Introduction Routine blood investigations are regularly performed in secondary and tertiary care to aid in predicting the presence or absence of intestinal inflammation. There is a need for laboratory costs and time to be taken into account when planning these investigations.
Aim To determine the most effective routine investigation as a marker of inflammation in paediatric inflammatory bowel disease (IBD).
Methods A retrospective case note review of patients attending the paediatric gastroenterology department, of a referral hospital with a confirmed histological diagnosis of Crohn's disease or ulcerative colitis was performed. Values for haemoglobin (Hb), neutrophils, lymphocytes, platelet count, erythrocyte sedimentation rate, C reactive protein, (CRP) albumin and α-1-acid glycoprotein were noted at the time of diagnosis and again when the patient was completely asymptomatic. Receiver operating characteristic (ROC) curves were analysed.
Results A total of 62 patients (CD n=36; UC n=26) were included. ROC curve analysis for presence or absence of disease activity (n=124 events) is shown in table 1.
Table 2 demonstrates that AGP functions as a good test parameter in both CD and UC, but that CRP and albumin are better discriminators of disease activity in patients with CD than UC (p<0.05). In patients with UC, ESR was a superior discriminator over CRP (p<0.05). A cost analysis for the test parameters is presented.
Conclusion Of the routine blood investigations commonly performed in monitoring paediatric patients with IBD, AGP gives the best likelihood of predicting disease activity or inactivity. This could be extrapolated to screening for presence or absence of IBD. Albumin is a good discriminator of disease activity in CD but not UC. CRP is not a useful marker in UC. AGP is a clinically significant discriminator compared to CRP (p<0.001) and ESR (p<0.05).