Plasma-Free Amino Acid Profiles in Crohn’s Disease: Relationship With the Crohn Disease Activity Index

We aimed to clarify the relationship between plasma-free amino acid (PFAA) profiles and the Crohn’s disease (CD) activity index (CDAI) in patients with CD. Methods: We measured fasting PFAA concentrations in 29 patients with CD and their correlation with disease activity. Results: In all patients, significant correlations were noted between CDAI and concentrations of valine, methionine, leucine, histidine, tryptophan, alanine, tyrosine, total amino acids (TAAs), nonessential amino acids (NEAAs), essential amino acids (EAAs), and branched-chain amino acids (BCAAs). In patients with the ileo-colonic type of CD, significant correlations were noted between CDAI and valine, histidine, tryptophan, glutamine, TAA, NEAA, EAA, and BCAA. In ileal type, significant correlations were observed between CDAI and threonine, valine, histidine, serine, and glycine. In colonic type, significant correlations were noted between CDAI and valine, histidine, tryptophan, TAA, NEAA, EAA, and BCAA. Conclusions: In patients with CD, plasma amino acids appear to be associated with disease activity.