Lecture 21: Iron Status 2 Flashcards
What are examples of iron overload?
- Acute iron toxicity
- Hereditary haemochromatosis
- African iron overload
What type of condition is hereditary haemochromatosis?
Autosomal recessive condition
What happens during hereditary haemochromatosis?
- Poor control of iron absorption
- Iron accumulates in liver, pancreas, heart muscle
Where is the mutation that causes hereditary haemochromatosis found?
the C282Y of the HFE gene
- position 282 on the HFE gene
Is treatment of hereditary haemochromatosis effective?
Very effective if started early
What serum ferritin levels indicate hereditary haemochromatosis?
> 300 ug/L in males
200 ug/L in females
What transferrin saturation indicates hereditary haemochromatosis?
> 45% men and women
Aswell as the biochemical indices, to diagnose hereditary haemochromatosis we need…
- Confirmation of the genetic mutation
- Showing symptoms
What are the clinical methods used to detect signs and symptoms?
A medical history and a physical examination
What are the main symptoms of IDA?
Fatigue and spoon shaped nails
How can iron status be analysed on an individual level?
- Screening
- Clinical assessment
How can iron status be analysed on a population level?
- Prevalence estimates of deficiency
- Planning appropriate interventions
- Evaluating impact of interventions
What context to we need think about during individual assessment of Fe status?
- Availability of assay
- Usefulness
- Cost
What are the main indices used during individual assessment of Fe status?
- Haemoglobin
- Serum ferritin & C-reactive protein
Maybe - Serum Fe, TS
What factors affect validity of iron cut offs?
- Method of blood collection
- Fasting status
- Time of day
- Equipment used
- Infection
- Genetics
How do TS levels change throughout the day?
Morning values are higher, and then reduce across the day
How does inflammation (acute phase response) affect iron status?
- Blocks release of Fe
- Increases translation of ferritin
- Leads to shortage of Fe in bone marrow
What are measures of infection?
C-reactive protein
A-1 acid glycoprotein
A-1-antichymotrypsin
What are other sources of variation in iron levels?
- Contraceptive
- Smoking
- Altitude
- Sports anaemia
- Dehydration
What does oral contraception do to TS?
Decreases it
What does smoking do to haemoglobin levels?
Increases them
What does altitude do to haemoglobin levels?
Increases them
What does sports anemia do to haemoglobin levels?
Decreases them
What does dehydration do to indices?
Increases them
- Less fluid = higher concentration
What is sports anaemia?
temporary condition - a lower-than-normal level of hemoglobin in the blood due to increased blood volume and turnover
What is the most common cause of anaemia?
Iron deficiency
Other than iron deficiency, what else could anaemia be caused by?
- Infection
- Decreased erythropoiesis
- Genetic disorders
What is decreased erythropoiesis?
a reduction in the production of red blood cells (erythrocytes) in the bone marrow
What is thalassemia?
a genetic blood disorder characterized by the body’s inability to produce adequate amounts of hemoglobin
Inflammation affects many iron indices but particulary….
Serum ferritin
Use of Hb alone results in an overestimate of….
Prevalence of IDA
