Immunomodulatory role of vitamin D and T-regulatory cells in acute idiopathic thrombocytopenic purpura patients

Abstract

Background
Idiopathic thrombocytopenia (ITP) is a hematological disease characterized by isolated thrombocytopenia caused by attacking autoantibodies. Vitamin D deficiency is a common finding in ITP, as is the case with many different autoimmune disorders. Thus, vitamin D deficiency is expected to have a crucial effect on the disease pathogenesis. Also, vitamin D supplementation is supposed to have an immunomodulating effect on disease activity and prognosis. Vitamin D increases CD4+CD25+regulatory T cell numbers and activation. Thus, vitamin D3 supplementation may increase Treg function.


Objective
This study aims to explore the level of serum 25-hydroxyvitamin D and percentages of T-regulatory cells in the peripheral blood of ITP patients to investigate their role in disease predisposing and severity and their prognostic impact in therapy.


Patients and methods
The present study included 40 cases of ITP patients and 60 normal healthy participants. The patients underwent a thorough laboratory investigation of serum vitamin D and percentages of regulatory T-cells (CD4+, CD25+).


Results
There was a decrease in vitamin D level in patients (21.683 ± 7.623) than control (35.170 ± 10.909). And regarding to the level of vitamin D deficiency; 18 (45%) patients were deficient, 14 (35%) patients were insufficient, two (5%) patients were severely deficient. When we compare these findings with healthy normal control, we observed that only 12 (20%) of them were deficient, and no one of them had severe deficiency, whereas 46 (76.67%) had normal levels. Also there was a decrease in the expression of Treg cells (CD4+ CD25+) in ITP patients (6.782 ± 4.830 SD) in comparison with control (16.274 ± 6.289 SD).


Conclusion
Our trial demonstrated a notable reduction in serum vitamin D levels and CD4+ CD25+ T-regulatory cells among ITP patients when compared to healthy individuals. However, no association was found between the serum 25-hydroxyvitamin D levels and the percentages of T-regulatory cells.