This sounds hopeful

A promising bit of research. Let us hope it's further developed and implemented in the not too distant future.

http://www.arthritisresearchuk.org/news/general-news/2014/september/new-method-for-predicting-psoriatic-arthritis-therapy-response-devised.aspx

It would be nice to have more certainty about what works and for whom. Right now for many US patients, once they qualify for biologics it is a crap shoot. I've seen more than one member of the site say something like "my doctor says I need to choose a biologic". That's a pretty alarming way to go about it. I would posit that the doctor ought be telling the patient. But that's just me!

This could be a boon or, as Sybil points out, a bit of a boondoggle.

As someone who got no relief and some unpleasant side effects from my first two biologics, It would have been great if the test had pointed toward the third biologic, which was working well before having to stop for a bit. On the other hand, #3 isn't actually approved for PsA, so would the test have even come up with it?

As we all know, biologics are slow to work and beyond expensive. If a blood test could save the time and expense involved in trying fruitless treatments, and help prevent the damage that occurs while chasing rainbows and the expense to clean up the extra damage, this could be a good thing from a public health standpoint, too.

Well I think I must have had my optimistic hat on (ha ha, I don't wear it very often), because I interpreted it as speeding up access to biologics as opposed to wallowing on DMARDS. But yes I can see how it might be used to limit use. On the other hand if it rules out anti TNFs per se, it might mean patients get to try the newer biologics faster that are coming out in the future?