Conclusions
Serum FGF19 could be developed as a simple blood test to increase the diagnostic rates of BAD.
Methods
Patients undergoing routine investigation provided fasting blood samples. C4 was determined by high-performance liquid chromatography, and used to stratify two groups: group 1 (n=119), consisting of patients with normal C4 (≤ 28 ng/ml), and group 2 (n=139), consisting of patients with high C4 (>28 ng/ml), including any of the possible causes of BAD. Serum FGF19 was measured in stored samples by enzyme-linked immunosorbent assay.
Results
FGF19 and C4 were significantly inversely related (r(s)=-0.64, P<0.001). Patients with raised C4 had significantly lower median FGF19 values. Both of these were more marked when secondary to ileal disease, in particular ileal resection, than in primary BAD. The sensitivity and specificity of FGF19 at 145 pg/ml for detecting a C4 level >28 ng/ml were 58% and 79%, respectively. For C4 >60 ng/ml, these were 74% and 72%; on receiver-operating characteristic analysis, the area under the curve was 0.80 (95% confidence interval 0.74-0.87). Conclusions: Serum FGF19 could be developed as a simple blood test to increase the diagnostic rates of BAD.