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

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+ Integrinß7+ (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+ Integrinß7+ (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.