An international group of scientists, led by Croatian experts from from St. Catherine’s Hospital and Genos published a very important scientific finding: glycans can predict rheumatoid arthritis 10 years before onset of symptoms!
The team led by prof. Dragan Primorac and prof. Gordan Lauc (Genos) and (St. Catherine’s Hospital) have published an article in Biochimica et Biophysica Acta (BBA) Molecular Basis of Disease, titled ”Low galactosylation of IgG associates with higher risk for future diagnosis of rheumatoid arthritis during 10 years of follow-up”.
In this scientific paper, the results of a ten-year long international study, performed in collaboration with the National Institute for Health and Welfare from Helsinki, Finland, are presented. The scientists analysed the samples that were taken from the Finnish population in 2007, to try and find out if the changes in certain characteristics that were present 10 years ago could have indicated an increased risk of development of rheumatoid arthritis (RA).
Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease, where the patient’s immune system attacks primarily the joints, or even more specifically, the cartilage in the joints. Over 100 million people worldwide are suffering from this debilitating disease, and early diagnosis is central to the treatment of RA, as starting a therapy as soon as possible can prevent or halt joint damage in many patients. For years it has been known that several antibodies, including the changes of the glycosylation of immunoglobulin G (IgG) are of particular importance for the early diagnostics of RA, as well as other autoimmune diseases such as lupus and inflammatory bowel disease (IBD).
Luckily, recent development of new, sophisticated analytical methods and approaches with much higher throughput has enabled the analysis of details of glycosylation of IgG in a larger number of patients and with higher accuracy. One such method was chosen by the authors of this study to analyse IgG glycosylation profiles of 179 individuals that were diagnosed with RA during 10-year follow-up after sampling (cases), and 358 matching controls that did not develop RA in the same period.
In the paper, the authors show that the significant IgG glycosylation aberrancy can be detected years before the onset of the disease and considered as a novel risk factor for RA. These differences in IgG glycosylation were relatively stable and present years before diagnosis. This indicates that long-acting factors affecting IgG glycome composition are among the underlying mechanisms of RA and that decreased galactosylation is a pre-existing risk factor involved in the disease development. The discovery could lead to the development of a new diagnostic algorithm that could predict a person’s risk of developing rheumatoid arthritis years before the onset of symptoms, which would allow for an even earlier start of the therapeutic regime.