Ruqayah Arif Abdul Ameer
Department of Microbiology, Collage of Medicine, Al-Nahrain University, Kadhimiya Baghdad, Iraq
Al-Marsomy, Huda Dhaher
Department of Microbiology, Collage of Medicine, Al-Nahrain University, Kadhimiya Baghdad, Iraq
ABSTRACT
Background: The acute phase of Toxoplasma gondii infection is critical for parasite proliferation and dissemination within the host. During this phase, the immune system plays a vital role in controlling the infection. However, T. gondii employs various immune evasion strategies, including manipulation of host cell signaling, inhibition of apoptosis, and cytokine regulation, to establish infection. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), an immune checkpoint molecule, regulates T-cell activation and immune homeostasis. Increased CTLA-4 expression during T. gondii infection creates an immunosuppressive environment that helps the parasite evade immune clearance. Objective: This study aimed to evaluate the serum levels of CTLA-4 in patients during the acute phase of toxoplasmosis and to investigate its correlation with serological markers of T. gondii infection. Methods: A total of 350 individuals suspected of toxoplasmosis, aged 18–48 years, were included in the study. Serum samples were collected and analyzed using quantitative ELISA to measure CTLA-4 levels and T. gondii IgM. Statistical analyses were performed to assess differences in CTLA-4 levels and their correlation with infection markers. Results: CTLA-4 levels were significantly higher in patients with toxoplasmosis compared to the control group (P = 0.0001). A significant difference in CTLA-4 concentrations was observed across the three categories of toxoplasmosis symptoms (P = 0.0001). However, the correlation analysis revealed a non-significant negative relationship between CTLA-4 levels and T. gondii IgM (P = 0.8). Conclusion: The study highlights a significant increase in serum CTLA-4 levels during acute toxoplasmosis, suggesting its role in the immunosuppressive environment that facilitates T. gondii survival. These findings provide insights into immune checkpoint mechanisms in toxoplasmosis and underscore the potential of CTLA-4 as a biomarker for immune regulation in this infection
Keywords: Immune Checkpoint, CTLA-4, Toxoplasmosis, T. Gondii.
