Hi everyone!

 

I was just wondering if anyone has had experience with Anti-G - if so could you share your experience with it?  I was asked about it today by an MD (his patient is pregnant) and I want to be able to give him more information.

 

Thanks everyone!!

Sara

Hi Sara,

I've had quite a bit. What do you particularly want to know, apart from the fact that, unless the titre is really high, it rarely causes severe haemolytic disease of the foetus and newborn?

With best wishes,

Malcolm

Thanks for the reply Malcolm!  I guess that is one of my questions - we do titers alot because have a focus on OB and I read somewhere that if the C titer is higher than the D, it would be considered G?

 

I am under the impression as long as we titer the patients and provide D and C negative blood, all is good   Am I am the rigth path?

 

Thanks again for your help!! Your insight is always appreciated!!

Hi Sara,

The first clue that the antibody may be anti-G, or anti-C+G, rather than anti-C+D, is indeed that the titre of the anti-C is higher than that of the anti-D, but the fact that the anti-C titre is higher than that of the anti-D is only a clue. It could be that you actually have an anti-C+D where, coincidentally, the anti-C titre is higher than the anti-D. It is absolutely essential, therefore, that you can prove that no anti-D is present.

One way of doing this is to divide the patient's plasma sample into two.

The first sample is adsorbed using Ro red cells treated with a proteolytic enzyme, such as papain or ficin, which would adsorb out any anti-G and any anti-D present, but would leave any anti-C present. At the end of the adsorption process (about 4 cycles), this plasma is tested against r'r red cells by IAT. If there is a positive reaction, then the original plasma contained anti-C and, possibly, anti-G. If there is a negative reaction, then the original plasma contained, possibly, anti-G and anti-D, but not anti-C.

The second sample is adsorbed using r'r red cells treated with a proteolytic enzyme, such as papain or ficin, which would adsorb out any anti-G and any anti-C present, but would leave any anti-D present. At the end of the adsorption process (about 4 cycles), this plasma is tested against Ro red cells by IAT. If there is a positive reaction, then the original plasma contained anti-D and, possibly, anti-G. If there is a negative reaction, then the original plasma contained, possibly, anti-G and anti-C, but not anti-D.

So, if there are no reactions with the plasma adsorbed with Ro red cells when tested with r'r red cells, and no reactions with the plasma adsorbed with r'r red cells when tested with Ro red cells, then the original plasma contained only anti-G.

If there is a reaction with the plasma adsorbed with Ro red cells when tested with r'r red cells, and also a reaction with the plasma adsorbed with r'r red cells when tested with Ro red cells, then the original plasma contained both anti-C and anti-D (and may also have contained an anti-G).

In all cases, however, you would give cross-match compatible C Negative, D Negative blood (you would still have to perform a serological cross-match, because there are some EXTREMELY rare donors around who are C Negative, D negative, but G POSITIVE.

As far as obstetric patients are concerned, both anti-C and anti-G usually cause far less severe haemolytic disease of the foetus and newborn (unless they have an unusually high titre), than does anti-D. However, it is important that the pregnant lady is offered prenatal and postnatal anti-D immunoglobulin prophylaxis, so that they do not get immunised against the D antigen.

I hope that this rather long and complicated post helps in some way, but, if you need to know more, please do not hesitate to ask more questions.

Testing for antiG.ppt

With a bit of luck, this may explain a bit easier what I was trying to explain in words.

Malcolm, thanks for the wonderful explanation. Really great.

Thanks Malcolm,for the great explanation as usual.

Testing for antiG.ppt

With a bit of luck, this may explain a bit easier what I was trying to explain in words.

Malcolm, I have tried opening this file between two different compters without success. The graph seen is too small to be useful.

Can you resend it?  Thank you, Ronald

Malcolm, I have tried opening this file between two different compters without success. The graph seen is too small to be useful.

Can you resend it?  Thank you, Ronald

I am a student of Malcolm,but I can help; just double click the small graph and it will turn big enough to be useful.

Thank you so much Malcolm!  That explanation was so very helpful! And the slide you attached was great!! Thanks again for your help!

No problem saralm88.