Increased expression of insulin-like growth factor I in skin in amyotrophic lateral sclerosis

Objectives-Insulin-like growth factor I (IGF-I) has potent effects on motor neuron survival and is being studied as a possible therapeutic agent for A LS. However, little is known concerning IGF-I in the skin of patients with amyotrophic lateral sclerosis (ALS). The aim was to evaluate IGF-I immunore activity of skin in patients with ALS. Methods-IGF-I immunoreactivity of skin from 18 patients with ALS and 16 con trols was examined. Results-IGF-I immunoreactivity was markedly positive in the epidermis and d ermal blood vessels and glands and was moderately positive in the reticular dermis in all patients with ALS. On the other hand, the epidermis and derm al blood vessels and glands and the reticular dermis showed a weak IGF-I im munoreactivity in controls. The optical density for IGF-I immunoreactivity of the epidermis and dermal blood vessels and glands, and the reticular der mis in patients with ALS was significantly higher than in diseased controls , and was significantly increased with duration of illness. Conclusions-These data suggest that a metabolic alteration of IGF-I may tak e place in the skin of patients with ALS.