Intestinal malabsorption

Table 8. Diagnostic value of small intestinal biopsy

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Disease Histological features

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Pathognomonic in diffuse disease

- Abetalipoproteinemia Normal villi, lipid vacuoles in enterocytes, no cellular infiltrate

- Agammaglobulinemia/ Villi atrophic or absent, lymphocytic

hypogammaglobulinemia infiltration, few plasma cells, often associated with giardiasis

- Whipple´s disease Villi often irregular, lamina propria contains

PAS-positive macrophages containing the bacilli

- Microvillus inclusion Nearly no microvilli, crypts defective, multiple secretory

disease granules, intracytoplasmatic inclusion bodies are characteristic

- Tufting enteropathy Partial villus atrophy, crypt hyperplasia, no inflammatory cells,

typical focal epithelial tufts consisting of patched enterocytes with

apical round protrusions of plasma membrane

Helpful, but not diagnostic by itself

- AIDS enteropathy Alternating villous atrophy with crypt hyperplasia, mild lymphocytic

infiltrate, often associated parasitosis: Cryptosporidia, Microsporidia,

Giardia lamblia; PAS- positive macrophages in lamina propria,

containing Mycobacterium avium intracellulare

- Amyloidosis Normal mucosa, Congo red-positive deposits in blood vessels and

lamina muscularis mucosae

- Crohn´s disease Mucosal appearance varies from normal to severe ulcerations,

inflammatory infiltrate, granuloma

- Eosinophilic enteritis Villi usually normal, eosinophillic infiltrate in lamina propria

- Giardiasis Mucosa normal or with various degrees of atrophy;

varying inflammation in lamina propria; sickle-shaped

organisms on the epithelial surface

- Intestinal Deformed villi, dilated lymphatics

lymphangiectasia

- Intestinal lymphoma Infiltration of submucosa and lamina propria with malignant

lymphocytes; often also villous atrophy

- Mastocytosis Villi normal or atrophic; lamina propria infiltrated with mast cells,

eosinophils and neutrophils

Abnormal, but not diagnostic

- Celiac disease Villi atrophic or absent; hyperplastic & elongated crypts; chronic

inflammatory infiltrate in lamina propria; epithelial surface infiltrated

with lymphocytes

- Autoimmune enteropathy Like in celiac disease, but no AMA & EMA antibodies

- Collagenous sprue Subepithelial collagen deposits; villous atrophy of various degree

- Tropical sprue Villous atrophy; epithelial damage and degree of atrophy less severe

than in celiac disease

- Vitamin B₁₂ & folic Short villi, damaged epithelial cells, decreased

acid deficiency mitosis rate in crypts; megaloblastic crypt cells

- Bacterial overgrowth Villi may be damaged; crypt hyperplasia; chronic inflammation of

lamina propria

- Radiation enteritis Acute lesions: deformed villi and megaloblastic crypt cells with

reduced mitosis rate. Chronic lesions: fibroblasts and intimal cells

proliferation of blood vessels

- Drugs (colchicin, Shortened villi, abnormal epithelial cells

neomycin, cytostatics)

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Table 9. Diseases resulting in malabsorption syndrome

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Maldigestion due to deficiency or inactivation of pancreatic enzymes

· Chronic pancreatitis

· Surgical resection of the pancreas

· Pancreatic cancer

· Cystic fibrosis

· Zollinger-Ellison syndrome

Maldigestion due to impaired luminal bile acid concentration

· Obstructive jaundice

· Intrahepatic cholestasis

· Primary biliary cirrhosis

· Primary sclerosing cholangitis

· Small intestinal bacterial overgrowth (blind loop syndrome, fistulas, strictures, diverticula, afferent loop syndrome, motility disorders in scleroderma and diabetic gastroenteropathy)

· Ileal resection (decompensated bile acid loss)

