Regimen-related mucosal toxicity is extremely common following cytotoxic
chemotherapy and
radiotherapy.
Mucositis is as an important determinant of the inflammatory response and infectious complications in
cancer treated patients. Most assessment scales for mucosal damage are focussed on
oral mucositis, since it is easy to evaluate. Measuring gastrointestinal musocal damage objectively remains difficult because it cannot be seen directly or readily detected. One of potential non-invasive
biomarkers of gastrointestinal mucosal damage is plasma
citrulline level.
Citrulline is an
amino acid produced by small bowel enterocytes. Low concentration of free circulating
citrulline signifies severe intestinal mucosal damage in humans with nonmalignant disorders, such as villous
atrophy-associated diseases,
short bowel syndrome,
Crohn's disease, and is used in follow-up after small bowel
transplantation. The plasma
citrulline level is a reliable and objective
biochemical marker of enterocyte mass and function in humans, and therefore can be used to monitor enterocyte toxicity resulting from
chemotherapy and
radiotherapy during anticancer
therapy in patients with severely disturbed gut integrity.