Background/Objectives: Hashimoto’s thyroiditis (HT) is an autoimmune disorder characterized by chronic inflammation of the thyroid gland. Recent evidence indicates that the inflammation may extend beyond the thyroid. The study aims to explore the potential of complete blood count (CBC)-derived indices as markers of systemic inflammation in HT. Materials and Methods: This cross-sectional retrospective study from 1 January 2015, to 31 December 2023 included 147 pediatric HT patients and 144 apparently healthy controls. Thyroid profiles, antibodies, CBC, and protein electrophoresis data were collected from patient records. CBC-derived indices were calculated and compared between the HT and control groups, as well as among HT subgroups. Results: The median age of HT patients was 13.6 years (range: 11.2–15.5 years), with 66% being girls. The control group had a similar age and gender distribution, with a median age of 13.7 years (range: 11–15.8 years) and 70.8% girls. Of the HT patients, 50% had subclinical HT, 15% were euthyroid, and 34% had overt thyroid dysfunction. HT patients showed significantly higher neutrophil and lymphocyte counts, as well as all evaluated CBC-derived indices than controls (p < 0.001)). These differences were not significant among HT subgroups. Logistic regression indicated a strong association between an elevated neutrophil-to-lymphocyte ratio (NLR) and HT diagnosis (p < 0.001), while ROC analysis confirmed NLR as the most accurate CBC-derived marker for distinguishing HT from controls. Conclusions: Elevated NLR levels in pediatric HT patients provide additional evidence that inflammation may extend beyond the thyroid gland. These results support the potential of NLR as a reliable and accessible biomarker for evaluating inflammation in Hashimoto’s thyroiditis.

Background: Celiac disease (CD) is a systemic autoimmune enteropathy triggered by gluten ingestion that frequently manifests with extra-intestinal complications, including enamel defects. Molar incisor hypomineralisation (MIH) has been proposed as a dental marker of systemic mineral dysregulation; however, its association with fat-soluble vitamin deficiencies in children with celiac disease remains insufficiently characterised. Methods: A prospective pilot case–control study was conducted over 12 months including 70 children (35 with confirmed CD, 35 healthy controls). MIH severity was graded using a validated four-point scale; enamel defect extent was scored using the Aine classification. Serum levels of vitamins K1, K2, and D, zonulin, calcium, phosphorus, alkaline phosphatase, and oral hygiene indices (Löe Plaque Index; OHI-S) were recorded. An exhaustive statistical analysis was conducted using these parameters. Results: MIH was detected in 27/35 CD children (77.1%) versus 0/35 controls. Vitamin K2, vitamin D and serum calcium were significantly lower in CD. Strong negative correlations were observed between MIH severity, vitamin K2 and vitamin D. ROC analysis revealed excellent diagnostic performance of zonulin, vitamin K2, and vitamin D for discriminating CD status. Conclusion: Children with celiac disease exhibited a higher prevalence and greater severity of molar-incisor hypomineralisation, which was associated with lower vitamin K2 and vitamin D levels. Zonulin, vitamin K2, and vitamin D also showed promising discriminatory ability for identifying children with celiac disease; however, given the pilot nature of the study, these findings should be considered exploratory and require validation in larger multicenter cohorts.

Background: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) represents a group of rare systemic autoimmune disorders marked by inflammation and damage to small- and medium-sized blood vessels. The clinical presentation of AAV is highly variable, ranging from isolated organ involvement to severe, life-threatening multisystem disease, posing significant challenges in diagnosis, treatment, and prognosis. Objective: To demonstrate the clinical heterogeneity and different outcomes in three pediatric cases of ANCA-positive disease and emphasize the importance of integrating clinical findings with laboratory and imaging investigations for accurate diagnosis. Methods: We present three pediatric patients (ages 12–15 years) with ANCA-positive results but distinct clinical presentations, evaluated at the Children’s Emergency Hospital “Louis Turcanu”, Timisoara, between 2020 and 2024. All cases were investigated according to EULAR/PRINTO/PReS criteria for pediatric vasculitis. Results: Case 1 (PR3-ANCA positive) developed severe multi-organ involvement, including granulomatosis with polyangiitis (GPA) with pulmonary hemorrhage, pericarditis, thrombotic events, and renal impairment, requiring intensive immunosuppression with cyclophosphamide, rituximab, and mycophenolate mofetil, ultimately developing chronic kidney disease stage 3a. Case 2 (BPI-ANCA positive) presented with purpuric lesions and painless joint swelling, responding favorably to corticosteroid therapy with subsequent remission. Case 3 (MPO-ANCA) manifested as polyarticular arthritis without other organ involvement and was ultimately diagnosed as seronegative juvenile idiopathic arthritis (JIA), achieving complete remission with adalimumab therapy. Conclusions: This case series highlights the diverse clinical and biological features of ANCA-positive conditions in children, emphasizing that ANCA positivity requires careful clinical correlation as it may indicate true vasculitis requiring aggressive treatment or alternative diagnoses such as JIA with incidental ANCA positivity. Tailored therapeutic strategies based on clinical presentation and continued research are essential to improve patient outcomes.