Aim:
Aim: To determine the soluble of Tim-3 levels and how a variation in the -574 locus gene in the TIM-3 gene's promotor region contributes to SLE.

Material and methods:
Materials and Methods: 180 participants participated in the current study: 90 SLE patients and 90 clearly healthy controls (HCs) from October2024 to February 2025. These subjects selected from Medical City, Baghdad, Iraq. Participant's genomic DNA was collected from blood sample. Every sample was diagnosed with SLE. The enzyme-linked immunosorbent assay (ELISA) was utilized to determine the quantity of soluble TIM-3 (sTIM-3) in the serum of SLE and HC patients. The TIM-3 gene's rs10515746 gene fragment, which corresponds to the -574 locus, was amplified and genotyped using the allele-specific polymerase chain reaction (AS-PCR).

Results:
Results: Patients had significantly higher Tim-3 levels (median = 396.5 ng/ml, range = 198-698 ng/ml), than controls (median of 1618 ng/ml and a range of 1306-1999 ng/ml). The GT-TT genotypes were more prevalent in patients than controls (98.89% vs. 93.33%), with a significant difference (OR= 6.36, 95%CI= 0.75-53.92). At the allelic level, compared to controls, patients' frequencies of the mutant allele (T) were noticeably higher (90.56% vs. 79.44%) (OR=2.15, 95%CI= 1.15-4.03, p=0.016).

Conclusions:
Conclusions: Individuals with SLE have significantly higher levels of soluble Tim-3, which suggests that the protein has a role in the pathophysiology of the condition and that the T allele of rs 10515746 is a risk factor for SLE.