Usefulness of serum eosinophil cationic protein (ECP) in predicting relapse of Churg and Strauss vasculitis.

Sirs, Eosinophil cationic protein (ECP), a cytotoxic granule protein of eosinophils known to play a major role in defence against parasites (1), has been shown to increase in various disorders (2-6) including acute flares of Churg and Strauss syndrome (CSS) (7, 8). We report a case of CSS with elevation of serum ECP months before onset of symptoms on two occasions over 5 1/2 years. High ECP titers preceded blood eosinophilia. C-ANCA titers did not rise before onset of symptoms. This 52-year-old asthmatic white male was diagnosed with CSS in February 1987. He then fulfilled the 1990 criteria for the classification of CSS (2). Treatment was successful and medication was discontinued in October 1993. ECP measurements were begun at that time using a fluorescent enzyme immunoassay (Pharmacia, Sweden) according to the manufacturers’ instructions with a normal value of < 12 μg/L. Self-limited cutaneous relapses occurred in March 1994, April 1995 and July 1995. ECP titers rose moderately from January 1994 to March 1995, then dramatically with titers reaching 92 μg/L by October 5 (Fig. 1) . At that time, an episode of fever, epigastralgia and pruriginous erythema was complicated