· Crohn´s disease of the ileum

Maldigestion/malabsorption due to small intestinal diseases

1. Primary malabsorption: congenital diseases with selective defect of single functions of epithelial cells (disorders of the brush border membrane)

· Lactose intolerance

· Sucrose-isomaltose intolerance

· Trehalose intolerance

· Enterokinase deficiency

· Glucose-galactose intolerance

· Hartnup´s disease

· Cystinuria

· Tryptophan malabsorption (“blue diaper disease”)

· Methionine malabsorption (Oasthouse syndrome)

· Vitamin B₁₂ malabsorption (congenital defect of intrinsic factor or vitamin B₁₂ receptor)

· Microvillus inclusion disease

· Tufting enteropathy

2. Secondary malabsorption: acquired small intestinal diseases

· Celiac disease

· Autoimmune enteropathy

· Dermatitis herpetiformis

· Tropical sprue

· Whipple´s disease

· Primary intestinal lymphoma

· Hypogammaglobulinemia

· Selective IgA deficiency

· Eosinophilic gastroenteritis

· Mastocytosis

· Amyloidosis

· Parasitoses (giardiasis, strongyloidosis, ascaridosis, ancylostomiasis)

· HIV enteropathy with wasting syndrome

· Tuberculosis

· Lymphogranulomatosis

· Kwashiorkor

· Short bowel syndrome

· Intestinal ischemia

· Radiation enteritis

Various disorders of digestion and absorption

· Postgastrectomy syndrome

· Postvagotomy syndrome

· Diabetic gastroenteropathy

· Endocrinopathies (hyper- and hypothyroidism, hyper- and hypoparathyroidism, Addison´s

disease, medullary carcinoma of the thyroid)

· Glucagonoma, gastrinoma, VIPoma

· Scleroderma

· Pernicious anemia

Drug-induced malabsorption

· Cholestyramine

· Laxatives

· Colchicin

· Antineoplastic drugs

· Neomycin

· p-aminosalicylic acid (PAS)

· Biguanides

· Acarbose and miglitol

· Lactulose, sorbitol, fructose

· Non-steroidal antiinflammatory drugs (NSAID)

· Alcohol

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Table 10. Lactase deficiency - ethnic differences

(modified from reference [5])

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Population Incidence (%)

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Northern European 5-15

Mediterranean 60-85

African 85-100

America (African-American) 45-80

America (Caucasian) 10-25

American Indian 50-95

Hispanic 40-75

Asian 90-100

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Table 11. Carbohydrate malabsorption

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Malabsorption of Disease

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Starch Congenital alpha-amylase deficiency not known

Secondary alpha-amylase deficiency in exocrine

pancreatic insufficiency

“Physiological” starch malabsorption

Therapy with alpha-glucosidase inhibitors

(acarbose)

Lactose Congenital lactase deficiency

Transient lactase deficiency in premature infants

Acquired lactase deficiency

Secondary lactase deficiency in small intestinal

disease

Trehalose Congenital trehalase deficiency

Secondary trehalase deficiency in small

intestinal disease

Sucrose Congenital sucrase-isomaltase deficiency

Secondary sucrase-isomaltase deficiency in small intestinal disease

Therapy with alpha-glucosidase inhibitors

Maltose, maltotriose Congenital maltase deficiency not known

Alpha-maltodextrins Secondary maltase deficiency in small intestinal disease

Therapy with alpha-glucosidase inhibitors

Glucose, galactose Congenital glucose-galactose malabsorption

Secondary malabsorption of glucose and galactose

in small intestinal disease, bacterial

overgrowth, or intestinal hypermotility

Fructose Congenital transport defect not known

“Physiological” malabsorption if > 30-50 g/day

are ingested

Secondary malabsorption of fructose in small

intestinal disease, bacterial overgrowth, or

intestinal hypermotility

D-xylose Congenital transport defect not known

Secondary malabsorption in small intestinal

disease, bacterial overgrowth, or intestinal

hypermotility

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