CD4+CD25high Regulatory T Cells Are Markedly Decreased in Blood of Patients with Pemphigus Vulgaris

Background: It remains to be determined whether pemphigus vulgaris (PV), an autoimmune blistering disease, has a reduction and/or dysfunction of CD4+CD25high regulatory T (Treg) cells. Objectives: To evaluate the frequency and phenotypes of Treg cells in blood of patients with PV. Methods: Peripheral blood mononuclear cells were prepared from PV patients as well as normal and disease control volunteers, and the frequency and phenotypes of Treg cells were determined by flow cytometry. CD4+CD25+ and CD4+CD25– T cells isolated from peripheral blood mononuclear cells of PV patients and normal controls were subjected to real-time semiquantitative RT-PCR for the expression of Foxp3 gene. Results: The proportion of Treg cells in all PV patients was severely reduced, approximately ten times less than controls. These observations were further confirmed by both diminished gene and protein expression of Foxp3 in the CD4+CD25+ T cell population in PV patients. Conclusions: Numerical impairment of Treg cells may be involved in the pathogenesis of PV.