Evaluation of mice, sheep and human IgG and IgE antibody responses against the mice Crude Hydatid Cyst Fluid (HCF) antigens

Abstract

Hydatidosis is a dangerous parasitic disease which commonly occurs in humans and animals. It annually causes many economic and health problems throughout the world. The existing diagnostic kit uses sheep cystic fluid antigen as an available antigen to evaluate the human IgG antibody. The current study was designed to evaluate an alternative antigen which is the mice HCF antigen for such diagnosing kit. For this purpose the IgG responses in sera of human, mice and sheep against the mice crude hydatid fluid antigens was applied using ELISA and Western Blot. Thirty Balb/c mice were immunized using sheep hydatid cyst and complete freunds adjuants. The hydatid cyst fluid antigens of human and sheep were obtained from naturally infected human and sheep and for mice from experimentally infected mice with protoscolices of hydatid cysts (HC). Antigens were used in ELISA and SDS PAGE after their concentrations were measured applying Bradford procedure. Thirty positive samples sera from mice, sheep and human were employed as the case and 30 healthy sera from each as the control group. The statistic analysis tests were ANOVA and post Hoc Analysis Model. The highest mice antibody response against mice HCF antigens was IgGAM antibody (with mean OD value 0.4) while the lowest was IgE (with mean OD value 0.26).  The best antibody response was seen for human total IgG against mice HCF with mean OD value of 0.71 while the lowest response against this antigen belonged to human IgG3 and IgE each with mean OD value of 0.12.  ANOVA analysis indicated significant differences between the human IgG class and subclass responses to mice HCF antigens (P < 0.05). The sensitivity and specificity of the ELISA for antibody responses to this antigen was mostly more than 90% almost for all sera of different hosts. The mean OD value of sheep IgG against mice HCF antigen was 0.34. The studied sera (mice, human and sheep) considerably showed a positive response against mice HCF antigens by ELISA test. The human and mice sera showed a higher response over the sheep sera in that their mean OD values and their OD ratio were significantly higher than that for the sheep. Totally there are some immune responses from the serum of each animal recognizing the crude hydatid cyst fluid antigen of mice. According to the results of the current study the mice HCF is an appropriate candidate for diagnosing of hydatidosis of human and animal.   Key words: Hydatid cyst, cross-reaction, IgG response, hydatid cyst fluid.