miR-604 and miR-1302-3p downregulated, IL-37 elevated in Iraqi toxoplasmosis patients, suggesting diagnostic potential

Toxoplasma gondii is a globally prevalent obligate intracellular protozoan parasite causing toxoplasmosis. This infection significantly impacts host immunity, often by reprogramming cytokine-driven responses. MicroRNAs (miRNAs) are crucial epigenetic regulators that modulate immune responses by influencing cytokine expression. However, the specific roles of miR-604 and miR-1302-3p in the pathogenesis of human toxoplasmosis, particularly concerning their correlation with the immunomodulatory cytokine IL-37, remain underexplored. Understanding these interactions could reveal novel diagnostic biomarkers or therapeutic targets for this widespread parasitic disease.

Researchers conducted an observational study involving 200 non-pregnant women in Iraq, comprising 100 toxoplasmosis-positive patients and 100 healthy controls. Toxoplasmosis status was confirmed using serological screening via a rapid diagnostic test (TORCH) and ELISA for IgM and IgG antibodies. For molecular analysis, total RNA was extracted from whole blood samples, reverse-transcribed into cDNA, and then quantitative real-time PCR (RT-qPCR) was performed to quantify the expression levels of microRNA-604 and microRNA-1302-3p in both groups. Serum IL-37 levels were also measured.

Expression levels of both microRNA-604 and microRNA-1302-3p were significantly reduced in toxoplasmosis patients compared to the control group. For microRNA-604, relative expression was 2.1896 ± 1.12221 ng/L in patients vs. 1.6384 ± 1.09466 in controls. For microRNA-1302-3p, relative expression was 4.0896 ± 1.42896 in patients vs. 2.5764 ± 1.16224 in controls. Conversely, serum levels of IL-37 were significantly higher in the patient group compared to controls. The average IL-37 level in patients was 295.0604 ± 45.79983 ng/L, which was substantially elevated compared to the control group's average of 36.7183 ± 3.83299 ng/L. These altered expression profiles suggest a coordinated role in the pathogenesis of toxoplasmosis. > The marked induction of IL-37 alongside the downregulation of miR-604 and miR-1302-3p highlights their potential as novel diagnostic biomarkers or therapeutic targets for toxoplasmosis.