Celiac Disease
Basics
- Immune-mediated intolerance to gliadin (gluten component) causing small bowel damage.
- Presentations:
- Typical: Diarrhea, steatorrhea, weight loss, vitamin deficiencies, anemia.
- Atypical: Minor GI symptoms, extraintestinal features (anemia, elevated LFTs, neurologic symptoms, infertility).
- Silent: Positive labs/genetics but no symptoms or biopsy abnormalities.
- Also called gluten-sensitive enteropathy, celiac sprue, non-tropical sprue.
Epidemiology
- Incidence: 1-13/100,000 worldwide; 6.5/100,000 in the US.
- Prevalence: ~0.7% in the US; ~1% worldwide.
- More common in females (3:2).
- Predominantly affects Northern European ancestry.
Etiology & Pathophysiology
- Immune reaction to gliadin modified by tissue transglutaminase (tTG).
- Causes villous atrophy and crypt hyperplasia, leading to malabsorption.
- Strong genetic association with HLA-DQ2/DQ8.
- Risk of enteropathy-associated T-cell lymphoma increased.
Risk Factors
- First-degree relatives (5-20% risk).
- Autoimmune conditions (type 1 diabetes, autoimmune thyroiditis).
- Genetic syndromes (Down syndrome, Turner syndrome).
- Pediatric risk: Down syndrome, IgA deficiency, autoimmune thyroid disease.
Common Associations
- Dermatitis herpetiformis (85% have celiac disease).
- Secondary lactase deficiency.
- Osteopenia/osteoporosis.
- Type 1 diabetes (3-10% prevalence).
- Iron deficiency anemia (10-15% prevalence).
- Autoimmune liver disease, hyposplenism, oral aphthae, restless leg syndrome.
Diagnosis
History
- GI: Diarrhea, steatorrhea, abdominal pain, nausea, vomiting, flatulence, weight loss.
- Systemic: Fatigue, muscle cramps, bone/joint pain, paresthesias, delayed puberty.
- Children: Failure to thrive, short stature, chronic fatigue.
Physical Exam
- May be normal or show:
- Pallor, aphthous stomatitis, glossitis, angular cheilitis.
- Dermatitis herpetiformis rash.
- Abdominal distension.
Differential Diagnosis
- Nonceliac gluten sensitivity.
- Gluten allergy.
- Lactose intolerance, SIBO.
- Crohn disease, Whipple disease.
- Tropical sprue, lymphoma.
- Microscopic colitis, autoimmune enteropathy.
Diagnostic Tests
- Serology:
- IgA anti-tTG antibody (sensitivity 95-98%, specificity 95%) on gluten-containing diet.
- Total serum IgA to detect IgA deficiency.
- Anti-DGP IgA and IgG if IgA deficient.
- Histology:
- Duodenal biopsy with villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis.
- Biopsy of both duodenal bulb and distal duodenum recommended.
- Other:
- Bone mineral density at diagnosis and follow-up.
- HLA DQ2/DQ8 testing in select cases.
Treatment
- Lifelong gluten-free diet (GFD): avoid wheat, barley, rye.
- Safe grains: rice, corn, oats (uncontaminated), quinoa, amaranth.
- Nutritional supplementation if deficiencies present.
- Second line: steroids or immunomodulators for refractory disease.
Issues for Referral
- Dietitian consultation.
- Refractory disease management.
- Pediatric patients with positive serology.
Follow-up
- Monitor symptoms and serologies (anti-tTG IgA or DGP antibodies).
- Repeat biopsy if no clinical improvement.
- Screen for osteoporosis and treat if indicated.
Patient Education
- Gluten identification in food and products.
- Importance of strict GFD adherence.
- Support groups and resources:
- Celiac Disease Foundation (https://www.celiac.org/)
- National Celiac Association (https://nationalceliac.org/)
- Beyond Celiac (https://www.beyondceliac.org/)
Prognosis
- Good if compliant with GFD.
- Symptom improvement within 7 days; resolution within 4-6 weeks.
Complications
- Increased risk of lymphoma and adenocarcinoma if untreated.
- Nutritional deficiencies.
- Osteoporosis.
- Refractory celiac disease (~1-2%).
Clinical Pearls
- Always test total IgA with anti-tTG to avoid false negatives.
- Diagnosis requires biopsy confirmation on a gluten-containing diet.
- Screen high-risk populations (first-degree relatives, type 1 diabetes).
References:
- Husby S, Murray JA, Katzka DA. AGA clinical practice update on diagnosis and monitoring of celiac disease—changing utility of serology and histologic measures: expert review. Gastroenterology. 2019;156(4):885-889.
- McDermid JM, Almond MA, Roberts KM, et al. Celiac disease: an Academy of Nutrition and Dietetics evidence-based nutrition practice guideline. J Acad Nutr Diet. 2023;123(12):1793-1807.e4.
- Bingham SM, Bates MD. Pediatric celiac disease: a review for non-gastroenterologists. Curr Probl Pediatr Adolesc Health Care. 2020;50(5):100786.