TABLE 2.
Characteristics of Infliximab Trough Concentrations Among Patients with Proactive TCM
| First Proactive Trough Concentration, n (%)a | Subsequent Proactive Trough Concentration, n (%)a | |
|---|---|---|
| Number of trough concentrations obtained | 48 | 40 |
| Tests performed per assay | ||
| ELISA | 37 (77) | 7 (18) |
| HPLC | 11 (23) | 33 (82) |
| Median first IFX trough concentration (IQR) | 5.9 ug/ml (2.8–9.9) | 7.6 ug/ml (4.3–12.3) |
| IFX undetectable | 7 ug/ml (15) | 1 (3) |
| IFX trough concentration <3 ug/ml | 13 (27) | 4 (10) |
| IFX trough concentration <5 ug/ml | 23 (48) | 13 (33) |
| IFX trough concentration = 5–10 ug/ml | 14 (29) | 14 (35) |
| IFX trough concentration >10 ug/ml | 11 (23) | 15 (38) |
| Change | 17 (35) | 10 (25) |
| Escalation of therapy | 12 (71) | 8 (80) |
| Decrease of therapy | 3 (18) | 2 (20) |
| Stopped therapy | 2 (12) | — |
a
Reactive IFX concentrations were excluded.
ELISA, solid phase enzyme-linked immunosorbent assay; HPLC, high performance liquid chromatography; IQR, interquartile range (25–75).