Non-Malignant Disorders of leukocytes

leukocytosis

an increase in the total WBC

WBC > 10.6 × 10³ / uL or (10^9/L)

• reference interval = 3.6 - 10.6 × 10³ / uL (10^9) (ASCP)

• reactive to infection: - bacteria, viral, fungal, tubercular, and leukemia

physiologic leukocytosis - excessive exercise, hypoxia, stress

neutrophilic leukocytosis

Relative vs. absolute values:
– Absolute neutrophilia
• Absolute total neutrophils/ul is increased > 7.5x 103/ul
• % neutrophils x WBC count
• Percent neutrophils is increased
– > 70%
• Response to bacterial infection
• Chronic Myelogenous Leukemia (CML)

Neutrophilia - relative

Relative neutrophilia
– A relative increase in % of neutrophils >70%
– without a corresponding increase in total WBC
count
– Normal neut % = 50-70%
• Left shift:
– Increase in immature neutrophils
• (bands, metas, myelos, promyelo’s)
– With decreased % mature neutrophils

neutrophilia right shift

increased presence of mature neutrophils

> 65%

hyper segmented - in B12 and folic acid deficiencies

causes of neutrophilia

Infections:
– Bacterial, some viral
• Myeloproliferative disorders:
– Chronic Myelogenous Leukemia (CML)
– Polycythemia
– Myelofibrosis
• Metabolic disorders:
– Uremia
– Diabetic ketoacidosis
– Eclampsia
• Inherited Disorders:
– Leukocyte adhesion deficiency
– Familial cold urticaria
– Hereditary neutrophilia
• Drugs such as steroids, lithium
• Smoking, Acute or Chronic blood loss, Myocardial Infarction,
Colitis, Vasculitis, Pancreatitis, Autoimmune Disease
• Stress, Exercise, Labor/Delivery, Surgery, Bur

distinguishing features between leukemoid reaction and chronic myeloid leukemia

eosinophilia

increased number of eosinophils

> 0.400 × 10³ / uL or >3%

reference 1-3%

IL-3 and IL-5 stimulate release

causes of eosinophilia

Allergic Reactions
– Asthma, rhinitis
– Food and drug allergies
• Chronic dermatoses - dermatitis
herpetiformis
• Parasitic infections, especially helminths
– Trichinellosis, Stronglyoidiasis, Hookworm,
Filariasis, Shistosomiasis
• Hepatitis, HIV
• CML – eosinophilia with basophilia
• PDGRFB Chronic Eosinophilic Leukemia
– Platlet derived growth factor beta
• AML (previous M4 Eo)
• Leukemoid reactions

basophilia

Reference: 0-2%
• Absolute Count: 0.10 x 103/ul
• > 3%
• Leukemia
– CML be presenting sign
• Myeloproliferative disease
– Polycythemia vera
• Dermatitis
• Urticaria pigmentosa
• Mast cell disease
• Chicken pox, Small pox

necrobiotic changes in WBCs

necrotic nucleus

most often seen in infections

pyknotic cells

degradation or breakdown of WBC

ehrlichosis and anaplasmosis

morulae may be seen as WBC inclusions in the first week of infection

different than Dohle Bodies

Qualitative Disorders of Granulocytes

Neutrophilic Hypersegmentation

Pelger-Huet Anomaly (neutrophilic hyposegmentation)

Pseudo-Pelger Huet

Chediak Higashi Syndrome

Alder-Reilly Anomaly

May Hegglin Anomaly

Neutrophilic hyper segmentation

> 5 lobes

caused by interference with DNA synthesis

PA, b12 deficiency

folate deficiency

methotrexate chemotherapy

benign inherited disorder

Pelger-Huet anomaly

• Neutrophil hyposegmentation of nucleus
• Benign autosomal dominant inheritance
• “pince-nez” nuclei (spectacle appearance)
• Bi-lobed, non segmented, dense nuclei
• Neutrophils are functional
• Pseudo Pelger-Huet
– AML-Leukemia
– Myeloproliferative disorder

