hospitalized patients with liver cirrhosis requiring paracentesis were stratified with respect to a diagnosis of bacterascites and SBP with a prospective follow-up for 1 year. Diagnostic power of relative PMN counts in ascites was evaluated by receiver operating characteristics curves. RESULTS: At inclusion, we observed 28/269 (10%) and 43/269 (16%) episodes of BA and SBP, respectively. Unlike absolute PMN counts, relative PMN counts in ascites were significantly elevated in bacterascites (p = 0.001). During follow-up, 16 and 30 further episodes of BA and SBP were detected, respectively. Relative PMN counts increased significantly once patients developed BA (p = 0.001). At a threshold of 0.20 for the relative PMN count, sensitivity, specificity, positive and negative predictive values for bacterascites which required antibiotic treatment were 83, 75, 26 and 98%, respectively (p < 0.001). Furthermore, a relative PMN count in ascites ≥0.13 and MELD score >17 was independent factors associated with occurrence of SBP during follow-up. CONCLUSION: The relative PMN count is a cheap immunological marker linked to bacterascites and future SBP, which may help to stratify patients according to their risk of infection.