Anti - Glucose Regulated Protein 78 (GRP78) antibody responses in Alum/ALM plus BCG vaccinee, visceral leishmaniasis, and Post Kala- azar Dermal leishmaniasis patients

Abstract

Introduction: The Glucose Regulated Protein 78 (GRP78) of Leishmania donovani is considered to be one of the potential Leishmania vaccine candidates. Patients and methods: Using Enzyme-Linked Immunosorbent Assay (ELISA), we measured IgG antibody responses to GRP78 in 39 healthy Sudanese volunteers vaccinated with Leishmania Alum/ALM + BCG vaccine, 29 patients with visceral leishmaniasis (VL), and 26 patients with post kala-azar dermal leishmaniasis (PKDL). Results: There was, no significant statistical difference in plasma levels of GRP78 antibodies in immunized and control group (P=0.37). Furthermore, no significant statistical difference in the levels of GRP78 antibodies in the pre and post vaccination plasma samples (P=0.60). Plasma IgG levels to GRP78 was significantly higher in visceral leishmaniasis and PKDL patients compared with control group (P=0.00). Conclusion: This study concludes that Alum/ALM vaccine does not induce a Th2 type of immune response. It also demonstrated clearly that VL and PKDL are associated with elevation of anti-GRP 78 antibodies and that GRP78 ELISA can be used to confirm diagnosis of Leishmania infections based on the clinical presentation.