Measurements of the
acute phase proteins,
C-reactive protein (CRP) and
orosomucoid are widely used to monitor the activity of
Crohn's disease. The effect of TPN upon the levels of
acute phase proteins is unknown. Serum levels of CRP and
orosomucoid were measured simultaneously over a four year period in 13 patients receiving TPN for
Crohn's disease, nine patients with noninflammatory causes of
intestinal failure, and 16 patients with
Crohn's disease treated without TPN. An
acute phase response was found with a similar frequency in both groups of patients with
Crohn's disease (73.6% and 83.9% for Crohn's with and without TPN respectively), but was less prevalent in patients receiving TPN for non-inflammatory causes of
intestinal failure (56.1%, P < 0.01). In this latter group, the
acute phase response consisted primarily of an isolated elevation of
orosomucoid (78.4%), compared with patients with
Crohn's disease alone (21.1%, P < 0.001) and with
Crohn's disease and TPN (46.6%, P < 0.05). Liver function abnormalities were seen on 68.8% of occasions in patients with noninflammatory causes of
intestinal failure who had elevated levels of
orosomucoid, compared with 34.9% of occasions on which
orosomucoid levels were normal (P < 0.001). TPN may lead to isolated elevation of serum levels of
orosomucoid, reducing the value of this
acute phase protein in monitoring the activity of
Crohn's disease in patients receiving TPN.