eMedicine Specialties > Hematology > Red Blood Cells and Disorders

Pernicious Anemia: Multimedia

Author: Marcel E Conrad, MD, (Retired) Distinguished Professor of Medicine, University of South Alabama
Contributor Information and Disclosures

Updated: Aug 26, 2009

Multimedia

Pernicious anemia. The structure of cyanocobalami...Media file 1: Pernicious anemia. The structure of cyanocobalamin is depicted. The cyanide (Cn) is in green. Other forms of cobalamin (Cbl) include hydroxocobalamin (OHCbl), methylcobalamin (MeCbl), and deoxyadenosylcobalamin (AdoCbl). In these forms, the beta-group is substituted for Cn. The corrin ring with a central cobalt atom is shown in red and the benzimidazole unit in blue. The corrin ring has 4 pyrroles, which bind to the cobalt atom. The fifth substituent is a derivative of dimethylbenzimidazole. The sixth substituent can be Cn, CC3, hydroxycorticosteroid (OH), or deoxyadenosyl.

The cobalt atom can be in a +1, +2, or +3 oxidation state. In hydroxocobalamin, it is in the +3 state. The cobalt atom is reduced in a nicotinamide adenine dinucleotide (NADH)–dependent reaction to yield the active coenzyme. It catalyzes 2 types of reactions, which involve either rearrangements (conversion of l methylmalonyl coenzyme A [CoA] to succinyl CoA) or methylation (synthesis of methionine [see Image 2]).
Pernicious anemia. The structure of cyanocobalami...

Pernicious anemia. The structure of cyanocobalamin is depicted. The cyanide (Cn) is in green. Other forms of cobalamin (Cbl) include hydroxocobalamin (OHCbl), methylcobalamin (MeCbl), and deoxyadenosylcobalamin (AdoCbl). In these forms, the beta-group is substituted for Cn. The corrin ring with a central cobalt atom is shown in red and the benzimidazole unit in blue. The corrin ring has 4 pyrroles, which bind to the cobalt atom. The fifth substituent is a derivative of dimethylbenzimidazole. The sixth substituent can be Cn, CC3, hydroxycorticosteroid (OH), or deoxyadenosyl.

The cobalt atom can be in a +1, +2, or +3 oxidation state. In hydroxocobalamin, it is in the +3 state. The cobalt atom is reduced in a nicotinamide adenine dinucleotide (NADH)–dependent reaction to yield the active coenzyme. It catalyzes 2 types of reactions, which involve either rearrangements (conversion of l methylmalonyl coenzyme A [CoA] to succinyl CoA) or methylation (synthesis of methionine [see Image 2]).

Pernicious anemia. Inherited disorders of cobalam...Media file 2: Pernicious anemia. Inherited disorders of cobalamin (Cbl) metabolism are depicted. The numbers and letters correspond to the sites at which abnormalities have been identified, as follows: (1) absence of intrinsic factor (IF); (2) abnormal Cbl intestinal adsorption; and (3) abnormal transcobalamin II (TC II), (a) mitochondrial Cbl reduction (Cbl A), (b) cobalamin adenosyl transferase (Cbl B), (c and d) cytosolic Cbl metabolism (Cbl C and D), (e and g) methyl transferase Cbl utilization (Cbl E and G), and (f) lysosomal Cbl efflux (Cbl F).
Pernicious anemia. Inherited disorders of cobalam...

Pernicious anemia. Inherited disorders of cobalamin (Cbl) metabolism are depicted. The numbers and letters correspond to the sites at which abnormalities have been identified, as follows: (1) absence of intrinsic factor (IF); (2) abnormal Cbl intestinal adsorption; and (3) abnormal transcobalamin II (TC II), (a) mitochondrial Cbl reduction (Cbl A), (b) cobalamin adenosyl transferase (Cbl B), (c and d) cytosolic Cbl metabolism (Cbl C and D), (e and g) methyl transferase Cbl utilization (Cbl E and G), and (f) lysosomal Cbl efflux (Cbl F).

