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Chapter 15Chapter 15

White Blood Cell White Blood Cell DisordersDisorders

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White Blood Cell DisordersWhite Blood Cell Disorders

► In Chapter 15, you will be introduced to In Chapter 15, you will be introduced to the various disorders of leukocytes.  the various disorders of leukocytes.  Included in this chapter will be a Included in this chapter will be a discussion on the kinetics and functions of discussion on the kinetics and functions of neutrophils, disorders of neutrophils, and neutrophils, disorders of neutrophils, and other morphologic changes of other morphologic changes of neutrophils.  The function and neutrophils.  The function and morphology of lymphocytes will also be morphology of lymphocytes will also be covered.  Diseases that affect covered.  Diseases that affect lymphocytes are discussed.  lymphocytes are discussed. 

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Circulating Kinetics and Circulating Kinetics and Morphology of Neutrophils Morphology of Neutrophils 1 of 31 of 3

►Granulocytes are divided into three subsets: Neutrophils Basophils Eosinophils

►Neutrophils are phagocytic cells.►They are capable of movement from the

circulatory system into the tissues to engulf and destroy bacteria.

►They mobilize to sites of infection and play a role in the inflammatory response.

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Circulating Kinetics and Circulating Kinetics and Morphology of Neutrophils Morphology of Neutrophils 2 of 32 of 3

►Two types of granules: Primary or azurophilic Secondary or specific

►All granules contain enzymes which are involved in killing and digesting bacteria and fungi.

►Neutrophils are very mobile cells.

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Circulating Kinetics and Circulating Kinetics and Morphology of Neutrophils Morphology of Neutrophils 3 of 33 of 3

►Once in the circulatory system, the neutrophils divide up into two pools: Marginating pool: These neutrophils remain in the

circulatory system searching for an area of inflammation. When inflammation is found, these neutrophils leave the circulatory system by process of diapedesis and enter surrounding tissues.

Circulating pool: Leave the blood stream by random migration and do not return to the bloodstream.

►Neutrophils are believed to survive 2-5 days after entering the tissues.

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Neutrophil Counts in Peripheral Neutrophil Counts in Peripheral BloodBlood

►Variations in the numbers of Variations in the numbers of neutrophils is a useful diagnostic tool; neutrophils is a useful diagnostic tool; Variations reflect response of Variations reflect response of neutrophils to underlying disease (i.e. neutrophils to underlying disease (i.e. bacterial infection) or of another bacterial infection) or of another disorder such as leukemia.disorder such as leukemia.

►Normal ranges vary widely with age:Normal ranges vary widely with age: Newborns may have more WBCsNewborns may have more WBCs Babies may have more lymphocytesBabies may have more lymphocytes

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Response to Infections Response to Infections 1 of 21 of 2

► Neutrophils play central role in fighting infections and Neutrophils play central role in fighting infections and inflammatory agents.  Can reach area of inflammation inflammatory agents.  Can reach area of inflammation within minutes by migrating (diapedesis) from within minutes by migrating (diapedesis) from circulatory system to site of infection. circulatory system to site of infection.

► NeutrophiliaNeutrophilia is increase in relative number of is increase in relative number of neutrophils in response to infection or inflammatory neutrophils in response to infection or inflammatory process. Accelerated release from bone marrow seen process. Accelerated release from bone marrow seen as as "shift to left""shift to left" which is defined as increased which is defined as increased number of metamyelocytes and bands in peripheral number of metamyelocytes and bands in peripheral blood.  Rarely see more immature neutrophil forms in blood.  Rarely see more immature neutrophil forms in infections (will see more immature forms in infections (will see more immature forms in leukemia). leukemia).

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Response to Infections Response to Infections 2 of 22 of 2

► In addition to changes in neutrophil number, will see In addition to changes in neutrophil number, will see morphologic changes such as toxic granulation, Dohle morphologic changes such as toxic granulation, Dohle bodies, and cytoplasmic vacuoles: bodies, and cytoplasmic vacuoles: Toxic granulationToxic granulation: granules become larger and stain more : granules become larger and stain more

darkly.  Granules tend to be primary granules that are darkly.  Granules tend to be primary granules that are peroxidase positive.  Frequently seen in severe infections. peroxidase positive.  Frequently seen in severe infections.

