leukocyte responses in disease

What stimulates leukocyte production/release

Infl cytokines

Leukocyte types in innate immunity → phagocytosis

Neutrophils, monocytes

Leukocyte types in adaptive immunity

Lymphocytes

Leukocyte types in parasite defence immunity + allergies

Eosinophils, basophils

Granulocyte/polymorphonuclear leukocytes (cytoplasmic granules + lobulated nu)

Neutrophil, eosinophil, basophils

Agranuloytes / mononuclear leukocytes

Lymphocytes, monocytes

Normal leukocyte morphology - a

Neutrophil

Normal leukocyte morphology - B

Lymphocyte

Normal leukocyte morphology - C

Eosinophil

Normal leukocyte morphology - D

Monocyte

Normal leukocyte morphology - E

Basophil

Leukocytosis def

Inc WBC count

Leukopenia def

Dec WBC count

Leukocyte kinetics + pools - precursors for leukocytes

Bone marrow, lymphoid tissue

Leukocyte kinetics + pools - What happens to granulocytes

Die

Leukocyte kinetics + pools - What happens to lymphocytes

Return to blood via lymph or die

Leukocyte kinetics + pools - What happens to monocytes

Transform into macrophages / dendritic cells then die

Neutrophil life cycle

Mature in bone marrow 5-7d

Short half life in blood

Migrate to tissues for function

Die or lost across mucosal surface

Left shift meaning

Hallmark of acute/active infl

Immature neutrophil release as storage dec

Band neutrophil (non segmented nu)

Features of regenerative left shift

Segmented neutrophils > immature neutrophils

Features of degenerative left shift

Immature neutrophils > segmented neutrophils

What is Pelger-Huët and how does it affect WBC analysis

Hyposegmented granulocyte hereditary disorder

→ appears like band neutrophils in left shift (infl)

Toxic changes to neutrophils

Foamy cytoplasm

Diffuse cytoplasmic basophilia

Döhle Bodies

Asynchronous nu maturation

Giant neutrophils

Toxic granules

Defects from accelerated neutropoiesis

Aetiology of Neutrophilia

Infl (infl Neutrophilia)

Excess catecholamines (physiologic Neutrophilia)

Excess glucocorticoids (stress Neutrophilia)

Chronic myeloid leukaemia

Paraneoplastic syndrome

Aetiology of Neutrophilia- infl Neutrophilia/ lymphopenia/ monocytosis causes + features

Inf, immune mediated disease, neoplasia, necrosis

Left shift if acute infl

Often not if CNS, superficial skin, lower urinary tract

Aetiology of Neutrophilia- stress Neutrophilia/lymphopenia/ monocytosis causes + features

Excess glucocorticoids

Inc neutrophils from bone marrow

With lymphopenia, monocytosis, eosinopenia

Stress leukogram features

Neutrophilia, lymphopenia, monocytosis, eosinopenia

Lymphocytosis/ eosinophilia due to hypoadrenocorticism results in (leukogram)

Neutropenia, Lymphocytosis, monopenia, eosinocytosis

Aetiology of Neutrophilia- physiologic Neutrophilia causes + features

Excess catecholamines

Transient

With Lymphocytosis, monocytosis

Aetiology of neutropenia

Inc use

Dec/ineffective production

Endotoxaemia

Immune mediated neutropenia

Haemophagocytic syndrome

Cyclic haematopoiesis (collies, FeLV)

Aetiology of neutropenia- inc use causes + features

Acute infl (When migration to inflamed tissue exceeds release from bone marrow), bacterial infections

Left shift

Aetiology of neutropenia- inadequate production causes + features

Bone marrow disorder, infection (parvo, FeLV, ehrlichia), drug toxicity (oestrogen, chemo), myelofibrosis, myelophthisis

Persistent without left shift

Lymphocytes - where are they made

Produced in bone marrow, primary lymphoid tissue

T cells mature in thymus

B + NK cells mature in bone marrow + lymphoid tissues

Types of lymphocyte

Small, intermediate, large, reactive, granular

Aetiology of Lymphocytosis

Chronic infl/antigenic stimulation

Excess catecholamines (physiologic)

Lymphoproliferative disease

Hypoadrenocorticism

Young

Aetiology of Lymphocytosis - chronic infl/antigenic stimulation features

Reactive lymphocytes, Neutrophilia, monocytosis, eosinophilia

Aetiology of Lymphocytosis - physiologic Lymphocytosis associated with

Physiologic Neutrophilia, granular lymphocytes

Aetiology of Lymphocytosis - types of lymphoproliferative disease leading to inc lymphocyte count

Neoplastic disease, chronic lymphocytic leukaemia, leukaemic phase of lymphoma

Aetiology of Lymphopenia

Excess glucocorticoids (stress)

Acute infl

Depletion (loss of fluid → enteric disease, chylothorax drainage)

Hypoplasia / destruction/ disruption of lymphoid tissue T cells- multicentric lymphoma, immunosuppressive drugs

Monocyte cytoplasm appearance

Lightly Basophilic/ amphorphilic

Vacuoles

Monocytes kinetics

Produced in bone marrow

1-3d half life in blood

Macrophages + dendritic cells longer half life

Monocytosis aetiology

Infl (acute, chronic)

Excess glucocorticoids

Secondary to neutropenia

Chronic myeloid leukaemia

Monocytosis aetiology - why is it secondary to neutropenia

Share common bipotential stem cell

What is most suggestive of acute infl

Neutrophilia + left shift

Leukocyte abnormalities in stressed dog

Neutrophilia, lymphopenia, monocytosis, eosinopenia, left shift

What is true regarding neutrophils

Infl can cause Neutrophilia

Eosinophils kinetics

Produced in bone marrow

Short blood half life

Long half life in tissues

Eosinophilia aetiology

Hypersensitivity reactions - fleas bite dermatitis, feline asthma, food

Parasitism

Infl - idiopathic (eosinophilic enteritis, eosinophilic bronchopneumonia, eosinophilic panosteritis)

Neoplasia - chronic eosinophilic leukaemia / paraneoplastic

Hypereosinophilic syndrome

Hypoadrenocorticism

Basophils kinetics

Produced in bone marrow

2-3 d half life in blood

Short tissue half life

Mast cells kinetics

Produced in bone marrow

In blood as undifferentiated cells

In tissues as long lived cells

Mast cells appearance

Large, round nu, purple cytoplasmic granules, not seen in health

Mast cells vs basophils

M- round nu, larger

B- lobulated nu

Aetiology of basophilia

With eosinophilia

Hypersensitivity

Parasitism

Neoplasia

Mastocytosis defined as

1+ mast cell in blood smear

Mastocytosis aetiology

Mast cell tumour

Acute infl disease

Which conditions are rare

Monocytopenia, eosinopenia, basopenia

Haematopoietic neoplasia def

Clonal proliferation of lymphocytes, leukocytes + their precursors (lymphoid + myeloid origin)

Haematopoietic neoplasia Features

Marked leukocytosis

Haematopoietic neoplasia Types

Acute leukaemia - poorly differentiated

Chronic - well differentiated

Leukaemic phase of lymphoma - infiltrating blood