Is this unit Jka pos or Jka neg

[Bb_in_the_rain]

I typed a unit of RBC with different sources of anti sera and the following are the results. 

1) Ortho monoclonal Anti-Jka (manufacture insert says incubate at room temp 5min to 30 min and read macro) 

at 5' incubation- 0 

at 15' incubation- w 

repeated result at 5 min incubation - 0 

at 15 min incubation - +/- or micro (even though insert says to read macro, I read micro because it seems "grainy" on the mirror) 

 

2) Immunocor IAT reagent types negative 

 

3) Unit will be typed with Bio Rad Monoclonal reagent today but I think I am going to type negative with this reagent since it react weaker. 

 

My question- is this unit Jka neg, Jka pos or maybe Jka variant? As Ortho reagent is monoclonal, should I be expecting other specificities in this antisera bottle? I learned that monoclonal reagent are very specific? 

Above all, is it safe to give this unit to patient with Anti-Jka? 

 

Thanks in advance for your replies. 

[Malcolm Needs ☆]

I typed a unit of RBC with different sources of anti sera and the following are the results. 

1) Ortho monoclonal Anti-Jka (manufacture insert says incubate at room temp 5min to 30 min and read macro) 

at 5' incubation- 0 

at 15' incubation- w 

repeated result at 5 min incubation - 0 

at 15 min incubation - +/- or micro (even though insert says to read macro, I read micro because it seems "grainy" on the mirror) 

 

2) Immunocor IAT reagent types negative 

 

3) Unit will be typed with Bio Rad Monoclonal reagent today but I think I am going to type negative with this reagent since it react weaker. 

 

My question- is this unit Jka neg, Jka pos or maybe Jka variant? As Ortho reagent is monoclonal, should I be expecting other specificities in this antisera bottle? I learned that monoclonal reagent are very specific? 

Above all, is it safe to give this unit to patient with Anti-Jka? 

 

Thanks in advance for your replies. 

 

dothandar, you are absolutely correct in saying that are known Jk^a variant antigens.

 

Under the circumstances, DO NOT give this unit to a patient with anti-Jk^a!  It is easy enough to find another Jk(a-) unit, without taking the risk.

 

I am going to attach (I hope!!!!!!!!!) a lecture I have recently written on the Kidd Blood Group System, which may explain why, BUT, be warned, I have yet to check this lecture for complete accuracy, so treat it cautiously.

 

In Depth Lecture on The Kidd Blood Group System.ppt

[Bb_in_the_rain]

I do not have much knowledge about these variants. Thank you very much for the lecture slide and helpful advice. I am hesitating  very much to enter this unit as Jka-, though this donor has been typed as Jk(a-) three times since 2011. Thank you very much for the assurance.  

 

P.S. Love slide number 38 

Edited August 25, 2015 by dothandar

[Malcolm Needs ☆]

Ah, slide 38 is an almost, but not quite, direct quote from Jill Storry.

[Bb_in_the_rain]

Yesterday, I found out from a senior tech that weak positive (rough reaction) were often found with this Ortho Monoclonal reagent (I will look up the clone number when I get to work today). in 1995 (way before I started working in this lab) when molecular genotyping was being validated here, most of these units that has weak reaction are Jk(a-) molecular typing and variant Jka was not found when sequencing was done. 

 

Anybody else having these "rough" reactions with Ortho Monoclonal Anti-Jka? Should I stay away from this reagent when performing donor typing? Or should I keep using this reagent to type donors and avoid labeling units with "rough" reaction as Jk(a-)? Any thought? 

Edited August 26, 2015 by dothandar

[goodchild]

We've been using it for quite a while, no weak/rough reactions come to mind..

[David Saikin]

I have found that the monoclonal Kidd typing sera available (from a few vendors) seems to give weaker rxs than I am comfortable with. 

[Bb_in_the_rain]

Unfortunately our lab switched our Anti-Jka reagent that it is no longer available for me to play with