Longitudinal Immune Profiling in Autoimmune Polyendocrine Syndrome Type 1

Autoimmune polyendocrine syndrome Type-1 (APS-1) is a rare, but severe organ-specific autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. Lack of AIRE causes autoreactive T cells to escape negative selection and alters the T regulatory cell subset. However, little is known about how the immune cell subsets vary across the lifespan in APS-1. Here we analysed the peripheral distribution of 13 immune cell subsets along the lifespan using epigenetic quantification. We found the largest discrepancy in immune cells to appear early in APS-1 patients' lives, coinciding with the time point they obtained most of their clinical symptoms. We further revealed longitudinal changes in cell compositions both within the adaptive and the innate arms of the immune system. We found that cell frequencies of B cells, T-cell subgroups, nonclassical monocytes, and Natural Killer cells to be reduced in young APS-1 patients. We also found B-cell frequencies to decrease with ageing in both patients and healthy controls. Our results suggest that Tregs, follicular helper T, and natural killer cells have opposing trends of cell frequencies during life, indicating the importance of considering the age profiles of cohorts which could otherwise lead to conflicting conclusions.