Testing overview 

  • testing recommended in patients with

    • suspected malabsorption 

    • symptoms, signs, or laboratory evidence consistent with CD especially if first-degree relative with CD or type 1 diabetes

    • unexplained elevated alpha-1 antitrypsin (AAT) levels 

    • children and adolescents with unexplained gastrointestinal symptoms, failure to thrive, delayed puberty, amenorrhea, iron deficiency anemia, or chronic fatigue

  • consider screening asymptomatic patients for

    • first-degree relatives of patients with confirmed CD

    • children and adolescents with increased risk

      • diagnosis of type 1 diabetes; family history of CD; growth failure, failure to thrive, or weight loss; diarrhea, flatulence, abdominal pain, or signs of malabsorption; frequent unexplained hypoglycemia; deterioration in glycemic control

  • serology testing recommended early in evaluation process (gluten still included in diet)  

    • IgA anti-tissue transglutaminase antibody (tTG) is preferred single serologic test in patients >2 years old 

    • if high risk of CD and possible IgA deficiency, measure total IgA or add immunoglobulin G (IgG)-based testing (for example, IgG deamidated gliadin peptides [DGPs]) 

    • in children <2 years old, include IgA tTG test, and IgA- and IgG-DGPs 

    • if IgA tTG >10 times upper limit of normal, consider testing endomysial antibody and HLA-DQ serotyping to diagnose CD without endoscopy and biopsy

  • HLA-DQ2 or DQ8 genotyping may rule out CD if other testing indeterminate 

  • upper endoscopy with small-bowel biopsy recommended to confirm diagnosis in patients with suspected CD; obtain multiple biopsies of duodenum including 1-2 of bulb and ≥ 4 of distal duodenum

  • consider gluten challenge test if unable to establish diagnosis in patient on gluten-free diet 

    • if symptoms develop and patient unable to tolerate in 2 weeks, proceed to biopsy

    • perform serology testing after 6 weeks

  • consider testing for nutritional deficiencies (hemoglobin, iron, folate, vitamin B12, calcium, and vitamin D)

Treatment 

  • lifelong gluten-free diet recommended with avoidance of proteins from wheat, barley, and rye 

    • all initial serology testing and biopsies should be performed before starting gluten restriction

    • avoid gluten in foods and medications; refer to registered dietitian experienced in CD 

    • gluten-free diet may reduce symptoms in patients with positive endomysial antibodies and mild enteropathy 

    • amount of gluten that causes symptoms varies among patients with CD 

    • strict adherence to gluten-free diet for >5 years might reduce risk for non-Hodgkin lymphoma 

    • oats and wheat starch-based gluten-free products in diet appear safe  

  • treat nutritional deficiencies including iron, folate, vitamin B12, and vitamin D

  • in patients with newly diagnosed CD who also have anxiety and depression, adding psychological support when starting gluten-free diet associated with lower rates of depression after 6 months 

  • consider medications in refractory CD (anecdotal use) such as

    • pancreatic enzyme

    • corticosteroids

    • immunosuppressants

  • monitor for new or residual symptoms, gluten-free diet adherence, and  complications

  • follow-up for children to confirm normal growth and development; (consider BMD testing for osteoporosis)

  • introduce oats (kilned [regular] and unkilned) into diet and monitor for adverse reaction 

  • Dietary supplements 

    • select B vitamins may be associated with reduced anxiety and depressed moods in adults on strict gluten-free diet 

    • L-carnitine might reduce fatigue in adults 

  • Immunosuppressants 

    • often considered necessary, but mostly anecdotal experience

  • Autologous hematopoietic stem cell transplantation 

    • limited evidence in refractory CD 

Consultation and referral 

  • ACG 2013 recommends referral to registered dietitian experienced in CD for full nutritional assessment and gluten-free diet education  

  • referral to support group and membership in a local celiac society may promote compliance with gluten-free diet

Complications 

  • nutritional 

    • iron deficiency anemia

    • vitamin D deficiency 

    • malabsorption of micronutrients including fat-soluble vitamins, iron, and possibly vitamin B12 and folic acid

  • reproductive 

    • reduced fertility in women for 2 years before diagnosis 

    • recurrent spontaneous abortions, intrauterine growth restriction, preterm birth, and stillbirth

  • developmental complications

    • growth failure/short stature

    • failure to thrive 

    • delayed puberty and menarche

  • low bone mineral density 

Prognosis 

  • increased all-cause mortality and non-Hodgkin lymphoma 

  • increased risk of 

    • end-stage renal disease

    • lymphoproliferative malignancy 

Prevention 

  • Timing of gluten introduction 
    • delayed introduction of gluten-containing foods to >age 6 months may increase risk of CD compared to introduction at age 4 to 6 months
    • timing of gluten introduction in at-risk infants does not appear to affect risk of CD at age 3 to 5 years 
  • Breastfeeding 
    • inconsistent evidence regarding breastfeeding and reduced risk of CD. 

Alan Drabkin, MD, is a senior clinical writer for DynaMed, a database of comprehensive updated summaries covering more than 3,200 clinical topics, and assistant clinical professor of population medicine at Harvard Medical School.


This article originally appeared on Cancer Therapy Advisor