Having a prior ASD was not associated with celiac disease (odds ratio 0.93; 95% CI: 0.51-1.68) or inflammation (OR, 1.03; 95% CI: 0.40-2.64), but was associated with an increased risk of having normal mucosa with a positive celiac disease serologic test result (OR, 4.57; 95% CI: 1.58-13.22), Jonas F. Ludvigsson, MD, PhD, from the Karolinska University Hospital in Stockholm, and colleagues reported in JAMA Psychiatry.
Although previous case reports have suggested a potential link between the two conditions, results from larger studies have been contradictory. To better understand the association between celiac disease and ASDs, Ludvigsson and colleagues analyzed data from 28 Swedish biopsy registers.
They identified 26,995 people with celiac disease, 12,304 individuals with inflammation, and 3,719 individuals with normal mucosa but positive celiac disease serologic test results, and compared them with 213,208 age- and sex-matched controls.
“Although this study found no association between celiac disease or inflammation and earlier ASDs, there was a markedly increased risk of ASDs in individuals with normal mucosa but a positive celiac disease serologic test result,” the researchers wrote.
Among individuals who did not have an ASD diagnosis at the time of biopsy, celiac disease (HR 1.39; 95% CI, 1.13-1.71) and inflammation (HR 2.01; 95% CI, 1.29-3.13) were both associated with moderate excess risks of developing an ASD later. This risk was even higher in individuals with normal mucosa, but a positive celiac disease serologic test result (HR 3.09; 95% CI, 1.99-4.80).
The researchers note that the mechanism of association with a positive celiac disease antibody is not clear. They speculate the association could be due to increased mucosal permeability in some patients with celiac disease or in individuals with elevated levels of some antibodies.
“Our data are consistent with earlier research in that we found no convincing evidence that celiac disease is associated with ASD except for a small excess risk noted after celiac disease diagnosis,” they added.