CEL antibodies are autoantibodies targeting carboxyl ester lipase (CEL), a digestive enzyme encoded by the CEL gene. Primarily expressed in the pancreas and mammary glands, CEL hydrolyzes cholesterol esters, triglycerides, and lipid-soluble vitamins, playing a role in nutrient absorption. The discovery of CEL antibodies emerged from studies on autoimmune pancreatitis (AIP) and type 1 diabetes (T1D), where they were identified as potential biomarkers.
In T1D, CEL antibodies are detected in a subset of patients, often alongside classic markers like GAD65 or IA-2 antibodies. Their presence may reflect autoimmune targeting of pancreatic exocrine cells, suggesting a link between exocrine and endocrine dysfunction in diabetes pathogenesis. In AIP, CEL antibodies are associated with type 1 AIP, a IgG4-related disease, though their diagnostic specificity remains under investigation.
Structurally, the CEL protein contains a variable number of tandem repeats (VNTR) in its mucin-like domain, and genetic variations here may influence immunogenicity. While commercial ELISA kits are available for detection, CEL antibodies are not yet routinely used in clinical practice due to variable prevalence (5–15% in T1D cohorts) and overlapping associations with other conditions like chronic pancreatitis or celiac disease. Current research focuses on clarifying their pathogenic role, improving assay standardization, and exploring prognostic value in pancreatic disorders.