Leggi l’articolo in italiano
Celiac disease: the incidence worldwide
The results of a meta-analysis on the Global Prevalence of Celiac Disease (2018), found the current worldwide prevalence of celiac disease to be 1.4% based on blood tests and 0.7% based on biopsy results. The prevalence of celiac disease was 4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania. The prevalence was higher in female than male individuals, and was significantly greater in children than adults. In conclusion, the prevalence of celiac disease varies with sex, age, and location. In Italy the diagnosis of celiac disease is increasing, with a higher frequency in women. At the end of 2017, 206.561 cases of celiac disease were diagnosed in Italy, of which over two thirds were women (Annual Report to Parliament on Celiac Disease). The greater number of diagnosed cases in recent years also depends certainly on the availability of new diagnostic tests, that are less invasive and easily proposed even in the pediatric age.
The genetic predisposition test is not invasive and has a high negative predictive value
The GENEQUALITY CD-TYPE test for the determination of predisposition to celiac disease is validated not only with blood samples but also with buccal swabs and has a high negative predictive value. This means that a subject, having a negative test result, has virtually no chance of developing the disease.
What are the genetic bases of celiac disease ?
Celiac disease is a multifactorial disease with a strong genetic component. It is a chronic inflammation of the small intestine triggered by gliadin (contained in gluten) exclusively in genetically predisposed subjects. These persons do not correctly recognize gliadin due to the particular conformation of the protein assigned to its recognition. The latter consists of a heterodimer formed by an α and a β chain, encoded respectively by the HLA DQA1 and DQB1 locus on chromosome 6.
The combination of the 2 genes (DQA1 and DQB1), which determine the formation of the heterodimer, is called haplotype. The most associated haplotypes with the risk of onset of celiac disease symptoms are: DQ2 (formed by DQA1*05 and DQB1*02) and DQ8 (formed by DQA1*03 and DQB1*03:02).
The genetic test then investigates whether one of the allelic combinations associated with predisposition is present in the patient’s genome and it is able to give an indication of the risk associated with the symptoms of the disease, which are different in adult or pediatric age.
Treatment for celiac disease ?
Celiac disease can manifest itself with very different symptoms and forms which means the identification is done after a long time. It’s currentely estimated that about 70% of the cases are underdiagnosed, the lack of diagnosis cal lead to subsequent majot complications. Otherwise, as a result of a celiac disease diagnosis the patient is prescribed a gluten-free diet, which appears to be the only available treatment to date with an effectiveness in determining the complete remission of the disease.
