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Prometheus Test - High Remicade Serum Level

Our son's last Prometheus test showed a Serum Infliximab level Concentration of 32 and 0 antibodies. This test was preformed 4 weeks into a 8 week cycle. As a result of this high level, and confirmed remission, his doctor suggests extending cycle from 8 weeks to 10 weeks. He is on the lowest dosage already, so they do not want to reduce the dosage, just increase the duration of the cycle.

Does anyone have any experience with this? We were told that the level of 32 is significantly higher than the level they typically see in pediatric patients. We are happy and grateful that our son is doing fantastic, but worried about causing a flare up on one hand, and on the other, worried about the high level of Remicade in his system!

Any advice?
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Staff member
I have no idea - my kiddo never even got to 8 weeks - but I'm glad he's doing so well!
Tagging my little penguin, Tesscorm and Clash, they may know more.

my little penguin

Staff member
Ds had high level of remi and high levels of humira currently
Never changed anything
I would ask for a second opinion on moving out to 10 weeks
All the studies showed more than 8 week intervals increased the risk of antibody formation and reactions


Staff member
I don't understand why it would be tested at 4 weeks?? I suppose there is a formula that allows you to calculate what his levels would be at 8 weeks but??? My son has had his levels tested twice, both times it was either the day before or the morning of his infusion. GI wanted to see where his levels were immediately before infusion.

I don't recall the numbers but, in our case, his levels were low and we were moved from 8 weeks to 6 weeks.
The test was performed at trough, midway through the cycle. The suggested therapeutic level at trough in the 8 week cycle is 12 or higher (I believe). There is no research on the negative effects of higher serum levels which is frustrating!

Our doctor is going to discuss with the other doctors in the practice. Hoping for an answer soon!
at 8 weeks, i just had serum tested... then i will have another serum level at four weeks....why?? i relapsed within that time frame. .. that was my fifth infusion! at 4kg. dr. raised to 5kg his time and still wants to go 8 weeks. i feel 8 weeks is too long. have to monitor the serum. it was my idea to monitor so i can show him he is wrong at 8 weeks. so at 4 weeks will get the serum tested/ we already have a base line which i call ground zero. this is where i felt i ran out of the remi.. that was recent October 26, 2016. so we have a ground zero number coming soon at 8 weeks, then a midway number coming end of month. its an expensive test, $2500.00 one time, one test.

my little penguin

Staff member
Standard. Dohn's dosing for remicade is 5mg/kg every 8 weeks
But can go as high as 10mg/kg every 4weeks
They can also add immunosuppressants to help. Boost the remicade

Ds never got to 8 weeks
And quickly switch from 5mg/kg

To 7mg/kg every 6 weeks

Good luck