Background: There is no effective treatment for aggressive systemic mastocytosis.
Objective: The purpose of this study was to investigate the effect of cyclosporin and low-dose methylprednisolone in a 64-year-old man with aggressive systemic mastocytosis.
Methods: Immunohistochemical studies were done on biopsy specimens from the skin and other organs. Mast cells, predominantly containing tryptase, were derived from human umbilical cord blood cells cultured in the presence of stem-cell factor and IL-6. IgE-sensitized cultured human mast cells were activated by anti-IgE, and the effect of cyclosporin on histamine release was investigated. In addition, blood and urine levels of various mediators were measured in the patient before and after therapy.
Results: Biopsy specimens of the patient's skin lesions showed an increase of mast cells; cells containing tryptase (but not chymase) comprised 20% to 50% of the skin mast cells. Histamine release from activated cultured mast cells was inhibited by cyclosporin in a concentration-dependent manner. When the patient was treated with cyclosporin and low-dose methylprednisolone, he showed a good response.
Conclusion: Cyclosporin combined with low-dose methylprednisolone may be a reasonable therapy for aggressive systemic mastocytosis.