MALABSORPTION SYNDROMES

(Can cause diarrhea, steatorrhea, weight loss, weakness)

Celiac Sprue: Autoimmune-mediated intolerance to gliadin (wheat, rye, and barley), leading to steatorrhea. Associated with people of northern European descent. Finding includes antigliadin antibodies, blunting of villi, and lymphocytes in the lamina propria.

Decrease mucosal absorption that primarily affects jejunum. Serum levels of tissue transglutaminase are used for screening. Associated with dermatitis herpetiformis. Moderately increases risk of malignancy, most often T-cell lymphoma.

Tropical Sprue: probably infectious; responds to antibiotics. Similar to Celiac Sprue, but can affect entire small bowel.

Whipple’s disease: Infection with Tropheryma whippelii (gram positive); PAS-positive macrophages in intestinal lamina propria, mesenteric nodes. Arthralgias, cardiac and neurologic symptoms are common. Most often occurs in older man.

Disaccharidase deficiency: Most common is lactase deficiency →milk intolerance. Normal appearing villi. Osmotic diarrhea. Since lactase is located at tips of intestinal villi, self-limited lactase deficiency can occur following injury (viral diarrhea).

Pancreatic Insufficiency: Due to cystic fibrosis, obstructing cancer, and chronic pancreatitis. Causes malabsorption of fat and fat-soluble vitamins (A, D, E, and K).

A beta-lipoproteinemia: ↓ synthesis of apo B →inability to generated chylomicrones→↓ secretion of cholesterol, VLDL into bloodstream → fat accumulation in enterocytes. Presents in early childhood with malabsorption and neurologic manifestation.