The use of sarcoptes scabiei crude extract as allergen: An attempt to prepare a vaccine

Scabies stands for a skin parasitic infestation as a result of mite Sarcoptes scabiei. It is a neglected international health problem; about 300 million cases develop scabies worldwide annually. Sarcoptes scabiei mite proteins are extracted, then heat-stable mite proteins concentration has been established by Bradford's method. SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis was used. The activity of mite allergens was assayed through skin prick test (SPT) in scabietic patients with 1.2 μg/ml and 2.4 μg/ml. House dust mite (HDM) antigens were skin prick tested in patients with scabies and controls. The results revealed that the SDS-PAGE profile of the parasite heat-stable proteins consisted of protein bands with molecular weights ranged from less than 10 to over than 100 kDa. Skin test demonstrated that 70% and 80% of scabietic patients had a positivity against 1.2 μg/ml and 2.4 μg/ml of sarcoptic mite extracts, respectively when prick tested. HDM extract was found to be positive in 40% of scabietic patients; while controls revealed a negative result. Sarcoptic proteins contain heat-stable allergens which able to cause immediate type-1 hypersensitivity when 1.2μg/ml of mite protein is skin prick tested, and there is cross-reactivity between Sarcoptes scabiei and HDM allergens.