The role of neutrophil-to-lymphocyte ratio as a predictor of testicular torsion in children

Introduction Doppler ultrasound constitutes the gold standard for the diagnosis of testicular torsion (TT), although sometimes the spermatic cord twisting and absence of testicular flow are difficult to visualize. To date, no laboratory markers have been shown to be useful for preoperative TT diagnosis. Objective Our aim is to analyze the role of the neutrophil-to-lymphocyte ratio (NLR) as a predictor of pediatric TT. Study design A retrospective single-center case-control study was performed in patients with ultrasound suspicion of TT, in whom surgical testicular examination was performed between 2016 and 2020. Patients were divided into two groups according to the intra-operative findings: TT group (testicular torsion), defined as spermatic cord twisting on itself around its longitudinal axis at least 360 degrees, and non-TT group (no torsion). Demographics, clinical, ultrasound and laboratory features at admission were analyzed. Sensitivity and specificity were determined by the area under the curve (AUC) represented on the receiver operating characteristic (ROC) curves. Results A total of 159 patients were included (117 TT group; 42 non-TT group), with no demographic or clinical differences. TT group patients presented significantly shorter median time since symptoms onset (4 vs. 8 h; p < 0.012). Laboratory inflammatory test were significantly higher in TT group: Leukocytes (10,900 x 10(3)/mu l vs. 7,980 x 103/mu l; p < 0.001), neutrophils (8,050 x 103/mu l vs. 3,350 x 10(3)/mu l; p < 0.001) and NLR (4.6 vs. 1.1; p < 0.001). In ROC curve analysis, NLR presented the highest AUC (0.903), significantly higher than all other laboratory and ultrasound parameters. NLR of 2.3 was the cut-off point with maximum sensitivity (86.9%) and specificity (94.8%). Discussion This is, to the best of our knowledge, the first study to analyze the usefulness of NLR in predicting the diagnosis of TT in patients with clinical and ultrasound suspicion. The limitations are mainly derived from being a single-center retrospective study. For this reason, multicenter studies with a higher number of patients and prospective design may be useful to minimize these biases. The sample size of our study, although not large, has allowed us to identify significant differences between the distinct parameters analyzed as predictors of TT. However, the absence of other similar studies in pediatric patients has hindered the comparison of our results. Conclusion NLR should be considered as a predictor of pediatric TT in cases with nuclear ultrasound suspicion that may help to anticipate the urgent surgical treatment in these patients.