Dogs: eczema patients' best friend in more than one way

And now for something completely different...

Dog eczema!

Quite frequently I see items in my news feed about canine eczema. I haven't paid them any attention. But today I saw something worth commenting on. Imulan, a company based in Arizona, announced that it had developed a biomarker for canine eczema.

Who cares? was my first thought. But I was intrigued, because in reading the NIAMS roundtable summary the other day, I'd seen that dogs are considered a potential experimental model for human eczema. So any research done using dogs as models might not only benefit dogs, but also humans.

I wondered why it was worth anyone's time to develop a biomarker for eczema in dogs. (A biomarker is any protein or metabolite in your body whose level is correlated with your risk of developing a disease-- or the chance that you have it already. Biomarkers are emerging as a biomedical field--for example, Tethys Bioscience in Emeryville, CA is developing biomarkers for diabetes.) If you have eczema, it shows. Why do you need a biomarker?

Then I understood. Dogs scratch all the time. They get fleas, etc. They roll in their own feces and other stuff. So it's harder for a veterinarian to diagnose eczema for a dog than for a human doctor to diagnose it for a patient. A biomarker would enable the vet to make a quick, definitive diagnosis.

Imulan says that its canine eczema biomarker is based on its "T cell receptor therapeutic peptide vaccine." This opened my eyes. They're claiming to have a vaccine for eczema! Bold. I have no idea what data this is based on. Nor do I know exactly what a "TCR peptide vaccine" is.

I did a Google search and it seems that there have been a number of papers published on TCR peptide vaccines, although the ones I checked out concerned vaccines against lymphocytic cancer in mice. And those were EXTREMELY preliminary.

The idea, Imulan says, is that a messed-up T cell balance (type 1 helper vs. type 2) is at the root of eczema (this, of course, is not established in humans; the imbalance is likely a symptom, not the original cause) and so you need to cancel out, or mute, the type 2 T cells. In short, as I understand it, you vaccinate so that your body produces a lot of antibodies against YOUR OWN T cells, thus shutting them down.

This seems nutty to me, and if tried in humans, likely to lead to something like the "cytokine storm" that nearly killed the six volunteers in a 2006 trial of an experimental T cell-stimulating antibody. But Imulan claims their vaccines have shown promise in dogs.

I'll have to ferret out their data (pun intended).

Eczema sufferers thank you, Dr. Anthrax

Voov and I are in a good stretch-- neither of us has any eczematous patches right now. Of course, that can change overnight. But when eczema isn't bothering you, you tend not to think about it-- you get to pretend everything's normal, and wear clothing that nobody but an eczema patient would find daring-- t-shirts, collarless "shirtly sweaters" (you know, those thin pullovers that were a fad a few years ago). Maybe go swimming.

Not to go on about this Atopic Dermatitis Research Network too much, but I had a thought. Why is this grant so big? One clue, maybe, is the story I mentioned yesterday (NYTimes version) about the 2-year-old son of a US soldier who developed eczema vaccinatum after his father was inoculated with vaccinia virus, the live smallpox vaccine.

The episode must have opened a lot of eyes to the danger this vaccine poses to eczema patients. But the NIH was aware of the problem beforehand. ADRN is the sequel to the ADVN, which was established as early as 2004 and perhaps before. Almost certainly the whole ADVN/ADRN focus on vaccines and eczema is a direct consequence of the 2001 anthrax attacks.

So, eczema sufferers, we can thank Bruce Ivins if, in a few years' time, drugs or other therapies start filtering down the pipeline to protect us against MRSA. Bioterror is big money. I don't know exactly how the NIH receives its funding, but the US civilian biodefense budget for financial year 2011 is about $6.5 billion. $32 million is peanuts. We should angle for more!

For me, although MRSA or staphylococcus in general is a continual concern, I feel that it would be a shame if a huge expenditure of research dollars removed the danger of eczema infection but left us all itching and scratching without relief. Let's not forget that.

A postscript: I asked a mathematical epidemiologist, Jamie Lloyd-Smith, an assistant professor at  UCLA, what fraction of the US population would have to be vaccinated against smallpox to shut down an epidemic. His answer, which he stresses is a back-of-the envelope calculation (I leave out the math):

"You can prevent an epidemic--or eliminate an endemic disease--by vaccinating a high enough proportion of people that Reff<1. This gives herd immunity...you'd need to vaccinate 70-83% of people to eliminate smallpox."

Since, including children, about 20% of the US population has experienced eczema in some form--and, say, there are three people in the average family, and even if you don't have eczema, you can't expose your child to viral danger-- it is clear that the government cannot vaccinate 70% of the population in the event of a smallpox attack without putting a small fraction at real risk of developing eczema vaccinatum. Given the loud objections of the anti-vaccination fringe to protecting their kids against measles and whooping cough--with vaccines for which the benefit overwhelmingly outweighs any imagined risk--you can imagine the trouble the government would run into if it tried to jab us all with smallpox vaccine.