MOG-Ab prevalence in optic neuritis and clinical predictive factors for diagnosis

International audienceObjective What is the proportion of antibodies to myelin oligodendrocyte glycoprotein (MOG-Ab) in optic neuritis (ON) in adults and what would be the ON presentation for which MOG-Ab should be tested? Methods Multicentric prospective study conducted during 1 year on all patients diagnosed with acute ON in all ophthalmological units in hospitals in a region in western France. Results Sixty-five patients were included. MOG-Ab prevalence was 14% (9/65) during an acute ON and 13% (7/55) after exclusion of patients already diagnosed with multiple sclerosis (MS) (8) or MOG+ON (2). Compared with MS and clinically isolated syndrome, MOG+ON had no female preponderance (67% of men in case of MOG+ON and 22% of men in case of MS and clinically isolated syndrome, p<0.05) were more often bilateral (44% vs 3%, p < 0.005) and associated with optic disc swelling (ODS) (78% vs 14%, p < 0.001). To predict MOG+ON, the positive predictive values (PPVs) of male sex, ODS and bilateral involvement were 29% (95% CI 9% to 48%), 41% (95% CI 18% to 65%) and 40% (95% CI 10% to 70%), respectively, while the negative predictive values (NPV) were 93% (95% CI 86% to 100%), 96% (95% CI 90% to 100%) and 91% (95% CI 83% to 99%), respectively. The combined factor ‘ODS or bilateral or recurrent ON’ was the best compromise between PPV (31% (95% CI 14% to 48%)) and NPV (100% (95% CI 100% to 100%)). Conclusion Among ON episodes, MOG-Ab were found in 14% of cases. MOG+ON occurred without female preponderance and was significantly associated with ODS and/or bilateral ON. Testing MOG-Ab only in patients presenting with ODS or bilateral or recurrent ON would limit MOG-Ab tests to fewer than half of all patients without the risk of missing any MOG+ON cases

A Plasma Metabolomic Profiling of Exudative Age-Related Macular Degeneration Showing Carnosine and Mitochondrial Deficiencies

To determine the plasma metabolomic profile of exudative age-related macular degeneration (AMD), we performed a targeted metabolomics study on the plasma from patients (n = 40, mean age = 81.1) compared to an age- and sex-matched control group (n = 40, mean age = 81.8). All included patients had documented exudative AMD, causing significant visual loss (mean logMAR visual acuity = 0.63), compared to the control group. Patients and controls did not differ in terms of body mass index and co-morbidities. Among the 188 metabolites analyzed, 150 (79.8%) were accurately measured. The concentrations of 18 metabolites were significantly modified in the AMD group, but only six of them remained significantly different after Benjamini&ndash;Hochberg correction. Valine, lysine, carnitine, valerylcarnitine and proline were increased, while carnosine, a dipeptide disclosing anti-oxidant and anti-glycating properties, was, on average, reduced by 50% in AMD compared to controls. Moreover, carnosine was undetectable for 49% of AMD patients compared to 18% in the control group (p-value = 0.0035). Carnitine is involved in the transfer of fatty acids within the mitochondria; proline, lysine and valerylcarnitine are substrates for mitochondrial electrons transferring flavoproteins, and proline is one of the main metabolites supplying energy to the retina. Overall, our results reveal six new metabolites involved in the plasma metabolomic profile of exudative AMD, suggesting mitochondrial energetic impairments and carnosine deficiency