25 Hydroxyvitamin D concentrations in patients with optic neuritis as a clinically isolated syndrome and healthy controls

The onset of multiple sclerosis in the majority of the cases occurs as a clinically isolated syndrome [CIS]. We sought to assess serum levels of 25-hydroxyvitamin D [25-OHD] in CIS patients and healthy controls. In this cross-sectional study 40 patients [36 women and 4 men] with CIS manifesting as a single isolated optic neuritis and 40 Age- and sex-matched healthy controls [35 women and 5 men] were enrolled between late October 2010 and early March 2011. General vitamin D deficiency was defined as serum 25-OHD levels of lower than 20 ng/ml and was classified as mild [15 < 25-OHD <20 ng/ml], moderate [8 < 25-OHD <15 ng/ml], and severe [25- OHD <8 ng/ml]. We found no difference in the median interquartile range [IQR] between CIS patients and controls [17.95 [10.40- 29.13] vs. 17.00 [12.25-31.00]; P=0.57]. However, when stratified by the levels of deficiency, among CIS patients a significantly higher proportion had severe vitamin D deficiency in comparison to healthy controls [20% vs. 2.5%; P=0.034]. Nevertheless, the frequency of general [62.5% vs. 60%, P=0.82], mild [25% vs. 30%, P=0.80], and moderate [17.5% vs. 27.5%, P=0.42] vitamin D deficiency were not different between the two groups. Our findings do not indicate any significant difference of serum 25-OHD between CIS patients and healthy controls. However, in our series severe vitamin D deficiency was more frequent among CIS patients.

Anti-aquaporin-4 IgG in patients presenting with unilateral optic neuritis: a cohort study

Optic neuritis [ON] can be the first presentation of multiple sclerosis [MS] or neuromyelitis optica [NMO]. Anti-aquaporin-4 IgG [AQP4 IgG] is a highly specific and moderately sensitive biomarker for NMO. This study was designed to assess the rate of seropositivity for AQP4 IgG, and the short-term outcome of patients presenting with single isolated ON [SION]. A cohort of 41 consecutive patients experiencing severe [< 20 / 200] SION [not fulfilling the diagnostic criteria for MS or NMO], was prospectively recruited. Blood sampling was carried out immediately after the diagnosis of ON, and AQP4 IgG was tested qualitatively, using an indirect immunofluorescence kit. After clinical and paraclinical investigations, all the patients were followed up for a short-term period of at least 18 months. The seroprevalence among the initial ON patients was 9.7% [4 / 41]. The short-term conversion rate to MS and NMO was estimated to be about 7.3 and 4.9%, respectively. The conversion rate to NMO in initially seropositive patients was greater than that for the whole cohort [2/4 [50%] vs. 2/41 [4.9%]; P = 0.035; Odds ratio: 19.5, 95% confidence interval: 1.73 to 219.50]. AQP4 IgG seropositive SION patients were more likely to develop NMO in comparison to the total SION population. Further studies, with a longer follow-up period and larger sample sizes are warranted to assess the clinical and prognostic value of assessing AQP4 IgG in SION