Delayed presentation of seropositivity in pre-existent coeliac disease in patients with Type 1 diabetes mellitus: a possible co-occurrence?

Objective: The co-occurrence of coeliac disease (CD) and type 1 diabetes mellitus (T1DM) is well described and is mainly explained by sharing of common pathogenic mechanisms, such as common high-risk human lymphocyte antigen (HLA) genotypes (DR-DQ).
Patients and Methods: We describe a 12-year-old female patient with T1DM who presented with prolonged and severe glucose dysregulation. Extensive investigations, including coeliac screen, were negative.
Results: 3 years after glucose dysregulation manifested, coeliac screen testing was positive and coeliac disease was confirmed with bowel biopsy. Compliance to a gluten-free diet resulted in improvement of glucose control and seronegativity 9 months post-diagnosis.
Conclusions: This is the first case report describing delayed seropositivity of CD and suggests that CD enteropathy may precede positive serology and could cause severe glucose dysregulation in patients with T1DM.