Regenerative anaemia Flashcards
What is anaemia
A reduction in erythrocyte number
Anaemia is identified by a decrease in one or more of
Red blood cell count
Packed cell volume/ haemocrit- PCV or HCT
Acute clincial features of anaemia
Pallor
Tachycardia
Muscular weakness
Subnormal temp
Coma
Death
Chronic clinical feature of anaemia
Fatigue/ lethargy
Exercise intolerance
Tachycardia
Fainting
Pallor
Cardiac number
Anaemia gives what colour change of membranes
Salmon colour to pale mucosal membranes
Anaemia can be caused by
Decreased erythrocytes entering the blood and decreased production or increase in erythrocytes exiting the blood
Anaemia can either be
Non regenerative
Regenerative
If bone marrow is functioning normally then
Increases number of reticulocytes appear in blood- takes 3-5 days to occur
Reticulocytes
Immature rbcs
How do we tell if anaemia is regenerative
Increased number of reticulocytes in the blood
Increased polychromasia
Increased anisocytosis
Manual or automated count
Macrocytic hypochromic
Nucleated red cells
What stain do we use
Methyl blue stain
What animal has no reticulocytes
Horses
What is basophilic stripping in cattle
Will release polychromasia but will have another variation- common in ruminants
What happens in regenerative anemia to the cell counts
Increased MCV
Decreased MCH
Decreased MCHC
Haemorrhagic anaemia is related to
Blood loss
Types of haemorrhagic anaemia
Acute eg. After accidents or surgery
Chronic eg. Bleeding from ulcers or tumours
Coagulopathies- clotting disorders eg, rat baits
Internal or external- bleeding through GI tract
Haemotology cbc findings features
Normocytic normochromic in first few days
In haemorrhagic regenerative anaemia features include
Macrocytic hypochromic
Polychromasia
Anisocytosis
Howell jolly bodies
Thrombocytosis
Neutrophilia
Degree of regeneration in haemorrhagic anaemia depends on
Severity of blood loss
Location of bleeding- internal or external
Internal bleeding, Fe is available for Hb synthesis which is greater regeneration
What else is lost in haemorrhagic regenerative anaemia
Proteins- not just rbcs being lost
Hypoproteinaemia- decrease in albumin and globulin
Haemolytic anaemia affects rbc survival time by
Reducing it
Haemolytic anaemia is
Reduced rbc survival time- early destruction of red cells
Blood picture features
Markedly regenerative- iron from destroyed erythrocytes is retained in the body
Additional findings depending on pathogenesis- colour of plasma, morphology of cells
Methods of red cell destruction
Extravascular lysis
Intravascular lysis
Extravascular lysis pathway
Phagocytosis of rbc or splenic enlargement
Iron and globin Haem
Biliverdin
Bilirubin
Circulation
Bilirubin and albumin
Jaundice
Intravascular lysis pathway
Lysis of rbc in circulation
Free Hb in the blood or Haemoglobinaemia- red colour in plasma
Free Hb
Haptoglobins
Phagocytosis jaundice
From addition of haptoglobins
Saturation of haptoglobins
Hb appears in kidney
Haemoglobinuria- red urine due to free Hb
Toxic nephrosis
Acquired causes of haemolytic anaemia
Infectious agents
Toxic/ oxidative compounds
Fragmentation
Immune mediated
Infectious haemolytic anaemia
Mycoplasma infection- cats
Babesiosis
Rbcs destroyed by intra or extravascular lysis
Pathogen visible on blood smear detected by PCR
Toxic and oxidative haemolytic anaemia
Oxidative agents in drugs/ chemicals can reduce glutathione levels on red cells
Haem iron can be oxidised to methaemoglobin
Haem Fe oxidation to
Methaemoglobin
What causes Heinz body formation
Oxidative damage to Haemoglobin
red cells destroyed by
Lysis
Examples of things that cause haemolytic anaemia
Paracetamol
Onions
Copper poisoning
Zinc
Brassicas
Red maple leaf
What causes fragmentation haemolytic anaemia
Rbcs subjected to excessive trauma
Features of Intravascular lysis may be present
Schistocytes, acanthocytes- different cell types
Small vessel disorder- microangiopathic
Large vessel disorder
Immune mediated haemolytic disorders pathway
Production of antibodies
Bind to red cells
Haemolysis
Blood group incompatibilities is
When blood groups mix
Blood group incompatibilities why
Blood transfusion reactions
Neonatal isoerythrolysis
Immune mediated haemolytic anaemia-IMHA
Primary/ autoimmune- idiopathic
Secondary- underlying trigger
-drugs/toxins
-infectious agents
-neoplasia
-vaccines
Canine autoimmune haemolytic anaemia. What happens?
Production of autoantibodies against own red cells
Autoantibodies lead to
Phagocytosis
Immunoglobulins involved in canine autoimmune haemolytic anaemia
IgM or IgG
Antibodies coat
Red cells
Aggulation is
When rbcs stick together
The direct Coombs test. Tests for
Immune mediated haemolytic disorder by identifying antibodies.
In the direct Coombs test once we have the antibody what is the next step
Add in reagent specific for canines then rbc will cause aggulation
What type of antibodies cause autoagglutation
IgM
What is the process of the slide agglutation test
Add saline on a slide, then add cells.
This tells agglutation, as blood cells will stick together
What is neonatal isoerythrolysis
A haemolytic disease of the newborn animals.
What is the cause of neonatal isoerythrolysis
Mother has antibodies of different blood group, if newborn has the different blood group then there is destruction of the neonates rbcs
How do a mother and neonates antibodies combine?
Absorbed through colostrum
How long does neonatal isoerythrolysis take to show signs
12 to 48hrs
What are the feline blood groups
A B AB
What blood group of felines have naturally occurring antibodies to blood group A felines
B
When does feline neonatal isoerythrolysis occur
When kittens with type A or AB are born to type B mothers
How can feline neonatal isoerythrolysis be prevented
In house blood typing kits
Prevent access to colostrum for susceptible kittens
