Table 4.
JC viral load and STRATIFY JCV® in biological samples of RRMS patients with the number of natalizumab infusions >12 (>12 months)
| Infusions (n) | Pt (n) | Pt JCV DNA+ (n)b | Pt JCV DNA− (n)b | Urine | Plasma | PBMC | |||
|---|---|---|---|---|---|---|---|---|---|
| JCV+/JCV− | log10 gEq/mL (range)c | JCV+/JCV− | log10 gEq/mL (range)c | JCV+/JCV− | log10 gEq/106 c (range)c | ||||
| STRATIFY JCV®a positive | |||||||||
| t4 | 6 | 3 | 3 | 2/5 | 5.57 (5.50–5.65) | 1/8 | 1.52 | 1/8 | 1.66 |
| t5 | 3 | 1 | 2 | 0/3 | – | 1/3 | 4.58 | 0/4 | – |
| STRATIFY JCV®a negative | |||||||||
| t4 | 16 | 7 | 9 | 2/25 | 5.19 (3.81–5.49) | 6/23 | 3.00 (2.67–4.72) | 2/27 | 2.42 (2.23–2.56) |
| t5 | 8 | 4 | 4 | 4/7 | 4.53 (2.94–6.67) | 1/13 | 3.25 | 3/11 | 3.03 (1.48–4.11) |
| Total (n) | 27d | 14d | 13d | 8/40 | 5.11 (2.94–6.67) | 9/47 | 3.01 (1.52–4.72) | 6/50 | 2.39 (1.48–4.11) |
n number of patients, Pt patients, t4 13–24 natalizumab infusions, t5 >24 natalizumab infusions
aSTRATIFY JCV®: two-step virus-like particle-based enzyme-linked immunosrobent assay (ELISA) was performed at t3 (after 12 natalizumab infusions), to detect specific anti-JC virus antibodies in serum
bPt JCV DNA+ and Pt JCV DNA−: number of patients with or without JCV DNA in at least 1 sample of plasma and/or PBMC and/or urine
cJCV load values were expressed as median (range) of log10 genome equivalent (gEq)/mL in urine and in plasma, and as median (range) log10 gEq/106 cells in PBMCs (gEq/106 c)
dFor 1 patient with a positive STRATIFY JCV® at t3 and 5 patients with negative STRATIFY JCV® at t3, samples collected both at t4 and t5 were available