Neutrophil-to-Lymphocyte Ratio in Children With STEC-HUS: A Prognostic Study

Early identification of children with Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) at risk of a complicated course may optimize management. The neutrophil-to-lymphocyte ratio (NLR) is a simple, widely available marker of inflammatory imbalance with prognostic value in several diseases; however, its prognostic performance in children with STEC-HUS remains unexplored.

In this retrospective observational prognostic study, we reviewed the medical records of patients hospitalized with STEC-HUS at a tertiary hospital in Argentina between 2000 and 2024. Demographic, clinical, and laboratory variables were compared between patients with complicated (dialysis >10 days and/or extrarenal complications and/or death) and uncomplicated disease. The prognostic performance of laboratory variables was calculated using receiver operating characteristic (ROC) curve analysis.

Of 214 patients, 70 (32.7%) had complicated disease. Patients who developed complicated disease had significantly higher NLR values than those who did not (4.8 vs 1.4, P < .001). In multivariable analysis, NLR (odds ratio [OR], 2.7, 95% CI, 2.03-3.58; P < .001) and C-reactive protein (OR, 1.01, 95% CI, 1.0006-1.02; P = .04) remained independent predictors of a complicated episode. The prognostic performance of NLR assessed by ROC curve analysis was 0.91 (95% CI, 0.87-0.96). At a cutoff value of at least 3.7, sensitivity was 88.6% (95% CI, 78.7%-94.9%) and specificity was 94.4% (95% CI, 89.3%-97.6%). Posttest probability of complications was 88.6% for NLR greater than or equal to 3.7 and 5.5% for NLR less than 3.7.

The NLR demonstrated strong predictive value for a complicated disease course in children with STEC-HUS. External validation in independent cohorts is required before routine clinical implementation.