Red cell antibodies in blood

I broke my arm a few weeks ago and had to have an operation to put two plates in my arm. Before the op they took blood samples.

This morning I got a letter through from the national blood service to say that my blood tests showed that there are red cell antibodies (anti-M antibodies) present in my blood. It says that usually, these develop after either a pregnancy or transfusion, but can occaisionally develop on their own. I've never been pregnant or had a tranfusion. The letter says that that these antibodies do not affect my health, but antibodies can affect the baby if you are pregnant.

I gave blood about a year ago and didn't receive a letter about these antibodies. I'e tried looking them up on the net, but all I can find about them is problems with matching blood for transfusions.

Does anybody know how I developed these antibodies or what they are? How do they affect babies during pregnancy? Is it a common thing or am I a rarity?

Thanks to any info anyone can give!

ok, firstly i want to be sure (this sounds really daft) that you don't mean Rh or Rhesus antigen.
I'm sure there probably is an M antigen too. ITs one of those things that some people have, and some don't. i've never even heard of M antigen, but there are so many minor ones out there, you often don't hear of them.

if you have a baby with someone who is M positive, and so make an 'M positive' baby, the worry is these antibodies will cross the placenta (as antibodies can) and attack the blood cells in the baby, causing many problems.

However, i would suspect M antigen is a very minor one which will be unlikely to cause a major reaction.
How did you get these antibodies? well if you've been pregnant and spontaneously aborted without ever realising you were pregnant - that can happen. or if you had blood mixing at some point - perhaps even during your own birth. Who knows.

If you are concerned, see your doctor. but i personally have never heard of them specifically.

Antibodies are different to antigens.
Anitbodies recognise antigens (which are proteins on the cell surface) and can neutralise the cell.
The best example of this is our white blood cells which produce antibodies that recognise the antigens on bacterial cells, and are able to destroy the bacterial cells.

I have no idea of the severity of the problem you have, but I would suspect that it involves a very minor risk that your body would sense these antigens on the cell surface of a developing embryo and destroy them, i.e. a spontaneous abortion very soon after fertilisation. (According to my biology A level text books, these kind of spontaneous abortions may occur in up to 30% of fertilisations, without the woman ever knowing.)

Go and talk to your doctor, and ask them for more information, as they are the best equipped people to inform you.

don't believe everything you read in an A-level text book...