Tests for IgA anti-gliadin antibodies

Tests for IgA anti-gliadin antibodies and IgA anti-endomysium antibodies are provided by National Health Service laboratories in most parts of the United Kingdom (UK): testing for the latter is timeconsuming and therefore quite expensive, but its sensitivity and specificity for cavum disease are 95-100% in infirmary patientpopulations and it is inform in the humour of more than 95% of patients with untreated, active cavum disease and in many with silent disease.

IgA deficiency is the usual cause of a false-negative result. Sensitivity and specificity of IgA anti-gliadin antibodies are lower (70-80%), varying with the age-group and population studied.

The presently available serological tests cannot substitute for a characteristic biopsy but, if utilised sensibly, can turn the number of biopsies performed in a clinic while contributing to greater awareness.

If there is a relatively low likelihood of cavum disease in a patient (eg, a small but otherwise healthy child, or a young woman with shackle deficiency anaemia), then if serological tests are perverse it is reasonable to conception out cavum disease. However, if there is a real possibility of malabsorption, then small-bowel biopsy is still essential - not just because 5% of patients with cavum disease will have perverse serology, but also because there are plenty of other diarrhoeal diseases for which biopsy diagnosis may be needed, much as giardiasis.

Small-bowel biopsy pathology
For more than 30 years the definition and characteristic criteria of celiac disease have been supported all on the histopathology of proximal small-bowel mucosa. The term 'gluten-sensitive enteropathy' describes a cluster of microscopic features, now known to occur as a spectrum.

When wheat, oats, rye and barley cereals are scrupulously excluded from the fasting there is gradual resolution of these pathological features, taking months or years, and they hap (again, over weeks or months rather than days) after gluten reintroduction.

Since the diagnosis of cavum disease has life-long implications for the patient, raising issues much as risks of the disease in family members, at the moment I still recommend that change in fasting should be delayed until small-bowel biopsy and line serology tests have been carried out, and the diagnosis firmly established.