Evaluation of the usefulness of laminated layer anigens in the serological follow up of cystic echinococcosis in humans

• Main Author: Okiti, O. E.
• Published: University of Salford 2015
• Subjects: 616.9
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.674929

Cystic Echinococcosis is a zoonotic infection of humans caused by the metacestode(larval) stages of the cestode Echinococcus granulosus (family Taeniidae). Diagnosis of the infection often involves immunodiagnostic approaches using cyst fluid antigens and these have also been used in serological follow up of patients after surgical treatment or chemotherapy. However the usefulness of other metacestode antigenic extracts for these purposes has not been fully investigated. The laminated layer is a polysaccharide/protein complex that surrounds the outside of the hydatid cyst and is a structure unique to the genus Echinococcus. In the current study a crude extract of this layer was prepared by sonication and tested for reactivity against sera from hydatid patients from Turkana, Kenya. This extract reacted both in ELISA and in Immunoblotting, primarily recognising antigenic bands around 55 kDa and 12 - 36 kDa. This latter region appeared to be more specific in terms of total IgG and IgG1 and IgG 4 subclass responses. The glycoproteins in this region also bound particular lectins such as soyabean Aglutinin and a lectin affinity purification column was produced to try and isolate the more specific glycoproteins. However this part of the project was not successful and no purified fraction was produced. The crude laminated layer extract was then compared with hydatid fluid to look for differences in antibody profile in treated and untreated Turkana patients over time in an attempt to identify possible markers of disease progression/regression. Sera were obtained from 10 albendazole treated patients over time courses ranging from 9 months to several years. Similar samples were also obtained from 4 patients who had refused treatment. Samples were analysed by ELISA against against Hydatid cyst fluid(HCF) and Laminated layer(LL). Results of the time courses showed that antibody levels fluctuated in both treated and untreated patients and that some of these changes were associated with changes in cyst morphology. In some cases the laminated layer showed similar recognition patterns to HCF but in others there were peaks of activity against one antigen which was not evident against the other.