Background: A type I transmembrane protein called T-cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) is involved in the development of a number of chronic autoimmune illnesses, including rheumatoid arthritis, by modulating T cell immune responses and the Th17/Treg balance.

Aim : is to detect if sTIM-3 are elevated in rheumatoid patients and correlated with disease activity.

Patients and Methods: This study was carried out on 40 RA patients and 40 apparently healthy controls attending to the inpatient and outpatient clinics of Rheumatology and Rehabilitation Department, Zagazig University Hospitals, Serum samples of all subjects were collected for routine laboratory assessment and for evaluating serum levels of TIM-3.

Results: Serum TIM-3 was elevated in RA patients (541.88 ± 389.62) compared with those in healthy subject than control group (150±31.61). On studying validity of TIM-3 serum level at cut off = 207.1, the sensitivity was (97.5%) and specificity was (94.9%) while Sensitivity of TIM 3 concentration at cut off =399.5 was (83.3%), specificity was = (70%). Different DAS 28 score gradings and TIM 3 concentrations showed statistically significant differences, with severe cases showing the highest median and moderate score gradings following.

Conclusion: By comparing RA patients and healthy controls, RA patients had considerably greater levels of circulating sTIM-3 than healthy group.sTIM-3 was correlated with active rheumatoid patients.