Immunoglobulin a Deficiency in Coeliac Disease: A Scoping Review

ABSTRACT

Coeliac disease (CeD) and immunoglobulin A deficiency (IgAD) frequently co‐occur and share a genetic background within the HLA‐DQ2 region. Although this has been known for decades, the underlying mechanisms linking the two conditions remain unclear. We conducted a scoping review to evaluate the prevalence, clinical characteristics, diagnostic challenges and histopathological features of IgAD in patients with CeD. Thirty‐one studies published between 1985 and 2024 were included. IgAD was more prevalent among individuals with CeD, 1.4%–4.8% than in the general population, and CeD occurred in 5.9%–14.1% of patients with IgAD. Most patients presented with gastrointestinal symptoms, although selection bias was common. IgG‐based serology remains essential for diagnosis and monitoring, but its reliability during follow‐up is limited by the slow decline of antibodies. Histological findings indicate compensatory IgM and IgG responses and persistent mucosal immune activation. Improved strategies for diagnosis and long‐term monitoring of patients with both conditions are warranted.