Weak D in OB patients

[lgabbert]

I would like to know thoughts and policies for reporting weak D on gel testing, specifically on OB patients. When we used tube method, we did not do a weak D test so the patient was typed as Rh neg and therefore received Rhogam if indicated. However, recently we had a male patient who was typed as a weak D on a previous visit, but in gel he was Rh pos. I also recently learned that the reagent for D testing is much more specific, and that different manufacutrers react differently with each D variant. Hence the confusion about mothers and when to administer Rhogam. Any suggestions would be appreciated.

[David Saikin]

This is one of those "sticky wickets" with gel testing. Some prefer to call 2+ or weaker D+s in gel as Rh negative. I have studied one patient who is a classic Weak D+ (only detectable at AHG phase), she is 2+ in gel. Some call all gel +s Rh positive. John Judd prefers 3+ or weaker gel D+s to be called negative. . . I think you and your Medical Director will need to decide how you want to handle these.