Interobserver Reliability and Sensitivity to Change of a Composite Ocular Inflammatory Activity Index: UVEDAI©

INTRODUCTION

This was a multicenter, prospective, longitudinal, observational study involving eight Spanish tertiary hospitals to determine the interobserver reliability of an uveitis disease activity index, (UVEDAI) and assess its sensitivity to change in patients with receiving pharmacologic treatment.

METHODS

Patients aged ≥ 18 years diagnosed with active noninfectious uveitis were included. A complete baseline assessment was performed by two ophthalmologists who determined ocular inflammatory activity using the UVEDAI index independently of each other. The principal ophthalmologist made a new visit at 4 weeks to determine the change in inflammatory activity. The interobserver reliability analysis was performed by calculating the intraclass correlation coefficient (ICC), with the values of the variables and the UVEDAI obtained by both ophthalmologists in the more active eye at the baseline visit. Sensitivity to change in the UVEDAI index was assessed at 4 weeks from the start of pharmacologic treatment by determining the clinically relevant change, defined as a change in UVEDAI of ≥ 0.8 points over baseline. The mean change between both measures was compared using the repeated-measures t-test.

RESULTS

A total of 111 patients were included. In the interobserver reliability analysis, the ICC for the UVEDAI value was 0.9, and, when compared with the mean UVEDAI values obtained by the ophthalmologists, no statistically significant differences were found (p value > 0.05). As for the sensitivity to change in UVEDAI, statistically significant differences (p value = 0.00) were found for the mean values of the index compared with baseline. In all cases, the index value decreased by > 1 point at the 4-week visit.

CONCLUSIONS

The interobserver reliability of the UVEDAI was high in the total sample. Furthermore, the index was sensitive in determining the change in inflammatory activity after treatment. We believe that UVEDAI is a disease activity index that enables objective comparison of results in clinical practice and trials.

Incidence and clinical manifestations of giant cell arteritis in Spain: results of the ARTESER register

OBJECTIVE

This study aimed to estimate the incidence of giant cell arteritis (GCA) in Spain and to analyse its clinical manifestations, and distribution by age group, sex, geographical area and season.

METHODS

We included all patients diagnosed with GCA between 1 June 2013 and 29 March 2019 at 26 hospitals of the National Health System. They had to be aged ≥50 years and have at least one positive results in an objective diagnostic test (biopsy or imaging techniques), meet 3/5 of the 1990 American College of Rheumatology classification criteria or have a clinical diagnosis based on the expert opinion of the physician in charge. We calculated incidence rate using Poisson regression and assessed the influence of age, sex, geographical area and season.

RESULTS

We identified 1675 cases of GCA with a mean age at diagnosis of 76.9±8.3 years. The annual incidence was estimated at 7.42 (95% CI 6.57 to 8.27) cases of GCA per 100 000 people ≥50 years with a peak for patients aged 80-84 years (23.06 (95% CI 20.89 to 25.4)). The incidence was greater in women (10.06 (95% CI 8.7 to 11.5)) than in men (4.83 (95% CI 3.8 to 5.9)). No significant differences were found between geographical distribution and incidence throughout the year (p=0.125). The phenotypes at diagnosis were cranial in 1091 patients, extracranial in 337 patients and mixed in 170 patients.

CONCLUSIONS

This is the first study to estimate the incidence of GCA in Spain at a national level. We found a predominance among women and during the ninth decade of life with no clear variability according to geographical area or seasons of the year.

Visual manifestations in giant cell arteritis: identification of risk factors from the ARTESER Registry

OBJECTIVE

To determine the prevalence and predictive factors of visual manifestations in a large registry of patients with GCA.

METHODS

ARTESER is a large Spanish multicentre registry supported by the Spanish Society of Rheumatology. It includes patients with GCA from across the entire country diagnosed between June 2013 and March 2019. The variables collected at diagnosis were demographics, clinical manifestations (including all visual manifestations), laboratory, temporal artery biopsy, and imaging findings (ultrasound, FDG-PET/CT, MRI angiography, CT angiography). Patients with and without visual involvement were compared in a bivariate analysis. Multivariate logistic regression was performed to determine potential predictive factors of visual manifestations.

