Lynnette Posted June 8, 2011 Share Posted June 8, 2011 40 y/o female, prenatal specimen: plasma reactions consistent with anti-Jka, showing dosage; patient's antigen typing Jka 2+, Jkb neg; patient's DAT negative. Is it possible to have an auto anti-Jka with a negative DAT?Thanks in advance for any feedback. Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted June 8, 2011 Share Posted June 8, 2011 The simple answer is yes.We see, on average, five or so patients with auto-anti-Jka every year in our Reference Laboratory.I wonder with what reagents you are performing your DAT? Are you including monospecific reagents, such as anti-IgG, anti-IgA, anti-IgM, anti-C3c and anti-C3d? If not, and are only using, for example, an anti-IgG and some form of anti-C', you may not detect a positive DAT.On the other hand, not all of our "auto-antibody" patients have a positive DAT, but often have a positive auto when their own red cells are treated with papain before testing. Link to comment Share on other sites More sharing options...
Kip Kuttner Posted June 9, 2011 Share Posted June 9, 2011 I did a quick literature search and found several articles describing an "apparent" auto anti- Jka in the presence of chlorpropamide, aldomet, and methyl esters of hydroxybenzoic acid. There was one report of a DAT negative auto Jka associated with a case of Evans' syndrome. Link to comment Share on other sites More sharing options...
Liz Posted June 9, 2011 Share Posted June 9, 2011 The Ab may be in the serum/plasma while her sensitised RBCs may be lysed at the time of the draw, or as we know 25 to 100 Igs on a cell often do not give a positive DAT. Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted June 9, 2011 Share Posted June 9, 2011 The Ab may be in the serum/plasma while her sensitised RBCs may be lysed at the time of the draw, or as we know 25 to 100 Igs on a cell often do not give a positive DAT.Very true. Link to comment Share on other sites More sharing options...
jayinsat Posted June 9, 2011 Share Posted June 9, 2011 You didn't mention whether or not the patient had been recently transfused. So, even though she is prenatal, I will ask. Has she been transfused in the last 90 days or so? Maybe you are getting a 2+ due to donor cells. Link to comment Share on other sites More sharing options...
Lynnette Posted June 9, 2011 Author Share Posted June 9, 2011 thanks to everyone for their feedback.We use a polyspecific AHG for our DAT's (anti-IgG and anti-C3d, but will try repeating with some monospecific anti-sera. Thanks for that hint.Lynnette Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted June 9, 2011 Share Posted June 9, 2011 Monospecific anti-human globulin may not be the answer of course, but it is worth a try. Link to comment Share on other sites More sharing options...
RR1 Posted September 21, 2011 Share Posted September 21, 2011 We see a fair few of these (as well as anti-Jkb) using Capture-R. Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted September 22, 2011 Share Posted September 22, 2011 No comment! Link to comment Share on other sites More sharing options...
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