It depends on which lab used as to whether 128 would fall in the Normal Reference Range. For instance, both Quest and Labcorp used the same units of measurement but Quest has a Normal Reference Range if <167 (or 162.7 can't remember exactly) whereas Labcorp has a Normal Reference Range of <50.
So, I don't have CD but my son does, I was tested due GI issues (turned out to be gastritis) and my fc level was in the 100s (can't remember but I think like 159) because I used quest labs my result was normal.
My son, has CD, and has never reached remission an fc level of 300 correlated with his scope and MRE tests at the time that showed simmering inflammation(although asymptomatic). In full blown flare he was 1700(fully symptomatic).
We are waiting on an fc result now and we know it's gonna be raised due ton a recent scope and iron deficiency anemia progressing. Kinda dreading the fc result!