Ethical approval of the study protocol
This study protocol was approved by the clinical studies review boards of Nagasaki University Hospital (Nagasaki, Japan). The clinical trial was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) UMIN000005969. Written informed consent was obtained from all patients enrolled in the study for both participation in the study, and for inclusion of personal data as shown in Table 1.
We enrolled 24 HAM/TSP patients (17 women and 7 men; 31 to 80 years (mean ± SD; 60.1 ± 11.2 years)) who fulfilled criteria described previously . The duration of illness was 3 to 51 years (mean ± SD; 20.9 ± 12.1 years). Motor function scores were rated from 0 to 13 according to the motor disability score described by Osame et al. . Concomitant therapies such as immunomodulators and drugs for the neurogenic bladder were continued on the condition that the dose was kept constant during the study period. Intermittent self-catheterization with regard to voiding was noted except in cases 7, 8, 10, 17, 21, 22, and 24. Patient profiles are shown in Tables 1 and 2.
Prosultiamine was imported from Ildon Pharmaceutical Co., Ltd (Seoul, South Korea). Capsulated prosultiamine (300 mg, orally) was administered once daily for 12 weeks.
Assessment of effect
We monitored changes in neurological signs, motor disability scores, time required for walking 10 m, and time required for walking down a flight of stairs at 4-week intervals. Spasticity of the lower extremities was graded using the modified Ashworth scale (MAS) .
Subjective symptoms were evaluated using the scores of the Nocturia Quality of Life (N-QoL) questionnaire [15–17] at 4-week intervals. The N-QoL questionnaire comprised 13 items and dealt with daytime energy, worry, productivity, sleep, and vitality. The total score ranged from 0 (poorest QoL) to 100 (best QoL). The Duet® Logic G2 system (Mediwatch UK Ltd., Rugby, UK) was used for the urodynamic study (UDS). Bladder capacity, detrusor pressure, maximum flow rate, detrusor overactivity (DO) and detrusor-sphincter dyssynergia (DSD) were evaluated by UDS.
Quantification of HTLV-I proviral load
For quantitative analyses of HTLV-I proviral loads, real-time quantitative polymerase chain reaction (RT-qPCR) was carried out in a Light-Cycler® FastStart DNA Master (Roche Diagnostics, Mannheim, Germany) based on fluorescence detection with SYBER® Green, as described previously . Briefly, genomic DNA samples from PBMCs from HAM/TSP patients were prepared using a Genomic DNA Extraction kit (Wako Pure Chemical Industries, Ltd., Osaka, Japan) and were subjected to RT-PCR in a LightCycler PCR system using Tax-specific primers, that is, forward primer (5′- AAACAGCCCTGCAGATACAAAGT-3′) and reverse primer (5′-ACTGTAGAGCTGAGCCGATAACG-3′), as well as β-actin-specific primers, that is, forward primer (5′-GCCCTCATTTCCCTCTCA-3′) and reverse primer (5′-GCTCAGGCAGGAAAGACAC-3′). The PCR condition for Tax was 40 cycles of denaturation (95°C, 15 s), annealing (55°C, 5 s), extension (72°C, 10 s). That for β-actin was 32 cycles of denaturation (95°C, 15 s), annealing (62°C, 5 s), and extension (72°C, 15 s). The HTLV-I proviral load per 10,000 cells was calculated according to the following formula: (copy number of Tax)/(copy number of β-actin/2) × 10,000
The Wilcoxon signed-rank test was used for statistical analyses of the change of HTLV-I proviral copy numbers and on the N-QoL scores or the urodynamic study except for DO and DSD. The McNemar test was used for statistical analyses of improvement of spasticity, DO and DSD. JMP 10 (SAS Institute Inc., Cary, NC, USA) was used as the software for statistical analyses. P< 0.05 was considered significant.