Lymphoid and Myeloid Flashcards
(148 cards)
1
Q
Myeloid
A
Anything to do with the bone marrow and the cells it produces
2
Q
Which cells are myeloid?
A
Granulocytes (neutrophils, eosinophils, mast cells)
Monocytes
Macrophages
Erythrocytes
Thrombocytes
Dendritic cells
3
Q
Which cells are lymphoid?
A
Lymphocytes
4
Q
Which tissues are lymphoid?
A
Lymph nodes
Thymus
Spleen
Peyer’s patches
5
Q
What hormone is associated with physiological leucocytosis (‘fight/flight’)?
A
Epinephrine
6
Q
What hormone is associated with physiological stress (‘stress leukogram’)?
A
Corticosteroid
7
Q
What is different about a stress leukogram in hypoadrenocorticism/Addisonian crisis?
A
Insufficient cortisol being produced to stimulate a stress leukogram
8
Q
In which ways is the myeloid/lymphoid system stimulated?
A
Epinephrine
Corticosteroid
Iatrogenic antigenic stimulation (vaccine)
Inflammation
Infection
Parasites/foreign bodies
9
Q
Lymph node enlarges as part of immune response to lymphatic drainage from affected site
A
Reactive hyperplasia
10
Q
Infection or inflammation of the lymph node
A
Lymphadenitis
11
Q
Non-neoplastic lymphadenopathy pathophysiology (2)
A
Reactive hyperplasia
Lymphadenitis
12
Q
Investigating a lymphadenopathy
A
History (infection/inflammation/medication)
Physical exam (LN enlargement)
Imaging?
FNA?
13
Q
What is chyle?
A
Mixture of lymph and chylomicrons
14
Q
What are chylomicrons?
A
Lipids absorbed from intestine and transported via lymphatics
15
Q
What are the causes of chylous effusions?
A
Rupture (trauma)
Obstruction of thoracic duct or other major lymphatic vessel (neoplasia)
Often idiopathic
16
Q
How does chylothorax usually present?
A
Bilateral pleural effusion
17
Q
Management of chylothorax
A
Thoracocentesis (therapeutic and diagnostic)
Surgical closure of thoracic duct?
18
Q
Lymphangiectasia pathophysiology
A
Intestinal lymphatics dilate, chyle lost in lumen (protein losing enteropathy)
19
Q
Causes of lymphangiectasia
A
Idiopathic
Congenital
Acquired obstruction (neoplasia)
20
Q
Is lymphangiectasia more common in dogs or cats?
A
Dogs
21
Q
Management of lymphangiectasia
A
Low fat diet
+/- Immunosuppressives (prednisolone)
22
Q
Diagnosis for lymphangiectasia
A
History (GI signs)
Physical exam (low BCS, ascites)
Biochemistry (hypoalbuminaemia/hypocholesterolaemia)
Haematology (lymphopaenia very suspect, not always seen)
Ultrasound (hyperechoic lacteals)
Biopsy (endoscopic or surgical)
23
Q
What is seen in endoscopic biopsy of lymphangiectasia?
A
White bumps in lumen where lacteal ducts have dilated
24
Q
Risk of surgical biopsy in lymphangiectasia
A
Low albumin associated with wound dehiscence
24
Risk of surgical biopsy in lymphangiectasia
Low albumin associated with wound dehiscence
25
Aplastic anaemia
Failure of myeloid cell production
26
In what order do cell lines become depleted in aplastic anaemia?
Neutropaenia, then thrombocytopaenia, then anaemia
27
Aplastic anaemia is usually secondary to...
Toxicity
Adverse drug reaction
Infection (Ehrlichia, parvo, FLV)
28
Pure red cell aplasia
Failure of erythrocyte production
Rare, may be secondary to FeLV
29
How do bone marrow infiltrates cause non-neoplastic myeloid disease? (Rare)
Myelofibrosis
Gelatinous transformation
30
Myeloid cell neoplasias
Mast cell tumour
Histiocytoma
Transmissible venereal tumour
31
Myeloid leukaemia key features
Rare
Acute: immature cells
Chronic: differentiated cells
32
What is polycythaemia vera?
Chronic form of myeloid leukaemia where excess erythrocytes are produced by the bone marrow
33
Where is the visceral form of mast cell tumour found in cats?
