Oh, fab, you asked, so I take no responsibility for answering... 
I'm not even going to mention the IVF or the test results, I need to get my head round the possible immune testing first.
Here's an indication of the last two days inside my head:
We were given lots of information including a paper which is pretty inconclusive but dates from 2008, so not that up to date.
In their own literature they say that up to two-thirds of early pregnancies miscarry (the highest figure I've heard) and chromosomal abnormalities are the major factor, but it mentions the possibility of the women's immune system compromising successful embryo implantation in the case of failed IVF or early miscarriage. The consultant stressed that the research is in the early stages and many possible treatments are not universally accepted.
They suggest that the following couples are at increased risk and should consider immune testing:
a) women over 35 who have had 2 mc or 2 failed IVF cycles
b) women under 35 who have had 3 mc or 3 failed IVF cycles
c) less than 6 eggs from an IVF cycle
d) unexplained infertility of over 3 years
e) previous pregnancies resulting in small babies
f) repeated mc while trying to have a 2nd child.
I can tick both 2 mc and 2 failed cycles in a), and d) as well, so seems like a good idea.
After research so far though, my conclusion is that CARE are expensive! From what I've read (I've now read a lot) the Nottingham clinic are the leaders in the field, and the consultant there worked closely with Chicago, but the consultant we saw works closely with the Nottingham bloke anyway...
These are the tests we've been recommended/quoted:
TH1:TH2 ratio abnormalities£590
C4/M2 variant£155
MTHFR£160
PAIP Gene Polymorphism£176
Auto Antibody Profile 1£108
NK Panel £670
Just these add up to over £2000!!
The TH1:TH2 is apparently £350 at Lister rather than £590 at CARE which is a significant difference! (although I don't know whether you can just rock up for tests without paying for a consultation, and I don't particularly want to travel to London). This is one of the 'Chicago' tests though, so one that you can also get done yourself directly with the hospital cheaper, you just need to fedex your blood across. Haven't found all the details yet, that's a job for later...
The other level 2 /Chicago test is the NK Panel and I'm really torn on this one and could do with some advice - if my nk cells biopsy came back as 'normal' is there any point doing the nk blood test? I do understand they are different, but is it worth £670 if nothing showed up in the biopsy?
The treatment for the C4/M2 variant seems to be heparin - but I'm going to be on this anyway due to the factor v leiden thrombophilia, so it seems pointless getting tested if I'll be having the treatment either way?
And I haven't looked in PAIP Gene Polymorphism yet...
This is my current thinking -
a) as far as my internet research tells me, Chicago is the birthplace no pun intended of all the immune stuff, and still where all the level 2 bloods are sent. In the UK, Dr G at Care in Nottingham worked closely with the Chicago dr (Beer?) and Dr Shehata is the other name always mentioned. We're with Care, just not in Nottingham (where there's usually a massive waiting list anyway) so our consultant has worked with Dr G and follows the same procedures so that's good enough for me.
b) We could go somewhere that would give me the pred and the intralipids anyway, but they aren't without risks and the Care clinic is walking distance from our house, and close to my office as well. It also has a car park. This sounds ridiculous, but there isn't anywhere else in our city apart from the NHS clinic that I never want to go back to (they also do private patients) and the private clinic that didn't give me gas and air for the horrible biopsy, which sends their patients to the NHS/private clinic for bits of the treatment anyway, so I don't want to go anywhere else unless there's a really good reason - the convenience of it reduces a lot of stress around work and travel when going in during the cycle.
c) ARGC doesn't do immunes for patients who aren't having IVF with them anyway (although I'm not sure how they could force you?!)
d) Doing it all the long way round would take longer as well as add to the stress, and I don't know yet how the clinic would react to us side stepping them (when he quoted us over £1000 for the drugs and I asked if we could source them ourselves he didn't say no but he kept going on about how potentially stressful that could be, and what if I ran out etc.) even if we make a decision this weekend, we've probably missed the boat to start in mid September by the time we've had the bloods done - and we'll be doing long protocol this time, so that then jumps to November/December being the month it will all happen, and that would mean an August baby (I'M JOKING!!! What I mean is the consultant told us we could start immediately if we wanted to - ie in 2 weeks, so Nov/Dec is far too far away for my impatient mind)
e) On the other hand it's MiL who has offered to pay for this, and I feel like I should be travelling round the country/posting my blood to the US myself if that's what it takes to get the costs down.
f) Oh, and I'm also considering the hidden infections test with Serum... (haven't told DH about that one yet).