Polyautoimmunity and multiple autoimmune syndrome in patients with neuromyelitis optica spectrum disorder.

BACKGROUND: The coexistence of neuromyelitis optica spectrum disorders (NMOSD) with other autoimmune diseases (AID) has been increasingly reported. The prevalence and significance of this association are not fully understood. OBJECTIVES: This study aimed to compare the clinical and laboratory characteristics in NMOSD patients with and without AID. METHODS: Retrospective cross-sectional observational study was conducted involving adults meeting NMOSD criteria followed in a neuroimmunology clinic at a tertiary center. Descriptive analysis of clinical/paraclinical/treatment/outcome data collected from the medical records was compared between NMOSD patients with AID (polyautoimmunity) and those without AID. RESULTS: From a cohort of 46 NMOSD patients, 16 (34.8 %) patients, mostly women around 40 years of age, presented with polyautoimmunity: 10 anti-AQP4 positive, 4 anti-MOG positive, and 2 seronegative. Five different organ -specific AID, and six systemic AID were identified in the polyautoimmunity patients group, in addition to 6 cases of multiple autoimmune syndrome. The AID manifestation preceded NMOSD in 10 (62.5 %) patients, with a median interval of 7 years. The NMOSD with polyautoimmunity and NMOSD without AID groups had similar initial clinical manifestations with optic neuritis and/or myelitis being most frequent. Inflammatory CSF, namely elevated proteins, was more common in the polyautoimmunity group (13.0 % in NMOSD vs. 31.3 % in NMOSD+AID, p = 0.003). After a 10±6 years follow-up period, more patients with polyautoimmunity had a relapsing disease (75.0 % in NMOSD vs. 46.7 % in NMOSD+AID, p = 0.012) but no difference in the functional outcome evaluated by the EDSS score was identified. CONCLUSIONS: Polyautoimmunity was common in AQP4 positive NMOSD patients leading to a significantly higher risk of disease recorrence. The presence of polyautoimmunity and multiple autoimmune syndrome in NMOSD patients suggests the existence of common susceptibility factors or pathophysiological mechanisms, emphasizing the importance of a multidisciplinary approach to those patients.

Alternative sources of n-3 long-chain polyunsaturated fatty acids in marine microalgae.

The main source of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in human nutrition is currently seafood, especially oily fish. Nonetheless, due to cultural or individual preferences, convenience, geographic location, or awareness of risks associated to fatty fish consumption, the intake of fatty fish is far from supplying the recommended dietary levels. The end result observed in most western countries is not only a low supply of n-3 LC-PUFA, but also an unbalance towards the intake of n-6 fatty acids, resulting mostly from the consumption of vegetable oils. Awareness of the benefits of LC-PUFA in human health has led to the use of fish oils as food supplements. However, there is a need to explore alternatives sources of LC-PUFA, especially those of microbial origin. Microalgae species with potential to accumulate lipids in high amounts and to present elevated levels of n-3 LC-PUFA are known in marine phytoplankton. This review focuses on sources of n-3 LC-PUFA, namely eicosapentaenoic and docosahexaenoic acids, in marine microalgae, as alternatives to fish oils. Based on current literature, examples of marketed products and potentially new species for commercial exploitation are presented.

Effects of dietary arachidonic acid on cortisol production and gene expression in stress response in Senegalese sole (Solea senegalensis) post-larvae.

Dietary fatty acids, particularly arachidonic acid (ARA), affect cortisol and may influence the expression of genes involved in stress response in fish. The involvement of ARA on stress, lipid, and eicosanoid metabolism genes, in Senegalese sole, was tested. Post-larvae were fed Artemia presenting graded ARA levels (0.1, 0.4, 0.8, 1.7, and 2.3%, dry matter basis), from 22 to 35 days after hatch. Whole-body cortisol levels were determined, before and 3 h after a 2 min air exposure, as well as the expression of phospholipase A2 (PLA 2 ), cyclooxygenase-2 (COX-2), steroidogenic acute regulatory protein (StAR), glucocorticoid receptors (GRs), phosphoenolpyruvate carboxykinase (PEPCK), and peroxisome proliferator-activated receptor alpha (PPARα). Relative growth rate (6.0-7.8% day(-1)) and survival at the end of the experiment (91-96%) and after stress (100%) were unaffected. Fish reflected dietary ARA content and post-stress cortisol increased with ARA supply up to 1.7%, whereas 2.3% ARA seemed to enhance basal cortisol slightly and alter the response to stress. Results suggested that elevating StAR transcription might not be necessary for a short-term response to acute stress. Basal cortisol and PLA 2 expression were strongly correlated, indicating a potential role for this enzyme in steroidogenesis. Under basal conditions, larval ARA was associated with GR1 expression, whereas the glucocorticoid responsive gene PEPCK was strongly related with cortisol but not GR1 mRNA levels, suggesting the latter might not reflect the amount of GR1 protein in sole. Furthermore, a possible role for PPARα in the expression of PEPCK following acute stress is proposed.

Cortisol response to air exposure in Solea senegalensis post-larvae is affected by dietary arachidonic acid-to-eicosapentaenoic acid ratio.

An experiment was conducted in order to evaluate the effects of feeding frozen Artemia diets differing in arachidonic acid-to-eicosapentaenoic acid ratios (ARA/EPA) on growth, survival and stress coping ability of Senegalese sole post-larvae (19-31 days after hatch). Two experimental diets presenting high ('High'; 3.0) or low ('Low'; 0.7) ARA/EPA ratios were tested under two rearing conditions: undisturbed (C) and stressed by a 2-min air exposure every two days (S). Growth, survival and basal cortisol levels were similar between groups indicating that independently of dietary ARA/EPA ratios, fish were able to cope with the repeated stress imposed. Also, cortisol levels at 3 h past air exposure were determined in all groups at the end of the experiment. Among fish fed the 'Low' diet, C groups seemed to present a quicker recovery from the acute stress (basal-like levels) than S groups. Repeated stress effects were not apparent in fish fed the 'High' diet and, relative to basal levels, twofold higher cortisol concentrations were detected at 3 h, in both C and S groups. This study suggests the importance of ARA in steroidogenesis regulation and the modulatory role of EPA in this process. Despite the tolerance to a wide range of dietary ARA/EPA as indicated by growth and survival results, acute stress coping response may be more efficient in Senegalese sole post-larvae fed low ARA/EPA ratios and, under these particular conditions, a faster recovery of cortisol to basal values could be indicative of rearing conditions (undisturbed vs. repeatedly stressed).