Adult onset of T-cell deficiency with impaired CD2 expression complicated by Rhodococcus infection: a case report.
BACKGROUND
The functional importance of CD2 in vivo is currently the subject of discussion.


OBJECTIVE
To describe a 47-year-old white man with systemic Rhodococcus infection, a rarely observed opportunistic disease, secondary to severe lymphopenia.


METHODS
We extensively characterized lymphocyte phenotype and function.


RESULTS
Both CD4+ and CD8+ T cells were severely diminished, with a particular reduction in alpha:beta T cells. Human immunodeficiency virus infection was excluded. CD2 expression was decreased not only on T cells but also on nonaffected natural killer cells. Production of interferon-gamma interleukin 2, and tumor necrosis factor a was normal. Neither B-cell numbers nor humoral immune responses were affected. In addition, adhesion molecules CD11a, CD54, and CD154 were normally expressed, as were the costimulatory molecules CD28, CD80, and CD86.


CONCLUSIONS
We hypothesize that prolonged disturbance of CD2 expression led to an acquired severe cellular immunodeficiency. This underlines the importance of CD2 in vivo, where it may play a role in the fine regulation of T-cell proliferation.
Kittner
Jens Martin
JM
Department of Clinical Immunology, Hannover Medical School, Hannover, Germany. jenskittner@yahoo.de
Jacobs
Roland
R
Buyny
Sabine
S
Peest
Dietrich
D
Stoll
Matthias
M
Schmidt
Reinhold Ernst
RE
D000193:Actinomycetales Infections / Q000150:complications / Q000276:immunology*; D018801:CD2 Antigens / Q000096:biosynthesis; D002478:Cells, Cultured; D006801:Humans; D008231:Lymphopenia / Q000209:etiology / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012240:Rhodococcus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology*
D018801:CD2 Antigens