Pernicious anaemia
From Ganfyd
Pernicious anaemia is an autoimmune gastritis that causes reduced intrinsic factor and gastric acid secretion. The upshot of this is that it leads to a megaloblastic anaemia because of vitamin B12 deficiency. It is not the sole cause of B12 deficiency, and indeed in the elderly atrophic gastritis is far more common[1]. Other causes of malabsorption should be considered, such as coeliac disease and drugs such as metformin.
Web Resources for Pernicious anaemia
Relevant Clinical Literature
UK Guidance
Other Wikis
Medpedia on Pernicious anaemia (Less technical, good quality control)
Wikipedia on Pernicious anaemia (Less technical, ? quality control)
Contents |
Associations
- Other organ-specific autoimmune conditions
- Early greying of hair
- Blue eyes
- Blood group A
- Family history of pernicious anaemia / autoimmune disease
- 2-3 fold increase in carcinoma of stomach
- The excess risk is highest in first year after diagnosis justifying possibly initial monitoring
- Female 1.6x male
- Peak age 60years
Laboratory findings
- Macrocytic anaemia
- Antibodies to intrinsic factor (IF) and / or gastric parietal cells
- B12 deficiency
- Schilling's test (saved for equivocal cases due to radioactivity)
- radioactive B12 ingested
- urinary excretion after 1mg 'flushing dose' as marker of intestinal absorption
- will be positive when intrinsic factor given at same time as B12
Treatment
- 1mg hydroxocobalamin IM
- every 2-3 days for 6 injections
- 1 every 3 months for life
Footnote
Has been described as Addison's anaemia after Thomas Addison.
References
- ↑ den Elzen WP, van der Weele GM, Gussekloo J, Westendorp RG, Assendelft WJ. Subnormal vitamin B12 concentrations and anaemia in older people: a systematic review. BMC geriatrics. 2010 Jun 23; 10(1):42.(Epub ahead of print) (Link to article – subscription may be required.)
