ISSN:
1600-0536
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Hyposensitization is it poorly understood phenomenon that refers to the conversion from a positive to a negative (or less positive) patch test. We studied 180 cement workers with contact dermatitis, who originally had a total of 163 positive patch test reactions to potassium dichromate and 98 positive reactions to cobalt chloride. They were patch tested a 2nd time after 2–6 years. On the 2nd patch test to dichromate. 103 (63%) remained positive, while reactivity decreased in 33 (20%) and 21(17%) had become non-reactive. Cobalt sensitivity persisted in 47%, diminished in 13%, and 40% of the patch tests became non-reactive. In 10 patients with persistent patch test reactions and 10 matched patients with diminished reactions or loss of reactivity, circulating T-cell responses to dichromate and cobalt were studied in vivo. Circulating T cells that proliferated only to specific contact allergens were isolated and in all patients they were primarily CD4+. However, in patients with persistent reactions, they were CD4+ CD45RO+ (memory cells), while in the group that lost sensitivity, they were CD4+ CD45RA (suppressor - inducer cells). These differences support an immunologic basis for hyposensitization.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1600-0536.1997.tb00419.x
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