Background and Objectives: Leishmanin skin test (Montenegro test) is a best indicator for evaluation of delayed-type hypersensitivity reaction and cell-mediated immunity in leishmaniasis. A standard antigen is needed for this test. In this research, several batches of leishmanin antigen were produced under standard conditions, and their immunogenicity, specificity, sensitivity and potency were evaluated.

  Methods: In order to produce leishmanin, standard strain of Leishmania major (MRHO/IR/75/ER) was cultured in equal volume of�liquid medium of D-MEM and Tc Medium 199 in large scale. Parasites from stationary phase of growth were harvested and washed under strict standard conditions and used for preparation of leishmanin. Immunogenicity of prepared antigen was tested by skin testing in pre-immunized guinea pigs. Specificity of the reagent and abnormal sensitization were evaluated by skin testing in healthy individuals in non-endemic areas of Tehran and Tabriz. Sensitivity and potency of leishmanin reagent were evaluated by skin testing in recovered individuals from cutaneous leishmaniasis (CL) in endemic areas of rural and urban areas.

  Results: The findings indicated the productions of leishmanin are sterile and safe with high immunogenicity. Specificity of the products was shown to be higher than 99% with no abnormal sensitization to reagent. Sensitivity and potency of preparations were determined > 96% with mean induration between 15-18 mm in endemic areas of rural CL, and > 93% with mean reactivity of 12-14 mm in endemic areas of urban CL.

  Conclusion: The findings indicated that this product is safe and sterile with high immunogenicity, specificity, sensitivity and potency and has no abnormal sensitization. These products which are easily available inside the country could be used easily for skin testing and detection of delayed-type hypersensitivity response in leishmaniasis.