M103 T2 L4 Flashcards
What is the % red cells after centrifugation?
~ 45%
What is the number of red cells per litre?
4 x 10^12/L
What are the symptoms of acute anaemia?
Lethargy, Headache
Dyspnea
Palpitations - racing heart or ear ‘whooshing’
Often non-specific symptoms
What are the signs of anaemia? (PTTK)
Pallor (paleness)
Tachypnoea
Tachycardia
Koilonychia - curling of finger nails
What are the five broad causes of anaemia?
Bleeding- chronic or acute Deficiency in necessary components - Iron, B12, folic acid Haemolytic Bone Marrow Dysfunction / Infiltration Poor O2 Utilisation / Carriage
What causes Hemolytic anemia?
increased haemolysis
shortened RBC lifespan due to cell fragility
What is the most common type of anaemia and where?
Iron deficiency anaemia
in the UK and in the world
What are the causes of iron deficiency anaemia?
Bleeding (esp. occult) Diet paired with something else - vegan / vegetarian, malabsorption, nutrient deficiency Increased requirements (Pregnancy but usually supplimented)
What substance in the body is measured to gauge how much iron is in the body and what’s a disadv?
ferritin, but levels can be misleadingly normal
What are the diagnostic tests for iron deficiency anaemia?
Serum Ferritin
Serum Iron
Transferrin
% Transferrin Saturation
What types of bleeding can lead to iron deficiency anaemia?
Menstrual bleeding
Occult GI Malignancy bleeding
GI peptic ulceration bleeding
What three types of categories of RBC size can be used to diagnose anaemia?
Microcytic (small)
Macrocytic (large)
Normocytic (normal)
What is the usual Mean Corpuscular Volume?
Normally about 80-100fL
What deficiencies must be ruled out before diagnosing another type of anaemia other than Macrocytic anaemia?
B12 and folate deficiency
Myelodysplasia
What conditions are related to normocytic anaemia?
Anaemia of chronic disease
Acute haemorrhage
Renal failure
How long do RBCs last in circulation?
100 days
How are reticulocytes counted and how?
flow cytometry, it counts cells with RNA
What can reticulocyte counts indicate the rate of?
the production of RBCs in bone marrow
What cells are present in the blood film of a patient with iron deficiency?
Pencil and Target Cells
What history is taken for when anaemia is suspected?
Dietary, Travel history Ethnicity, family history any GI Symptoms Menstrual history - menorrhagia Bowel history - coeliac / Crohn’s disease
What are symptoms of an issue in the GI?
Dyspepsia / Reflux
Change in bowel habit (melaena)
Weight loss- bowel malignancy
What are the causes of a B12 deficiency?
Dietary - strict vegans, is supplemented with oral B12
malabsorption
can lead to pernicious anaemia
How is pernicious anaemia caused?
parietal cell loss
leads to a deficiency of IF
AAR it cannot absorb B12 in the terminal ileum
How is pernicious anaemia confirmed and treated?
confirmed - check for autoantibodies
treatment - B12 injections (load initially then every 3 months)
What are the causes of a folate deficiency? (DEMAD)
Dietary (most common cause)
Excess utilisation
Malabsorption
Alcohol, Drugs
What are two conditions associated with malabsorption?
Coeliac and Crohn’s disease
What are two conditions associated with the excess utilization of folates?
Chronic haemolysis
Pregnancy
Which drugs could cause a folate deficiency? (PM)
Phenytoin
Methotrexate
What is the most common form of anaemia in hospitalised patients?
anaemia of chronic disease
What are the most common causes of anaemia of chronic disease? (CARC)
Cancer, Auto-immune conditions
Renal failure
Chronic inflammation or infection
What is an example of a chronic infection and an auto-immune condition associated with anaemia of chronic disease?
chronic - TB
auto - rheumatoid arthritis
How does the poor utilisation of iron in the body occur?
Iron is stuck in macrophages of the RES
so it can’t be mobilised into the erythroblasts
What is the dysregulation of iron homeostasis caused by?
Decreased transferrin
Increased hepcidin
Immobilised transferrin
What are the less common causes of anaemia of chronic disease?
poor utilisation of iron in the body
dysregulation of iron homeostasis
Impaired proliferation of erythroid progenitors
How is the proliferation of erythroid progenitors impaired?
due to a blunted response to Epo
an unavailability of iron
Clinically, what is the effect of a low MCV?
iron deficiency or beta thalassemia trait
What is the genetic cause behind sickle cell anaemia?
a point mutation in beta globin gene causing HbS
What is a sickle cell crisis caused by?
low blood O2 level
the blockage of capillaries due to non-uniform flow of sickle RBCs
What can a vaso-occlusive crisis lead to? (PONI)
pain
organ damage
necrosis
ischaemia
What are a few causes of a vaso-occlusive crisis?
