Antigliadin antibody measurement by chemiluminescence ELISA in the diagnosis of coeliac disease.

AIMS

To develop a chemiluminescence enzyme linked immunosorbent assay (ELISA) for the detection of circulating gliadin antibodies in the diagnosis of coeliac disease. To compare this method for linearity and sensitivity with an established colorimetric method.

METHODS

Three sets of age and sex matched patient groups were studied: normal controls (patients with no clinical signs of intestinal disorders); gastrointestinal controls (patients with a known gastrointestinal disorder other than coeliac disease); and patients in whom suspected coeliac disease had been confirmed by positive jejunal biopsy. IgG antigliadin antibody (IgG-AGA) and IgA antigliadin antibody (IgA-AGA) titres were determined.

RESULTS

Comparison of the colorimetric and chemiluminescence methods showed close correlation of measured antibody levels for both control patient groups. In the coeliac patients correlation of antibody levels measured by both methods was not possible because the colorimetric assay is limited by the spectrophotometer's limits of detection. This problem was overcome by the chemiluminescence method which was linear over a greater range and to far higher values.

CONCLUSIONS

The chemiluminescence ELISA performs as well as the colorimetric assay at low and average antibody levels and has the advantage of also giving a numerical value to higher antibody titres. The method was accurate and reproducible in confirming the diagnosis of coeliac disease in patients with positive jejunal biopsy and was capable of monitoring progress of the disease.