An eosinophil chemotactic factor (ECF) was partially purified from plerocercoids of Spirometra erinacei by a combination of anion-exchange chromatography on DE52 and gel filtration on Sephacryl S–200. The molecular weight of ECF was estimated to be 25 000–45 000 by high-pressure liquid chromatography. The ECF was bound with concanavalin A-Sepharose. The ECF was sensitive to periodate oxidation and to heating (56°C, 30 min). On isoelectric focusing, eosinophil chemotactic activity was clearly revealed at pI 4·1. These results suggest that ECF of S. erinacei plerocercoid is an acidic glycoprotein. An intradermal injection of ECF induced eosinophil attractions in the normal guinea pig skin.
