Macrocytic anemia patient information

NOTOC Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Omer Kamal, M.D.[2]

Overview

In 60% of anemic patients, megaloblastic anemia affects 2-4% of population. Patients of all age groups may develop megaloblastic anemia. The incidence of megaloblastic anemia increases with age. Megaloblastic anemia commonly affects older age group. Males are more commonly affected by megaloblastic anemia than females. In deficiencies of vitamin b12 and folate causing megaloblastic anemia, supplementation are made with Cyanocobalamine and Folic Acid respectively based on the severity and the cause. LDH falls in 2 days. Hypokalemia requiring replacement can occur in the acute phase as new cells are being generated rapidly. A reticulocytosis begins in 3-5 days and peaks in 10 days. The Hematocrit will rise within 10days. If it does not, suspect another disorder. Hypersegmented polymorphonuclear cells disappear in 10-14 days.

What are the symptoms of Macrocytic Anemia?

Macrocytosis is a common feature of MDS, especially in older adults. Patients with B12 deficiency show neurologic dysfunction, anemia symptoms such as fatigue, dyspnea, lightheadedness, and anorexia, high output cardiac failure, angina, diarrhea, cheilosis, glossitis, subacute combined degeneration, broad based gait, ataxia, numbness or paresthesias, Rhomberg and Babinski’s sign. Dementia may progress to frank “Megaloblastic Madness”:. Also may include:

• Feeling weak or tired
• Headache
• Paleness
• Shortness of breath

What causes Macrocytic Anemia?

• Vitamin B12 Deficiency:  
  1. Deficient intake
  2. Deficient intrinsic factor (pernicious anaemia or gastrectomy)
  3. Bilogical competition for B12 by diverticulosis, fistula, intestinal anastomosis, achlorhydria and infection by the marine parasite Diphyllobothrium latum
  4. Selective B12 malabsorption (congenital and drug-induced)
  5. Chronic pancreatitis
  6. Ileal resection and bypass
• Folate Deficiency:
  1. Deficient intake
  2. Alcoholism
  3. Increased needs: pregnancy, infant, rapid cellular proliferation, and cirrhosis
  4. Malabsorption (congenital and drug-induced)
  5. Intestinal and jejunal resection

Who is at highest risk?

Common risk factors of megaloblastic anemia:

• Folate deficiency
  • Nutritionally deficient - Elderly, alcohol, narcotic abuse
  • Those with increased demand: pregnancy, infancy, low grade hemolysis, malignancy or chronic hemodialysis.
• Autoimmune disease such as Hashimoto’s, vitiligo, diabetes, adrenal insufficiency. (Schmitt’s Syndrome).
• Strict vegans and/or their infant
• Malabsorptive disorders such as blind loops/bacterial overgrowth, sprue, whipple’s and crohn’s can malabsorb folate and B12.
• D.Latum is a competitor for B12 absorption. This entity is most commonly found in Scandinavia.

Diagnosis

The doctor will perform a physical examination.

Because anemia may be the first symptom of a serious illness, determining its cause is very important.

Tests that may be done to diagnose anemia or rule out other causes include:

• Hemoglobin level
• Red blood count
• Reticulocyte count
• Serum ferritin
• Serum iron
• Other blood tests

When to seek urgent medical care?

Call for an appointment with your health care provider if you have a chronic disorder and you develop symptoms of anemia.

Treatment options

In deficiencies of vitamin b12 and folate causing megaloblastic anemia, supplementation are made with Cyanocobalamine and Folic Acid respectively based on the severity and the cause. LDH falls in 2 days. Hypokalemia requiring replacement can occur in the acute phase as new cells are being generated rapidly. A reticulocytosis begins in 3-5 days and peaks in 10 days. The Hematocrit will rise within 10days. If it does not, suspect another disorder. Hypersegmented polymorphonuclear cells disappear in 10-14 days.

Where to find medical care for Macrocytic Anemia?

Call for an appointment with your health care provider if you have a chronic disorder and you develop symptoms of anemia.

Prevention of Macrocytic Anemia

Green leafy vegetables and meat are a good source of Vitamin B-12. Alcohol consumption can lead to macrocytic anemia. These are some of the primary ways to reduce the incidence of macrocytic anemia.

What to expect (Outlook/Prognosis)?

The anemia will improve when the disease that is causing it is successfully treated.

Possible complications

Discomfort from symptoms is the main complication in most cases. Anemia may lead to a higher risk of death in patients with heart failure.

Sources

http://www.nlm.nih.gov/medlineplus/ency/article/000565.htm