Toxic granulation

increase production of primary granules in neutrophils

reactive change caused by bacterial infections

small, dark staining granules in cytoplasm of neutrophils and monocytes

associated with leukemoid reactions and infections

not seen in CML

toxic vacuoles

as bacteria phagocytized and digested by neutrophils, vacuoles appear in cytoplasm

peripheral blood reveals “holes” in cytoplasm of neutrophils

may also be caused by prolonged contact with EDTA

associated with leukamoid reactions and infections

not seen in CML

Dohle bodies

cytoplasmic inclusions

associated with bacterial infections

causes neutrophils to mature faster than normal

hurried development causes residual RNA in cytoplasm

single or multiple, sky blue to gray blue inclusions

associated with reactive changes in leukemoid reactions and infectios

appear also with toxic granules and vacuoles

auer rods

aggregates of primary granule

seen in myeloblasts (primarily in these) and monoblasts

AML

cytoplasmic needle-shaped, red, rods

peroxidase positive

CML, AML, AMML

immune deficiency disorders

Inherited disorders resulting in disruption or
dysfunction of immune cells
• Primarily T, B & Natural Killer Cells
• Severe Combined Immune Deficiency
• Wiskott-Aldrich Syndrome
• 22q11 Syndromes
• Bruton-Tyrosine Kinase Deficiency

Chediak-Higashi syndrome

Autosomal recessive trait
– CHS1 LYST gene on chromosome 1q42.1-2 that encodes for a
protein that regulates the morphology and function of
lysosome-related organelles
• Large lysosomal inclusions that cannot release contents
during bacterial digestion
• Fusion of primary granules
• Large peroxidase positive granules in granulocytes and
lymphocytes
• Anemia, neutropenia, thrombocytopenia
• Patients have ocular and cutaneous albinism
• Susceptible to pyogenic organisms
• Recurrent infections
• Decreased WBC count, Defective chemotaxis

Alder-Reilly Anomaly

Autosomal recessive
• Leukocyte function is not affected
• Gene prevents breakdown of mucopolysaccharides in
cytoplasm of neutrophils and monocytes
• Dense, Large, dark staining cytoplasmic granules in clusters
surrounded by vacuoles
• Mucopolysaccaridoses: Hunter’s and Hurler’s syndromes
• May be confused with toxic granulation

May-Hegglin Anomaly

Autosomal dominant
• Large (2-5 u), well defined pale blue cytoplasmic
inclusions in granulocytes
– Dohle body like inclusions
• Disordered production of myosin heavy chain type
IIA
– Thrombocytopenia with giant platelets
• Abnormal bleeding
• RNA derived from Rough Endoplasmic Reticulum.
• Characterized by mutations in the MYH9 gene

Nuclear appendages

• Drumstick appendage
• Seen in neutrophils
• Thought to be inactivated X chromosome.
• Abnormal numbers in Kleinfelter syndrome.

Lupus Erythematosus Cell (LE) cell phenomenon

neutrophil with phagocytized nuclear material

found in patients with systemic lupus erythematosis (SLE)

lymphocytosis

Increase in circulating lymphocytes
• >42-45%
• Reference: 18-42%; 1.2-3.2 x 103/ul
• 2 types: Absolute and relative
– Absolute
• 4.5 x 103/uL
– Relative
• Increase in % lymphs, < 4.5 x 103/uL absolute count
• Normal in blood of infants
– (reversed differential)
– Up to about 10 years of age

lymphocytosis - diseases and other affects

• Absolute lymphocytosis- with neutropenia:
– Viral infections (EBV & IM, CMV, Rubeola, Mumps, Rubella, Varicella, Herpes)
– Viral pneumonia, viral meningitis
• Aplastic anemia, pernicious anemia
• REACTIVE LYMPHOCYTOSIS:
– Proliferation during infections with Epstein Barr virus (EBV)
– infectious mononucleosis
– > 10% atypical lymphocytes
– Cytomegalo virus (CMV)
• Increase in atypical lymphocytes
• Leukemia
– ALL
– CLL
• Lymphoma

monocytosis

increase in the number of monocytes
Reference: 2-11 % and 0.1-1.3 x 103/ul
• >11%
• > 1.0 x 103/ul
• Causes:
– Infections (bacterial , viral, TB)
– Parasites
– Hodgkin’s disease
– Leukemia
• CML
• CMoL

leukopenia

decrease in total number of leukocytes

• below 5.0 × 10³ / uL

most often coincides with neutropenia

increased risk for infection

neutrophenia

• Absolute decrease
– neutrophils < 2.3 x 103 /ul or 2.3 x 109/L
– <50%
• Causes:
– Decreased production by bone marrow
• Aplastic anemia, Fanconi’s anemia
– Viral Infections
– Increased Destruction
• Overwhelming infection, splenomegaly
– Alcoholics, chemicals, drugs
– Starvation, anorexia nervosa
– Chemotherapy
– Radiation (think Fukushima, Chernobyl, Three Mile Island, Hiroshima)

eosinopenia

decrease in number of eosinophils

below 0.15 × 10³ / uL

causes:

