Effect of cyclosporine on lymphocytic variant hypereosinophilic syndrome

Lymphocytic variant hypereosinophilic syndromes (L-HES) is thought to be caused by the over-production of interleukin (IL)-5 by type 2 helper cells, which leads to reactive eosinophil expansion and activation. Here we demonstrate the effect of cyclosporine in a patient with L-HES. In the present case, the surface markers of cells from resected lymph nodes or peripheral blood were analyzed by flow cytometry. Serum concentrations of IL-4, IL-5, and IL-8 were measured using an enzyme-linked immunosorbent assay. Methyl-prednisolone pulse therapy followed by the administration of 150 mg/day of cyclosporine combined with 15 mg/day of prednisolone ameliorated eosinophilia. However, abnormal CD3-CD4+ T cell clones remained even when the eosinophil count recovered to normal levels. An elevated IL-8 level was observed only when eosinophils increased. On the other hand, serum IL-4 and IL-5 levels were under detectable limits during the course. Cyclosporine was effective in decreasing the eosinophil count without the elimination of abnormal T cell clones in the present case. Cytotoxic agents may be necessary to cure this serious disease. Moreover, target therapy for IL-8 may be a new strategy for L-HES with high IL-8 and low IL-5 concentrations.