Quantitative Changes In The White Cells

Various conditions give rise to increases or decreases in a particular cell line. These conditions are usually transient, and once the underlying condition has resolved itself, for the most part the counts return to normal. A partial list of disorders that increase or decrease leukocytes is included. Lymphocytes will be considered under a separate heading.

Conditions With Increased Neutrophils

• Infections

• Inflammatory response

• Stress response

• Malignancies

Conditions With Increased Eosinophils

• Parasitic disease

• Transplant rejection2

• Myeloproliferative disorders

Conditions With Increased Basophils

• Myeloproliferative disorders

• Hypersensitivity reactions

• Ulcerative colitis

Conditions With Increased Monocytes

• Chronic infections like tuberculosis

• Malignancies

• Leukemias with a strong monocytic component

• Bone marrow failure

With regard to a decrease in cell lines, perhaps the most significant finding is neutropenia in which the absolute neutrophil count is less than 2.0 X 109/L. This occurs due to medications, bone marrow assaults due to chemicals, viral infections, or splenic sequestration.3

Specific Terminology Relating to Quantitative White Cell Changes

For the most part, four terms are used to describe white cell conditions: leukocytosis, left shift, leukemoid reaction, and the leukoerythroblastic picture. These terms are usually not used interchangeably, but they are a source of confusion for the student. Leukocytosis simply means that an increase in white cells has occurred; left shift means that the bone marrow is responding to the increased white count by sending out younger cells (metamyelocytes, bands) into the peripheral circulation. Leukemoid reaction is an exaggerated response to infections and inflammation in which the baseline leukocyte count may be between 20 and 50 X 109/L. This count may appear as preleukemic; however, the white cells that are seen in the peripheral smear are slightly immature to mature with no blasts present. The leukoerythroblastic picture is a significant feature of the myeloproliferative disorders and refers to the presence in the peripheral smear of immature white cells, immature red cells (nucleated RBCs [RBCs]), and platelet abnormalities (Table 10.1).

Was this article helpful?

0 0

Post a comment