Restricted motion of the median nerve in carpal tunnel syndrome

Motion of the median nerve was compared on an axial ultrasonographic image in the mid-carpal tunnel in 30 wrists of 15 women with bilateral idiopathic carpal tunnel syndrome and 30 wrists of 15 healthy women. During passive flexion and extension of the index finger, the control wrists had transverse sliding of the nerve beneath the flexor retinaculum (1.75 +/- 0.49 mm), which was regarded as a physiological phenomenon. In contrast, the wrists of patients with carpal tunnel syndrome had significantly less sliding (0.37 +/- 0.34 mm; P = 0.0001), which indicates that physiological motion of the nerve is restricted. This decrease in nerve mobility may be of significance in the pathophysiology of carpal tunnel syndrome.

Production of l -Phenylalanine from trans -Cinnamic Acid with Rhodotorula glutinis Containing l -Phenylalanine Ammonia-Lyase Activity

An enzymatic method using l -phenylalanine ammonia-lyase (EC 4.3.1.5) for the rapid conversion of trans -cinnamic acid to l -phenylalanine has been investigated. With Rhodotorula glutinis , enzyme activity as high as 0.3 U/ml of culture broth was obtained. The enzyme activity was kept stable for a relatively long time during cultivation by the addition of l -isoleucine. Optimization of the parameters of the conversion reaction resulted in accumulation of 18 mg of l -phenylalanine per ml of reaction mixture. The conversion yield from trans -cinnamic acid was about 70%. The method may provide a rapid and practical way to produce l -phenylalanine useful as an essential amino acid.

Histology of the transverse carpal ligament and flexor tenosynovium in idiopathic carpal tunnel syndrome

Histology of the transverse carpal ligament and flexor tenosynovium was investigated in 166 wrists from 130 patients with idiopathic carpal tunnel syndrome. Nine wrists from 9 controls were used for comparison. In the patients, 73.5% of the ligament and 56.0% of the tenosynovium showed normal histology. In the remaining specimens, the ligament showed mucoid change (17.5%), amyloid deposits (7.8%), inflammation (3.0%), and chondrometaplasia (2.4%), and the tenosynovium showed fibrosis (25.3%), edema (7.2%), inflammation (10.2%), amyloid deposits (8.4%), and vascular hypertrophy (4.8%). The majority of these changes were mild in degree and the pathophysiology did not appear to be meaningful. We conclude that in idiopathic carpal tunnel syndrome, the ligament and tenosynovium often show normal histology and there are no typical or consistent changes with which idiopathic carpal tunnel syndrome can be associated.

Different distribution of endothelin receptor subtypes in pulmonary tissues revealed by the novel selective ligands BQ-123 and [Ala1,3,11,15]ET-1

We have demonstrated the different distribution of two distinct endothelin (ET) receptor subtypes in porcine pulmonary tissues using a radioligand binding assay. The clear differentiation of the subtypes was made possible by the discovery of two compounds, BQ-123 and [Ala1,3,11,15]ET-1 (4AlaET-1), that are highly selective for ETA and ETB receptors, respectively. In the bronchus and lung parenchyma, BQ-123 inhibited 65% and 30% of [125I]ET-1 binding on the sensitive sites, while 4AlaET-1 displaced 25% and 60%, respectively. The combination of the two compounds completely inhibited ET-1 binding in both tissues. An autoradiographic study of [125I]ET-1 binding using BQ-123 and 4AlaET-1 also supported the different localization of two ET receptor subtypes in pulmonary tissues. In particular, the blood vessels and bronchi are rich in ETA, but the lung parenchyma is rich in ETB.

Rabies virus-induced activation of mitogen-activated protein kinase and NF-kappaB signaling pathways regulates expression of CXC and CC chemokine ligands in microglia

