What are the effects of alcohol on the hematological system?

Alcohol is the most commonly used drug that suppresses blood cell production. Toxic effects are dose dependent. Thus, they usually occurs only in people with severe alcoholism. The following description of hematological changes in alcoholics is based on an old but excellent (and still relevant) review by Harold Ballard:

• Red cells
  • Anemia :
    • Sideroblastic anemia:
      • Accumulation of ringed sideroblasts in the bone marrow.
      • Caused by accumulation of ferritin, which can accumulate in RBC precursors, often forming granules that encircle the cell’s nucleus.
      • Reduced differentiation to mature red cells, leading to anemia.
      • Appear as cells with Pappenheimer bodies on peripheral smear.
      • Present in 30% of severe alcoholics.
      • The ringed sideroblasts generally disappear from the bone marrow within 5 to 10 days of abstinence, and RBC production resumes.
    • Megaloblastic anemia – The most common cause of this deficiency is a diet poor in folic acid, a frequent complication in alcoholics, who often have poor nutritional habits.
    • Spur cell hemolysis – secondary to alcoholic liver disease
    • Stomatocyte hemolysis
      • > 25 percent of alcoholics exhibit an increased proportion of stomatocytes in the blood.
      • Stomatocytes disappear during abstinence.
    • Hypophosphatemia-induced hemolysis
  • Macrocytosis (independent of folate deficiency or liver disease)
    • Precise mechanism underlying macrocytosis still is unknown.
    • However, alcohol appears to interfere directly with RBC development, because the macrocytes disappear within 2 to 4 months of abstinence.
  • Vacuolated red cell precursors in the bone marrow:
    • The vacuoles usually appear in the pronormoblasts 5 to 7 days following the initiation of heavy alcohol consumption.
    • The vacuoles on average disappear after 3 to 7 days of abstinence, although in some patients they persist for up to 2 weeks
    • Mechanism underlying vacuole development in blood cell precursors currently is unknown.
    • Unknown whether these vacuoles affect the cell’s function and thus the drinker’s health.
    • Their appearance generally is considered an indicator of excessive alcohol consumption.
• Thrombocytopenia
• Leukopenia, especially neutropenia