Association of gut‐specific non‐inflammatory T lymphocytes with chronic anorexia nervosa and constitutional thinness

Abstract Objective Previous studies of AN showed low‐grade inflammation. Are low‐grade inflammation and circulating lymphocytes associated with chronic conditions? Method Peripheric blood cytokines were measured using Luminex™ technology in a chronic AN cohort (mean = 67.42 months), compared to Constitutional Thinness (CT), Constitutional Obesity (CO), and Healthy Controls (HC). Secondarily a prospective cohort of chronic AN (mean = 54.11 months) was recruited to compare the functional lymphocyte profile in blood by flow cytometry to CT and HC. Results In the AN group, most cytokine concentrations were lower than in CT and HC groups. The IL‐23 (98.02 pg/ml) was elevated related to HC and CO, and the IL‐10 (4.178 pg/ml) was elevated versus CO. In the CT group, IL‐9 (0.06216 pg/ml) was elevated compared to AN. The AN group had high Treg (9.259% of CD4 + ) and CD8 + Integrinβ7 + (9.552% of CD3 + ) versus HC for lymphocyte populations. In CT group, elevated Treg (9.7% of CD4 + ) elevated percentage of CD4 + CCR9 + (5.867% of CD3 + ) and CD8 + Integrinβ7 + (10.21% of CD3 + ) were found versus HC. Conclusions The chronic state of AN and CT is surprisingly non‐inflammatory with elevated Treg cells. These results suggest that maintaining a dysregulated response to intestinal antigens may contribute to maintaining AN.