Benign WBC Disorders PDF

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Summary

Relative vs Absolute Counts- Relative Counts, refer to the percentage of a cell in a differential. - Absolute Count, refers to the absolute amount of a cell in a differential (Relative percentage x WBC Count).Morphological Changes in CellsNucleus- Loss of nuclei as time goes on. - The nucleus will d...

Description

MLSC-3121U, Clinical Hematology II Relative vs Absolute Counts -

Relative Counts, refer to the percentage of a cell in a differential. Absolute Count, refers to the absolute amount of a cell in a differential (Relative percentage x WBC Count).

Morphological Changes in Cells Nucleus -

Loss of nuclei as time goes on. The nucleus will decrease in size due to chromatin condensation. Possible ejection and shape change of the nucleus may occur as well.

Cytoplasm -

Decrease in basophilia over time. Cytoplasm content increases as the nucleus shrinks. Granules may start to appear.

Neutrophils -

Function as phagocytes by engulfing bacteria and mediating the inflammatory process. Dense multilobed purple nuclei are seen with pink cytoplasm.

Myeloblast -

Round nucleus that stains reddish and is “open” (loose chromatin with space in between). Nucleus takes up most of the cell (4:1 nucleus to cytoplasm)

Promyelocyte -

Contains blue granules that differentiate themselves from a myeloblast. May be round or irregular in shape. Nuclei faintly granular with the nuclei faintly visible.

Myelocyte -

Chromatin is much more condensed. Cells commits to what it will be. Last cell capable of division. The secondary granules start to appear and tell us what cell type it will be. Smaller than a promyelocyte.

MLSC-3121U, Clinical Hematology II Metamyelocyte -

Condensed chromatin with an indented nucleus. Small pinkish secondary granules with an equal amount of cytoplasm and nucleus.

Band Neutrophils -

Even width of nucleus with an indentation greater than half the width of the nucleus. Pink cytoplasm with evenly distributed fine granules.

Mature Neutrophil -

Nucleus has 2-5 lobes with fine granules. Pink cytoplasm.

Neutrophilia -

Occurs in inflammation and infection. Seen as a significant increase in neutrophil count. Increase neutrophil release causes a left shift in neutrophils. Results in an increased number of premature neutrophils (meta and band cells).

Reactive Changes -

Toxic Granulation, results in cytoplasmic granules becoming darker and heavier staining. Toxic granules are peroxidase positive primary granules. Döhle Bodies, can accompany toxic granulation. Seen as pale blue inclusions in the periphery of the cytoplasm. Sign of increasingly severe infection and can be hard to see. Toxic Vacuolation, seen when the cytoplasm becomes vacuolated. Vacuoles may contain ingested microorganisms. This can also occur in old blood samples as an artefact. Reactive changes occur in a left shift during infection since more neutrophils are being made quickly to fight off bacteria. A Leukocyte Alkaline Phosphatase test can be used to differentiate neutrophilic responses (infection) from leukemia.

Neutrophil Disorders -

Quantitative, lack of cell number. Qualitative, lack of cell function.

Neutropenia -

Characterized by a neutrophil count of less than 1.5 x 10^9/L. Acquired neutropenia can be caused by extrinsic factors to the bone marrow, infection, drugs, allo/autoantibodies and secondary underlying diseases.

MLSC-3121U, Clinical Hematology II -

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Chédiak-Higashi Syndrome, qualitative congenital disorder characterized by giant lysosomal granules in granulocytes, monocytes, lymphocytes, melanocytes, tissues, macrophages, and platelets. Pelger-Huet, autosomal malignancy leading to bilobed neutrophils. Nucleus looks like dumbells. Alder-Reilly Anomaly, looks similar to toxic granulation. Involves dark staining coarse cytoplasmic granules in neutrophils. Composed of precipitated mucopolysaccharides. May-Hegglin Anomaly, blue staining cytoplasmic inclusions that resemble döhle bodies.

Eosinophils -

Same development process as neutrophils. Contains specific orange/red granules. Contribute to inactivation of mast cells, hypersensitivity regulation (calm down histamine reactions) and fighting of larval stages of parasitic helminths.

Basophils -

Enter the tissue to become mast cells and are involved in delayed and acute allergies. Have dark staining granules. Have a role in immediate hypersensitivity reactions.

Lymphocytes -

Formed in lymphoid tissue of the thymus and lymph nodes. In children, there can be more lymphocytes than adults. Lymphocytosis occurs when the lymphocyte count is greater than 4.0 x 10^9/L. Reactive lymphocytes occur in normal patients but are less that 10% of the total lymphocytes present. Lymphoblasts, have immature chromatin and a little bit of blue cytoplasm with mainly nucleus dominating the cell. Prolymphocyte, hard to identify, intermediate chromatin pattern with a less defined nucleoli. Lymphocyte, condensed chromatin making up a round and slightly indented nuclei. Chromatin is lumpy/clumped. Reactive lymphocytes are larger than regular ones with darker cytoplasm and slightly less condensed chromatin. Lymphocytes are involved in viral infections.

Infectious Mononucleosis

MLSC-3121U, Clinical Hematology II -

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An infection that enters the body orally through lymphoid tissue in the pharynx to infect B cells. May present with mild hemolytic anemia from cold reacting “i” antibodies or immune thrombocytopenia from splenic activity. The Monospot test is used to identify infectious mononucleosis and was made after the antibody was discovery by Paul in 1932. Measures the IgM heterophile antibodies. Diagnosis comes from clinical signs and morphology to differentiate reactive lymphocytes from IM infections from those involved in leukemia. Patients can potentially have elevated white cells. Will have many reactive lymphocytes with inconsistent appearances. Reactive lymphocytes have basophilic pale blue cytoplasm unlike the blue-gray cytoplasm of monocytes. Reactive lymphocytes still have more condensed chromatin than the lacey chromatin in monocytes.

Plasma Cells -

Final stage of B lymphocyte development. Characterized by production and release of immunoglobulin molecules.

Monocytes -

Become macrophages in the tissue. Don’t have as many maturation steps as neutrophils. Monoblast, immature monocyte that is quite big with loose open chromatin. Has a blue cytoplasm. Promonocyte, similar to prolymphocytes and similar to mesoblast. Have fine chromatin and often have a visible nucleolus. Monocyte, largest normal WBC. Usually has vacuoles with an irregular lacey nucleus. Serve to ingest/clean up cellular debris and move slower than neutrophils. Also process antigens to present them to T-Lymphocytes. T-Lymphocytes will then activate the immune system accordingly....