Of all the “permanent” diseases, celiac disease is the one with the highest degree of incidence. In Italy, according to the Ministry of Health, celiac subjects (diagnosed and not) are about 1% of the population, for a total of more than 600 thousand people, including children. After diagnosis, the only “therapeutic” prescription for those suffering from gluten intolerance is a strictly gluten-free diet. To ascertain that it is celiac disease, the adult patient must undergo, in addition to blood tests, also a gastroscopy, even if in the future it is hoped to be able to do without it.
According to a recent study conducted by a group of researchers from the University of Sheffield (GB), in most cases there may no longer be a need to undergo gastroscopy to arrive at a diagnosis of celiac disease, as is already the case in pediatrics. Objective: to optimize the diagnosis, making it less invasive. For now it remains a hope, the practice is very different as confirmed by Ruetir Salute Fabiana Zingone, professor of Gastroenterology at the University of Padua.
“The diagnosis of celiac disease – explains Zingone, who is also a member of the Italian Society of Gastroenterology and Digestive Endoscopy (Sige) – is based on two fundamental pillars. The first is the search in the blood for specific antibodies that gluten induces in genetically predisposed people, the anti-transglutaminase IgA and antiendomysioIgA. The second, on which, even before the antibodies were discovered, the diagnosis of celiac disease was based for adults and children, is the intestinal biopsy, that is, on the removal, through an endoscopic examination, of small pieces of duodenal mucosa where it is possible to highlight the gluten damage. Already in 2012, a multi-country study by the European Society of Pediatric Nutrition showed that in children, if the anti-transglutaminase IgA antibodies are very high, it is possible to avoid the stress of a gastroscopy and proceed with the diagnosis. These studies were then confirmed over time “.
The study from the University of Sheffield – says Carolina Ciacci, full professor of Gastroenterology at the University of Salerno, also a member of SIGE – is just “the latest in a long series of studies”. One of the first was published in 2014 by a group of researchers from the “Federico II” University of Naples, “who demonstrated – adds Ciacci – that adult celiacs with a high titer of anti-transglutaminase IgA antibodies, the blood marker of celiac disease , they always have intestinal damage, and therefore in most cases, it is not necessary to demonstrate it with a biopsy “.
Not doing a gastroscopy would certainly have advantages but also some risks. “Gastroscopy – underlines Zingone – is the only way to obtain the small piece of intestinal mucosa (biopsy) that allows the pathologist to describe the intestinal damage induced by gluten. However, it is an invasive test, which in most cases requires sedation and, like all invasive tests, it is not totally risk-free. Furthermore, it is an expensive examination because apart from the endoscopic and histological investigation, the cost of a working day or study day lost by the patient must also be considered ”.
Not carrying out an intestinal biopsy, however, could “also lead to important consequences – warns Zingone – such as increasing the misdiagnosis by centers not specialized in celiac disease and the risk of losing celiac diseases already complicated at the time of diagnosis. However, the definition of a well-defined diagnostic procedure and the indications to perform the biopsy in case of specific alarm bells should reduce these risks “.
The alternative to gastroscopy is “the use of biomarkers, dosable substances in serum and other biological liquids such as saliva – again Ciacci – that allow us to know with certainty if a person is celiac. In the case of celiac disease, we have the possibility, with a blood sample, to test for the presence of anti-transglutaminase IgA and anti-endomysium antibodies. It should be noted that these tests have a very high sensitivity and specificity (reaching 98%), which means that they are absolutely specific to celiac disease because they are induced by gluten and are also very sensitive in predicting the presence of intestinal damage. Furthermore, their diagnostic accuracy increases with the detection of high levels of IgA antitransglutaminase antibodies, supported by the positivity of the anti-endomysium antibodies “.
An interdisciplinary work on celiac disease sees researchers from the University of Salerno and the University of Padua as the leader.
“The international and multicenter study – recalls Fabiana Zingone – launched in 2018 aimed to prospectively recruit all patients with suspected celiac disease, who had undergone both the serological assay for IgA antitransglutaminase antibodies and intestinal biopsy. Of all the subjects included, a blood sample was kept, to be tested in a centralized Californian laboratory, in order to have a centralized and uniform evaluation of the antibody dosage, as well as all biopsies with doubtful results, were re-evaluated by Vincenzo Villanacci, an anatomopathologist among the leading celiac disease experts in the world “. “This approach is new – confirms Carolina Ciacci – because all the studies that have been done so far have used a retrospective recruitment method, without a centralized dosage and with biopsies analyzed by different pathologists”.
The study ended at the end of 2019 but the Covid-19 emergency prevented the sending of serum samples collected in the various centers to the San Diego laboratory. “Only from mid-January 2021 did some channels open and we started sending – concludes Ciacci – We had some bureaucratic difficulties. The Italian serums are already in California, as well as the Spanish, Romanian and Israeli ones. The English samples are still missing, from the center that published the Sheffield study, the Argentine and New Zealand ones, because there are bureaucratic hitches substantially linked to the fear of the spread of the SarS-CoV-12 virus through biological samples “.