Serum Calprotectin: An Antimicrobial Peptide as a New Marker For the Diagnosis of Sepsis in Very Low Birth Weight Newborns

Table 3

Diagnostic accuracy of various markers in identifying septic patients among symptomatic newborns.

	Sensitivity	Specificity	PPV	NPV	Likelihood ratio (+ test)
WBC	14 (7–26)	93 (77–99)	82 (48–98)	34 (23–45)	2 (1–8)
I/T ratio	60 (46–72)	82 (64–94)	88 (74–96)	48 (34–64)	3 (2–8)
Platelet count	13 (6–24)	76 (56–90)	53 (27–79)	29 (19–40)	0.5 (0-1)
CRP	29 (18–42)	93 (77–99)	90 (68–99)	38 (27–50)	4 (1–16)
Serum calprotectin	89 (78–95)	96 (82–99)	98 (90–99)	80 (63–92)	26 (5–145)

PPV: positive predictive value. NPV: negative predictive value. WBC: white blood count. CRP: C-reactive protein. I/T ratio: immature-to-total-neutrophil ratio.
N.B. Cut-off value: total neutrophil count < 4.0 or > 25.0 ×10³/mm³; platelet count < 50.0 or > 500.0×10³/mm³ ; I/T ratio > 0.2; CRP >10 mg/dL; serum calprotectin >1.7 μg/mL [8–10, 12, 16].