الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 196 |  |  |
| | | from | 196 | | |
Abstract
ITP is a complex, chronic, often cell-specific, autoimmune disease that is still not fully understood. The improved understanding of the innate and adaptive immune systems however is allowing us to understand and appreciate some of the complex interactions between platelets, the immune system, and the development of ITP. Immune-mediated platelet destruction and/or insufficient platelet production in ITP occurs by a complex process involving multiple components of the immune system.
In the last 5 years, there has been a remarkable change in our understanding of the health benefits of vitamin D. Apart from its central role in calcium and bone metabolism, Vitamin D possesses immunomodulatory properties and represents an important component of the immune system homeostasis .Vitamin D exerts the biological effects through its own nuclear receptor, the vitamin D receptor (VDR). VDR is expressed in most tissues and regulates the expression of as many as 500 target genes in the human genome.
Many polymorphisms exist in the VDR gene, and their functional significance and potential effects on disease susceptibility have been investigated. They have been implicated in several immune and inflammatory disorders. In the immune system, upon activation VDR can promote monocyte differentiation and inhibits lymphocyte proliferation and secretion of cytokines, such as interleukin 2, interferon-gamma, and tumor necrosis factor.
The study were carried on 48 adult ITP patients diagnosed according to ASH 2011 guidelines (8 patients were excluded as secondary ITP and 40 female patients were enrolled as primary ITP)
and 60 unrelated apparently healthy controls. A written informed consent were taken from all subjects before enrollment in the study.
All the included subjects were subjected to the following:
•Complete history taking.
•Complete physical examination.
•Laboratory investigations: CBC with blood film, ESR, CRP, liver and kidney function tests, virology screen, stool for H pylori antigen, direct antiglobulin test.
•Antinuclear antibodies, antithyroid antibodies, antiphospholipid antibodies and pregnancy test.
•Abdominal ultrasound imaging
•Bone marrow examination when needed for patients only.
•VRD BsmI polymorphism (rs1544410) was detected by polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR–RFLP).
Exclusion criteria: all patients with secondary causes of thrombocytopenia were excluded.
Results showed that:
•There was a statistical significant difference between primary ITP patients and controls as regards distribution of BsmI genotype frequency with no statistical significant differences as regards the distribution of BsmI genotype allele. Moreover, there was no statistical significant differences between mutant (BB) and co-recessive (Bb+bb) BsmI genotype variants in ITP cases group and controls and between co-dominant (BB+Bb) and recessive BsmI genotype variants (bb)