Background Rheumatoid arthritis (RA) is an incessant synovial inflammation of an autoimmune origin, destroying
articular cartilages and bones. Galectins are an evolutionarily conserved family of immune-modulatory animal lectins
detected in a number of immune cells like T cells, fibroblasts and macrophages. Galectin 9 (Gal-9) has been the subject
of many studies for being linked to regulation of both innate and adaptive immune reactions. The objective
of the study was to evaluate the link between the Galectin-9 gene (LGALS9) polymorphisms and the susceptibility
of RA in Egyptian patients, as well as, detection of the serum level of Gal-9 in RA and its association with LGALS9 polymorphisms,
the activity of RA and radiological damage.
Methods A study of 85 participants; group (I): 60 RA cases and group (II): 25 apparently healthy subjects. RA Disease
activity index (DAS-28) and Larsen index score were assessed. LGALS9 gene and serum Gal-9 were investigated.
Results rs4239242 TT genotype and T allele occurred more frequently in RA cases than controls with a significant
difference (P = 0.006; P < 0.001 respectively). Gal-9 level was significantly higher among RA cases than control group
(P = 0.017). The Gal-9 level showed negative significant correlations with DAS-28 and Larsen score (P < 0.001).
Conclusion RA is strongly linked to genetic alterations in the LGALS9 gene and the single nucleotide polymorphism
(SNP) rs4239242 TT genotype in the Egyptian population. RA cases in remission or those with low disease activity
had higher levels of serum Gal-9 in comparison to cases with moderate and high disease activity and this would be
promising in the future of RA treatment.