What autoimmune conditions are associated with celiac disease?

Celiac Disease Associated Conditions

Based on the provided options, celiac disease is definitively associated with: (b) Sjögren's syndrome, (d) insulin-dependent diabetes mellitus, and (e) primary biliary cholangitis. Option (c) appears to refer to dermatitis herpetiformis (not "herpes dermatitis"), which is also strongly associated with celiac disease. Type II autoimmune pancreatitis has insufficient evidence for a clear association.

Confirmed Associations from Guidelines

Sjögren's Syndrome (Option b)

• The American Gastroenterological Association explicitly identifies Sjögren's syndrome as a condition where celiac disease testing should be selectively considered during medical evaluation, particularly when symptoms compatible with celiac disease are present 1.
• The increased prevalence is explained by shared HLA susceptibility genes (DQ2 and DQ8) 1.
• A 2024 Gastroenterology review recommends CeD screening in patients with Sjögren's syndrome due to high prevalence 2.

Insulin-Dependent (Type 1) Diabetes Mellitus (Option d)

• The AGA position statement recommends selective testing for celiac disease in patients with type 1 diabetes mellitus, especially when symptoms suggesting celiac disease are present 1.
• The prevalence of celiac disease in type 1 diabetes patients ranges from 2-5% in adults and 3-8% in children 3.
• Between 10-30% of celiac disease patients are type 1 diabetes antibody positive, while 5-7% of type 1 diabetes patients test positive for celiac disease 4.
• The genetic link is primarily through shared HLA-DQ2 and HLA-DQ8 antigens 5, 4.

Primary Biliary Cholangitis/Cirrhosis (Option e)

• The AGA explicitly recommends testing for celiac disease in patients with primary biliary cirrhosis, with prevalence ranging from 0% to 6.0% 1.
• The 2024 Gastroenterology review specifically lists primary biliary cholangitis as a condition warranting celiac disease screening 2.
• Case reports demonstrate that gluten-free diet can normalize liver biochemistries in patients with both conditions, potentially avoiding immunosuppressive therapy 6.

Dermatitis Herpetiformis (Option c - if this is what was meant)

• The 2024 Gastroenterology review explicitly recommends celiac disease screening in patients with dermatitis herpetiformis 2.
• This is a well-established cutaneous manifestation of celiac disease, though the question lists "herpes dermatitis" which may be a translation or terminology issue.

Insufficient Evidence

Type II Autoimmune Pancreatitis (Option a)

• The 2024 review mentions "idiopathic pancreatitis" as warranting screening, but does not specifically address type II autoimmune pancreatitis 2.
• The AGA guidelines do not mention autoimmune pancreatitis in their list of associated conditions 1.
• This association lacks sufficient guideline-level evidence to be considered definitively established.

Clinical Algorithm for Testing

When to screen for celiac disease in these conditions:

1. Mandatory screening contexts (per AGA high-risk recommendations) 1:

   • Primary biliary cholangitis patients with unexplained symptoms
   • Type 1 diabetes patients, especially with any GI symptoms, unexplained anemia, or growth issues

2. Selective screening contexts (test when compatible symptoms present) 1:

   • Sjögren's syndrome with fatigue, diarrhea, weight loss, or anemia
   • Any of these conditions with unexplained iron deficiency, osteoporosis, or elevated transaminases

3. Testing approach 3:

   • IgA tissue transglutaminase (tTG) with total IgA level
   • If IgA deficient, use IgG-based tests
   • Confirm positive serology with duodenal biopsy (≥6 specimens)
   • Critical: Test BEFORE initiating gluten-free diet 7

Important Clinical Pitfalls

• Do not assume normal weight or obesity excludes celiac disease - many patients present without classic malabsorptive symptoms 3.
• Measure total IgA simultaneously with tTG-IgA - IgA deficiency occurs 10-15 times more frequently in celiac patients and causes false-negative results 3.
• In patients with advanced liver disease, tTG antibodies may be falsely elevated, particularly with older guinea pig-based assays 1, 8.
• The shared HLA-DQ2/DQ8 genetic background explains clustering of these autoimmune conditions in the same patients 1, 5, 4.