kevin (L4) Flashcards
HAEMATOLOGY
The study of blood & in particular the medical specialty concerned with disorders of the blood
Blood and the tissues in which it is formed represent - large single organ system.
Haematopoietic system basics:
- Many key paradigms underlying stem cell biology, cancer and thrombosis.
- Involved in every aspect of patient care from:
. routine blood counts
. blood transfusion
. specialised management of patients with leukaemia or haemophilia.
Blood
CELLS - white cells (leukocytes), - red cells (erythrocytes) - platelets (thrombocytes) - very rarely other cells foetal cells, cancer cells. - DNA
PLASMA
Plasma is water, electrolytes, dissolved gases, urea, proteins, lipids, glucose & lots of other things in trace quantities
- some of which really should not be there
- alcohol? cotinine?
cell types in blood
erythrocyte (red) / 4^-6 x 10^12 / 40-50% by volume
leukocyte (white) / 4^-11 x 10^9
thrombocyte (platelet) / 1^-4 x10^11
blood cell lineages
DIAGRAM IN L4 S7
lymphoid cells
Lymphoid from lymph
the clear fluid from the thoracic lymph duct
and by extension lymphoid tissue i.e. containing (large numbers of) lymphoid cells e.g. lymph nodes, spleen
Myeloid means from bone marrow.
Erythrocyte membranes
Adaptation of erythrocyte to carrying O2 through very fine blood vessels:
- can deform to squeeze through fine (3 μm) vessels but springs back to usual shape;
- (this gets screwed up in sickle cell anaemia);
- the shape is maintained by the cytoskeletal system and allows for flexibility
erythrocytes diseases
Too few erythrocytes = anaemia
pallor, breathlessness, fatigue due to lack of O2 transport to tissues.
Too many = polycythaemia
raised blood viscosity & so strain on heart.
leukocytes are present in?
- primary lymphoid tissues where they are produced
bone marrow, thymus, - and also in secondary lymphoid tissues where they function
(( spleen, lymph nodes, mucosa-associated lymphoid tissue (MALT: e.g. Peyer’s patches mostly in gut) tonsils. ))
leukocytes in other tissues for health
Generally (in health) few leukocytes are present in other tissues
a scattering of mast cells, macrophages dendritic cells especially in the gut and skin usually in the connective tissue underlying epithelium
sometimes lymphocytes in the epithelium (intraepithelial lymphocytes).
Infection - inflammation
Leukocyte recognition
Morphology/Size – compare to RBCs
Stains and dyes
Histochemistry
Antibodies to cell surface markers
(All are cells involved with the immune response:
on the whole, lymphocytes belong to adaptive immunity
leukocytes of the myeloid series belong to innate immunity.)
leukocytes morphology
Cells in suspension are always round in tissues may form a characteristic shape e.g. dendritic cells nuclei may have distinctive shape size varies granules in the cytoplasm
leukocytes stains
Most common H&E Haematoxylin & Eosin
eosin is a pink acidic dye, binds proteins stains cytoplasm pink
haematoxylin is a blue-purple basic dye which binds nucleic acids
colouring depends on the cell type.
Platelets are the dust looking particles in the back - they are not cells, they are fragments of cells
STAIN IMAGE IN L1 S16
Leukocyte Histochemistry
Staining characteristics:
Histochemistry:
Exploitation of specific enzymes (e.g. esterases, phosphatases) within cell types convert colourless substrate into coloured product
Non specific esterases important in defining monocytic lineage related leukemias. Label monocyte lineage – brown neutrophils not good!
Leukocytes - Immunocytochemistry and Immunohistochemistry
IMMUNOLOGICAL DETECTION
- Antibody Binding of extracellular/intracellular antigens
- Antibodies linked to fluorescent chromophores = cyto
- Antibodies linked to enzymes to convert substrates = histo
types of markers and what lineage it comes from
DIAGRAM TO LEARN IN L4 S19
Flow cytometry
The different “coloured cells” are counted and the intensity of their fluorescence measured. The data is presented in a variety of formats, most usually “dot plots” (as here) where each dot represents one cell and the axes are fluorescence intensity.
Two colour flow cytometry of bone marrow aspirate from patient with myeloma showing excess of plasma cells (white blood cells, effector B cells) CD38+CD138+ (region R2)
Monocyte morphology
platelets have markers but they are not cells
monocytes are at least 3 times bigger than a red blood cell with a lot of cytoplasm in it, a lot of granules and a c-shaped nucleus
its marker is CD14+ is a protein that sits on the external surface of these cells and can be detected by antibodies
as the monocytes move out of the blood cells into the tissues they change shape
Thrombocytes = Platelets
platelets are produced by fragmentation of Megakaryocytes in the bone marrow
they attach to a site where blood vessels are forming and the membrane is pushed through holes in these blood vessels to be sheared off into platelets
that are smaller than red blood cells
plasma
Plasma is the fluid component of blood
Electrolytes, acid/base etc
Proteins: ~70 g/L classified as albumin, α globulins (1 and 2), β globulins and γ globulins
All except γ-globulins (aka immunoglobulins, Ig, = antibodies) are synthesised by the liver.
serum VS plasma
Serum is the fluid that is left after blood has clotted.
It contains all the proteins of plasma
e.g. antibodies
except those that are involved in the clot.
plasma proteins
Why are γ globulins in e.g. patients 8, 9 & 10 diffuse but in e.g. 2 & 7 clear prominent bands? Myeloma results in the production of ONE class of gamma globulin – rather than the normal diffuse band
Make sure you don’t confuse Myeloid and Myeloma The examples in 2 and 7 and even 1 here are likely producing Myeloma Protein as above the ONE class of gamma globulin. Number 5 might have a leukemia – as gamma globulins are lost and therefore susceptible to infection.
DIAGRAM IN L4 S26
these are taken from patients who might have myeloma
the gamma globulin bands are diffused because you produce a lot of different types of antibodies each of a unique size
Patients 2/4/7 have cancer because they are producing only one type of gamma globulin
Patient 5 is immunodeficient because that is not producing any type of gamma globulin and so do not have any antigen resistance
plasma proteins concentrations
albumin 35-50 g/L
alpha-globulins 5-15 g/L
- alpha-anti-trypsin 1-2 g/L
- haptoglobulin 1-2 g/L
beta-globulin 5-12 g/L
- coagulation factors 2-4 g/L
- complement 1-3 g/L
- lipoproteins 1 g/L
gamma-globulins 6-17 g/L
TOTAL 60-80 G/L
plasma protein roles
What are they for?
Many proteins are present in low concentrations and have specialised functions
polypeptide hormones (e.g. ?) regulators of blood pressure (e.g. ?) some enzymes (e.g. ?)
albumin
Albumin: a carrier for many substances with low solubility in plasma:
- especially lipids: hormones (e.g. ?), fatty acids
- binds Ca2+
- helps maintain osmolarity of blood.
High concentration of albumin in serum makes this protein a major carrier of steroids and lipophilic hormones and a regulator of their access to receptors.
Albumin is a sink for xenobiotics, diminishing the binding of xenobiotics to hormone receptors and other cellular proteins. This protects animals from endocrine disruption by xenobiotics.
Albumin will bind things with low affinity so they can bind and be removed very easily
it is both a transporter and a sink for foreign chemicals (like things you want to take to your liver to be metabolised)