• stress, shock, severe burns, blood loss, infections

• hypoadrenalism (Cushing’s syndrome)

  • elevated ACTH

• ACTH injections

lymphopenia

• Absolute count < 1.2 x 103/L (109/uL)
• <18%
• Neutrophilia (infections, leukemia)
• Immune deficiency disorders:
– Bruton’s B cell deficiency.
– SCID
– Thymic aplasia
• Aplastic anemia
• HIV
• Chemotherapy

atypical/reactive lymphocytes

• Occurrence
– Viral infections
– i.e. Infectious mononucleosis
– Epstein Barr Virus (EBV)
– Cytomegalovirus (CMV)
• General characteristics
– Pleomorphism
– Increase in nuclear and cytoplasmic size,
– Changes in cell size, shape of nucleus, chromatin pattern and
cytoplasm
– Changes in stain intensity

infectious monoculeosis

• An acute, benign, self-limiting disease caused
by Epstein-Barr virus (EBV)
• IM like illness - Cytomegalovirus (CMV)
– proliferation of atypical/reactive lymphocytes
– high titer of mononucleosis antibodies
– Presence of EBV antibodies

• Virus infects B lymphs
• Reactive lymphs are T lymphocytes reacting to
infected B cells
• Clinical findings:
– Occurrence: most frequent in children and young adults
– Virus lives in B lymphs and epithelial cells of oropharynx
– Transmitted primarily by oropharyngeal secretions , blood,
and transplacental

side effects of infectious mononucleosis

• May be severe with high fever and systemic manifestations
suggestive of septicemia or leukemia
• Most often mild and undiagnosed
• ½ population is exposed before 5 years old, ages 15 to 24 -
90% have antibodies
• Splenomegaly- 50% of patients
• Common symptoms: sore throat, headache, generalized
aching, loss of appetite, malaise, lymphadenopathy
• Incubation- 10 to 50 days; lasts 1- 4 weeks

laboratory evaluation of infectious mononucleosis

• Laboratory evaluation:
– Lymphocytosis
– leukocyte count increases as disease progresses
– Absolute lymphocyte count is >4.5 x 103/ul
– Relative lymphocytosis 60-90 %
– with > 10% reactive lymphocytes
– Plasmacytoid lymphocytes
– Heterophile Antibodies
– Monotest or Monospot: positive after 1 week
– CMV titre : negative

cytomegalovirus (CMV)

• Absolute lymph count > 4.5
• Blood – reactive lymphs > 10%
• Heterophile abs – negative
• EBV antibodies- negative
• CMV antibodies- positive- IgG, IgM

leukemoid reaction

• Non-leukemic leukocytosis
• WBC > 30,000/ul
• Peripheral blood change resembling leukemia, but
due to other cause
• Lack of myeloblast in Peripheral Blood
• Shift to the left
• LAP increased
• Cause: infections, pneumonia, meningitis,
tuberculosis, inflammation, metastatic cancer

general characteristics:

aka leukoerythroblastotoic reaction

increase in total number of leukocytes (50,000 - 100,000) as well as presence of immature and pathological forms in peripheral blood

presence of nucleated RBCs in blood

leukemoid reactions fall in the following categories

• Neutrophilic leukemoid reaction
– infections: bacterial, viral, parasitic, TB
– causes similar to leukocytosis
– trauma: electrical, chemical, ischemia, bleeding
– collagen vascular diseases: SLE, RA
– neoplasm- metastisis in bone marrow

• Hematologic causes
– myeloproliferative disorders
– hemolytic anemias: transfusion reactions
– folic acid therapy of megaloblastic anemia of pregnancy
– recovery of drug induced agranulocytosis
• Splenectomy
• Gram negative bacilli endotoxins
• Exercise, convulsions, post surgery, uremia, diabetes,
gout, genetic and idiopathic

differentiating between leukemoid rxn and CML

lab evaluation of leukemoid rxn

• WBC count
• Detailed differential
• LAP count (leukocyte alkaline phosphatase)
– differentiates CML and leukemoid rxn
– > in leukemoid rxn, > 100
– < in CML, < 10
• Check for Philadelphia chromosome +