Quantitative assessment of serum‐specific IgE in the diagnosis of human cystic echinococcosis

Summary Anti‐ Echinococcus serum immunoglobulin (Ig)E was assessed by the ImmunoCAP system and compared with anti‐ Echinococcus serum IgG assessed by enzyme‐linked immunosorbent assay (ELISA) and Western blot. The ImmunoCAP system revealed very high specificity (one false positive of 110 healthy individuals), low cross‐reactivity (one false positive of 58 patients with other diseases) and decreased sensitivity (73·55%). Receiver operating characteristic analysis displayed a beneficial diagnostic value with high accuracy. Comparison of the ImmunoCAP system with ELISA and Western blot showed significantly higher specificity and significantly lower cross‐reactivity compared with the ELISA. Examination of sera from 155 patients with cystic echinococcosis (CE) showed varying levels of anti‐ Echinococcus IgE (range, 0·01–118·33 kUA/L). However, most samples had moderately elevated IgE levels. Analysis of serum‐specific IgE revealed significantly higher sensitivity of the ImmunoCAP system and significantly higher antibody levels in hepatic CE compared with pulmonary CE.