Platelet indices and inflammatory markers as diagnostic predictors for ascitic fluid infection

Ascitic fluid infection (AFI) is a common complication in patients with cirrhosis and ascites. Mean platelet volume (MPV) and platelet distribution width (PDW) may be considered as simple and inexpensive indicators of inflammation in some diseases. We aimed to investigate whether platelet size alterations and platelet indices would be useful in predicting AFI in cirrhotic patients.

Of 210 patients, only 150 patients with ascites because of cirrhosis and 70 control participants were enrolled in this study. After ascitic fluid analysis, patients were divided into two groups: 84 patients had AFI and 66 patients did not have AFI. MPV, PDW, and inflammatory marker values were determined for all patients. The ability of platelet indices values to predict AFI in cirrhotic patients was analyzed using receiver operating characteristic curve analysis.

A significant increase in MPV levels was observed in cirrhotic patients with AFI compared with cirrhotic patients without AFI and healthy controls (P<0.001). A significant increase in MPV, PDW, C-reactive protein, and white blood cell levels was observed in the AFI group compared with the other group (P<0.001, P=0.002, P<0.001, and P=0.001, respectively). The receiver operating characteristic curve for sensitivity and specificity of MPV was assessed. At a cutoff value of 8.77, MPV had 95.9% sensitivity and 91.7% specificity for detecting AFI (area under the curve: 0.964).

Platelet indices and C-reactive protein are increased in cirrhotic patients with AFI. MPV measurement can be considered an accurate diagnostic test in predicting AFI, possibly because of a continuous systemic inflammatory response.