Evaluation of the diagnostic efficiency of three anti-Echinococcus antibody-based assays for the serodiagnosis of echinococcosis / 中国血吸虫病防治杂志

ABSTRACT

ObjectiveTo evaluate the efficiency of three Chinese commercial anti-Echinococcus antibody-based assays for the serodiagnosis of echinococcosis. MethodsA total of 142 sera from cystic echinococcosis patients, 89 sera from alveolar echinococcosis and 39 sera from healthy controls were sampled, and detected by kits A (ELISA), B (ELISA) and C (colloidal gold immunoassay). The routine blood testing results and biochemical parameters were compared between the cystic and alveolar echinococcosis patients, and the associations of the absorbance (A value) of the serum specific antibody detected by A and B kits with the routine blood testing results and biochemical parameters were examined in echinococcosis patients. In addition, the performance of these three assays for the serodiagnosis of echinococcosis was evaluated. Results There were no significant differences between the cystic and alveolar echinococcosis patients in terms of the median white blood cell count (WBC), neutrophil count (NEU), monocyte count (MONO), basophil count (BASO), alanine aminotransferase concentration (ALT), aspirate aminotransferase concentration (AST), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL) (all P values > 0.05), and higher median lymphocyte count (LYM) and albumin levels (ALB) were detected in cystic echinococcosis patients than in alveolar echinococcosis patients (both P values < 0.05), while the median eosinophil count (EOS) was greater in the alveolar echinococcosis patients than in the cystic echinococcosis patients (P < 0.01). The A value of the serum specific antibody detected by kit A showed a linear positive correlation with WBC (rs = 0.153, P < 0.05) and EOS (rs = 0.174, P < 0.05), and a linear negative correlation with TBIL (rs = -0.134, P < 0.05) and IBIL (rs = -0.146, P < 0.05), while the A value of the serum specific antibody detected by kit B showed a linear positive correlation with WBC (rs = 0.257, P < 0.01), NEU (rs = 0.203, P < 0.01), MONO (rs = 0.159, P < 0.05), EOS (rs = 0.330, P < 0.01), ALT (rs = 0.171, P < 0.01) and AST (rs = 0.160, P < 0.05), and a linear negative correlation with ALB (rs = -0.168, P < 0.05). The overall coincidence rate, sensitivity, specificity, Youden’s index and Kappa value of A, B and C kits were 86.30%, 69.63% and 91.48%; 84.42%, 64.94% and 92.21%; 97.44%, 97.44% and 87.18%; 0.82, 0.62 and 0.79; and 0.600, 0.337 and 0.750 for the diagnosis of echinococcosis, respectively. The overall coincidence rate, sensitivity, specificity and Youden’s index of A, B and C kits were 84.54%, 64.64% and 71.82%; 80.99%, 55.63% and 68.31%; 97.44%, 97.44% and 87.18%; and 0.78, 0.53 and 0.56 for the diagnosis of cystic echinococcosis, respectively, while the overall coincidence rate, sensitivity, specificity and Youden’s index of A, B and C kits were 92.19%, 85.16% and 85.16%; 89.89%, 79.78% and 84.27%; 97.44%, 97.44% and 87.18%; and 0.87, 0.77 and 0.72 for the diagnosis of alveolar echinococcosis, respectively. The C kit showed cross-reactions in the serodiagnosis of cystic echinococcosis and alveolar echinococcosis. There were no significant difference in the area under the receiver operating characteristic curve (ROC) between A and B kits for the diagnosis of echinococcosis (0.970 vs. 0.948, Z = 1.618, P > 0.05), and there was a high agreement between A and B kits in the diagnosis of echinococcosis (Kappa = 0.585, P < 0.01). Conclusions The three commercial anti-Echinococcus antibody-based kits exhibit a higher serodiagnostic efficiency for alveolar echinococcosis than for cystic echinococcosis. The A kit shows a high sensitivity and specificity for the diagnosis of echinococcosis, and has a relatively stable diagnostic performance and fewer influencing factors, which is suitable for the pre-surgical preliminary diagnosis and post-surgical follow-up monitoring of serum anti-Echinococcus antibody, while the C kit shows a high sensitivity and specificity for the diagnosis of echinococcosis, and is easy to perform and high in reporting rate, which is feasible for initial screening of echinococcosis.