The aim of the study: The objective of our study was to determine, how severe calorie restriction in anorexia nervosa (AN) may influence regulatory T (Treg) cells and their cellular networks, i.e. their main inducers (dendritic cells and macrophages) and their target cells, CD4+ lymphocytes.

Methods: We measured the prevalence of Tregs, myeloid and plasmocytoid dendritic cells (DC). The prevalence of TNF-alpha and IL-12 positive macrophages, interleukin(IL)-2, IL-4 and interferone-gamma positive CD4+ cells was determined by intracellular staining after activation. In total, 11 AN adolescents and 10 healthy age-matched controls (BMI SD-values, median [range]: - 2.4 [-3.5 – -1.9 ] vs +0.2 [- 1.1 – +1.9]) have been recruited from the child and adolescent psychiatry out-patient clinic of the Department of Pediatrics.

Results: Prevalence of Tregs, DCs, TNF-alpha and IL-12 positive macrophages, IL-4 and interferon-gamma producing CD4+ cells were similar in AN and controls. The prevalence of IL-2 positive CD4+ cells was somewhat lower in AN (% value, median [range]: 11.50 [7.60 - 15.30] vs. 13.50 [12.00 - 22.00], p = 0.023).

Conclusions: Our results suggest that in adolescents the antigen presenting cell – regulatory T cell – CD4+ lymphocyte axis is not affected by calorie and nutritional deficiencies observed in anorexia nervosa.