Remicade antibodies - what are the ranges/whats high?

I have a question that I can't seem to find the answer to when I research online regarding antibodies. I have had the level and antibody testing done. It was done one week prior to my infusion when I was at 5 mg/kg back in August. I got a 16. I am trying to get to the lab paperwork to see the measurements they used and categories. My GI's assistant just said my antibodies were less than 22 and that was completely normal but couldn't give me an exact number.

Can anyone shed light on what that means? Is there a level of 0-22 or something that I am falling into?

I am going to get the testing done again 24 hours prior to my infusion in March. Since I am now at 10 mg/kg and moving slowly toward remission I want to see if we can eventually get back to 5 mg/kg. I honestly think my issues were based on hormonal post partum stuff. I'm not even thinking about dropping the dosage til at least April so I will have 2 more infusion at 10 mg/kg.

My GI originally said I didn't need to increase the dose because my levels were good at 16. He said that I could stay at 10 mg/kg or he would be willing to drop me back down once things were settled. I want to see what my levels are 24 hours prior to my infusion at 10 mg/kg.

I am just wondering about the antibodies and if I should be concerned with the way the assistant gave me the numbers. I'm hoping she just doesn't understand the testing that well.

EDIT: The weird thing is when my GI called with the results in August he said I had no antibodies at all.

I'd ask your gastroenterologist. I took a look this afternoon, and came up with the following for uc patients. From what I understand, a loss of response is often defined as a remicade/infliximab serum trough (minimum) concentration of 0.8 μg/mL or less , and also a high concentration of infliximab antibodies, which is 10 U/mL or more.

For comparison, a good or high infliximab trough concentration is defined as greater than 5.0 mg/L. Good antibody concentration is ideally zero, but lower than 10 U/mL is fine.

"Low infliximab concentrations (median trough level, 0 μg/mL) and high anti-infliximab antibody concentrations (median trough level, 85 U/mL) were associated with a loss of response (P=.0083 and P=.0007 for association of infliximab and anti-infliximab antibody trough levels, respectively).

The cutoff values for infliximab and anti-infliximab antibody trough levels were also determined for UC patients: 0.8 μg/mL for infliximab (75% sensitivity [95% CI, 35-97] and 100% specificity [95% CI, 48–100]) and 10 U/mL for anti-infliximab antibodies (80% sensitivity [95% CI, 44–97] and 100% specificity [95% CI, 69–100])."

Source: www.ncbi.nlm.nih.gov/pmc/articles/PMC3317512/

I got the paperwork from LabCorp. Whatever measurement they used stated as the results anything under 22 ng/ml shows no detection of antibodies. WHEW!!

Just thought I would throw out there how they tested it. I also was relieved to learn my insurance co ended up paying for the test.