Table 1.
Clinical Characteristics of the Initial Study and Validation Groups
|
Initial Study Group (n = 268) |
Validation Group (n = 242) |
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|---|---|---|---|---|---|---|---|---|
|
Anti-IFN-β-Positive Patients |
Anti-IFN-β-Positive Patients |
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| Parameter | All AB+ (n = 136) | NAB+ (n = 85) | BAB+ (n = 51) | Anti-IFN-β-Negative Patients (n = 132) | All AB+ (n = 77) | NAB+ (n = 59) | BAB+ (n = 18) | Anti-IFN-β-Negative Patients (n = 132) |
| Age in years [mean (range)] | 40 (17–69) | 40 (19–64) | 41 (17–69) | 39 (16–66) | 39 (21–75) | 39 (21–60) | 39 (21–75) | 39 (16–67) |
| Gender (male/female) | 48/88 | 27/58 | 21/30 | 45/87 | 23/54 | 19/40 | 4/14 | 40/124 |
| Therapy duration in months [mean (range)] | 55 (16–147) | 53 (16–147) | 57 (17–112) | 59 (12–156) | 47 (7–127) | 47 (7–111) | 46 (20–127) | 55 (7–146) |
| IFN-β1a (i.m., Avonex)-treated (n) | 6 | 5 | 1 | 28 | 4 | 2 | 2 | 64 |
| IFN-β1b (s.c., Betaferon)-treated (n) | 70 | 37 | 33 | 48 | 36 | 24 | 12 | 50 |
| IFN-β1a (s.c., Rebif 22 μg)-treated (n) | 10 | 6 | 4 | 16 | 9 | 9 | 0 | 15 |
| IFN-β1a (s.c., Rebif 44 μg)-treated (n) | 50 | 37 | 13 | 40 | 28 | 24 | 4 | 36 |
| cELISA, antibody reactivity (%) [median (range)] | 74 (26–119) | 91 (35–119) | 48 (26–97) | 3 (−9–23.5) | 83 (35–140) | 85 (57–140) | 76 (35–96) | 2 (−17–24) |
| In vivo MXA assays, induction (%) [median (range)] | 23 (−64–135) | −4 (−64–50) | 89 (41–135) | 92.6 (−12–93) | 23 (−45–128) | 17 (−45–57) | 79 (53–128) | 95 (70–202) |
Both groups comprised a total of 510 IFN-β-treated subjects. Mean treatment duration exceeds 45 months in both cohorts. Ranges are given in brackets. Whereas the mean age of both groups was between 39 and 41 yr, the sex ratio differed among both groups. Females were slightly overrepresented in the validation group. Note that the number of BABs-positive subjects is higher in the IFN-β1b (Betaferon)-treated group.