Haematological Inflammatory Indices in Preschoolers With Developmental Language Disorder: The Role of the Systemic Inflammation Response Index.

BACKGROUND: This study compared peripheral haematological inflammation indices obtained from complete blood count (CBC) parameters between preschoolers with developmental language disorder (DLD) and typically developing peers (TD) and examined the role of peripheral inflammatory processes in preschoolers with DLD. METHODS: One hundred twenty-seven children (61 with DLD and 66 TD) aged 36-60 months were included in this hospital-based, retrospective, case-controlled study. Complete blood count parameters and the resulting indices were compared: Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI). Statistical analyses included group comparisons, multivariable logistic regression, and Receiver Operating Characteristic (ROC) analysis. RESULTS: The DLD registered significantly lower lymphocyte, higher monocyte, and NLR, SII and SIRI values compared to the TD (p = 0.015, p < 0.001, p < 0.001, p = 0.007, p < 0.001, respectively). Analysis of covariance revealed that the groups had a significant main effect on monocytes, NLR, SII and SIRI levels and that this effect was independent of age and gender. At multivariable logistic regression, SIRI emerged as a significant independent predictor of DLD, alongside male gender and a lower paternal education level ((p = 0.002, p = 0.007, p = 0.009, respectively). ROC analysis showed that SIRI had discriminative ability for DLD (AUC = 0.765, p < 0.001). CONCLUSION: The findings suggest that peripheral inflammatory processes, reflected by NLR, SII and particularly SIRI, may be associated with DLD in preschoolers. Although SIRI showed high specificity but low sensitivity, the present results provide preliminary evidence that it may represent a potential peripheral inflammation index associated with DLD.