Foxp3 expression in cutaneous T-cell lymphocytic infiltrates.
BACKGROUND
The primary function of regulatory T cells (Treg cells) is to regulate the function and proliferation of immunologically responsive T cells; the transcription factor Foxp3 is expressed by this cell populace and is held to be the standard marker for Treg cells.


METHODS
A variety of cutaneous T-cell lymphocytic infiltrates were evaluated for Foxp3 expression.


RESULTS
Of the 95 cases, 33 (35%) were reactive, 40 (42%) were prelymphomatous cutaneous T-cell dyscrasia and 22 were (23%) T-cell lymphoma. The reactive category included dermatomyositis, lupus erythematosus, hypersensitivity reactions and graft-vs.-host disease. The prelymphomatous dyscrasia category was represented chiefly by pityriasis lichenoides chronica (PLC) and pigmented purpuric dermatosis (PPD). The Foxp3 reactivity was less than 10% for cases of dermatomyositis and lupus erythematosus, 23% for hypersensitivity cases, 0% for graft-vs.-host disease, 16% for the dyscrasias and 11% for the lymphomas. Intermediate grade and aggressive lymphomas had very few Foxp3+ cells (< 5%). There were fewer numbers of Foxp3+ T cells in the monoclonal variants of PLC and PPD.


CONCLUSIONS
T-reg cells may play a role in controlling the extent of T-cell proliferations in the skin with a lack of T-regulatory function permissive to the development of various T-cell disorders.
Solomon
Garron J
GJ
Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, NY 10065, USA.
Magro
Cynthia M
CM
D014408:Biomarkers, Tumor / Q000378:metabolism; D003882:Dermatomyositis / Q000378:metabolism / Q000473:pathology; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D006086:Graft vs Host Disease / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006967:Hypersensitivity / Q000378:metabolism / Q000473:pathology; D007124:Immunoenzyme Techniques; D017254:Leukemic Infiltration; D008178:Lupus Erythematosus, Cutaneous / Q000378:metabolism / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000378:metabolism / Q000473:pathology*; D017514:Pityriasis Lichenoides / Q000378:metabolism / Q000473:pathology; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D011693:Purpura / Q000378:metabolism / Q000473:pathology; D012867:Skin / Q000378:metabolism* / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism / Q000473:pathology*
D014408:Biomarkers, Tumor; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors