ABSTRACT
Immune thrombocytopenic purpura(ITP)is an autoimmune disease by increased platelet destruction and/or impaired platelet production,which mainly has a manifestation of hemorrhage in some locations such as skin,mucosa or viscera.The pathogensis of the disease is complex,so far,it is not clear.CD4 + CD25 +regulatory T lymphocyte (Treg) is a full-time suppressor cell and has a unique immune regulating function of mature CD4 +T lymphocyte subgroup.They have the function of immune suppression.About 5 to 10 percentage of peripheral CD4 + T lymphocytes and 1 to 2 percentage of peripheral mononuclear cells are CD4 + CD25 + regulatory T lymphocytes in mouse or healthy human.They can suppress immune response through many pathways and sustain the stabilization of intemal environment.Their abnormality in function or quantity is one of the important factors that lead to autoirmmune diseases and they play a critical role in the occurrence and development of immune thrombocytopenic purpura.This review focuses on characteristics and function of Treg cell,and furthermore,its role in the pathogenesis of immune thrombocytopenic purpura is summarized.