Following virus infection of the central nervous system, microglia, the ontogenetic and functional equivalents of macrophages in somatic tissues, act as sources of chemokines, thereby recruiting peripheral leukocytes into the brain parenchyma. In the present study, we have systemically examined the growth characteristics of rabies virus (RV) in microglia and the activation of cellular signaling pathways leading to chemokine expression upon RV infection. In RV-inoculated microglia, the synthesis of the viral genome and the production of virus progenies were significantly impaired, while the expression of viral proteins was observed. Transcriptional analyses of the expression profiles of chemokine genes revealed that RV infection, but not exposure to inactivated virions, strongly induces the expression of CXC chemokine ligand 10 (CXCL10) and CC chemokine ligand 5 (CCL5) in microglia. RV infection triggered the activation of signaling pathways mediated by mitogen-activated protein kinases, including p38, extracellular signal-regulated kinases 1 and 2 (ERK1/2), and c-Jun N-terminal kinase, and nuclear factor kappaB (NF-kappaB). RV-induced expression of CXCL10 and CCL5 was achieved by the activation of p38 and NF-kappaB pathways. In contrast, the activation of ERK1/2 was found to down-regulate CCL5 expression in RV-infected microglia, despite the fact that it was involved in partial induction of CXCL10 expression. Furthermore, NF-kappaB signaling upon RV infection was augmented via a p38-mediated mechanism. Taken together, these results indicate that the strong induction of CXCL10 and CCL5 expression in microglia is precisely regulated by the activation of multiple signaling pathways through the recognition of RV infection.

Transverse sliding of the median nerve beneath the flexor retinaculum

Transverse sliding of the median nerve beneath the flexor retinaculum during active-resistant flexion of the fingers was sonographically demonstrated. Although it is a physiological phenomenon, it may cause mechanical nerve deformation in addition to longitudinal sliding when the nerve is subject to compression against the flexor retinaculum by tensed overlying flexor tendons.

Rabies virus stimulates nitric oxide production and CXC chemokine ligand 10 expression in macrophages through activation of extracellular signal-regulated kinases 1 and 2

Macrophages represent an essential part of innate immunity, and the viral infection of macrophages results in the release of multiple proinflammatory mediators, such as nitric oxide (NO), cytokines, and chemokines. This study was undertaken to define the molecular mechanism of macrophage activation in response to rabies virus (RV) infection. In RAW264 murine macrophage cells, a well-characterized macrophage model, RV replication was strictly restricted, whereas cell proliferation was significantly enhanced upon RV inoculation. Transcriptional analyses for the expression of inducible forms of NO synthase (iNOS), cytokines, and chemokines revealed that RV virions potentiate the gene expression of iNOS and CXC chemokine ligand 10 (CXCL10), a major chemoattractant of T helper cell type 1. However, RV stimulation had little or no effect on the expression profiles of proinflammatory cytokines and other types of chemokines. In macrophages stimulated with UV-inactivated RV virions, as well as infectious viruses, the phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2, members of the mitogen-activated protein kinase family, was significantly induced. Specific inhibitors of MAPK/ERK kinase reduced the RV-induced production of NO and CXCL10. Furthermore, the RV-induced activation of the ERK1/2 pathway was severely impaired by the neutralization of the endosomal and lysosomal pH environment with lysosomotropic agents, indicating that endocytosis is a key step leading to the activation of ERK1/2 signaling. Taken together, these results suggest that the ERK1/2-mediated signaling pathway plays a cardinal role in the selective activation of macrophages in response to RV virions, thereby regulating cellular functions during virus infection.

Unilateral carpal tunnel syndrome and space-occupying lesions

To assess the association between unilateral carpal tunnel syndrome and space-occupying lesions, 128 patients have been reviewed. They were divided into bilateral, subclinical (unilateral signs and symptoms, and bilateral slowing in the median nerve conduction) and unilateral carpal tunnel syndrome. Space-occupying lesions were investigated on the basis of physical examination and wrist imaging using plain radiographs and ultrasonograms. Of 20 patients with unilateral carpal tunnel syndrome, space-occupying lesions were found in seven (occult ganglion in five and occult calcified mass in two). In contrast, none of 89 patients with bilateral carpal tunnel syndrome and 19 with subclinical carpal tunnel syndrome had space-occupying lesions. We conclude that careful examination and wrist imaging on suspicion of local pathology, especially a space-occupying lesion, are needed when the condition is unilateral and the aetiology is not clear from the history and on physical examination.

