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EG |
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| Egypt J Pediatr Allergy Immunol |
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2014 |
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12 |
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49-61 |
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ESP - 168 |
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Review article |
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| Pathophysiology of immune thrombocytopenic purpura: a bird's-eye view |
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| Immune thrombocytopenic purpura (ITP) is a
common autoimmune disorder resulting in isolated
thrombocytopenia. It is a bleeding disorder
characterized by low platelet counts due to decreased
platelet production as well as increased platelet
destruction by autoimmune mechanisms. ITP can
present either alone (primary) or in the setting of other
conditions (secondary) such as infections or altered
immune states. ITP is associated with a loss of
tolerance to platelet antigens and a phenotype of
accelerated platelet destruction and impaired platelet
production. Although the etiology of ITP remains
unknown, complex dysregulation of the immune
system is observed in ITP patients. Antiplatelet
antibodies mediate accelerated clearance from the
circulation in large part via the reticuloendothelial
(monocytic phagocytic) system. In addition, cellular
immunity is perturbed and T-cell and cytokine profiles
are significantly shifted toward a type 1 and Th17
proinflammatory immune response with impaired
regulatory compartment, including Tregs and Bregs,
have been reported, suggesting a generalized immune
dysregulation in ITP. Understanding how
Th1/Th17/Treg differentiation and expansion are
controlled is central to uncovering how autoimmunity
may be sustained in ITP. |
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