Determining acute complicated and uncomplicated appendicitis using serum and urine biomarkers leucine rich alpha-2 glycoprotein 1, neutrophil gelatinase-associated lipocal and interleukin-6

Severe complications of acute appendicitis (AA) arise with delays in treatment; to avoid this an early and accurate diagnosis is crucial. Our primary objective was to demonstrate the potential of leucine-rich alpha-2 glycoprotein 1 (LRG1), Neutrophil gelatinase-associated lipocal (NGAL) and Interleukin-6 (IL-6) in differentiating acute complicated (AcA) from uncomplicated appendicitis (AnA). In this prospective single centered cohort study, LRG1, NGAL, IL-6 in serum and urine levels were assayed preoperatively and on the second and fifth days postoperatively. Patients were divided into three groups: AcA, AnA and a control group without infectious or inflammation-mediated pathology. A total of 153 patients participated, of which 97 had AA and 56 were control. The s-LRG1 levels of AA versus the control with a cut-off value of 51.69 μg/mL generated an AUC of 0.95 [95% CI 0.91-0.99, p<0.001]. The cut-off value of s-LRG1 was 84.06 μg/mL for diagnosis of AcA when compared to AnA and therefore, significant [AUC 0.69 95% CI 0.59-0.80, p=0.001].Median serum IL-6 and serum NGAL levels Day 0 were higher in appendicitis versus non-appendicitis. The average serum NGAL on Day 0 were 199.55 ng/mL for AcA, 135.20 ng/mL for AnA and 90.60 ng/mL for the control group (p = 0.020). The basal average serum IL-6 levels were 79.45 ng/mL for AcA, 23.14 for AnA and 10.93 ng/mL for the control group (p < 0.001). On the second postoperative day, serum NGAL levels were higher in AcA vs. AnA (p<0.001). Serum LRG1, NGAL and IL-6 are elevated in pediatric appendicitis cases compared to the control group upon disease presentation. Serum LRG1 and NGAL exhibited excellent diagnostic performance as an inexpensive, non-invasive, rapid, accurate biomarkers in comparison to IL-6. The data shows promising results for the usage of these biomarkers in determining whether a patient has a high risk of appendicitis that requires surgical treatment.