Anti-aquaporin-4 immunoglobulin G colorimetric detection by silver nanoparticles.

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory and autoimmune disease whose biomarker is the anti-AQP4-IgG autoantibody that binds to aquaporin-4 (AQP4) protein. We introduced a nanosensor with a sensitivity of 84.6%, higher than the CBA's 76.5%. Using silver nanoparticles (AgNPs), we detected not only seropositive but also some false-negative patients previously classified with CBA. It consisted of AgNPs coated with one of a panel of 5 AQP4 epitopes. The ability in detecting the anti-AQP4-IgG in NMOSD patients depended on the epitope and synergy could be obtained by combining different epitopes. We demonstrated that NMOSD patients could easily be distinguished from healthy subjects and patients with multiple sclerosis. Using the most sensitive AQP461-70 peptide, we established a calibration curve to estimate the concentration of anti-AQP4-IgG in seropositive NMOSD patients. The ability to enhance the accuracy of the diagnosis may improve the prognosis of 10-27% of anti-AQP4-IgG seronegative patients worldwide.

Juvenile myoclonic epilepsy: analysis of factors implied in delayed diagnosis and prognosis after clinical and electroencephalographical characterization

Considered a common epileptic syndrome, corresponding to 2.8 - 11.9 per cent of all epilepsies, Juvenile Myoclonic Epilepsy (JME) is still not well diagnosed, a fact that may bring about important deleterious consequences, Valproato (VPA) is considered the drug of choice for seizure control. With the aim to characterize the factors implied in the delay of diagnosis (DD) and the response after adequate therapeutic institution we analyzed 41 JME patients attended to since october 2000. The initial diagnosis, the DD and factors implied in it and prognosis after establishment of adequate treatment since most of the patients were receiving antiepileptic drugs (AED) other than VPA were characterized. Only 8 out of the 41 patients (19,5 per cent) had had syndromic diagnosis while 33 (80,5 per cent) had not yet had, being more frequently labeled as undeterminate epulepsy. The diagnosis was established in a mean of 8.2 yr. 15 days to 34 yr.). The factors identified in the DD were: omission in 4 (9.7 per cent) and asymmetry of the myoclonia in 12 (29.3 per cent): normal first EEGs in 16 (41 per cent); presence of focal abnormalities in the EEGs in 12 (31.7 per cent). At the time of the stdy, the sleep-deprived EEG was abnormal in 32 (86.5 per cent) and showed generalized spike-waves in 29 (78.4 per cent) or multispike-waves in 19 (51.4 per cent). There was a frontocentral predominance in 30 (81.1 per cent) being asymmetric in 12. Focal discharges were obsersed in 12 (29.2 per cent). The mean in years of DD was 11.6 yr. for the group with asymmetric compared to 8,5 yr. in those with symmetric paroxysms. VPA associated with avoidance of precipitant factors (APF) led to complete seizure control in 29 of all patients in the first year. This rate dropped to 16 in the third year. The main factor inplied in this drop was non-compliance. JME continues to be misdiagnosed and the response to VPA + APF in one year is excellent suggesting pharmacosenstivity. Despite all the instructions it is very difficult for JME patients to regorously follow medical advices over the yeras