Rh IG contain anti-G?

[Mabel Adams]

Does Rh Immune globulin contain anti-G?

[Auntie-D]

Do you mean IgG?

[Mabel Adams]

No, does it contain anti-G along with anti-D?

[Auntie-D]

Product insert states other ingredients include sodium chloride, glycine, sodium acetate trihydrate and sodium hydroxide. No mention of Anti-G

But there are a few papers...

http://onlinelibrary.wiley.com/doi/10.1046/j.1537-2995.2000.40050551.x/full

Although it's talking about the use of generic IgG for severe ITP I suppose that there is a similar possibility that there is the possibility of multiple antibodies in Rhogam.

Why the question??? I'm intrigued now...

[David Saikin]

Are you finding an anti-C after administration of the RhIg?

[Pony]

Yes -RhIg contains anti-C, -E, G and quite a few more of the common string of antibodies depending on lot. The primary antibody with the highest titre is anti-D by a long shot. This was presented at the last Philly AABB as an oral poster from Georgetown University Hosp. I think the paper came out in Transfusion shortly afterwards. All testing to identify antibodies other than Rh was performed by solid phase. In tube LISS, the main 3 identifiable were anti-D, and slightly weaker anti-C & -E.

Consider where the product comes from - large pools of plasma from immunized donors (a lot of them multiparous women) as long as the major component is anti-D, it will get the job done. When using it for TTP, the other specificites may help with blocking the destruction of platelets. It is a very valuable tool!

[John C. Staley]

Just a note, my wife was a RhIG donor and she also had anti-K and anti-S. I have always assumed that they tried to absorb out the "unwanted" antibodies but I don't imagine they were 100% effective with that if in fact they even tried.

[Pony]

Good point John! What I found out when talking to Georgetown was that the manufacturers' really just count on the dilution to weaken the extra antibodies while adding to the concentration of anti-D. the anti-C, -E and -G just happen to be present more often than the others so they don't dilute quite as much. And for the majority of rr prenatals, it's a moot point.

[Mabel Adams]

We have an apparently partial D prenatal that has made anti-D & anti-C. We sent it to our reference lab and they were able to verify with D+G- cells that she has made a low titer anti-D and with C-D-G+ cells that she has anti-G. They did not have cells to prove the presence of anti-C for certain. With r'r' cells she showed a titer of 64 (although we got a titer of only 4 with r'r cells). Titer in both our hands and ARC's with R2R2 cells was less than one. They titered against R1R1 cells and got only 8. I can't quite explain that degree of difference between the titer values based on dosage and the like. They mentioned something about steric interference for why the titer with R1R1 cells was weaker but I would be happy for other input if you have a suggestion. It seems likely that it is time to follow the fetus with ultrasound or something other than titers anyway since there are 3 antibodies and dad is R1R1, but I was thinking about our problems following titers if they went ahead and gave her RhIG (either out of habit or just to be safe in case the anti-D is not really there) and it made me wonder if it contained anti-G. What I could find on the RhoGam package insert said it is 5% gamma globulin made from D sensitized people so I thought maybe they didn't filter it. Still, we seldom see anything resembling anti-C in our passive RhIG moms so the titers of anti-G & C must be pretty low. Later I will post my questions about what sort of partial D she has. And of course she lives way out in the boonies and will have a 6 hr drive to see a perinatologist.

[Auntie-D]

And of course she lives way out in the boonies and will have a 6 hr drive to see a perinatologist.

Dont they always?!?!?

Mabel - I think this is one that needs writing up as a paper. Sounds like a really interesting case

[Rh-fan]

Our institute makes anti D (just as Rhogam) form plasma of immunised donors.

Although they are immunised with cells that are D pos, C neg (mostly E pos, further compatible for K, Fy,Jk, Ss) they almost all make also an anti C (or anti G), So there is anti C present in the final product.

The titer of the anti D is between 8.000 and 16.000 and the amount of anti C (and other antibodies) must be below 1:32. When you compare these amounths then there is a little bit of anti C, but it is present (just like some anti E, anti K, but mostly weaker than C) and also anti A and anti B will be present.

The methode of production is the same as for every IgG product (like IVIg), they just concentrate all the IgG antibodies. When you want random IgG they use random donor plasma, if they want Hepatitis A IgG they use donors with a high titer of anti Hep A, and for the anti D product they use donors with high titers of anti D. There is no purification step to remove other antibodies.

Peter

[Dr. Pepper]

Mabel, once in a while a vial of RhIG (Rhophylac) will outdate. If I dilute it a bit and give it to my students to do a panel, there is always anti-C (or -G) along with the anti-D.

[Pony]

Mabel - this is a fascinating case and really should be written up. The Ref lab that sorts out the D variant will help you. I'd talk to Connie Westhof at NY Blood Center about this one. She's got the resources to do a really good job for you.

As to your unexpected titre results - remember this is not a normal anti-D you are working with. It's aimed at the part of the D your patient is missing. The steric hinderence issue could very well be part of how well and how effectively the red cells are able to bind antibody. That may come clearer when the D variant work is completed. The presence of anti-G and -C just adds to the general confusion.

