Abolghasem Siyadatpanah, Rafieh Bagherifar, Kimia Moradi, Reyhaneh Moghaddami, Nahideh Nazdikbin Yamchi, Kareem Hatam-Nahavandi, Monir Khordadmehr, Sahar Rezaei, Esmaeil Gharepapagh, Seyed Jafar Adnani Sadati, Zahra Amiri, Mohammad Taghi Rahimi, Ehsan Ahmadpour
Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disorder characterized by pancreatic β-cell destruction and sustained inflammation. Parasitic infections and associated antigens may influence disease progression through immune modulation. This study evaluated the effects of Leishmania infantum lysate-adsorbed alum nanoparticles (LiLA-AlumNPs) on metabolic, histopathological, and immunological profiles in a streptozotocin (STZ)-induced rat model of T1DM. Twenty female Wistar rats were randomly divided into four groups (n = 5): control, STZ-induced diabetic, LiLA-AlumNPs immunized, and LiLA-AlumNPs + STZ. Blood glucose, C-reactive protein (CRP), and cytokine levels (IL-1, IL-10, TNF-α) were measured. Histopathological examinations of the pancreas and kidney were conducted, and metabolic activity was evaluated using positron emission tomography (PET) by determining SUVmax. The STZ and LiLA-AlumNPs + STZ groups showed significantly elevated blood glucose levels compared with the control group (p < 0.01), along with increased CRP (p < 0.05) and pro-inflammatory cytokines (p < 0.05). These changes were accompanied by marked pancreatic islet destruction and renal lesions. LiLA-AlumNPs administration alone elicited mild inflammatory responses without significant tissue pathology. The combined administration of STZ and LiLA-AlumNPs further elevated CRP, TNF-α, SUVmax, and the severity of tissue damage in the rats. These findings indicate that co-infection or exposure to parasite antigens can exacerbate inflammatory and metabolic dysregulation in diabetic hosts, highlighting the need for further pathophysiological investigations and clinical studies.