Ultrasonographically assisted carpal tunnel release

An operative technique of carpal tunnel release using intraoperative ultrasonography is described. In this technique, "safe line" is defined in the transverse carpal ligament and the adjacent deep forearm fascia midway between the ulnar margin of the median nerve and the radial margin of the ulnar artery. After ultrasonographic design of a 1.0 to 1.5-cm skin incision along the safe line at the distal carpal tunnel, the distal ligament is released under direct vision. Proximal release is performed along this line under ultrasonographic monitoring using a device that consists of a basket punch and an outer metal tube. In a prospective randomized study, the outcomes were compared for carpal tunnel release using either this technique in 50 hands of 50 patients or conventional open release in 53 hands of 53 patients. Follow-up assessment at 3, 6, 13, 26, 52, and 104 weeks showed no significant difference with respect to numbness and paresthesias, static two-point discrimination, findings on Semmes-Weinstein monofilament testing, findings on manual muscle testing of the abductor pollicis brevis, and electrophysiologic findings. The ultrasonographic-release group had better outcomes regarding pain, tenderness of the scar, and key-pinch strength at 3, 6, and 13 weeks, and grip strength at 3 and 6 weeks after surgery. The scar was more aesthetic in this group. There were no complications with either technique.

Suppressive effect of simvastatin on interferon-beta-induced expression of CC chemokine ligand 5 in microglia

Despite the pivotal role of microglia in immune system of the brain, a growing body of evidence suggests that the excessive microglial activation provokes neuronal and glial damages, leading to neurodegenerative and neuroinflammatory disorders. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, have recently received much attention for their suppressive effects on inflammation in the central nervous system. In the current study, we have examined the statin-mediated inhibition of microglial function, especially that of chemokine production. Stimulation of microglial cells with interferon-beta (IFN-beta) resulted in the expression of CC chemokine ligand 5 (CCL5), a major chemoattractant of inflammatory cells. Microglial CCL5 response was synergistically potentiated by costimulation with IFN-beta and tumor necrosis factor-alpha (TNF-alpha). The simvastatin treatment significantly diminished the microglial CCL5 expression induced by IFN-beta alone or by IFN-beta/TNF-alpha combination. In the presence of simvastatin, the IFN-beta-induced activation of Janus kinase (Jak)-signal transducer and activator of transcription (STAT) pathway was attenuated, although this compound had little or no effect on the TNF-alpha-evoked activation of nuclear factor kappaB and c-Jun N-terminal kinase pathways. In addition, chemical inhibitor of Jak-STAT signaling significantly diminished the IFN-beta-induced expression of CCL5 in microglia. Taken together, these results suggest that simvastatin suppresses the IFN-beta-induced expression of CCL5 via down-regulation of Jak-STAT signaling pathway.

Generation and characterization of P gene-deficient rabies virus

Rabies virus (RV) deficient in the P gene was generated by reverse genetics from cDNA of HEP-Flury strain lacking the entire P gene. The defective virus was propagated and amplified by rescue of virus, using a cell line that complemented the functions of the deficient gene. The P gene-deficient (def-P) virus replicated its genome and produced progeny viruses in the cell lines that constitutively expressed the P protein, although it grew at a slightly retarded rate compared to the parental strain. In contrast, no progeny virus was produced in the infected host when the def-P virus-infected cells that did not express the P protein. However, we found that the def-P virus had the ability to perform primary transcription (by the virion-associated polymerase) in the infected host without de novo P protein synthesis. The def-P virus was apathogenic in adult and suckling mice, even when inoculated intracranially. Inoculation of def-P virus in mice induced high levels of virus-neutralizing antibody (VNA) and conferred protective immunity against a lethal rabies infection. These results demonstrate the potential utility of gene-deficient virus as a novel live attenuated rabies vaccine.

Two endothelin receptor subtypes in porcine arteries

Endothelin-1 (ET-1) and ET-3 caused constrictions of endothelium-denuded porcine coronary artery strips with different concentration-response curves: a typical sigmoidal curve to ET-1 and a two-phase sigmoidal curve to ET-3. Binding assays using a membrane preparation demonstrated different Bmax values for [125I]ET-1 and [125I]ET-3 binding. In addition, [125I]ET-1 binding was inhibited by ET-1 and ET-3 with different potencies (ET-1 greater than ET-3), while [125I]ET-3 binding was inhibited by both ETs equally. From these results, two distinct ET receptor subtypes were proposed in the artery; site 1 (selective to ET-1) and site 2 (equally sensitive to both ETs). However, only site 1 was identified on cultured arterial smooth muscle cells (VSMCs) by the binding assay, and this was confirmed since only ET-1 (not ET-3) caused a significant increase in the intracellular free Ca2+ concentration. Therefore, it seems likely that vasoconstriction is mediated via the binding of ET-1 to site 1 (VSMCs) and site 2 (non-VSMCs), or the binding of ET-3 to site 2 (non-VSMCs). Furthermore, site 2 was predominant in nonvascular tissues such as lung, kidney, and cerebellum, thereby suggesting that site 1 may exist in limited tissues such as VSMCs.

