Ida Sjøstrøm, Gunn Helen Malmstrøm, Arne Røseth
Lovisenberg Diakonale Hospital, Unger Vetlesen Research Institute. Oslo, Norway.

Therapeutic drug monitoring (TDM) has become standard clinical practice over the last few years, but has been hampered by 2 aspects; the high cost and that ELISA based test delays the result with several days. Approx. 44% of the pts are correctly dosed, 21% under dosed and 26% had IFX levels >7. This accounts for nearly half of all pts do need dose optimization.

Aims of the study
The study had two aspects; first is to correlate a CE -marked rapid test for IFX trough level, the Quantum Blue Infliximab test (QB-IFX) (Bühlmann Laboratories, Basel, Switzerland) to an ELISA. Secondly, to correlate the performance of such a test performed by; A)a nurse and B) a trained laboratory person

The study comprised 19 pts with IBD receiving IFX treatment.
Part A : A nurse (IS) received one hour of “laboratory” training before running the QB-IFX under supervision of AR. The serum was thawed, diluted 10uL in 190 uL buffer and vortexed for 5 sec. 70uL was applied to the test cassette and read after 15 min.
Part B: The same procedure was followed but this time by a highly experienced lab technician (GHM)

The was a very good correlation between the QB-IFX rapid test and the laboratory ELISA test, r= 0.94, p< 0.001.