[Serum eosinophil cationic protein (sECP) level after cow's milk challenge test in allergic children]

The eosinophil cationic protein (ECP) level in the sera is higher in allergic diseases. The change of the ECP level in the sera of patients with cow milk allergy was examined during the cow's milk challenge test after a long cow's milk free diet period. The sECP level of 35 milk sensitive patients was determined by a fluoroimmunoassay (Pharmacia CAP System ECP FEIA) before the milk challenge test, as well as 2 and 24 hours after it. The average age of the patients was 16 (6-49) months. The basic sECP level of cow's milk allergic patients was significantly higher (12.2 micrograms/l vs. 7.0 micrograms/l, p < 0.05) than that of the control group (n = 20). The sECP level significantly decreased 2 hours after the milk challenge test (12.2 micrograms/l vs. 9.2 micrograms/l, p = 0.01), 24 hours after the challenge it was again on the basic level (11.2 micrograms/l, p = 0.26). Out of the 35 allergic children ten had positive clinical reactions after the milk challenge test (positive group), while 25 had no reaction after it (negative group). Comparing the sECP level of these two groups, no significant difference was found in the sECP level either before the milk challenge test or after it. The significant decrease of the sECP level 2 hours after the beginning of milk challenge test might be explained by the fact that this toxic protein is secreted into the bowel.