Changes in glycosylation of IgG during fasting in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis (RA) have a higher proportion of agalactosyl IgG than healthy individuals. Glycosylation status was examined in 26 RA patients who fasted for 7-10 days and afterwards followed a vegetarian diet for 3.5 months. The decrease in the proportion of agalactosyl IgG correlated significantly with the clinical improvement after the fasting period, but not after the vegetarian diet period. Although the glycosylation status of IgG may have played a role in the improvement of disease during the fasting period, it did not seem to be associated with, and therefore responsible for, the clinical improvement observed after the vegetarian diet.