Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Pernicious anemia is a type of
anemia (reduced number of red blood
cells or hemoglobin in the body) due to the body's inability to absorb vitamin B-12 from the gastrointestinal tract.
Symptoms from anemia are a result of the decreased capacity of the blood to
carry oxygen and include fatigue and shortness of breath. In addition, the
deficiency of vitamin B-12 also can damage the nervous system.
Vitamin B-12 is also known as cobalamin (Cbl). Animal products, both meat and
dairy, are the only dietary sources of vitamin B-12 for humans. Because the body
has stores of vitamin B-12, inadequate dietary intake must persist for years
before a true deficiency of vitamin B-12 occurs. For this reason, the pernicious
anemia usually takes years to establish and is most commonly diagnosed in adults
with an average age of 60. Also, a rare, form of pernicious anemia is present at
birth.
Pernicious anemia is a form of megaloblastic anemia. Megaloblastic anemia is
characterized by an abnormally large type of red blood cell (megaloblast)
that is formed by the bone
marrow when vitamin B-12 or folic acid levels are low.
Megaloblastic anemia can also develop with other conditions that affect the bone
marrow and as an effect of some chemotherapy drugs.
Pernicious Anemia Causes
The decreased absorption of vitamin B-12 from the gastrointestinal tract in
pernicious anemia is believed to result from an autoimmune process in which
the body's immune system
attacks the lining of the stomach. Antibodies are produced
against intrinsic factor (IF), a protein made in the stomach that is necessary
for the absorption of vitamin B-12. Normally, vitamin B-12 binds to intrinsic
factor in the stomach, and this facilitates its absorption later when digestive
products pass through the small
intestine. The autoimmune process attacks the IF protein and lowers IF
levels in stomach secretions. An autoimmune process directed at the stomach
lining cells also occurs and results in a chronic form of stomach inflammation
(gastritis) known as chronic atrophic gastritis.
Pernicious anemia is most common in Caucasian persons of northern European
ancestry than in other racial groups. In this population, 10-20 cases per 100,000 persons are diagnosed each year. Pernicious anemia may
occur in association with other autoimmune diseases such as autoimmune
thyroid disease and
vitiligo.
While pernicious anemia is defined as anemia resulting from inadequate
absorption of vitamin B-12 from the gastrointestinal tract due to the autoimmune
process described above, other causes of vitamin B-12 deficiency can also produce
the characteristic signs and symptoms of pernicious anemia. Other potential
causes of vitamin B-12 deficiency include surgical removal of the stomach or a
portion of the stomach (gastrectomy), other gastrointestinal diseases such as
celiac disease or Crohn's disease, infection, and poor nutrition.
The complete blood count (CBC) is one of the most commonly ordered blood
tests by doctors. To understand this test, it is important to know that the
blood generally consists of two major parts; plasma and cellular
elements. The plasma is the part of the blood that is liquid which allows the
blood to flow easily. The other part of the blood consists of blood cells or
cellular elements.
The major cells in the blood are white blood cells
(WBC), red blood cells (RBC), and platelets. Each of these types of cells carries out specific and
important functions.
The complete blood count test measures the quantity of
all the different types of cells in the blood. It also provides some valuable
information on other parameters related to each type of blood cell.
Complete Blood Count Procedure
The complete blood count may be done in many different health care
settings including doctors' ...
