Influence of Immunogenicity on the Efficacy of Long-Term Treatment with TNF
α
Blockers in Rheumatoid Arthritis and Spondyloarthritis Patients
Table 4
Detectable serum levels of TNFα blockers and anti-drug Abs.
All,
RA,
SpA,
ADA tests total,
25
9
16
ADA trough levels, patients (%)
25 (100.0)
8 (88.9)
16 (100.0)
ADA concentration, mean ± SD
8.04 ± 4.2
8.24 ± 3.8
7.1 ± 4.48
Anti-ADA Ab positive, patients (%)
1 (4.0)
1 (11.1)
0
Anti-ADA Ab concentration (one sample)
2000
2000
na
ETA tests total,
61
29
32
ETA trough levels, patients (%)
57 (93.4)
28 (96.6)
29 (90.6)
ETA concentration, mean ± SD
6.54 ± 2.34
6.06 ± 1.18
6.83 ± 3.5
Anti-ETA Ab positive, patients (%)
0
0
0
INF tests total,
57
24
33
INF trough levels, patients (%)
41 (71.9)
14 (58.3)
27 (81.8)
INF concentration, median (IQR) (range)
2.36 (1.95–4.26) (1.52–14.3)
3.77 (1.88–9.4) (1.52–14.3)
2.33 (1.96–4.48) (1.69–35.0)
Anti-INF Ab positive, patients (%)
14 (24.6)
8 (33.3)
6 (18.2)
Anti-INF Ab concentration, median (IQR) (range)
130 (7.97–289.9) (4.89–1440)
136.0 (21.17–313.03) (9.2–527)
74.4 (5.4–489) (4.89–1440)
Notes: calculations for drug and anti-drug Abs concentrations was done only for trough serum levels. ADA ≤0.024 μg/mL, ETA and INF concentrations ≤0.035 μg/mL were considered as not detectable for drugs. Anti-ADA Ab ≤3.5 AU/mL, anti-ETA Ab ≤142.0 AU/mL, and anti-INF Ab ≤2.0 AU/mL concentrations were considered as negative. Abbreviations: SD: standard deviation, na: data is not applicable.
