Table 3.
Demographics and clinical characteristics of asymptomatic and symptomatic PML patients
| Asymptomatic PML patients (n = 30) | Symptomatic PML patients1 (n = 342) | All PML patients (n = 372) | |
|---|---|---|---|
| Age at diagnosis, years | |||
| Mean | 42.7 | 45.1 | 44.9 |
| Median (range) | 43.5 (22–61) | 45.0 (14–73) | 45.0 (14–73) |
| (n = 30) | (n = 337) | (n = 367) | |
| Female, n (%) | 21 (70.0) | 242 (70.8) | 263 (70.7) |
| Weight, kg | |||
| Mean | 68.7 | 75.4 | 75.1 |
| Median (range) | 65 (50–98) | 68 (46–163) | 68 (46–163) |
| (n = 12) | (n = 142) | (n = 154) | |
| Duration of MS at diagnosis, years | |||
| Mean | 12.1 | 14.1 | 13.8 |
| Median (range) | 12.0 (4–29) | 12.5 (1–51) | 12.0 (1–51) |
| (n = 19) | (n = 120) | (n = 139) | |
| Natalizumab exposure, months | |||
| Mean | 40.6 | 39.8 | 39.9 |
| Median (range) | 40.5 (24–94) | 40.0 (8–77) | 39.5 (8–94) |
| (n = 30) | (n = 342) | (n = 372) | |
| Prior IS use, yes, % | 23.3 | 28.1 | 27.7 |
| EDSS score on natalizumab pre-PML | |||
| Mean | 3.2 | 3.8 | 3.7 |
| Median (range) | 3.0 (1–6.0) | 4.0 (0–8.5) | 3.5 (0–8.5) |
| (n = 18) | (n = 172) | (n = 190) | |
| KPS score on natalizumab pre-PML | |||
| Mean | 85.0 | 80.2 | 80.6 |
| Median (range) | 90.0 (60–100) | 80.0 (40–100) | 80.0 (40–100) |
| (n = 10) | (n = 112) | (n = 122) | |
| Time to PML diagnosis2, days | |||
| Mean | 37.6 | 44.6 | NA |
| Median (range) | 12 (0–168) | 28 (0–368) | |
| (n = 30) | (n = 330) | ||
| CSF JCV DNA3, copies/mL | |||
| Mean | 277,000 | 185,000 | 192,000 |
| Median (range) | 668 (12–4,970,000) | 510 (1–10,200,000) | 510 (1–10,200,000) |
| (n = 24) | (n = 289) | (n = 313) | |
| Geography, n (%) | |||
| United States | 4 (13.3) | 123 (36.0) | 127 (34.1) |
| Rest of world | 26 (86.7) | 219 (64.0) | 245 (65.9) |
CSF, cerebrospinal fluid; EDSS, Expanded Disability Status Scale; IS, immunosuppressant; JCV, JC virus; KPS, Karnofsky Performance Scale; MS, multiple sclerosis; NA, not applicable; PML, progressive multifocal leukoencephalopathy.
1
Two Crohn’s disease patients are included.
2
Time from first suspect MRI (for asymptomatic patients) or PML symptom (for symptomatic patients) to PML diagnosis date, defined as first positive JCV DNA in CSF or positive brain biopsy.
3
First positive test.