Cause:Ingestion of gluten, a protein in rye, barley, wheat (not oats, but often cross-contaminated w others). Genetic component, HLA-DQ2 or -DQ8 linked and are also diabetes linked
Pathophys:
T-cell- and IgA-mediated immune response to gluten in genetically predisposed pts. Wide variety of clinical manifestations from classic malabsorption to atypical w fevers and gi sx, to asx
Iron deficiency occurs both from malabsorption as well as occult gi bleeding (Nejm 1996;334:1163)
Associated with dermatitis herpetiformis (Dermatitis Herpetiformis), Hashimoto's thyroiditis, and insulin-dependent diabetes (Nejm 1983;308:816). Seen in 1/300 Caucasians, 1/100 in Finland (Nejm 2003;348:2517), not blacks or Asians. Timing and dose of gluten exposure at age 4-7 mo may induce the disease
Sx:Onset at any age. Malabsorptive sx including diarrhea, flatulence, weight loss, and fatigue
Si:Of malabsorption; iron or folate deficiency anemias; osteoporosis and fractures; peripheral neuropathies, ataxia, bad teeth
Infertility; malabsorption; ulceration, perforation; increased incidence of foregut tumors of esophagus, pharynx and stomach, and lymphomas r/o IgA deficiency
Lab:
Path:endoscopic biopsy of duodenum for dx shows villous atrophy and crypt hyperplasia which improves on gluten-free diet
Serol:Anti-endomysial antibodies, 90+% sens, 98+% specif; or IgA/IgG tissue transglutaminase antibodies (tTG) 90% sens, 98% specif (Jama 2010;303:1738; Nejm 2003;348:2517); but do not obviate need for bx (Scand J Gastroenterol 1994;29:148); both falsely neg on diet; antigliadin IgA and IgG antibodies too insensitive to use now; selective IgA deficiency common and can mimic sprue.
Genetic:HLA testing for DQ2 (95% sens, 70% specific) and DQ8; if both tests neg, 99% sens/specif; can do while on diet
Hem:incr protime; mixed anemias
Chem:hypocalcemia, incr alk phosphatase; abnormal LFT
Xray:Small bowel follow through
Rx:
Patient info: www.celiac.com
Gluten-free and initially; or later if not improved, lactose-free diet; can resume milk products in 3-6 mo once enteropathy improves; rice, corn (maize), and oats ok (Nejm 1995;333:1033); if fails, consider lactose deficiency or giardia infection coincident with disease; 70% improve in <14 d; confirm dx with biopsy pror to d/c gluten (S. Crowe, ACP Ann Mtng 2011)