What rheumatic manifestations have been described in patients with celiac disease (CeD; gluten sensitive enteropathy)?
CeD is an enteropathy resulting from an autoimmune reaction to wheat gluten and gliadin by T lymphocytes in the gut in genetically predisposed individuals. It is primarily seen in white patients and is associated with HLA-DQ2 or HLA-DQ8, usually in linkage with HLA-DR3 . Tissue transglutaminase (tTG) is the major autoantigen. Dietary gluten is partly digested by gastric enzymes to peptides including gliadin that is deaminated by tTG, which increases its immunogenicity. This immunogenic gliadin peptide is presented in the context of HLA-DQ2 or DQ8 to CD4 + T cells, resulting in interferon γ release and inflammation, altered gut permeability, and villous atrophy. The most frequent rheumatic manifestations include:
- • Symmetric polyarthritis (4% to 26%) involving predominantly large joints (knees and ankles more frequently than hips and shoulders) occurs. Oligoarthritis and sacroiliitis can also occur. Importantly, the arthritis may precede enteropathic symptoms in 50% of cases.
- • Osteomalacia is caused by steatorrhea from severe enteropathy causing vitamin D deficiency
- • Dermatitis herpetiformis
CeD can be screened for by testing for immunoglobulin A antibodies against tTG (95% sensitivity/90% specificity) and confirmed by endoscopy with small bowel biopsy. The rheumatic manifestations can respond dramatically to a gluten-free diet but not always.