My rule of thumb on giving RhIg to patients who have some D on their cells has always been give it to D variants if it can still modify the immune response (ie anti-D titre 2048 is past hope). The downside to this is the positive DAT after the fact. It makes your followup investigations more complex and you never know how long and how much RhIg has been in circulation to be effective. Your medical director is likely to have the best idea of how much serologic risk the local OB docs can handle.

For weak D patients, I've always thought it is a total lost cause as these patients have completely normal D on their red cells, just less of it. These are the least likely to make anti-D.

These are just my opinions and with a dollar, might get you a coffee. I'll be waiting eagerly to hear how this case goes and what you find out. Best of luck!!

[John C. Staley]

Pony, I want to know where you get a cup of coffee for just a dollar!! :coffeecup I'll even bring my own cup.

[Mabel Adams]

I don't know that there are any financial resources to pay for further workup unless it is going to really tell us something different to do with the patient in managing her pregnancy. Does anyone have research funding and might do this for free (if I can get a new sample sent in)?

[Malcolm Needs ☆]

For weak D patients, I've always thought it is a total lost cause as these patients have completely normal D on their red cells, just less of it. These are the least likely to make anti-D.

NO!!!!!!!! This may be true for Weak D Types 1 and 2, and possibly Weak D Type 3, but not for many of the others. Just put "The Rhesus Site" into your search engine and look how many Weak D's there are, with different genetic backgrounds (with power to add), and how many have made alloanti-D.

[Mabel Adams]

We really need a different term for weak D these days. Many consider it the results of the weak D test, while others consider it those strange D's that don't appear to be partial D's but don't test normally. Others must arrive at the term from molecular testing.

Let's come up with something that works whether you are a small place just doing basic typing on transfusion patients and babies or whether you are a reference lab or blood center.

[Malcolm Needs ☆]

Well, a few years ago, Geoff Poole, Joyce Poole (not related) and Geoff Daniels (not sure of the order of the authors, or the exact reference) suggested that we should call all of these D variants, rather than either Weak or Partial D, and this sounds eminently sensible to me.

[Pony]

Malcolm - I think we do have a confusion of names here. When I say weak D, I mean what we used call Du. When I'm talking about D variant, I mean those situations where the various genetic mix and match produce antigens which are missing epitopes.

There was quite a debate about this at the Baltimore AABB. Joyce wasn't there but Geoff Daniels was. We walked away from that thinking we were all on the same page. But it sounds like your side of the pond is calling everything a D variant? Is that what's happening?

[Malcolm Needs ☆]

Unfortunately nor Pony. If only it were that simple!

Until fairly recently, if the mutation resulted in a change to an amino acid residue either in the cytoplasm of the cell or was in the transmembraneous part of the Rh molecule, but not any change to the extra cellular amino acid residues, we (in the Reference Service) tended to call it a Weak D. If the amino acid residue alteration was in the extracellular part of the Rh polypeptide, we would call it a Partial D. This, however, did not take into account the fact that amino acid residue alterations in the cytoplasmic or transmembraneous part of the Rh polypeptide can drastically alter the tertiary structure of the molecule, including that part of the molecule that is extracellular.

It is partly because of this that I agree that any RHD gene that is different from the wild-type should be called a variant.

All that having been said though, very many individuals within the hospital community (and some in the Reference community, to be fair), seem to use the terms Weak D, Partial D, D variant and Du interchangably (if that is how it is spelt!), and this becomes immensely confusing as one person talking to another, about exactly the same mutation, may be totally at odds with one another, and not undertsand for a long time that they are talking about exactly the same thing!

The first ever thread I started on this site was about the use of correct nomenclature. It bombed!!!!!!!!!!!!!!!!!!!

[bcham]

Although they are immunised with cells that are D pos, C neg (mostly E pos, further compatible for K, Fy,Jk, Ss) they almost all make also an anti C (or anti G), So there is anti C present in the final product.

Peter

Why do you they make the anti-C if the cells are C negative?

[Mabel Adams]

The D typing nomenclature needs to reflect how much we know of a particular case.

How about Immed. Spin D+, or Antiglobulin D+ for basic serologic testing. If these are weak or inconsistent, then "IS D variable" etc. If you have done molecular testing or tested with the partial D kit, then maybe you know enough more about them to call them D variants. Feel free to fill me in on what the experts figured out in Baltimore.

We also need to get away from some people's idea that everyone that types pos with the AHG D test is a partial D and everyone that types clearly at IS is the full "wild type" D.

[Rh-fan]

Why do you they make the anti-C if the cells are C negative?

After immunisation they make anti G (the cells are D+C- and therefore G+), in your panel you do not see the difference between an anti G and an anti C. Therefore I named them anti C.

[Malcolm Needs ☆]

After immunisation they make anti G (the cells are D+C- and therefore G+), in your panel you do not see the difference between an anti G and an anti C. Therefore I named them anti C.

Hmmmmmmmmm, I not sure I agree with that one Peter. If that had been "standard", we would still be calling anti-LW, anti-D and may never have discovered anti-G! The fact is that they are directed against different antigens and this should be reflected in what they are called.

[Malcolm Needs ☆]

The other thing is, of course, that the first anti-G to be recognised, reacted with an r"r red cell (C negative) that just happened to be a very rare example that expressed the G antigen.