Dohle bodiesDohle bodies: pale blue cytoplasmic inclusions.  Seen on : pale blue cytoplasmic inclusions.  Seen on periphery of cell.  Consist of few strands of rough endoplasmic periphery of cell.  Consist of few strands of rough endoplasmic reticulum that have banded together. reticulum that have banded together.

VacuolesVacuoles: Neutrophils may develop vacuoles in cytoplasm.  : Neutrophils may develop vacuoles in cytoplasm.  May see ingested microorganisms as well.  May see ingested microorganisms as well. 

► Presence of any of these changes may suggest Presence of any of these changes may suggest progression toward sepsis; however, are not progression toward sepsis; however, are not specifically related to infections.  May see in massive specifically related to infections.  May see in massive trauma, during pregnancy, in inflammatory responses, trauma, during pregnancy, in inflammatory responses, and in drug reactions. and in drug reactions.

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Neutrophil Neutrophil FunctionFunction

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Neutrophil FunctionNeutrophil Function

►Main function is destruction of Main function is destruction of microorganisms through process called microorganisms through process called phagocytosisphagocytosis.  . 

►Once bacteria infiltrate tissues, Once bacteria infiltrate tissues, neutrophils immediately respond.  neutrophils immediately respond.  Phagocytosis begins. Phagocytosis begins.

►Phagocytosis consists of three phases:  Phagocytosis consists of three phases:  migration and diapedesismigration and diapedesis opsonization and recognitionopsonization and recognition ingestion, killing, and digestioningestion, killing, and digestion

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Migration and DiapedesisMigration and DiapedesisPhase 1Phase 1

►Neutrophils are attracted to the area by Neutrophils are attracted to the area by chemical signals produced by chemical signals produced by inflammation, injury, and infectious inflammation, injury, and infectious agents. agents.

►ChemotaxisChemotaxis is the movement of is the movement of neutrophils towards the chemoattractant.neutrophils towards the chemoattractant.

►Neutrophils migrate from the vessels by Neutrophils migrate from the vessels by diapedesisdiapedesis between the endothelial between the endothelial cells of the vessels, and migrate towards cells of the vessels, and migrate towards the chemoattractor.the chemoattractor.

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Opsonization and RecognitionOpsonization and RecognitionPhase 2Phase 2

►Neutrophils cannot recognize or attach to Neutrophils cannot recognize or attach to microorganisms.  They need help. microorganisms.  They need help.

►OpsonizationOpsonization is process which facilitates is process which facilitates recognition and attachment of neutrophil to recognition and attachment of neutrophil to organism.  Marks organism for ingestion by organism.  Marks organism for ingestion by neutrophil. neutrophil.

► As chemotaxis occurring, immunoglobulins As chemotaxis occurring, immunoglobulins and complement components coat surface of and complement components coat surface of bacteria.  Marked bacteria (bacteria.  Marked bacteria (opsoninopsonin) easily ) easily recognized by neutrophil and ingested. recognized by neutrophil and ingested.

► Ingestion requires presence of membrane-Ingestion requires presence of membrane-bound immunoglobulin. bound immunoglobulin.

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Ingestion, Killing and DigestionIngestion, Killing and DigestionPhase 3 Phase 3 1 of 21 of 2

► Ingestion begins as soon as organism and Ingestion begins as soon as organism and neutrophil bind together.  Membrane neutrophil bind together.  Membrane pseudopods surround organism, forming pseudopods surround organism, forming isolated vacuole within cytoplasm of isolated vacuole within cytoplasm of neutrophil.  Called a neutrophil.  Called a phagosomephagosome. .

► Simultaneously, cytoplasmic granules Simultaneously, cytoplasmic granules migrate to and fuse with phagosome, migrate to and fuse with phagosome, forming a forming a phagolysosomephagolysosome. .

►Once phagolysosome formation complete, Once phagolysosome formation complete, granules release contents.  Ingested granules release contents.  Ingested organism exposed to lytic activity of organism exposed to lytic activity of granular enzymes that leads to death of granular enzymes that leads to death of organism and its eventual digestion. organism and its eventual digestion.

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Ingestion, Killing and Digestion Ingestion, Killing and Digestion Phase 3 Phase 3 2 of 22 of 2

► In the leukocyte, there are pH changes, In the leukocyte, there are pH changes, dumping of digestive enzymes into the dumping of digestive enzymes into the phagolysosome, production of hydrogen phagolysosome, production of hydrogen peroxide and superoxides. These peroxide and superoxides. These digestion processes are collectively digestion processes are collectively called called respiratory burstrespiratory burst.  These .  These oxygen metabolites injure the organism oxygen metabolites injure the organism and interact with other granular and interact with other granular contents to produce toxic agents such as contents to produce toxic agents such as hydrochloric acid (household bleach). hydrochloric acid (household bleach).

