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Posts Tagged ‘iron’

Anaemia and Arthritis

Iron Deficiency B12 Deficiency

Pernicious Anaemia

Anaemia of Chronic Disease
RBC Size Microcytic Macrocytic Normocytic
MCV (82-99) Decreased Increased Normal
MCH (27-32) Low Normal or High Normal
TIBC High Normal Normal or Low
Ferritin (10-291) Low High Normal  or High
B12 (130-700) Normal Low Normal
Folate (200-650) Normal Normal Normal
RBC (4-5) Low Low Low
Hb (12-16) Low Low Low

I am waiting on the results of some blood tests. My previous blood results showed I was anaemic and I was prescribed iron tablets. I’ve been doing a bit of research into anaemia and there are lots of different types. In all types of anaemia your red blood cell and haemoglobin (the bit inside your red blood cells that is made with iron) are low.

The most common one that most people have heard of is, iron deficiency anaemia, this is the one that is helped by iron pills (or by eating lots of black pudding and chocolate, yum!). From what I can gather, if your red blood cells look small down the microscope, the volume of your red blood cells is small. Your iron stores (ferritin) are low, your mean cell (MCH) haemoglobin is low but your total iron binding protein is high then you probably have iron deficiency anaemia (assuming your B12 and folate levels are normal).

Another type of anaemia is pernicious anaemia, which is caused by your bodies inability to absorb the vitamin B12. This type of anaemia is not cured by taking iron pills, you need to have B12 injections (roughly every 3 months). To be diagnosed with this you need to have low levels of B12 and high levels of iron stores (ferritin), your red cells will also look bigger than normal down the microscope. Unlike iron deficiency anaemia your total iron binding protein will be normal and so will your mean cell haemoglobin.

There is another type of anaemia, related to inflammatory conditions like psoriatic and rheumatoid arthritis, this is caused by high (untreated) levels of inflammation in your body. It is quite hard to tell it apart from iron deficiency anaemia (and some people can have both at the same time). If you are anaemic and you have an inflammatory condition and all your other blood results are normal you probably have an “anaemia of chronic disease”. Sometimes people with high inflammation do show a raised ferritin level, but if the B12 level is normal then this isn’t caused by pernicious anaemia. Anaemia of chronic disease improves when the underlying condition is treated and doesn’t improve with iron tablets.

Interestingly pernicious anaemia can be an autoimmune disease (like psoriatic arthritis, rheumatoid arthritis and thyroid problems).  If you have one autoimmune disease you are more likely to get another. My Grandmother had pernicious anaemia and an underactive thyroid which is why I did a bit more research into anaemia and psoriatic arthritis. Hopefully I’m just tired and anaemic because of the psoriatic arthritis and not because I have something else wrong with me!

I like to learn things by looking at pictures, so I also drew the table at the top with some diagrams, which help me remember the important points.  I still forget what questions to ask when I see my GP though!

Aneamia Table

Information from

http://en.wikipedia.org/wiki/Total_iron-binding_capacity

http://www.nursingtimes.net/nursing-practice-clinical-research/laboratory-diagnosis-and-investigation-of-anaemia/203856.article

http://www.aafp.org/afp/20030301/979.pdf

http://www.arc.org.uk/arthinfo/patpubs/6269/6269.asp

Pathophysiology By Carie Ann Braun, Cindy Miller Anderson (Pg 398) (found using google books searching for folate, iron deficiency anemia)

The reference ranges given in the table are from a UK NHS hospital and apply to females.