Evaluation of a floating dosage form of nicardipine hydrochloride and hydroxypropylmethylcellulose acetate succinate prepared using a twin-screw extruder

A floating dosage form composed of nicardipine hydrochloride (NH) and hydroxypropylmethylcellulose acetate succinate (enteric polymer) was prepared using a twin-screw extruder. By adjusting the position of the high-pressure screw elements in the immediate vicinity of die outlet, and by controlling the barrel temperature, we were able to prepare a puffed dosage form with very small and uniform pores. It was found that the porosity and pore diameter could be controlled by the varying amount of calcium phosphate dihydrate. In the shaking test, the puffed dosage form was found to have excellent floating ability and mechanical strength in acid solution (JP First Fluid, pH 1.2). The dissolution profile of NH was controlled by the amount of wheat starch. In the dissolution test using JP Second Fluid (pH 6.8), rapid dissolution of NH and loss of buoyancy were observed. It was shown that the puffed dosage form, consisting of enteric polymer prepared using the twin-screw extruder, was very useful as a floating dosage form that was retained for a long period in the stomach.

Iatrogenic injury of the spinal accessory nerve. Results of repair

We reviewed the results of repair of the spinal accessory nerve in seven patients seen between September 1994 and January 1996. The nerve had been injured during biopsy of a cervical lymph node in six patients and during removal of a bullet in one. The average interval between the time of the injury and the repair of the nerve was eight months (range, three to fourteen months). An end-to-end repair of the nerve was performed in six patients, and a neurolysis was done in one. The average duration of follow-up was thirty-two months (range, twenty-four to thirty-nine months). Postoperatively, all seven patients had relief of pain and stiffness in the shoulder girdle. Manual muscle-testing revealed normal strength of the trapezius, which was comparable with that on the unaffected side. Four patients regained normal function of the shoulder. Three patients reported a stretching sensation or discomfort in the neck, periscapular discomfort, and fatigue of the extremity when lifting heavy objects or performing overhead activities. However, these residual symptoms were mild and tolerable and thus were different in nature from the preoperative pain and stiffness. Iatrogenic injury of the spinal accessory nerve should be suspected if a patient has pain or stiffness in the shoulder girdle and a history of a recent operation on the neck. The nerve should be explored if spontaneous recovery does not occur.

The use of ultrasonography in detection of synovitis in carpal tunnel syndrome

The findings of pre-operative ultrasonography of the carpal tunnel were compared with synovial histology in 50 surgically treated wrists with carpal tunnel syndrome. Eight wrists with a massive hypoechoic area (group 3) had synovitis. 28 with a minimal hypoechoic area (group 1) had no evidence of inflammation. 14 with a moderately increased hypoechoic area (group 2) consisted of three with synovitis, four with lymphocytic infiltration and seven without inflammation. Group 3 strongly indicates synovitis, in which case one should consider aetiology other than the idiopathic cause. Bilateral synovial thickening suggests carpal tunnel syndrome as the initial clinical picture of rheumatoid arthritis, and group 1 indicates idiopathic carpal tunnel syndrome provided that there are no primary causes.

Ganglion-associated ulnar tunnel syndrome treated by ultrasonographically assisted aspiration and splinting

We describe a case of ulnar nerve compression at the wrist due to a ganglion. This was treated by aspiration of the ganglion under ultrasonography and splinting because the patient was pregnant. The ulnar nerve palsy resolved completely and the ganglion disappeared. A follow-up ultrasonographic examination after 2 years showed no recurrence of the ganglion.

Radial nerve entrapment by the lateral head of the triceps

A case of slowly progressive radial nerve entrapment of spontaneous onset is presented. Surgical exploration revealed compression of the radial nerve by a musculotendinous arch of the lateral head of the triceps. Relief of signs and symptoms did not ensue.

