Complete blood count-derived inflammatory parameters in pediatric idiopathic uveitis.

BACKGROUND: Pediatric idiopathic uveitis is a potentially vision-threatening inflammatory condition with limited available laboratory biomarkers for disease monitoring. Complete blood count (CBC)-derived inflammatory parameters have emerged as inexpensive and accessible markers of systemic inflammation in various inflammatory diseases. This study aimed to investigate the potential role of CBC-derived inflammatory parameters in pediatric idiopathic uveitis and their association with disease activity. METHODS: This retrospective study included 40 children with idiopathic uveitis and 44 age-matched healthy controls. Comparisons were performed between patients with active uveitis and healthy controls, between patients in remission and healthy controls, and between the active and remission phases of the same patients. The same patients were evaluated during both active disease and remission periods. Patients with elevated C-reactive protein (CRP) levels, acute infection, systemic disease, or corticosteroid use at the time of blood sampling were excluded. Hematological parameters including white blood cell count (WBC), platelet count (PLT), mean platelet volume (MPV), red cell distribution width (RDW), neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and platelet-to-monocyte ratio (PMR) were analyzed. RESULTS: A total of 40 children with idiopathic uveitis, all of whom had normal CRP levels, and 44 age- and sex-matched healthy controls were included. Compared with healthy controls, patients during the active phase had significantly higher WBC, RDW, PLT, MPV, neutrophil count, lymphocyte count, and PMR values (all p < 0.05). During remission, RDW, PLT, MPV, and lymphocyte counts remained significantly elevated, whereas NLR values were lower than those of healthy controls, with borderline statistical significance (p = 0.049). In paired comparisons, WBC, PLT, neutrophil count, and PMR values were significantly higher during active disease than during remission, whereas MPV values were significantly higher during remission (all p < 0.05). CONCLUSIONS: CBC-derived inflammatory parameters, particularly RDW, platelet-related indices, and PMR, may reflect inflammatory activity in pediatric idiopathic uveitis despite normal CRP levels. Persistent alterations during remission may indicate ongoing subclinical inflammation. These inexpensive and readily available parameters may serve as complementary biomarkers in disease evaluation and follow-up.