Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by isolated thrombocytopenia defined as platelet count in peripheral blood <100 × 109/L. Hypovitaminosis D is very common in children with autoimmune diseases. To analyze whether hypovitaminosis D is associated with the clinical presentation of ITP in children, medical records of 45 pediatric patients with newly diagnosed immune thrombocytopenia in the coastal region of Croatia were evaluated. The severity of bleeding was assessed using two bleeding scores. Children with lower 25-hydroxyvitamin D (25(OH)D) values had higher values of the skin-mucosa-organ-gradation (SMOG) bleeding score and respectively more severe bleeding on diagnosis of ITP. With further analysis of the main domains of that score, we found that patients with a lower 25(OH)D value had more severe bleeding in the skin and organs. When 25(OH)D and ITP Bleeding Scale (IBLS) score were analyzed, a negative correlation was found, but it was not significant. Our findings suggest that hypovitaminosis D influences the severity of the clinical presentation of ITP in children on initial diagnosis of the disease. Therefore, therapy with 25(OH)D could be a new potential option for treatment of ITP. To investigate the connection between 25(OH)D and the incidence and severity of ITP, further studies, especially randomized controlled studies, are needed.
Keywords: 25(OH)D; immune thrombocytopenia; vitamin D deficiency.