Javier Arredondo Montero1,2, Giuseppa Antona3, Adriana Rivero Marcotegui4, Carlos Bardají Pascual3, Mónica Bronte Anaut5, Raquel Ros Briones3, Amaya Fernández-Celis6, Natalia López-Andrés6, Nerea Martín-Calvo7,8,9. 1. Pediatric Surgery Department, Hospital Universitario de Navarra, Irunlarrea 3, 31008, Pamplona, Spain. Javier.montero.arredondo@gmail.com. 2. School of Medicine, Department of Preventive Medicine and Public Health, University of Navarra, Pamplona, Spain. Javier.montero.arredondo@gmail.com. 3. Pediatric Surgery Department, Hospital Universitario de Navarra, Irunlarrea 3, 31008, Pamplona, Spain. 4. Clinical Analysis Department, Hospital Universitario de Navarra, Pamplona, Spain. 5. Pathology Department, Hospital Universitario de Navarra, Pamplona, Spain. 6. Cardiovascular Translational Research, NavarraBiomed (Miguel Servet Foundation), Hospital Universitario de Navarra, Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain. 7. School of Medicine, Department of Preventive Medicine and Public Health, University of Navarra, Pamplona, Spain. 8. CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Health Institute Carlos III, Madrid, Spain. 9. Instituto de Investigación Sanitaria de Navarra, IdiSNA, Pamplona, Navarra, Spain.
Abstract
BACKGROUND: Serum interleukin-6 (IL-6) has a moderate diagnostic performance in pediatric acute appendicitis (PAA). The evidence regarding its capacity to discern between complicated and uncomplicated PAA is scarce. METHODS: We designed a prospective observational study to validate serum IL-6 as a marker for diagnostic classification between complicated and uncomplicated PAA. This study included 205 patients divided into three groups: (1) patients who underwent major outpatient surgery (n = 57); (2) patients with non-surgical abdominal pain (NSAP) in whom the diagnosis of PAA was excluded (n = 53), and (3) patients with a confirmed diagnosis of PAA (n = 95). The PAA patients were further classified as uncomplicated or complicated PAA. IL-6 concentration was determined in all patients at diagnosis. Comparative statistical analysis was performed using the Mann-Whitney U test, the Fisher exact test and the Kruskall Wallis test. The area under the receiver operating characteristic curves (AUC) were calculated. RESULTS: Median (interquartile range, IQR) serum IL-6 values were 2 pg/mL (2.0-3.4) in group 1, 3.9 pg/mL (2.4-11.9) in group 2, and 23.9 pg/mL (11.1-61.0) in group 3 (P < 0.001). Among the participants in group 3, those with uncomplicated PAA had median (IQR) serum IL-6 values of 17.2 pg/mL (8.5-36.8), and those with complicated PAA had 60.25 pg/mL (27.1-169) serum IL-6 (P < 0.001). At the cut-off point of 19.55 pg/mL, the AUC for the discrimination between patients in group 2 vs. 3 was 0.83 [95% confidence interval (CI) 0.76-0.90], with a sensitivity of 61.3% and a specificity of 86.8. The AUC for the discrimination between patients with uncomplicated and complicated PAA was 0.77 (95% CI 0.68-0.86) and the cut-off point was 25.90 pg/mL, with a sensitivity and specificity of 84.6% and 65.6%, respectively. CONCLUSIONS: Serum IL-6 has a good performance in discerning between complicated and uncomplicated PAA. A score including clinical and radiological variables may increase the diagnostic performance of this molecule.
BACKGROUND: Serum interleukin-6 (IL-6) has a moderate diagnostic performance in pediatric acute appendicitis (PAA). The evidence regarding its capacity to discern between complicated and uncomplicated PAA is scarce. METHODS: We designed a prospective observational study to validate serum IL-6 as a marker for diagnostic classification between complicated and uncomplicated PAA. This study included 205 patients divided into three groups: (1) patients who underwent major outpatient surgery (n = 57); (2) patients with non-surgical abdominal pain (NSAP) in whom the diagnosis of PAA was excluded (n = 53), and (3) patients with a confirmed diagnosis of PAA (n = 95). The PAA patients were further classified as uncomplicated or complicated PAA. IL-6 concentration was determined in all patients at diagnosis. Comparative statistical analysis was performed using the Mann-Whitney U test, the Fisher exact test and the Kruskall Wallis test. The area under the receiver operating characteristic curves (AUC) were calculated. RESULTS: Median (interquartile range, IQR) serum IL-6 values were 2 pg/mL (2.0-3.4) in group 1, 3.9 pg/mL (2.4-11.9) in group 2, and 23.9 pg/mL (11.1-61.0) in group 3 (P < 0.001). Among the participants in group 3, those with uncomplicated PAA had median (IQR) serum IL-6 values of 17.2 pg/mL (8.5-36.8), and those with complicated PAA had 60.25 pg/mL (27.1-169) serum IL-6 (P < 0.001). At the cut-off point of 19.55 pg/mL, the AUC for the discrimination between patients in group 2 vs. 3 was 0.83 [95% confidence interval (CI) 0.76-0.90], with a sensitivity of 61.3% and a specificity of 86.8. The AUC for the discrimination between patients with uncomplicated and complicated PAA was 0.77 (95% CI 0.68-0.86) and the cut-off point was 25.90 pg/mL, with a sensitivity and specificity of 84.6% and 65.6%, respectively. CONCLUSIONS: Serum IL-6 has a good performance in discerning between complicated and uncomplicated PAA. A score including clinical and radiological variables may increase the diagnostic performance of this molecule.