A mouse model for the Sézary syndrome.

BACKGROUND: The Sézary syndrome is an aggressive leukemic form of cutaneous T cell lymphoma and there is no cure of this disease. Until now there is no true animal model for Sézary syndrome, by which new drugs against the disease could be tested.
METHODS: Immune deficient CB-17 SCID beige mice were injected subcutaneously with HUT78 cells, a cell line, derived from a Sézary syndrome patient. Developing tumors were analyzed by immunohistochemistry.
RESULTS: Injected HUT78 cells formed tumors at the site of injection. In contrast to the Sézary syndrome in man, no malignant cells were observed in the blood of tumor bearing CB-17 SCID beige mice. The tumors appeared 44-62 days after injection and tumor bearing mice survived further 25 - 62 days until they had to be euthanized according to the guidelines of the Swiss animal protection law, since the tumors had reached the maximal allowed size.
CONCLUSION: Although the mouse model does not exactly match the human disease, it will be suited for tests of new substances for the treatment of the Sézary syndrome. The formation of an isolated tumor on the skin has the advantage that the effect of a potential drug can be directly monitored without the use of invasive methods.