Mean platelet volume indicator for systemic inflammation in cirrhotic patients with spontaneous bacterial peritonitis

Abstract Introduction spontaneous bacterial peritonitis (SBP) is the most common infection in patients with cirrhosis [1] .Spontaneous bacterial peritonitis is found in patients where besides the increase of polymorphonuclear counting, they present a positive result of culture [2] . The BMN count as not always quickly available in clinical practice and the culture result usually takes 72 hours or more [3] .The use of additional markers that are rapidly and easily applicable, may add significant benefit for predicting the development of spontaneous bacterial peritonitis and achieving diagnostic accuracy [4] .Platelet size is a determinant factor of platelet proinflammatory functions. Several studies have found relationship between the mean platelet volume (MPV) and pro-inflammatory conditions, particularly acute infections [5] . Aim to identify a mean platelet volume (MPV) cutoff value which should be able to predict the presence of sponataneous bacterial peritonitis. Settings and designs a cross sectional observational study, carried out on 40 patients with AFI and 40 patients without AFI. Methods Patients were classified into two groups, group A (SBP) which included 40 patients with ascetic fluid PMN count ≤ 250 cells/mm3 and group B (non/SBP) which included another 40 patients with ascetic fluid PMN count < 250 cells/mm3. All studied patients were subjected to history taking, Clinical examination and routine laboratory investigations including: CBC including platelet number and MPV, liver function test including (ALT, AST, albumin, and direct & total bilirubin), kidney function test including (BUN &creatinine), PT, PTT, INR, ESR and CRP .Abdominal-pelvic ultrasonography was done for all patients. Aspirated ascetic fluid samples were immediately examined for bacteriological cultures. Statistical analysis used Statistical presentation and analysis of the present study was conducted, using the mean, standard deviation, independent samples t-test, Chi-square, Mann-Whitney U test and Analysis of variance [ANOVA] tests by SPSS version 22 software .Tukey test was used .Receiver operating characteristic (ROC) curve analysis was used to identify optimal cut-off values of MPV and with maximum sensitivity and specificity for differentiation of cirrhotic patients with SBP from those without SBP. Spearman’s correlation analysis was done. Results MPV was significantly higher in SBP-patients (Group A) than that of non-SBP patients (Group B) (11.6820±1.19303 fL versus 9.0325±1.12441 fL) (P-value = 0.001) .MPV has positive correlation with Ascitic sample TLC and Ascitic sample PMNC in Group A. ROC curve shows that MPV cut off value is10.25with 85% sensitivity and 75% specificity . Conclusion MPV may serve as a non-invasive, cheap and rapid test for detection and diagnosis of spontaneous bacterial peritonitis (SBP) with a sensitivity and specificity of 85% and 75% respectively.