Pernicious anemia. Cobalamin (Cbl) is freed from ...Media file 3: Pernicious anemia. Cobalamin (Cbl) is freed from meat in the acidic milieu of the stomach where it binds R factors in competition with intrinsic factor (IF). Cbl is freed from R factors in the duodenum by proteolytic digestion of the R factors by pancreatic enzymes. The IF-Cbl complex transits to the ileum where it is bound to ileal receptors. The IF-Cbl enters the ileal absorptive cell, and the Cbl is released and enters the plasma. In the plasma, the Cbl is bound to transcobalamin II (TC II), which delivers the complex to nonintestinal cells. In these cells, Cbl is freed from the transport protein.
Pernicious anemia. Cobalamin (Cbl) is freed from ...

Pernicious anemia. Cobalamin (Cbl) is freed from meat in the acidic milieu of the stomach where it binds R factors in competition with intrinsic factor (IF). Cbl is freed from R factors in the duodenum by proteolytic digestion of the R factors by pancreatic enzymes. The IF-Cbl complex transits to the ileum where it is bound to ileal receptors. The IF-Cbl enters the ileal absorptive cell, and the Cbl is released and enters the plasma. In the plasma, the Cbl is bound to transcobalamin II (TC II), which delivers the complex to nonintestinal cells. In these cells, Cbl is freed from the transport protein.

Peripheral smear of blood from a patient with per...Media file 4: Peripheral smear of blood from a patient with pernicious anemia. Macrocytes are observed, and some of the red blood cells show ovalocytosis. A 6-lobed polymorphonuclear leucocyte is present.
Peripheral smear of blood from a patient with per...

Peripheral smear of blood from a patient with pernicious anemia. Macrocytes are observed, and some of the red blood cells show ovalocytosis. A 6-lobed polymorphonuclear leucocyte is present.

Bone marrow aspirate from a patient with untreate...Media file 5: Bone marrow aspirate from a patient with untreated pernicious anemia. Megaloblastic maturation of erythroid precursors is shown. Two megaloblasts occupy the center of the slide with a megaloblastic normoblast above.
Bone marrow aspirate from a patient with untreate...

Bone marrow aspirate from a patient with untreated pernicious anemia. Megaloblastic maturation of erythroid precursors is shown. Two megaloblasts occupy the center of the slide with a megaloblastic normoblast above.

Response to therapy with cobalamin (Cbl) in a pre...Media file 6: Response to therapy with cobalamin (Cbl) in a previously untreated patient with pernicious anemia. A reticulocytosis occurs within 5 days after an injection of 1000 mcg of Cbl. This lasts for about 2 weeks after injection. The hemoglobin (Hgb) concentration increases at a slower rate because many of the reticulocytes are abnormal and do not survive as mature erythrocytes.
Response to therapy with cobalamin (Cbl) in a pre...

Response to therapy with cobalamin (Cbl) in a previously untreated patient with pernicious anemia. A reticulocytosis occurs within 5 days after an injection of 1000 mcg of Cbl. This lasts for about 2 weeks after injection. The hemoglobin (Hgb) concentration increases at a slower rate because many of the reticulocytes are abnormal and do not survive as mature erythrocytes.

More on Pernicious Anemia

Overview: Pernicious Anemia
Differential Diagnoses & Workup: Pernicious Anemia
Treatment & Medication: Pernicious Anemia
Follow-up: Pernicious Anemia
Multimedia: Pernicious Anemia
References
Further Reading

References

  1. Elmadfa I, Singer I. Vitamin B-12 and homocysteine status among vegetarians: a global perspective. Am J Clin Nutr. May 2009;89(5):1693S-1698S. [Medline].

  2. Chan JC, Liu HS, Kho BC, Lau TK, Li VL, Chan FH, et al. Longitudinal study of Chinese patients with pernicious anaemia. Postgrad Med J. Dec 2008;84(998):644-50. [Medline].

  3. Andrès E, Vogel T, Federici L, Zimmer J, Ciobanu E, Kaltenbach G. Cobalamin deficiency in elderly patients: a personal view. Curr Gerontol Geriatr Res. 2008;848267. [Medline].

  4. Erkurt MA, Aydogdu I, Dikilitas M, Kuku I, Kaya E, Bayraktar N, et al. Effects of cyanocobalamin on immunity in patients with pernicious anemia. Med Princ Pract. 2008;17(2):131-5. [Medline].

