Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation Associated Biomarkers Using Multiplex Profiling

Background Proteomics offers potential for detecting and monitoring anorexia nervosa (AN) and its variant, atypical-AN (atyp-AN). However, research has been limited by small protein panels, focus on adult AN, and lack of replication. Methods This study performed Olink Multiplex profiling of 92 inflammation-related proteins in females with AN/atyp-AN (N = 64), all < 90% of expected body weight, and age-matched healthy controls (HC; N=44). Results Five proteins differed significantly in the primary AN/atyp-AN group relative to HC group (lower levels: HGF, IL-18R1, TRANCE; higher levels: CCL23, LIF-R). The expression levels of three proteins (lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in females with AN in our primary model. No unique expression levels emerged for atyp-AN. Across the whole sample, twelve proteins correlated positively with body mass index (ADA, CD5, CD6, CXCL1, FGF-21, HGF, IL-12B, IL18, IL-18R1, SIRT2, TNFSF14, TRANCE) and five (CCL11, FGF-19, IL8, LIF-R, OPG) were negatively correlated with body mass index in our primary models. Conclusions Our results replicate the prior study demonstrating a dysregulated inflammatory status in AN, and extend these results to atyp-AN. Of the 17 proteins correlated with body mass index, 11 were replicated from a prior study using similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of AN disease monitoring. Our findings underscore the complexity of AN and atyp-AN by highlighting the inability of the identified proteins to differentiate between these two subtypes, emphasizing the heterogeneous nature of these disorders.