The development of chronic ITP may be linked to vanin-1 overexpression. When blood mononuclear cells were subjected to oxidative stress inducers, VNN1 was markedly upregulated and PPARg was markedly downregulated. These results show that VNN1 serves as a peripheral blood oxidative stress sensor. The current study aimed to measure Vanin -1 protein level by ELISA as a predictive factor in patients with primary immune thrombocytopenic purpura. A Comparative, case-control study, included 30 primary ITP cases along with 20 healthy subjects as a control group. A comprehensive clinical examination, a complete history taking, and laboratory investigation (Vanin-1 protein level by ELISA) were performed on all patients. The level of Vanin-1 level was significantly higher among ITP cases compared to the controls. There were no statistically significant correlations between Vanin-1 levels and laboratory findings among ITP patients except for HCT (%) which shows a significant negative moderate correlation with Vanin-1. Analysis of the ROC curve shows that Vanin-1 can discriminate ITP patients from healthy controls, with a highly significant difference. Using coordinate points of the above ROC curve, the most relevant level of Vanin-1 is 0.7 to differentiate ITP patients from healthy controls, with a sensitivity of 100%, and a specificity of 95%. Vanin -1 can be used as a predictive factor to differentiate ITP cases from healthy non-diseased subjects.