EXPRESS: Assessment of serum level of galectin-9 in systemic lupus erythematosus patients in Tanta university hospitals.

Background: galectin-9 (Gal-9) has a significant regulatory function in autoimmune disorders, including systemic lupus erythematosus (SLE). The objective of this study was to assess the blood levels of Galectin-9 in patients with SLE and investigate the correlation between the protein and disease activity.

Methods: The study employed a case-control design involving 75 participants, aged between 25 and 55 years, representing both sexes, all of whom had been diagnosed with SLE and were either in a quiescent or active phase of the disease. Three equal groups of participants were created.

Results: It was shown that Galectin-9 has 88% sensitivity and 80% specificity, with an area under the curve (AUC) of 0.901. With a computed positive predictive value of 81% and a negative predictive value of 87%, the total accuracy was 84%. Additionally, a strong positive connection (R=0.606) was found between anti-double strand DNA and Gal-9 levels, urea (R=0.482), creatinine (R=0.530), proteinuria (R=0.488), albumin-to-creatinine ratio (R=0.7) and SLEDAI (R=0.815) and there is negative correlation with hemoglobin (R=-0.772), white blood cells (R=-0.849), platelets (R=-0.481) and complement 3 (R=-0.578).

Conclusions: Compared to healthy persons, patients with SLE had considerably higher serum concentrations of Gal-9. Patients without active illness did not have elevated levels of Gal-9; those with active SLE did. Moreover, Gal-9 showed a robust association with the activity of SLE illness, indicating a possible involvement in the onset of SLE.