Laboratory Evaluation of Commercial Immunoblot Assay Kit for Serodiagnosis of Echinococcus Infections Using Sera from Patients with Alveolar Hydatidosis in Hokkaido

• Published in: Kansenshogaku Zasshi Vol. 78; no. 4; pp. 320 - 326
• Main Authors: FURUYA, Koji, KAWANAKA, Masanori, YAMANO, Kimiaki, SATO, Naoki, HONMA, Hiroshi
• Format: Journal Article
• Language: Japanese
• Published: Japan The Japanese Association for Infectious Diseases 01.04.2004
• Subjects: alveolar hydatidosis; Echinococcosis, Pulmonary - blood; Echinococcosis, Pulmonary - diagnosis; Evaluation Studies as Topic; Humans; immunoblotting; Immunoblotting - instrumentation; Pulmonary Alveoli; Reagent Kits, Diagnostic - standards; serodiagnosis; Serologic Tests - methods
• DOI: 10.11150/kansenshogakuzasshi1970.78.320
• ISSN: 0387-5911

Using serum specimens from patients with alveolar hydatidosis (AH) in Hokkaido, we assessed the usefulness of “Echinococcus Western Blot IgG” (the French immuoblot assay, FIA), which has recently been launched from Ldbio Diagnostics (Lyon, France) as new commercial immunoblot assay kit of immunodiagnosis of Echinococcus infections. Eighty serum specimens were used for the present study: 64 preoperative sera and nine postoperative sera, which were taken from AH patients in Hokkaido, and seven sera from persons who were ELISA (enzyme-linked immunosorbent assay)-positive in mass screening which was conducted for checking on Echinococcus infections in Hokkaido since 1982. When the 64 preoperative sera were examined by the Western blotting method (the Hokkaido method of Western blotting, HWB) which had been carried out at Hokkaido Institute of Public Healthbetween 1987 and 1993, it was found that 53 cases were positive and six cases were quasi-positive, i. e. the rate of the positive cases including quasi-positive cases was 92.2%. From immunostaining patterns, HWB-positive sera could be grouped in two types: the complete type, which showed a pattern of multiple bands containing the 55 and 66 kDa bands, and the incomplete type, which showed patterns of only few bands containing the AH-specific polysaccharide antigen named C antigen. Forty-three of the 53 HWB-positive sera were of the complete type and the residue was of the incomplete type. On the other hand, when the 64 preoperative sera were examined by FIA, 60 sera (93.8%) were judged to be positive and the others as negative sera. On the basis of the interpretation of immunostaining patterns described in the instruction manual, 47 (78.3%) of the 60 positive sera were regarded as pattern P3, five (8.3%) as pattern P4, and eight (13.3%) as pattern P5. All of the completetype sera were regarded as P3, indicating high antibody titers. Contrarily, most of the incompletetype or quasi-positive sera resulted in other patterns such as P4 and P5, indicating low antibody titers. Of 5 HWB-negative sera, two were FIA-positive (which showed P3 and P5 patterns respectively), however their immunoreactions were significantly low. Therefore, apart from interpretation of pathological conditions of cases with exceedingly low antibody titers, FIA may be able to give a serologically clear interpretation to HWB-quasi-positivecases, indicating that it is a highly sensitive and useful method for immunodiagnosis of Echinococcus infections.