Distance between the median nerve and ulnar neurovascular bundle: clinical significance with ultrasonographically assisted carpal tunnel release

In ultrasonographically assisted carpal tunnel release, the zone of the transverse carpal ligament between the median nerve and ulnar neurovascular bundle is of significance because proximity of the cutting device to these structures depends on its width. In this study, we measured the width of the zone at 5 levels in 60 wrists from 54 patients with surgery-indicated idiopathic carpal tunnel syndrome. The width of the 5 levels ranged from 2.8 to 11.2 mm (mean, 7.1 mm) at the hook of the hamate, 3.0 to 12.5 mm (mean, 7.9 mm) at the distal one fourth of the carpal tunnel, 2.8 to 12.4 mm (mean, 8.0 mm) at the midsection of the tunnel, 1.5 to 13.0 mm (mean, 7.4 mm) at the proximal one fourth of the tunnel, and 5.3 to 17.2 mm (mean, 10.2 mm) at the wrist crease. These widths were not significantly correlated with radiographic measurements of the hand (cord of the radiocarpal joint arc, carpal height, third metacarpal, and hand length). We conclude that there is considerable variation of the width among individuals. Based on our clinical experience (3 wrists of 3 patients in this study), patients with a width of < or =3 mm at any level should be screened out preoperatively by wrist imaging. Our findings also may be of use to surgeons performing endoscopic carpal tunnel release.

One-portal technique of endoscopic fasciotomy: Chronic compartment syndrome of the lower leg

Many athletes complain of exercise-induced pain in the lower leg that can be caused by inflammatory diseases, peripheral nervous system disease, fatigue fracture, shin splint, and chronic compartment syndrome (CCS). CCS is the most typical exercise-induced condition and it often requires surgical decompression of the several compartments. There are already many techniques reported in the literature. Recently, an endoscopic technique for CCS was reported with which excellent results were achieved. We have modified it and developed a new technique for treating CCS of the lower leg. We report a case of CCS of the lower leg treated with 1-portal endoscopic fasciotomy. The technique helps to decrease damage to soft tissue and patients will immediately return to normal activities of daily living.

Low signal intensity in U-fiber identified by susceptibility-weighted imaging in two cases of progressive multifocal leukoencephalopathy

Magnetic resonance imaging (MRI) is a useful tool for diagnosing and monitoring progressive multifocal leukoencephalopathy (PML). Although characteristic MRI findings of PML are well known, we noted a potential new finding for this disease on susceptibility-weighted imaging (SWI). Two patients with PML were studied and followed using MRI. SWI revealed low signal intensities in U-fibers adjacent to the white matter lesions of PML. These findings progressed along with the disease progression. The cause underlying these findings remains unclear. This new finding suggests that SWI is useful for the diagnosis of PML. It can provide a helpful clue in a clinical setting.

Inhibitory effect of serotonin antagonists on JC virus propagation in a carrier culture of human neuroblastoma cells

Human polyomavirus, JCV, causes fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). It has been shown that 5HT(2A)R acts as a cellular receptor for JCV on human glial cells. In the current study, we examined the inhibitory effects of 5HT(2A)R antagonists, ketanserin and ritanserin, both on JCV infection and on propagation by using human neuroblastoma cells IMR-32 and JCI, which continuously produce JCV. Transcriptional analysis revealed that 5HT(2A)R was constitutively expressed in JCI cells. Treatments with 5HT(2A)R antagonists led to a significant reduction in the titers of progeny viruses and the population of infected JCI cells. In addition, the amount of JCV genomic DNA was decreased in JCI cells in the presence of 5HT(2A)R antagonists. These results indicate that 5HT(2A)R antagonists have an inhibitory effect on JCV infection and reproduction, and JCI cells are applicable to an experimental model for pharmacological evaluation of antiviral agents against JCV.

