Objective: Measurement of the faecal markers calprotectin, lactoferrin and tumour M2-PK has been reported to be useful in the diagnosis and management of a range of gastrointestinal disorders in both children and adults. The aim of this study was to investigate the requirement for age-related reference ranges.
Methods: Faecal samples were obtained from 132 healthy subjects and analysis of calprotectin, lactoferrin and tumour M2-PK performed using commercially available enzyme-linked immunosorbent assay.
Results: In the healthy subjects median concentrations were as follows: for calprotectin - 2-9 y, 34 microg/g, 10-59 y, 22 microg/g and > or =60 y, 27 microg/g; for lactoferrin - 2-9 y, 2.2 microg/g, > or =10 y, 0.5 microg/g; and for tumour M2-PK all subjects <1 U/mL. Significant differences between age groups for different markers resulted in the following age-related reference ranges: calprotectin - 2-9 y, <166 microg/g, 10-59 y, <51 microg/g, > or =60 y, <112 microg/g; lactoferrin - 2-9 y, <29 microg/g, > or =10 y <4.6 microg/g.
Conclusion: In healthy individuals, we found there to be variation in the faecal inflammatory markers calprotectin and lactoferrin with age. For both calprotectin and lactoferrin children aged 2-9 y had significantly higher concentrations than subjects aged >/=10 y. For calprotectin but not lactoferrin, adults > or =60 years had a higher concentration than those aged 10-59 y. There was no change with age in the metabolomic marker faecal tumour M2-PK in healthy subjects. The knowledge of age-related reference ranges in healthy subjects is important to fully interpret changes in gastrointestinal disease.