Immunoblot evaluation of the 100 and 130 kDa antigens in camel hydatid cyst fluid for the serodiagnosis of human cystic echinococcosis in Libya.

Two high molecular weight antigens with molecular masses approximately 100 kDa and 130 kDa were identified by immunoblotting camel hydatid cyst fluid, with 94% sensitivity in sera from surgically confirmed Libyan cystic echinococcosis cases. 40% of sera from surgically confirmed alveolar echinococcosis cases cross-reacted with the 100 and 130 kDa antigens, as did 5.3% of sera from human Taenia solium cysticercosis patients. No cross-reaction occurred with sera from human schistosomiasis mansoni or onchocerciasis patients. In addition, all sera from patients with non-hydatid space-occupying lesions (i.e. simple liver cysts, kidney cysts, lung tuberculosis, pulmonary carcinoma, pulmonary empyema, and lung abscess) were seronegative against the same antigens, as were control serum samples from healthy individuals. The 100 and 130 kDa antigens were strongly recognized by sera from cystic echinococcosis patients when camel or horse hydatid cyst fluid was used in immunoblotting but were only weakly recognized if sheep or human hydatid cyst fluid was used. Camel hydatid cyst fluid could be an important source of diagnostic antigens for human cystic echinococcosis in the Middle East endemic region.