Early autoimmunity and outcome in virus encephalitis: a retrospective study based on tissue-based assay.

To explore the autoimmune response and outcome in the central nervous system (CNS) at the onset of viral infection and correlation between autoantibodies and viruses. METHODS: A retrospective observational study was conducted in 121 patients (2016-2021) with a CNS viral infection confirmed via cerebrospinal fluid (CSF) next-generation sequencing (cohort A). Their clinical information was analysed and CSF samples were screened for autoantibodies against monkey cerebellum by tissue-based assay. In situ hybridisation was used to detect Epstein-Barr virus (EBV) in brain tissue of 8 patients with glial fibrillar acidic protein (GFAP)-IgG and nasopharyngeal carcinoma tissue of 2 patients with GFAP-IgG as control (cohort B). RESULTS: Among cohort A (male:female=79:42; median age: 42 (14-78) years old), 61 (50.4%) participants had detectable autoantibodies in CSF. Compared with other viruses, EBV increased the odds of having GFAP-IgG (OR 18.22, 95% CI 6.54 to 50.77, p<0.001). In cohort B, EBV was found in the brain tissue from two of eight (25.0%) patients with GFAP-IgG. Autoantibody-positive patients had a higher CSF protein level (median: 1126.00 (281.00-5352.00) vs 700.00 (76.70-2899.00), p<0.001), lower CSF chloride level (mean: 119.80±6.24 vs 122.84±5.26, p=0.005), lower ratios of CSF-glucose/serum-glucose (median: 0.50[0.13-0.94] vs 0.60[0.26-1.23], p=0.003), more meningitis (26/61 (42.6%) vs 12/60 (20.0%), p=0.007) and higher follow-up modified Rankin Scale scores (1 (0-6) vs 0 (0-3), p=0.037) compared with antibody-negative patients. A Kaplan-Meier analysis revealed that autoantibody-positive patients experienced significantly worse outcomes (p=0.031). CONCLUSIONS: Autoimmune responses are found at the onset of viral encephalitis. EBV in the CNS increases the risk for autoimmunity to GFAP.

Impact of water level fluctuations on the development of phytoplankton in a large subtropical reservoir: implications for the management of cyanobacteria.

Lake water level fluctuations (WLF) are an important factor driving the selection and seasonal dynamics of phytoplankton and potentially toxigenic cyanobacteria. Nevertheless, the relative importance of environmental drivers connected to WLF may be completely different, depending on the typology and use of waterbodies, latitude and climatic regimes. In this study, we investigated the impact of WLF in a large subtropical reservoir in south-eastern China (Hongfeng Reservoir, Guizhou Province). The study was based on monthly samplings carried out in 2014 in six stations. The strong increase in the water level observed in early summer caused a radical shift in the phytoplankton community. While in the pre-flooding period phytoplankton was composed of large diatoms, chrysophytes and Oscillatoriales (mostly Limnothrix sp.), the post-flooding period showed an increase in smaller and more competitive chlorophytes, smaller diatoms and cryptophytes better adapted to a fast colonisation of new and nutrient-rich environments. The environmental drivers that drove the change were dilution, flushing and interference with the seasonal water stratification processes. We concluded that, because WLF represents a complex variable integrating different physical effects in one explanatory descriptor, its value as a predictor of phytoplankton and cyanobacteria dynamics in lake ecosystems is difficult to generalise and needs to be investigated on a case-by-case basis. For this reason, considering the year-to-year hydrological variability that potentially characterise reservoirs, definite indications for management should be outlined considering more than 1-year study.

[Seasonal stratification and eutrophication characteristics of a deep reservoir, Longtan Reservoir in subtropical area of China].

In order to reveal the seasonal stratification and eutrophication characteristics of the subtropical large deep reservoir--Longtan Reservoir, the spatial and temporal distribution of environmental factors and eutrophic index were investigated during November (dry period) 2012, April (level period) and July (wet period) 2013. The results suggested that: (1) The stratification structure of Longtan Reservoir was meromictic lake, it had a single thermocline structure in the dry season, the surface layer to the 60 m was a mixomolimnion, 60-80 m was a thermocline, deeper more than 80 m was a monimolimnion. It had a double thermocline structure in flow period and wet period, the surface to 10 m was a mixed layer, 10-20 m was a thermocline, 20-40 m was a mixed layer, 40-60 m was a thermocline, deeper more than 60 m was a mixed layer. (2) The thermal stratification dominated the structure of other environmental factors, the stratification structure limited the water convection, especially the monimolimnion reduced the harm of the endogenous pollution. (3) The trophic level index (TLI) was 23.4-32.8 in the dry period, 27.1-38.6 in the flow period and 26.0-45.1 in the wet period, which were all Mesotropher. The trophic state index of total nitrogen was 60.3-72.5, which was eutropher to hyper eutropher, N: P was 107:1, which was phosphorus limited.