Remicade concentration of 20

I haven't been on Remicade is a long time and before these tests were covered by insurance. I wouldn't go to 8 weeks right off the bat, I'd maybe ask if you could push one dosage to 8 weeks and then continue on the same 6 week schedule. Or even 7 weeks.

oh and btw I thought my antibody levels were tested and I didn't have any- and my level was way above 5 so that does not make sense.

no I meant that my antibodies were tested and it did not show that I had any antibodies but the test was done.

The ideal range is somewhere around 3-7mcg/ml for maintenance but that is based on an eight week infusion. If you are getting infusions every 6 or 4 weeks than your trough levels should be higher. I'm pretty sure Mayo Clinic runs most of the infliximab level tests and based on data that they have if you are above 5mcg/ml it extremely unlikely that you have developed considerable antibodies so they don't bother testing.

Thanks for the thoughts/insight everyone. Certainly the values above the recommended one were a bit of a mystery to me.

Essentially this blood test has two purposes.

First, it helps verify that you/I are taking the correct initial dosage of infliximab, by measuring the amount of medication within your body when it is at its very lowest point, which is just before your next infusion. There's general guidelines of how much medication you/i should take, but there's a variety of factors (from disease severity differences, to some of us have a faster blood-clearance of proteins than others do) so some of us need more meds than others (10mgs per kilogram instead of 5, and/or infusions spaced closer together). I'd say it would be unusual to take this test before you get on the 8-week maintenance dosage schedule.

Second, it helps explain why a patient begins loosing response later on and checks for your immune system creating anti-bodies to stop remicade, make it less effective over time and even stop working entirely. Say you've been on remicade for multiple years and you are starting to flare. All biologics, including remicade, are essentially antibodies by design. Biologics are tiny proteins that are design to shut off another protein that naturally occurs within our bodies, in this case one called tnf-alpha. Remi is a tnf-alpha-blocker by design. Our immune system looks at those tiny proteins of remicade which look a lot like viruses, and begins attempting to create antibodies to stop said believed virus. The success rate is low, but some of us do eventually succeed. Sometimes more medication will counter it, sometimes you switch to another med (like from remicade to humira) because the antibody concentration is super high. Having antibodies to one tnf-alpha-blocker has no guarantee of you getting antibodies to another, like humira, as the chemical structure between those meds is very different.

The test isn't 100% necessary in all cases (often dosage of remi can be increased experimentally to see if that helps, rather than test beforehand). It does help explain why, in a lot of cases, rather than just guess. Prometheus labs in CA developed the test and calls it Anser IFX, Labcorp offers it, as does Mayo Clinic and others.
https://www.labcorp.com/test-menu/29496/infliximab-concentration-and-anti-infliximab-antibody