Pernicious anemia: New insights from a gastroenterological point of view

Table 1 H pylori infection and related gastric histological features in a series of PA patients n (%)

First author/publication year[Ref.]	No. of patients	Mean age (yr)	F:M ratio	Geographical origin	Severe body atrophy	Body intestinal metaplasia	Antral inflammation	Antral atrophic gastritis	Positive H pylori histology	Positive H pylori serology
Fong TL/1991[22]	28	59	1.2:0.8	USA1	ND	18 (64)	14 (50)	2 (7)	3 (11)	2 (7)
Haruma K/1995[23]	24	65	0.9:1.1	Japan	24 (100)	18 (75)	22 (92)	17 (71)	0 (0)	0 (0)
Sari R/2000[24]	30	60	0.9:1.1	Turkey	15 (50)	13 (43)	14 (47)	8 (27)	12 (30)	ND
Annibale B/2000[10]	81	62	0.9:1.1	Italy	56 (69)	70 (86)	43 (53)	27 (30)	8 (10)	41 (51)
Annibale B/2009[unpublished data]	177	60	1:1	Italy	124 (70)	161 (91)	81 (46)	40 (23)	19 (11)	61 (34)

¹Hispanic, n = 20; white, n = 3; black, n = 5. ND: Not done.

Table 2 Differential diagnosis of PA: other causes of macrocytic anemia and cobalamin deficiency

Other causes of macrocytic anemia	Other causes of cobalamin deficiency
Folate deficiency due to decreased intake, impaired absorption or increased requirements	Gastric causes of impaired absorption/mal-digestion:
Drugs (e.g. methotrexate, azathioprine, 6-mercaptopurine, acyclovir, 5-fluorouracil, phenobarbital)	Gastrectomy
Accelerated erythropoiesis: hemolytic anemia, response to hemorrhage	Corpus-predominant H pylori gastritis
Liver disease (alcoholic, advance cirrhosis, poor dietary intake)	Long-term proton pump inhibitor therapy
Hypoplastic anemia, myelodysplastic syndrome	Intestinal causes of impaired absorption:
Chronic obstructive pulmonary disease	Ileal disease or resection
	Blind loop syndrome
	Fish tapeworm
	Severe pancreatic insufficiency
	Decreased intake due to vegetarianism