Spleen
Lymph nodes
Liver
34
Histiocytoma key features
Common
Young dogs (<2y)
usually benign
Can regress over several weeks
35
What can a histiocytoma look like?
Mast cell tumour
36
What tumour would you suspect with this presentation?
Transmissible venereal tumour
37
Treatment for transmissible venereal tumour
Chemotherapy (e.g. vinchristine)
38
What tumour is likely to be associated with this cytological finding?
Mast cell tumour
39
Lymphoid neoplasias
Lymphoid leukaemia
Plasmocytoma
Lymphoma
40
Lymphoid leukaemia key features
Rare
T/B/natural killer cells
Acute or chronic
41
Is plasmacytoma malignant or benign?
Benign
42
Does B or T cell lymphoma respond better to therapy?
B (remember B = better)
43
What structure does a T-zone indolent lymphoma usually affect?
Submandibular lymph node
44
What are the problems with treatment of a T-zone indolent lymphoma?
Low Ki67 index
Surgical removal of lymph node may be attempted
45
Rare cutaneous form of lymphoma
Epitheliotropic
46
Reasons for WBC number/morphology change in blood
Infection
Stress related (inflammation/endocrine)
Lymphoid/myeloid neoplasia
47
Where are neutrophils produced?
Bone marrow
(Occasionally extramedullary haematopoiesis: spleen/liver etc.)
48
What are the stages of immature to mature neutrophils?
Myeloblast
Progranulocyte
Myelocyte
Metamyelocyte
Band
Segmented
49
Which neutrophils stages are proliferating and maturing?
Myeloblast
Pyogranulocyte
Myelocyte
50
Which neutrophil stages are just maturing and may be found in blood?
Metamyelocyte
Band
Segmented
51
Stages required for a cell to leave blood vessels
Marginalisation
Adhesion
Migration
52
Factors which cause cells to shift from marginal to circulating pool
Epinephrine
Glucocorticoids
Infection
Stress
53
What happens when cells shift from marginal to circulating pool?
Apparent increase in circulating volume without increase in production
54
How do cells become marginalised?
Binding selectin receptors on blood vessels to ligands on cell walls
55
Causes of neutrophilia
Inflammation (infection/immune mediated anaemia/necrosis)
Steroids (stress/therapy/HAC)
Physiological (epinephrine/excitement/fear)
Chronic neutrophil leukaemia
Paraneoplastic
Leukocyte adhesion deficiency
56
If there are more segmented neutrophils than immature and neutrophil numbers are increased then is the left shift regenerative or degenerative?
Regenerative
57
If there are more immature neutrophils than segmented and neutrophil numbers are increased/decreased/normal then is the left shift regenerative or degenerative?
Degenerative
58
What happens in a right shift?
Glucocorticoids down-regulate adhesion molecules, less neutrophils leave circulation
59
Common causes of neutropaenia
Inflammation (per-acute/overwhelming bacterial infections, parvo)
Decreased production (infections, toxicity, neoplasia, marrow necrosis, myelofibrosis)
60
Rare causes of neutropaenia
Immune mediated
Chediak-Higashi
Acyclic haematopoiesis (grey collies)
Canine hereditary neutropaenia
61
Causes of neutrophil toxic change
Usually severe bacterial infection
Parvo
IMHA
Acute renal failure
DIC
Neoplasia
62
Prognosis when there is lots of neutrophil toxic change
Poor
63
What is this cytological finding?
Neutrophilic toxic change (foamy cytoplasm, dispersed organelles)
64
What is this cytological finding?
Dohle bodies (focal blue grey cytoplasmic structures)
65
Cytological features of reactive lymphocytes
More cytoplasm
Most cytoplasmic basophilia
Perinuclear halo
Prominent golgi zone
Larger, eccentric, cleaved nucleus
More large/medium sized (small in peripheral blood)
66
Functional lymphocyte inclusions
Large granular lymphocytes
67
Infectious lymphocyte inclusions
Ehrlichia
Distemper
68
Metabolic lymphocyte inclusions
Lysosomal storage diseases
69
In which age group are reactive lymphocytes more prevalent?
Young animals
70
Reasons for lymphocytosis
Physiological
Chronic inflammation
Young animals/recent vaccination
Lymphoproliferative disorder (FeLV/BLV)
Hypoadrenocorticism
71
Why is lymphocytosis seen with hypoadrenocorticism?