  5. Beutler E, Lichtman MA, Coller BS. Williams Hematology. 6th ed. New York, NY:. McGraw-Hill;2001:425-446.

  6. Hoffman R, Benz EJ Jr, Shattil SJ. Hematology: Basic Principles and Practice. 3rd ed. New York, NY:. Churchill Livingstone;2000:446-484.

  7. Jandl JH. Blood: Textbook of Hematology. 2nd ed. Boston, Mass:. Little, Brown and Co;1996:251-288.

  8. Lee GR, Foerster J, Lukens J. Wintrobe's Clinical Hematology. 10th ed. Baltimore, Md:. Williams & Wilkins;1999:941-978.

  9. Scriver CR, Beaudet AL, Sly WS. The Metabolic and Molecular Bases of Inherited Disease. 2nd ed. New York, NY:. McGraw-Hill;1995:3129-3149.

Keywords

pernicious anemia, vitamin B-12 deficiency, megaloblastic anemia, cobalamin deficiency, Cbl deficiency, iron deficiency anemia, addisonian anemia, Biermer anemia, Hunter-Addison anemia, Lederer anemia, Biermer-Ehrlich anemia, Addison-Biermer disease, macrocytic achylic anemia, malignant anemia,

adenosylcobalamin, methylcobalamin, intrinsic factor, IF, macrocytic anemia, neurological complications, severe gastric atrophy, achlorhydria, gastrectomy, gastric stapling, bypass procedures for obesity, extensive infiltrative disease of the gastric mucosa, Zollinger-Ellison syndrome,

tropical sprue, regional enteritis, ulcerative colitis, ileal lymphoma, Imerslünd-Grasbeck syndrome, chronic pancreatitis, sore tongue, smooth tongue with loss of papillae, paresthesias, megaloblastic madness, tapeworm infestation, Diphyllobothrium latum, congenital pernicious anemia, hereditary transcobalamin I deficiency, homocystinuria, homocystinemia

Contributor Information and Disclosures

Author

Marcel E Conrad, MD, (Retired) Distinguished Professor of Medicine, University of South Alabama
Marcel E Conrad, MD is a member of the following medical societies: Alpha Omega Alpha, American Association for the Advancement of Science, American Association of Blood Banks, American Chemical Society, American College of Physicians, American Physiological Society, American Society for Clinical Investigation, American Society of Hematology, Association of American Physicians, Association of Military Surgeons of the US, International Society of Hematology, Society for Experimental Biology and Medicine, and Southwest Oncology Group
Disclosure: No financial interests None None

Medical Editor

David Aboulafia, MD, Medical Director, Bailey-Boushay House; Clinical Professor, Department of Medicine, Division of Hematology, University of Washington
David Aboulafia, MD is a member of the following medical societies: American College of Physicians, American Medical Association, American Medical Directors Association, American Society of Hematology, Infectious Diseases Society of America, and Phi Beta Kappa
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Troy H Guthrie, Jr, MD, Director of Cancer Institute, Baptist Medical Center
Troy H Guthrie, Jr, MD is a member of the following medical societies: American Federation for Medical Research, American Medical Association, American Society of Hematology, Florida Medical Association, Medical Association of Georgia, and Southern Medical Association
Disclosure: Nothing to disclose.

CME Editor

Rajalaxmi McKenna, MD, FACP, Consulting Staff, Department of Medicine, Southwest Medical Consultants, SC, Good Samaritan Hospital, Advocate Health Systems
Rajalaxmi McKenna, MD, FACP is a member of the following medical societies: American Society of Clinical Oncology, American Society of Hematology, and International Society on Thrombosis and Haemostasis
Disclosure: Nothing to disclose.

Chief Editor

Emmanuel C Besa, MD, Professor, Department of Medicine, Division of Hematologic Malignancies, Kimmel Cancer Center, Thomas Jefferson University
Emmanuel C Besa, MD is a member of the following medical societies: American Association for Cancer Education, American College of Clinical Pharmacology, American Federation for Medical Research, American Society of Hematology, and New York Academy of Sciences
Disclosure: Nothing to disclose.

 
 
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