The serum levels of eosinophil cationic protein (ECP) are related to the infiltration of eosinophils in the tumours of patients with Hodgkin's disease

We have previously described a relation between abundance of eosinophilic g ranulocytes in Hodgkin's disease (HD) tumours and poor prognosis. In order to further explore the importance of the eosinophilic infiltration, we immu nohistochemically examined the presence of eosinophils, using the monoclona l antibodies EG 1 and EG 2, in the tumours of 54 newly diagnosed patients w ith HD and related the degree of infiltration to clinical characteristics a nd the serum levels of eosinophil cationic protein (S-ECP). S-ECP levels (u pper normal value 16 mug/l) varied between 2.2 and 71.7 mug/l, mean 25.4 mu g/l. There was an association (p = 0.01) between the number of eosinophils in the tumour tissue and S-ECP. S-ECP levels were also associated to high e rythrocyte sedimentation rate (ESR, p < 0.01) and nodular sclerosis (NS) hi stology (p < 0.05), and there was a tendency of a correlation to bulky dise ase (p = 0.06). The number of eosinophils stained with EG 2 correlated to h igh ESR (p < 0.05), and to high leukocyte count (p = 0.02). A follow-up val ue of S-ECP after treatment was, in most of the cases measured, lower than the initial value. The high values of S-ECP in several patients with HD probably originates fr om eosinophils infiltrating the tumours. The same patients had a higher ESR and tended to have a more advanced stage and bulky disease. There are no s ignificant correlations with disease-free and overall survival, as the foll ow-up time is short, and prognosis favourable.