What is ‘+s’? Please look at attached antigram. It’s in the reaction column of the P1 antibody. Anybody knows? Thank you 

It simply means that the P1 antigen is particularly strongly expressed on these red cell samples.  Therefore, if you come across a weak anti-P1, it may apparently react with these particular red cell samples, whilst apparently not with, for example, the third red cell sample shown in your antigram.  Although not identical to dosage, per se, it is fairly synonymous with dosage at a phenotypical level.

The strength of the expression of the P1 antigen is an inherited trait.

Thank you Malcolm. Would you have any sources/web sites on this subject? I would like to read more on the subject if possible. I tried googling it but with no success. Thank you so much! 

Hope this helps.

The P1PK Blood Group System.pptx

11 hours ago, Malcolm Needs said:

Hope this helps.

The P1PK Blood Group System.pptx 1.71 MB · 3 downloads

Yes, it is very helpful! Thank you Malcolm. 

The BioRad panel sheets only usually give + or 0 for P1 whereas NHSBT give numeric scores which is much more helpful when the antibody only reacts by IAT with strong examples.

A cold panel helps with any ambiguity too. (and P1 type on the patient, but who stocks anti-P1 at a hospital?)

Edited June 30, 20214 yr by RichU
ambiguous sentence!

2 hours ago, RichU said:

The BioRad panel sheets only usually give + or 0 for P1 whereas NHSBT give numeric scores which is much more helpful when the antibody only reacts by IAT with strong examples.

A cold panel helps with any ambiguity too. (and P1 type on the patient, but who stocks anti-P1 at a hospital?)

The problem is that the NHSBT "scores" for the P1 expression strength is subjective, rather than objective, and so it depends upon who does the "scoring" as to how accurate, and, indeed, how precise the scoring may be (but it does give an idea).

Edited June 30, 20214 yr by Malcolm Needs