All-trans-retinoic acid in POEMS syndrome. Therapeutic effect associated with decreased circulating levels of proinflammatory cytokines.

Chronically elevated serum levels of proinflammatory cytokines is a feature of the syndrome known as POEMS (plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, monoclonal [M] protein, skin changes). A patient had a POEMS syndrome with thrombocytosis and biclonal gammopathy and was treated as follows: all-trans-retinoic acid (tretinoin) at 90 mg/day for 50 days, no treatment for 70 days, readministration of tretinoin at 75 mg/day for 180 days. Focal bone lesion irradiation was performed from day 26 to day 50. Serum levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF alpha), and IL-1 beta normalized within 7 days after the first administration of tretinoin, transiently increased at the time of radiotherapy, increased again after withdrawal of the tretinoin, and decreased again after its reintroduction. The platelet count and gammopathy paralleled the changes in the cytokine levels. This study documents in vivo the ability of all-trans-retinoic acid to down-regulate the release of IL-6, IL-1 beta, and TNF alpha, and illustrates its potential as a therapeutic agent in conditions associated with chronic overproduction of proinflammatory cytokines.