Poly Specific and its Use on Cord Blood

[TurboTech]

How many Bloodbanks use Poly Specific Coombs Reagent on Cord Bloods.

I see this as wasteful, since I do believe that Poly is more expensive then Mono IgG.

Am I missing something.

From what I have understood for years, we were only looking for IgG on Cords. Did something new arise to justify the added possible cost of using Poly on Cords?

Just Curious

[Lcsmrz]

Any AHG reagent containing Anti-IgG is acceptable for use with cord bloods, but we haven't stocked polyspecific AHG reagent in quite a while.

If using the product for both IgG and C3, you'd have to QC both with IgG and C3 check cells ...

[janet]

We use IgG gel cards for our cords/babies less than 4 months and a gel card made be Diamed distributed by Ortho (in Canada) with IgG/C3d/Ctl for adults.

[Mabel Adams]

I think my supplier charges the same for poly and IgG for what that is worth. We do only IgG on babies although many years ago I did find a cord sample that was positive with complement. I don't think it meant anything. We dropped poly when the companies required that we buy it in large quantities and tons of it would have expired since we used it only for adult DATs at the time. Now we do both IgG and C3bc3d on all adult DATs with their appropriate check cells.

[GilTphoto]

We dropped poly when the companies required that we buy it in large quantities and tons of it would have expired since we used it only for adult DATs at the time.

What's with that? Why won't they sell us 1 bottle? They force us to buy 10, when we only need 1 bottle of Poly a year. Same thing for PEG and Albumin. We only use 1 bottle of Albumin a year to do serological centrifuge calibration (to dilute the antisera).

Gil

BTW.... to answer the original question, we only use IgG on cords.

[Mary]

Hear, hear!

[donellda]

We only use Anti-IgG for our cord bloods.

[Yanxia]

I have a question: some antibodies will have a better reaction when complement is present( i.e. Lewis and Kidd), so sometimes we use anti-complement to detect this kind of antibodies. Can this exist in newborn's blood stream?

[galvania]

I think it would be fair to say that if the antibody is ONLY coming up by complement, even if it had crossed the placenta it would not cause clinical problems in the baby. Lewis antibodies never cause HDN anyway

[Yanxia]

I agree with Galvania.

Kidd blood group antibodies can produce HDN, I don't know if the baby's DAT positive for C3 or IgG or both.

[galvania]

I agree with Galvania.

Kidd blood group antibodies can produce HDN, I don't know if the baby's DAT positive for C3 or IgG or both.

For it to be clinically relevant it would have to be positive with IgG

[Yanxia]

In vitro test we will use the antibody's preference of bind complement to find it. I don't know if in vivo it will have the same ability. If it is like in vitro we use anti-IgG may miss it.

Yanxia

[Mabel Adams]

Only IgG antibodies cross the placenta. Only certain classes of IgG can fix complement. Certain IgG classes cross the placenta better than others. I know it is in Issitt, but I don't have the book at home with me.

Then there is the fact of a baby's complement levels and if they even work like an adult's.

Even if it is theoretically possible, I think the experts agree that it isn't necessary to look for complement-only antibodies in cord blood.

[Malcolm Needs ☆]

I entirely agree that only anti-IgG is required for testing cord blood. That having been said, I have seen several examples of maternal Kidd antibodies causing a positive DAT with both anti-IgG and anti-C3d, albeit weakly with the anti-C3d.

I have never seen a case of clinically significant HDN/HDF caused by a Kidd antibody, although I am well aware of isolated cases being in the literature.