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Neutrophil Neutrophil DisordersDisorders

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Disorders of NeutrophilsDisorders of Neutrophils

►Neutrophil disorders may be classified Neutrophil disorders may be classified as quantitative (abnormal numbers) or as quantitative (abnormal numbers) or qualitative (abnormal function).qualitative (abnormal function).

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Quantitative Disorders of Quantitative Disorders of NeutrophilsNeutrophils

►LeukocytosisLeukocytosis: an increase in the : an increase in the number of WBCs.number of WBCs.

►LeukopeniaLeukopenia: a decrease in the : a decrease in the number of WBCs.number of WBCs.

►NeutropeniaNeutropenia: an absolute decrease : an absolute decrease in the number of circulating in the number of circulating neutrophils.neutrophils.

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Acquired NeutropeniaAcquired Neutropenia

►Five factors associated with acquired Five factors associated with acquired neutropenia:neutropenia: Viral infectionsViral infections Ingestion of medications Ingestion of medications Alloantibody formation (from transfusion Alloantibody formation (from transfusion

or pregnancy, much like HDN)or pregnancy, much like HDN) Autoantibody formation Autoantibody formation Secondary condition due to another Secondary condition due to another

process (aplastic anemia, bone cancer) process (aplastic anemia, bone cancer)

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Qualitative Disorders of Qualitative Disorders of NeutrophilsNeutrophils

► Involve neutrophil function.Involve neutrophil function.►Extremely rare occurrences.Extremely rare occurrences.►Classified according to major defect Classified according to major defect

expressed:expressed: Cytoplasmic granules Cytoplasmic granules Disturbance of respiratory burst Disturbance of respiratory burst Chemotaxis Chemotaxis Combination of defects Combination of defects

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Chediak-Higashi Syndrome Chediak-Higashi Syndrome 1 1

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► Rare autosomal recessive condition.   Rare autosomal recessive condition.   ► Features include recurrent bacterial infections, Features include recurrent bacterial infections,

partial albinism, and presence of giant partial albinism, and presence of giant lysosomal granules in cells such as lysosomal granules in cells such as granulocytes, monocytes, lymphocytes, and granulocytes, monocytes, lymphocytes, and platelets.  Mild bleeding tendencies may occur. platelets.  Mild bleeding tendencies may occur.

►Have progressive neurologic complications Have progressive neurologic complications during childhood.  Many patients die as result during childhood.  Many patients die as result of infection during childhood.  Adults enter into of infection during childhood.  Adults enter into accelerated phase that progresses through accelerated phase that progresses through pancytopenia, organomegaly, systemic pancytopenia, organomegaly, systemic infections, and eventually, death.  infections, and eventually, death.  Staphylococcus aureusStaphylococcus aureus primary cause of primary cause of infections. infections.

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Chediak-Higashi Syndrome Chediak-Higashi Syndrome 2 2

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► ****Have inefficient and prolonged bacterial Have inefficient and prolonged bacterial killing.  Release of lysosomal enzymes killing.  Release of lysosomal enzymes impaired by abnormal granules.  In Wright's impaired by abnormal granules.  In Wright's stain, giant granules more likely seen in stain, giant granules more likely seen in lymphocytes (stain deep purple to dark red). lymphocytes (stain deep purple to dark red).

►Management includes prophylactic antibiotic Management includes prophylactic antibiotic treatment and high daily doses of ascorbic treatment and high daily doses of ascorbic acid.  In cases of infection, aggressive acid.  In cases of infection, aggressive intravenous treatment required. intravenous treatment required.

► Bone marrow transplant only hope of cure.  Bone marrow transplant only hope of cure.  Should be performed before accelerated Should be performed before accelerated phase begins. phase begins.

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Chronic Granulomatous DiseaseChronic Granulomatous Disease(CGD) (CGD) 1 of 21 of 2

► Heterogeneous disorder of neutrophil that can be Heterogeneous disorder of neutrophil that can be chronic or intermittent. chronic or intermittent.

► ****Attributed to failure in activation of respiratory Attributed to failure in activation of respiratory burst that results in little or no superoxide burst that results in little or no superoxide production. production.

