Granulocytopenia and lymphocytopenia
In granulocytopenia, a marked reduction in the number of circulating granulocytes occurs. Although this implies that all the granulocytes (neutrophils, basophils, and eosinophils) are reduced, granulocytopenia usually refers only to decreased neutrophils.
This disorder, which can occur at any age, is associated with infections
and ulcerative lesions of the throat, GI tract, other mucous membranes, and skin. Its most severe form is known as agranulocytosis.
and ulcerative lesions of the throat, GI tract, other mucous membranes, and skin. Its most severe form is known as agranulocytosis.
Lymphocytopenia (lymphopenia), a rare disorder, is a deficiency of circulating lymphocytes (leukocytes produced mainly in lymph nodes).
In granulocytopenia and lymphocytopenia, the total white blood cell (WBC) count may reach dangerously low levels (less than 500/μl), leaving the body unprotected against infection. The prognosis in both disorders depends on the underlying cause and whether it can be treated. Untreated, severe granulocytopenia can be fatal in 3 to 6 days.
Causes
Granulocytopenia and lymphocytopenia have several causes.
Granulocytopenia
Granulocytopenia may result from decreased production of granulocytes in bone marrow, increased peripheral destruction of granulocytes, or greater utilization of granulocytes.
Decreased production of granulocytes in bone marrow generally stems from radiation or drug therapy; it’s a common adverse effect of antimetabolites and alkylating agents and may occur in the patient who is hypersensitive to phenothiazines, sulfonamides (and some sulfonamide derivatives such as chlorothiazide), antibiotics, or antiarrhythmic drugs.
Drug-induced granulocytopenia usually develops slowly and typically correlates with the dosage and duration of therapy. Production of granulocytes also decreases in such conditions as aplastic anemia and bone marrow cancers and in some hereditary disorders such as infantile genetic agranulocytosis.
Loss of peripheral granulocytes is due to increased splenic sequestration, diseases that destroy peripheral blood cells (viral and bacterial infections), and drugs that act as haptens (carrying antigens that attack blood cells and causing acute idiosyncratic or non-dose-related drug reactions).
Infections, such as infectious mononucleosis, may result in granulocytopenia because of increased utilization of granulocytes.
