The master's thesis defense of **Ruqaya Arif Abdulameer** in the Department of Microbiology.

**"Evaluation of the level of Immune checkpoint Cytotoxic T-lymphocyte Antigen-4 (CTLA-4) and Programmed Death Protein 1 (PD-1) in Toxoplasmosis"**

The main objective of this study was to determine the levels of CTLA-4 and PD1 during infection with *Toxoplasma gondii* from blood samples collected in the acute phase of toxoplasmosis, aiming to measure these markers using the ELISA technique.

The study showed that both CTLA-4 and PD1 were significantly elevated in toxoplasmosis patients compared to the control group, with a highly significant difference (P=0.0001). Additionally, the concentrations of CTLA-4 and PD1 were higher in the main symptoms of toxoplasmosis (miscarriage, delayed pregnancy, and cervical lymphadenitis), revealing significant differences between these three symptoms. There was a positive correlation between the disease and PD1, as well as a positive correlation between PD1 and CTLA-4 in toxoplasmosis patients.

- **Prof. Dr. Haider Sabah Kazem** — Chair

- **Asst. Prof. Dr. Ali Issa Fadhel** — Member

The thesis was successfully accepted with distinction.