Galectin 1, Galectin 9 and IL6 in different Immune-mediated Inflammatory Diseases

In previous studies, our group (PMID: 33082382; doi: 10.1038/s41598-020-74185-8) validated data published by the group of Rabinovich, G.A. (PMID: 30687310; doi: 10.3389/fimmu.2018.03057) describing that serum Galectin 1 (Gal1) levels in patients with Rheumatoid Arthritis (RA) were higher than those in healthy controls. Furthermore, our group had demonstrated that Gal1 levels in patients with RA were higher than those in patients with early Axial Spondyloarthritis. Therefore, the objective of this project was to determine whether elevated levels of Gal1 were specific to rheumatoid arthritis (RA) and, therefore, a potential diagnostic biomarker, or whether they were a common finding in other immune-mediated inflammatory diseases (IMIDs).

To this end, samples and clinical data were requested from patients in the IMID-kit study (GRR of Vall d'Hebron) corresponding to the following diseases: RA, Psoriatic Arthritis, Psoriasis without arthritis, Crohn's Disease, Ulcerative Colitis, and Systemic Lupus Erythematosus (SLE). Clinical information was provided in pseudonymized form, but our group did not have access to the coding relationships, so it can be considered anonymized (since the patient code has been removed).
In addition, anonymized samples were obtained from healthy controls from the La Princesa Biobank and the National DNA Bank of Salamanca.
Plasma levels of Gal1 and Gal9 were studied in a discovery cohort of 600 cases and a validation cohort of 380 cases. Plasma levels of interleukin-6 were also studied in the discovery cohort. In the overall IMID group, plasma levels of Gal1 were comparable to those of healthy controls, while Gal9 levels were significantly elevated. Levels varied according to disease: patients with SLE consistently showed the highest levels of Gal1/9 compared to healthy controls and other IMIDs, and patients with RA had elevated levels of Gal9 compared to healthy controls. Plasma levels of Gal1 and Gal9 were positively correlated with greater disease activity, and Gal1 was higher in patients with longer disease duration.