► Patients present with lymphadenitis, deep tissue Patients present with lymphadenitis, deep tissue infections such as osteomyelitis, and visceral and infections such as osteomyelitis, and visceral and hepatic abscesses.  Have frequent pulmonary hepatic abscesses.  Have frequent pulmonary infections, organomegaly, and infected eczematoid infections, organomegaly, and infected eczematoid rashes. rashes.

► Patients have neutrophilia rather than neutropenia. Patients have neutrophilia rather than neutropenia. ► Hallmark characteristic is formation of granulomas Hallmark characteristic is formation of granulomas

during chronic inflammatory reactions that keep during chronic inflammatory reactions that keep organisms localized. organisms localized.

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Chronic Granulomatous DiseaseChronic Granulomatous Disease(CGD) (CGD) 2 of 22 of 2

► May be inherited as either sex-linked-recessive or as May be inherited as either sex-linked-recessive or as autosomal-recessive.  Regardless of form, end result autosomal-recessive.  Regardless of form, end result is that superoxide can not be produced, and in turn, is that superoxide can not be produced, and in turn, bacterial killing is ineffective.  Ingestion of bacteria, bacterial killing is ineffective.  Ingestion of bacteria, degranulation, and phagolysosome formation normal. degranulation, and phagolysosome formation normal.

► Diagnosis made by demonstrating bactericidal defect Diagnosis made by demonstrating bactericidal defect resulting from absence of respiratory burst on resulting from absence of respiratory burst on nitroblue tetrazolium test (NTB), or by measuring nitroblue tetrazolium test (NTB), or by measuring respiratory burst activity by flow cytometry. respiratory burst activity by flow cytometry.

► Aggressive prophylactic antibiotic therapy begun as Aggressive prophylactic antibiotic therapy begun as soon as diagnosis made.  Gamma interferon effective soon as diagnosis made.  Gamma interferon effective in limiting frequency of infections.  Granulocyte in limiting frequency of infections.  Granulocyte transfusions useful.  Bone marrow transplants transfusions useful.  Bone marrow transplants beneficial in children. beneficial in children.

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Hypersegmentation of Hypersegmentation of NeutrophilsNeutrophils

►Larger than normal neutrophils (and Larger than normal neutrophils (and sometimes eosinophils) with six or sometimes eosinophils) with six or more nuclear lobes present.more nuclear lobes present.

►May be an indicator of megaloblastic May be an indicator of megaloblastic anemia or of benign autosomal anemia or of benign autosomal recessive condition called benign recessive condition called benign hypersegmentation of neutrophils.hypersegmentation of neutrophils.

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Hyposegmentation of Hyposegmentation of NeutrophilsNeutrophils

►Characteristic of Characteristic of Pelger-HuetPelger-Huet anomaly. anomaly.►Nucleus is bilobed or lacks lobes Nucleus is bilobed or lacks lobes

altogether. Nuclear chromatin altogether. Nuclear chromatin excessively coarse and condensed.  excessively coarse and condensed.  Nuclei described as "Nuclei described as "dumbbelldumbbell" or " or ""pince-nezpince-nez"  appearing with two "  appearing with two symmetric lobes being joined by symmetric lobes being joined by filament. filament.

►True Pelger-Huet is autosomal-dominant True Pelger-Huet is autosomal-dominant condition.  Is benign condition. condition.  Is benign condition.

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Cytoplasmic ChangesCytoplasmic Changes

►Cytoplasmic changes may also occur.Cytoplasmic changes may also occur.►Alder anomaly or Alder-Reilly inclusions:Alder anomaly or Alder-Reilly inclusions:

Presence of prominent, dark staining, coarse Presence of prominent, dark staining, coarse granules in many or all cell lines. Prominent granules in many or all cell lines. Prominent granules are similar to toxic granulation, granules are similar to toxic granulation, except they are larger and permanent (not a except they are larger and permanent (not a transient change cause by infection or toxins).transient change cause by infection or toxins).

►May-Hegglin anomaly:May-Hegglin anomaly: Demonstrates larger, blue-staining cytoplasm Demonstrates larger, blue-staining cytoplasm

in the granulocytes, resembling Dohle bodies.in the granulocytes, resembling Dohle bodies.

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Lymphocyte Lymphocyte DisordersDisorders

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Lymphocyte DisordersLymphocyte Disorders

►Lymphocytosis: An excess of Lymphocytosis: An excess of lymphocytes in peripheral blood.lymphocytes in peripheral blood.

