Are you missing cases of Coeliac Disease? Dr David Curran gave us an update at the October Medical Update.
Coeliac disease is a growing problem. There is a genetic predisposition, but there are also other factors involved – even among monozygotic twins the prevalence is only about 70%. Many people with coeliac disease remain undiagnosed. There is also a population of people who have positive antibodies but the disease is still silent (negative mucosal morphology and no symptoms), although it is important to take a thorough history to detect subtle clinical symptoms.
We often associate coeliac disease with the classic symptoms of diarrhoea and malabsorption, but more commonly people present in other ways. Iron deficiency anaemia is a common feature. Fatigue, weight loss, diarrhoea, flatulence and bloating are common. Premature or refractory osteoporosis is another common feature.
Investigations for Coeliac disease need not be complex. If you simply write ‘Coeliac serology’ on the request form, Southern Pathology will run the full combination of tests along with checking for IgA deficiency. There is a possibility of false positive serology (i.e. liver disease, tumours), but these are usually low titre. Genetic testing can be used to rule OUT Coeliac disease. The associated genes HLA DQ2 or DQ8 are present in 30% of all people but only 1 in 30 of those people will actually develop Coeliac disease. Small bowel biopsy is still required in all cases for definitive diagnosis. Southern Pathology have produced a useful algorithm for these investigations:
The differential diagnosis for Coeliac disease is broad. Chronic giardiasis, IBS and small bowel bacterial overgrowth top this list. PPI use is a risk factor for small bowel bacterial overgrowth. Immunosuppressive medications can also lead to villous atrophy. Coeliac disease is associated with other autoimmune diseases such as diabetes mellitus, autoimmune thyroid disease, SLE, ulcerative colitis, dermatitis herpetiformis, Down syndrome.
Most patients will undergo a follow up biopsy around 12 months after diagnosis. Complications are rare but include lymphoma and GI cancers. There are some neurological sequelae, including cerebellar ataxia.
Management of Coeliac disease still includes avoidance of gluten (wheat, barley, rye). Look out for vitamin and mineral supplements that may contain gluten. New treatments are emerging and in future desensitisation may be possible.