prenatal antibody screening - is anti-C3d necessary?

[YorkshireExile]

We are a maternity hospital and currently we perform all our in-patient and outpatient antibody screens using the Diamed (Biorad) Gel Liss/Coombs cards. These cards contain Anti-IgG and Anti-C3d. Bearing in mind my patient population, my question is do I really need to use cards with Anti-C3d or can I just use cards with Anti-IgG only?

Antibodies detectable only by their ability to bind complement are quite rare, and I suppose in "normal" maternal patients they are rarer still. We don`t do an auto as a routine with our antibody screening, although if all three of my screening cells were positive I would include a monospecific DAT in the workup along with my antibody investigation.

If anti-C3d was present hopefully I would discover it eventually.

What do other hospitals (maternity or otherwise) use for their routine screens? Is there a compelling reason why I should stick with my Anti-IgG + C3d cards or could I safely use the (cheaper ) IgG cards only?

[Malcolm Needs ☆]

Although I no longer work in a Hospital Laboratory, and have not done so for some time, I would agree with your supposition that an anti-IgG card would be quite sufficient.

[Abdulhameed Al-Attas]

Yes, Anti-C3d is NOT necessary because Anti- C3d monospecific coombs reagent would react with red cells sensitized with components of human complement involved and cause agglutination of the red blood cells,so they are ONLY useful for identification of complement fixing antibodies.

[Yanxia]

If the KIdd antibody and other complement binding antibody is present, anti-c3d may be helpful to detect it.

[Steven Jeff]

We only use a Diamed (Biorad) IgG card at hospital that has a large maternity workload. All our samples are collected into EDTA anticoagulant which negates the use of a card with anti-c3d.

Steve

[Abdulhameed Al-Attas]

We also use Biorad,But I think that you can use freshly drawn Citrate,EDTA or CPD-A anticoaglant, Samples drawn into plain tubes may also be used.

We only use a Diamed (Biorad) IgG card at hospital that has a large maternity workload. All our samples are collected into EDTA anticoagulant which negates the use of a card with anti-c3d.

Steve

[David Saikin]

We ony use anti-IgG for all testing. Anti-Complement reagent has its uses but only in selected cases, not for routine use.

[webersl]

We use anti-IgG gel cards for all antibody screens and collect our specimens in EDTA - 1/2 our patients are maternity patients.

[Mabel Adams]

EDTA binds calcium to prevent coagulation. Calcium (and magnesium?) is required for complement fixation. If the calcium is removed from your sample before you test it (as it is in EDTA), you can't get a positive result in a test for complement. Right?

[Malcolm Needs ☆]

Right (except EDTA chelates Ca++, Mg++ and Mn++, a;; of which are required as cofactors for complement).

[EDibble]

We do not use cards, but solid phase, before that tubes. The solid phase (capture method, Immucor) only picks up IgG antibodies. When we used tubes alone, AHG reagent was only used for DAT's and other random testing, not for routine screens and panels.

[Nisar]

Very few antibodies can activate complement,If you are using EDTA sample for antibody screening, as C++ is chelated in EDTA samples and Ca++ is needed for complement actvation,so in the absence of Ca++ complement can not be activated then you can use IgG cards.dont think about the money always do best for the patient care:cries: