Measurement of calprotectin in ascitic fluid to identify elevated polymorphonuclear cell count

Table 1 Baseline characteristics of patients with liver cirrhosis (n = 54)

Aetiology of liver cirrhosis
Alcoholic	36 (66.6)
Viral hepatitis	7 (13.0)
Alcoholic + viral hepatitis	5 (9.3)
Non alcoholic steatohepatitis	1 (1.9)
Others	5 (9.3)
Child-turcotte-pugh class
Child A	0
Child B	29 (53.7)
Child C	25 (46.3)
MELD score	12.2 (10.0-16.0)

Others included 2 patients with autoimmune hepatitis, 2 patients with primary biliary cirrhosis and 1 patient with primary sclerosing cholangitis. The child-turcotte-pugh classification contains five variables, including serum levels of bilirubin and albumin, prothrombin time, ascites, and encephalopathy. Child A: 5-6 points; Child B: 7-9 points; Child C: 10-12 points. The model for end-stage liver disease (MELD) score: 9.57 Ln [serum level of creatinine (mg/dL)] + 3.78 Ln [serum bilirubin (mg/dL)] + 11.2 Ln (international normalised ratio for prothrombin time) + 6.43. Data are presented as number of patients (%) or medians (25^th to 75^th percentiles).

Table 2 Ascitic fluid analysis

Variable	PMN count > 250/μL (n = 19)	PMN count ≤250/μL (n = 111)
Total cell count	1300.0 (350.0-19800.0)	250.0 (10.0-1970.0)
PMN count	553.0 (277.0-17820.0)	21.0 (1.0-212.0)
Albumin, g/L	13.0 (4.8-16.8)	7.0 (3.0-10.0)
Protein, g/L	22.0 (9.3-37.5)	12.0 (8.0-20.0)
LDH, U/L	117.0 (100.8-138.5)	55.0 (42.0-81.0)
Glucose, mmol/L	7.6 (6.2-9.7)	7.0 (6.2-8.2)

Values are given as medians (range) for total cell count and polymorphonuclear cell count (PMN) count and median (25^th to 75^th percentiles) for all other values. LDH: Lactate dehydrogenase.

Table 3 Test characteristics of ascitic calprotectin to identify > 250 polymorphonuclear leukocytes per mL ascites

	AUC (95%CI)	Best cut-off (μg/mL)	Sens (%)	Spec (%)	LR+	LR-	PPV (%)	NPV (%)	Accuracy (%)
ELISA	0.977 (0.933-0.995)	0.63	94.8	89.2	8.76	0.06	60.0	99.0	90.0
POC	0.982 (0.942-0.997)	0.51	100	84.7	6.53	0.00	52.8	100	87.7

Area under the receiver operating characteristics curve (AUC) with corresponding sensitivity (Sens), specificity (Spec), positive and negative likelihood ratio (LR+, LR-), and negative and positive predictive values (NPV, PPV) for ascitic calprotectin to identify polymorphonuclear > 250/μL. Overall accuracy was calculated using the following formula: (true positive test results + true negative test results)/total population. ELISA: Enzyme-linked immunosorbent; POC: Point-of-care.