►Reactive lymphocytes: Used to describe Reactive lymphocytes: Used to describe transformed or benign lymphocytes. transformed or benign lymphocytes. You should use the term “reactive”, not You should use the term “reactive”, not “atypical”. The word “atypical” is used “atypical”. The word “atypical” is used to describe malignant-appearing cells.to describe malignant-appearing cells.

►A few reactive lymphocytes is not A few reactive lymphocytes is not abnormal.abnormal.

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Lymphocyte MorphologyLymphocyte Morphology

►Lymphocytes are supposed to vary in Lymphocytes are supposed to vary in size; In malignant disorders, the size; In malignant disorders, the lymphocytes appear the same size and lymphocytes appear the same size and shape because they arise from the same shape because they arise from the same monoclonal cell.monoclonal cell.

►Reactive lymphocytes:Reactive lymphocytes: May have azurophilic granulesMay have azurophilic granules Cytoplasm stains unevenly, with the Cytoplasm stains unevenly, with the

peripheral regions of the cytoplasm staining peripheral regions of the cytoplasm staining darker.darker.

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Plasma CellsPlasma Cells

►Plasmacytoid lymphocytes (plasma Plasmacytoid lymphocytes (plasma cells) have coarse, clumped nuclear cells) have coarse, clumped nuclear chromatin, a perinuclear halo, and an chromatin, a perinuclear halo, and an eccentric nucleus.eccentric nucleus.

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Causes of Reactive Causes of Reactive LymphocytosisLymphocytosis

► Infectious mononucleosis, which is Infectious mononucleosis, which is caused by the Epstein-Barr Virus (EBV), caused by the Epstein-Barr Virus (EBV), is most commonly seen in young adults is most commonly seen in young adults between the ages of 17 and 25 years of between the ages of 17 and 25 years of age.age.

►Cytomegalovirus Infection (CMV), which Cytomegalovirus Infection (CMV), which belongs to the herpes virus family, is belongs to the herpes virus family, is usually asymptomatic in usually asymptomatic in immunocompetent individuals.immunocompetent individuals.

►Other viral infections.Other viral infections.

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Malignant ConditionsMalignant Conditions

►The lymphocytes seen in malignant The lymphocytes seen in malignant disorders, such as leukemia, may be disorders, such as leukemia, may be confused with reactive lymphocytosis.confused with reactive lymphocytosis.

►Malignant cells in leukemia have the Malignant cells in leukemia have the same appearance and, therefore, are same appearance and, therefore, are morphologically different from reactive morphologically different from reactive lymphocytes seen in reactive lymphocytes seen in reactive conditions.conditions.

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Laboratory Laboratory ExaminationExamination

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Laboratory Examination Laboratory Examination 1 of 21 of 2

► Tests include CBC, serology, and microbiologic Tests include CBC, serology, and microbiologic cultures.  The most useful tests are still the CBC with cultures.  The most useful tests are still the CBC with differential and serology tests. differential and serology tests.

► Proper evaluation of peripheral blood smear crucial for Proper evaluation of peripheral blood smear crucial for correct diagnosis of absolute lymphocytosis - correct diagnosis of absolute lymphocytosis - especially for patients with infectious mononucleosis. especially for patients with infectious mononucleosis.

► Serology tests important, especially Monospot test for Serology tests important, especially Monospot test for infectious mononucleosis.  A positive Monospot and a infectious mononucleosis.  A positive Monospot and a differential with reactive lymphocytes diagnostic for differential with reactive lymphocytes diagnostic for infectious mononucleosis in some labs.  infectious mononucleosis in some labs. 

► Further serology testing differentiates among variety Further serology testing differentiates among variety of viral infections.  of viral infections. 

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Laboratory Examination Laboratory Examination 2 of 22 of 2

► Can trace course of disease by testing for IgM Can trace course of disease by testing for IgM and IgG antibodies.  IgM antibodies formed and IgG antibodies.  IgM antibodies formed early in infection, while IgG antibodies formed early in infection, while IgG antibodies formed after a couple of weeks.  Periodic testing of after a couple of weeks.  Periodic testing of antibody titers can trace course of disease antibody titers can trace course of disease through acute and convalescent phases. through acute and convalescent phases.

► If malignancies suspected, lymphocytes may If malignancies suspected, lymphocytes may be distinguished by immunophenotyping be distinguished by immunophenotyping tests. tests.