Bovine herpesvirus 1 glycoprotein G is necessary for maintaining cell-to-cell junctional adherence among infected cells

Glycoproteins gE and gG of bovine herpesvirus 1 (BHV-1) are involved in viral cell-to-cell transmission. We have compared the subcellular localizations of gE and gG and examined the cell-to-cell adherence of bovine kidney (MDBK) cells infected with BHV-1 mutants lacking gE or gG. In BHV-1-infected MDBK cells, gE was observed at cell junctions but did not localize at apical or basal plasma membranes. BHV-1 gG was primarily found in the cytoplasm and was also observed at boundaries among infected cells. During the infection with wild-type or gE-negative BHV-1, the filamentous actin and the adherent junctional proteins accumulated at the cell junctions. In contrast, cell junctions of MDBK cells infected with gG-negative BHV-1 were loosened, and the junctional proteins and BHV-1 gE were distributed in the cytoplasm. These data indicate that BHV-1 gG facilitates viral cell-to-cell spread by maintaining the cell-to-cell junctions among the infected cells.

Rituximab-associated progressive multifocal leukoencephalopathy derived from non-Hodgkin lymphoma: neuropathological findings and results of mefloquine treatment

A 66-year-old man with non-Hodgkin lymphoma (NHL) developed progressive multifocal leukoencephalopathy (PML) after undergoing chemotherapy including rituximab. Although the administration of mefloquine at a dose of 500 mg weekly temporarily led to a dramatic decrease in the copy number of JC Virus DNA in the cerebrospinal fluid, the patient's symptoms gradually worsened. The CD4(+) T count remained continuously low, at least until approximately five months after the last cycle of chemotherapy. A postmortem examination performed 10 months after the onset of PML disclosed a severe condition associated with rituximab-treated PML originating from NHL and a high mefloquine concentration in the brain. The accumulation of further data regarding mefloquine treatment in PML cases may help to elucidate the optimal dosage and time window for effectively treating PML.

Sequential changes in the non-coding control region sequences of JC polyomaviruses from the cerebrospinal fluid of patients with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is caused by JC polyomavirus (JCV) infection in the brain. JCV isolates from PML patients have variable mutations in the non-coding control region (NCCR) of the genome. This study was conducted to examine sequential changes in NCCR patterns of JCV isolates obtained from the cerebrospinal fluid (CSF) of PML patients. CSF specimens were collected from PML patients at different time points, the NCCR sequences were determined, and their compositions were assessed by computer-based analysis. In patients showing a marked increase in JCV load, the most frequent NCCR sequences in the follow-up specimens were different from those in the initial samples. In contrast, the dominant NCCRs in the CSF remained unaltered during the follow-up of individuals in whom the viral load decreased after therapeutic intervention. These data demonstrate that the majority of JCV variants emerge with the progression of PML and that these changes are suppressed when the viral load is decreased.

Characteristics of progressive multifocal leukoencephalopathy clarified through internet-assisted laboratory surveillance in Japan

Background

Progressive multifocal leukoencephalopathy (PML), a rare but fatal demyelinating disease caused by JC virus (JCV), occurs mainly in immunocompromised patients. As PML develops in individuals with various underlying disorders sporadically and infrequently, a nationwide survey of PML is difficult. This study was conducted to elucidate the characteristics of PML in Japan through an internet-assisted laboratory surveillance program.

Methods

A diagnostic support system for PML was established using a real-time PCR assay of JCV DNA in cerebrospinal fluid (CSF), and requests for testing were received from clinicians via specialized websites. Medical histories of patients were collected through standardized questionnaires, and a database of CSF JCV loads and clinical information was created and analyzed.

Results

For 4 years from April 2007 to March 2011, CSF specimens from 419 patients were tested. Forty-eight individuals were found positive for JCV DNA in their CSF and were diagnosed with PML. PML primarily occurred not only in HIV-positive patients (33.3%) but also in patients with hematologic disorders after receiving stem cell transplantation, chemotherapy, and/or immunosuppressive treatment (39.6%). The frequencies of PML cases among the subjects in these two categories were 20.3% and 23.5%, respectively. Although no significant features were observed with respect to CSF JCV loads in PML patients with an HIV infection or hematologic disorder, males were predominant in both groups (100% and 89.5%, respectively). The proportion of PML cases with autoimmune disorders (6.3%) or solid-organ transplants (2.1%) was smaller than those with HIV infection or hematologic disorders, probably due to the limited availability of therapeutic monoclonal antibodies and transplantation from brain dead donors.

Conclusions

The results suggest that the internet-assisted laboratory surveillance program might be a useful strategy for collecting precise real-time information on PML on a national level. The current database provides important background information for the diagnosis and treatment of patients with risk factors for PML.