Prenatal antibody titers

[John C. Staley]

The following is a question making the rounds amoung the transfusion supervisors of our corporation. I was just wondering how others would respond to the question.

Thanks

John

:pcproblem

Are you automatically reflexing a titer for any IgG antibody found during prenatal testing in a pregnant woman or are there some you just report out the ID and wait for the physician to order a titer if they want one?

If you are reflexing a titer for all IgG antibodies, why?

[rcurrie]

Yes, we automatically do a baseline titer on pregnant women when we identify a significant antibody. All antibody identifications generate a pathology consultation from our medical director. For OBs, the MD will recommend that the patient be followed serologically with subsequent titers every 4-6 weeks.

BC

[bbbirder]

Ditto on what Bob said.

Linda Frederick

[AMcCord]

Same for us.

[Mabel Adams]

We started reflexing them (after proper one-time notification, of course) because our OBs were getting annoyed that we were waiting for them to order them.

[Eagle Eye]

We do same as all of you.

[John C. Staley]

Does any one other than me find this interesting since the ony antibody I know of that has any published clinical correlations is anti-D? What do the OBs do with the info and what do they base their actions on?

It was a slow week, I had time to think of stuff like this.

[AMcCord]

Well.........what they do here is PUNT! They send the patient off to the big city to see a specialist. The specialist orders the same titers we were going to do anyway and no matter what the antibody, if the titer hits 8 the specialist does an amnio. The fact that there are no facts doesn't seem to bother them at all. It's more the 'cover my rear' policy.

Of course, when it comes time to deliver a baby, no one has the least thought of letting the Blood Bank know that antigen negative blood might possibly be required. It's all a surprise!

Please excuse my cynicism .

[johna]

Does any one other than me find this interesting since the ony antibody I know of that has any published clinical correlations is anti-D? What do the OBs do with the info and what do they base their actions on?

It was a slow week, I had time to think of stuff like this.

-----------------------------------------------

The OBs generally do what ACOG recommends. Basically when the Coombs titer is = or > than 16 "amniocentesis should be considered". In the AABB's "Guidelines For Prenatal and Perinatal Immunohematology" there are some comments related to FyA and Kell antibody titration significance that differ from the standard anti-D but I doubt whether many OBs are aware of this. I would question that even those that are would use this information for decision-making.

As far as the reflex titer is concerned I had become aware of one reference lab that had a separate test number for an antibody ID without a titer reflex. Why anyone would order this is beyond me. There would surely be occasions in which this test would be ordered by mistake and create more problems than it was worth when the physician starts screaming for a titer result.

[Mabel Adams]

I seem to remember an article in Transfusion in the past 10 years where someone defined paramaters for anti-Fya titers.