Loss of normal lymphocyte inhibition by glucocorticoids
72
Causes of lymphopaenia
Stress/steroid
Acute inflammation
Loss of lymph (chylothorax/lymphagiectasia)
Cytotoxic drugs/radiation
Immunodeficiency
Lymphoma
73
Where are monocytes found?
Blood
74
Where are macrophages found?
Tissue
75
What are monocytes and macrophages responsible for?
Phagocytosis
76
Causes of monocytosis
Inflammation
Steroid/stress
Monocytic/myelomonocytic leukaemia
77
Cause of eosinophilia
Hypersensitivity
Parasitism
Hypoadrenocorticism
Paraneoplastic (mast cell)
Idiopathic syndromes (canine eosinophilic bronchopneumopathy, myositis, feline eosinophilic granuloma)
Eosinophilic leukaemia (rare)
78
When are nucleated red cells seen in moderate numbers?
Regenerative anaemia
Lead toxicity
Extramedullary hematopoiesis/EMH
Splenic contraction
Damaged marrow
Erythroleukaemia
79
How should you confirm WBCC?
Smear
80
Neoplastic condition of the bone marrow in which neoplastic cells of lymphoid or non-lymphoid stem cells undergo clonal expansion with or without cellular differentiation
Leukaemia
81
Which tissues may be infiltrated by leukaemic cells in the circulation?
Liver
Spleen
Lymph nodes
82
What is the cause of clinical signs in leukaemia?
Failure of normal marrow function
Infiltrated organ dysfunction
Hyperviscosity
Paraneoplastic syndromes (IMHA, hypercalcaemia)
83
Specific B-cell (plasma cell) neoplasia
Myeloma
84
Is AML (acute myeloid leukaemia) or ALL (acute lymphoid leukaemia) more common in dogs and cats?
AML more common
85
Is AML (acute myeloid leukaemia) or ALL (acute lymphoid leukaemia) more responsive to aggressive therapy?
ALL
86
How are cell types differentiated in acute leukaemias?
Not cytology as morphology is similar
Immunophenotyping
(Cytochemistry)
Clonality testing (PARR/ PCR for Antigen Receptor Rearrangements)
87
How are cell types differentiated in chronic leukaemia?
Cytology (morphology of cells close to normal but there are too many)
88
4 main reasons there might be a lymphadenopathy
Reactive hyperplasia
Lymphadenitis
Metastatic neoplasia
Lymphoma
89
FNA lymph node findings with reactive hyperplasia
Cytologically indistinguishable from normal (heterogenous, majority small cells, some plasma cells/macrophages, few neutrophils/eosinophils/macrophages)
90
Lymph node FNA findings in lymphadenitis
Increased neutrophils/eosinophils
Inflammatory cells mildly increased or completely replace normal structure
91
Lymph node FNA findings in metastatic neoplasia
Carcinoma cells
Mast cells
Melanoma cells
92
Lymph node FNA findings in lymphoma
Increased % of large immature lymphocytes (>50%)
More mitoses than reactive
More tingible body macrophages
More lymphoglandular bodies (cell fragility)
93
Reactive or neoplastic lymph node FNA?
Reactive
94
Reactive or neoplastic lymph node FNA?
Neoplastic
95
What organ is this?
Spleen
96
What is the pink?
Red pulp
Meshwork of sinusoids with blood and macrophages
97
Function of red pulp
Removal and destruction of erythrocytes (damage/antibody coated)
Retrieval of iron from erythrocyte destruction
Blood storage
98
What is the purple?
White pulp
99
What is the function of white pulp?
T and B lymphocyte system (Ag processing)
100
What are all of these?
Incidental findings in older animals, not significant
101
Causes of splenomegaly
Infection/reactive hyperplasia
Congestion (barbiturate euthanasia/Anthrax/torsion)
Neoplasia
Autoimmune haemolytic anaemia
102
What can cause a splenic nodule?
Haematoma
Hyperplasia
Abscess
103
What is seen in this spleen?
Reactive hyperplasia to white pulp lymphoid tissue
104
What is seen in these spleens?
Senile hyperplasia
105
Reasons for splenic haemorrhage
Haemangiosarcoma
Benign haemangioma
Splenic rupture (GDV)
106
What neoplasia causes blood filled irregular channels on histology of spleen?
Haemangiosarcoma
107
Primary neoplasia of the spleen
Lymphoma (diffuse and white in bad cases)
108
Site of T cell maturation
Thymus
109
What organ is this?
Thymus
110
What happens to the thymus after puberty?
Involutes (still present)
111
Responses of thymus to injury
Lymphoid atrophy/depletion
Haemorrhage/haematoma
Neoplasia
(Inflammation)
112
Are cysts a concerning finding in the thymus?
No, incidental and not a problem
113
Viral infections that cause thymus depletion
EHV1
FPV
CPV
CDV
FIV
114
When do cats develop thymic lymphoma?
FeLV
115
What is SCID/Severe Combined Immunodeficiency?
Constellation of entities which vary in severity but all result in failed production of lymphocytes
116
Immunocompromised
Any aspect of host defense is deficient
117
Immunosuppressed
Immune defense is specifically impaired
118
Immunodeficient
Body's immune response is compromised or absent
119
Morbillivirus, RNA, enveloped virus which destroys a number of cells but has a tropism for lymphocytes?
Canine Distemper Virus
120
Infection with canine distemper virus
Oronasal infection (inhale aerosol)
Replication in local lymphoid tissue
Enters macrophages
Disseminated into local lymph nodes
Spreads to other haemopoietic organs (spleen, bone marrow etc.)
121
What virus would you suspect with these changes to the nasal planum?
Canine distemper virus
122
How is canine distemper virus prevented?
Part of core vaccinations
123
Non enveloped DNA viruses that have a tropism for fast dividing cells (GI tract crypts, bone marrow, lymphoid tissue)
Canine parvovirus 2 and feline panleukopenia virus
124
What precaution should be taken due to the fact that CPV and FPV are related viruses?
Do not isolate puppy in a kitten ward
125
Pathogenesis of CPV/FPV
Panleukopaenia: destruction of white blood cell precursors in bone marrow
Vomiting and diarrhoea: sequestration of neutrophils within GI tract = damage to barrier = bacterial translocation (use antibiotics suitable for E. coli)
126
Retrovirus RNA virus in oncovirus family that causes tumours in cats
Feline Leukaemia Virus
127
Transmission of FeLV
Mutual grooming ('love virus')
Bites (rare)
Transplacental
128
Risk factors for FeLV
Young (more susceptible, groomed by mother)
Increased population density
Poor hygiene (unwashed bowls)
Shared bowls
129
Clinical stages of FeLV
Abortive
Regressive
Progressive
130
Once cats have progressive FeLV what can happen?
They can come in and out of regressive/progressive
131
How is FeLV different to FIV?
More severe, less selective (pancytopaenia)
132
Retrovirus RNA virus of lentivirus genus that is closely related to HIV
Feline Immunodeficiency Virus
133
Do cats have to be clinically affected with FIV to have a positive serology?
No
134
Transmission of FIV
Deep wounds inoculated with saliva
(Kittens born to persistently infected queens rarely infected but antibodies may be present)
135
Pathophysiology of FIV
Infects CD4+ T lymphocytes (helper cells), dendritic cells and macrophages
Functional immunodeficiency leading to AIDS-like deterioration
136
ats at risk of FIV
Promiscuous (unneutered)
Old
Male
Stray (free-ranging)
137
What disease is associated with severe stomatitis
FIV
138
Control of FIV
Vaccination not recommended
139
Enveloped RNA virus causing FIP which is ubiquitous in the feline population
Feline Corona Virus/FCoV (enteric virus)
140
Pathophysiology of FIP
Mutation allows FCoV to infect monocytes
Extravasation of monocytes (become macrophages)
Increased vascular permeability leading to effusions
141
Clinical sign of FIP
Pyrexia
Fluid in abdomen
Uveitis
142
What disease can cause uveitis in cats?
FIP
143
Forms of FIP
Effusive ('wet')
Non-effusive ('dry')
144
How does the effusive form of FIP usually present?
Fluid in any body cavity (pleural, pericardial, abdominal)
145
How does non-effusive form of FIP usually present?
Ocular and neurological presentations
146
What if the main factor in severity of FIP?
Cats immune system
147
What is antibody-dependent enhancement/ADE in FIP?
The potential for exacerbation of disease by pre-existing antibodies
