Thursday, December 16, 2010

okay, someone explain this to me?

At the National Hemophilia Association's annual meeting, a poster described the results of a study comparing plasma derived factor IX (pdFIX) and recombinant factor IX (rFIX), in terms of allergic reactions.  You can read about it here. 88 patients with factor IX deficiency, or hemophilia B, were given the pdFIX, and 163 patients were given the rFIX. The researchers looked to see the prevalence of allergic reactions and the development of antibodies, called inhibitors, that inhibit (hyuck, hyuck) the function of the protein in the system. Or, stop the protein from working at all.

Which, for the severe cases, takes you right back to where mama nature dropped ya. No clot, no dice.

I'm intrigued to see that there really wasn't a difference in the outcomes - 4 from the pdFIX group and 3 from the rFIX group developed inhibitors, and 7 had allergic reactions; 4 from the rFIX group, and 3 from the pdFIX group. But here's what has me gaping:
Potentially serious allergic reactions including anaphylaxis and the development of inhibitors -- antibodies that can neutralize replacement factor -- are uncommon but do occur and often concurrently, the investigators explained during a poster session at the annual meeting of the National Hemophilia Foundation.

From a purely personal note, well, duh. Allergy Boy (a.k.a., the Eldest) developed inhibitors and his first food allergy, roughly at the same time. Years later, we started asking questions about immunology, and not surprisingly, the hematologists admitted to being out of their depth. We found experts at a conference on inhibitors, and asked: allergic reactions are usually IgE mediated, but what kind of antibody is the inhibitor?
How does it work? Is there a relationship between the two processes? The inhibitor experts shook their heads, or looked doubtful. But, absolutely! an immunologist told my mom, and years later, researchers are studying the two as a pair, as you can see here.

The field has come a long way, baby, but this link between allergy and inhibitor remains a teasing, odd note. Interdisciplinary research, anyone?

More immediately, perhaps, what implication does this finding have for the management of hemophilia B? And specifically, if inhibitors and anaphylaxis tend to go together, are there specific implications for families with a history of allergy - or, I suppose, inhibitors? Should they keep an EpiPen on hand when they administer fIX?

Inquiring minds would really rather like to know...

By contrast, however, the following press release required no explanation:
Tofutti recalled 25 pallets of the Tofutti Yours Truly dessert, for possible dairy contamination. I could not find any information about the recall on the Tofutti website, however, which is surprising. Or, well, not. I admit to sighing the sigh of the unsurprised - my experiences with Tofutti has left me unimpressed by their level of education regarding food allergies.

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