Hypoxemia
Dehydration
Changes in body temperature
How is a vaso-occlusive crisis managed medically? (HAT)
Hydration
Analgesics
Transfusion
What are the genetics of SCD?
inheritable, autosomal recessive
How does SCD occur?
there is a Mutated Sickle Haemoglobin (HbS) Hb forms long filamentous strands becomes insoluble at low O2 tension RBCs become inflexible and spiky results in crisis
What are some health benefits of having sickle cell trait?
much lower risk of sickling and crisis
resistance to malaria infection
What are the genetics of a person with sickle cell trait?
when one sickle cell gene and one normal gene is present - heterozygous for HbS and HbA
they usually do not have any of the symptoms of SCD, but they can pass the trait on to their children
What are the causes of thalassaemia?
the insufficient production of normal Hb due to an imbalance of a / b chains
Inherited autosomal recessive in either a / b thalassaemia
What are the clinical features of thalassaemia?
enlarged spleen, liver, and heart
bones may be misshapen
What is B-thal major like genetically and how is it managed?
homozygous
life-long transfusions
What is B-thal minor like genetically?
heterozygous
carrier (B-thal trait)
a patient with the condition is usually healthy
What are the symptoms of leukaemia?
Non-specific symptoms
but eventually leads to bone marrow failure
What are the symptoms of lymphoma?
Lymphadenopathy
Weight loss
What are the symptoms of myeloma? (HARf)
Hypercalcaemia
Anaemia
Renal failure
How are the underlying causes of chronic anaemia treated?
iron supplementation (oral ferrous sulphate 3 months) folic acid (oral folate for 3 months) B12 (load initially then injections every 3 months)
How is chronic anaemia managed?
EPO weekly sub-cut injections in patients with kidney failure or receiving haemodialysis
What are the causes of long-term transfusion?
Iron overload (deposits in organs) Allo-antibodies (to foreign RBCs)
What are the socio-economic consequences of chronic anaemia?
poor pregnancy outcome
impaired physical and cognitive development
increased risk of morbidity in children
reduced work productivity in adults
contributes to 20% of all maternal deaths
What is the % transferrin saturation for iron deficiency and for overload?
iron deficiency - less than 20%
iron overload - more than 50%
How common are neutrophils as WBCs?
they make up approximately 40% to 60% of WBCs in our bodies
How many types of TLRs are there in the human body?
10 different versions
In what populations is SCD common?
How does SCD affect life expectancy?
Sub-Saharan Africa
Shortened life expectancy
When are reticulocyte counts low?
during precursor deficiencies (e.g. iron)
if bone marrow infiltrated
When are reticulocyte counts high?
chronic bleeding and haemolysis
Why might a reticulocyte count be within a normal range in an anaemic patient?
It means that the bone marrow is not responding appropriately
What is a clinical use of reticulocyte counts?
can be used to monitor progress of treatment - causes polychromasia on a blood film (large blue-ish red cells)
What is the normal reticulocyte level count and that in SCD patients?
normal - 1%
SCD - >10%
What conditions can be seen in the blood film of a patient with iron deficiency?
Hypochromia
Microcytosis
What is a low MCV caused by?
having a low Hb and a high RBC
What is a high MCV caused by?
having an extremely low Hb and a low RBC
Clinically, what is the effect of a high MCV?
megaloblastic anaemia due to B12 or folate deficiency or myelodysplasia
What is sickle cell anaemia caused by?
genetic mutation - HbS
an increased RBCs turnover = approx 20 days due to haemolysis
raised reticulocytes >10%
How do immunosuppressants work?
they slow down the body’s immune system to help reduce inflammation
What are the two condition types is Methotrexate used to treat?
inflammatory conditions
autoimmune conditions
What is an example of an autoimmune condition that Methotrexate is used to treat?
sarcoidosis
What are examples of an inflammatory condition that Methotrexate is used to treat?
rheumatoid arthritis
psoriasis (including psoriatic arthritis)
Crohn’s disease
When administered as an injection, what is Methotrexate used to treat?
some types of cancer in hospitals
By what forms is Methotrexate administered for inflammatory or autoimmune conditions?
tablets
a medicated drink
pre-filled injection pens or dermal syringes (if pills or drink aren’t working)
What is trigeminal neuralgia caused by?
an inflammation of the fifth cranial nerve
What is the pain caused by trigeminal neuralgia like?
sudden, intense, severe lightning-like pain
What is Phenytoin used to treat?
epilepsy
trigeminal neuralgia
How is Phenytoin administered?
chewable or dissolvable tablets
capsules
medicated drink
What areas of the body are commonly the first places where sarcoidosis will develop?
lungs, skin, lymph nodes
What are the two most common types of arthritis?
osteoarthritis (most common)
rheumatoid arthritis
What group of people does osteoarthritis most often develop in?
mid-40s or older
women
family history of it
What area is first affected by osteoarthritis?
the smooth cartilage lining of the joint
How does osteophytes develop from osteoarthritis?
the smooth cartilage joint lining is affected
movement is more difficult than usual, leading to pain and stiffness
the cartilage lining starts to roughen and thin out, the tendons and ligaments have to work harder
cause swelling and the formation of osteophytes
What is the effect of severe loss of cartilage?
bone rubs on bone, altering the shape of the joint and forcing the bones out of their normal position
What are the effects of osteoarthritis?
osteophytes develop
swelling
severe loss of cartilage
What does flow cytometry involve?
the cells are suspended in a fluid and injected into the flow cytometer instrument
What is the purpose of flow cytometry?
to detect physical properties of cells
What areas are usually affected by rheumatoid arthritis?
the hands, feet and wrists
What part of the body is affected by Myelodysplasia?
the bone marrow (cancer)
What is the effect of Myelodysplasia?
low levels of 1+ blood cell types in circulation
What age group is Myelodysplasia common in?
people aged over 70