RESULTS

The study population comprised 1636 GCA patients, of whom 599 (36.6%) presented visual manifestations. Anterior ischemic optic neuropathy was the most frequent (n = 274 of 599; 45.7%) ocular complication. The independent predictors that increased the risk (OR; 95% confidence interval) of visual involvement were older age (1.027; 1.009-1.045) and jaw claudication (1.724; 1.325-2.243). The variables associated with a reduced risk were polymyalgia rheumatica (0.541; 0.414-0.708), fever (0.373; 0.264-0.527), longer symptom duration (0.946; 0.909-0.985), and higher erythrocyte sedimentation rate (ESR) (0.992; 0.988-0.997), common features of patients with large vessel-GCA.

CONCLUSION

One-third of GCA patients present visual manifestations at diagnosis. Older age and jaw claudication are independent predictors of visual manifestations, whereas polymyalgia rheumatica, fever, longer symptom duration, and high ESR reduce the risk of visual involvement.

3D Analysis of the Synaptic Organization in the Entorhinal Cortex in Alzheimer's Disease

The entorhinal cortex (EC) is especially vulnerable in the early stages of Alzheimer's disease (AD). In particular, cognitive deficits have been linked to alterations in the upper layers of EC. In the present report, we examined Layers II and III from eight human brain autopsies (four subjects with no recorded neurologic alterations and four AD cases). We used stereological methods to assess cortical atrophy of the EC and possible changes in the volume occupied by different cortical elements (neuronal and glial cell bodies; blood vessels; and neuropil). We performed 3D ultrastructural analyses of synapses using focused ion beam/scanning electron microscopy (FIB/SEM) to examine possible alterations related to AD. At the light microscope level, we found a significantly lower volume fraction occupied by neuronal bodies in Layer III and a higher volume fraction occupied by glial cell bodies in Layer II in AD cases. At the ultrastructural level, we observed that (1) there was a significantly lower synaptic density in both layers in AD cases; (2) synapses were larger and more complex in Layer II in AD cases; and (3) there was a greater proportion of small and simple synapses in Layer III in AD cases than in control individuals. These structural differences may play a role in the anatomic basis for the impairment of cognitive functions in AD.

Three-dimensional analysis of synaptic organization in the hippocampal CA1 field in Alzheimer's disease

Alzheimer's disease is the most common form of dementia, characterized by a persistent and progressive impairment of cognitive functions. Alzheimer's disease is typically associated with extracellular deposits of amyloid-β peptide and accumulation of abnormally phosphorylated tau protein inside neurons (amyloid-β and neurofibrillary pathologies). It has been proposed that these pathologies cause neuronal degeneration and synaptic alterations, which are thought to constitute the major neurobiological basis of cognitive dysfunction in Alzheimer's disease. The hippocampal formation is especially vulnerable in the early stages of Alzheimer's disease. However, the vast majority of electron microscopy studies have been performed in animal models. In the present study, we performed an extensive 3D study of the neuropil to investigate the synaptic organization in the stratum pyramidale and radiatum in the CA1 field of Alzheimer's disease cases with different stages of the disease, using focused ion beam/scanning electron microscopy (FIB/SEM). In cases with early stages of Alzheimer's disease, the synapse morphology looks normal and we observed no significant differences between control and Alzheimer's disease cases regarding the synaptic density, the ratio of excitatory and inhibitory synapses, or the spatial distribution of synapses. However, differences in the distribution of postsynaptic targets and synaptic shapes were found. Furthermore, a lower proportion of larger excitatory synapses in both strata were found in Alzheimer's disease cases. Individuals in late stages of the disease suffered the most severe synaptic alterations, including a decrease in synaptic density and morphological alterations of the remaining synapses. Since Alzheimer's disease cases show cortical atrophy, our data indicate a reduction in the total number (but not the density) of synapses at early stages of the disease, with this reduction being much more accentuated in subjects with late stages of Alzheimer's disease. The observed synaptic alterations may represent a structural basis for the progressive learning and memory dysfunctions seen in Alzheimer's disease cases.

3D Ultrastructural Study of Synapses in the Human Entorhinal Cortex

The entorhinal cortex (EC) is a brain region that has been shown to be essential for memory functions and spatial navigation. However, detailed three-dimensional (3D) synaptic morphology analysis and identification of postsynaptic targets at the ultrastructural level have not been performed before in the human EC. In the present study, we used Focused Ion Beam/Scanning Electron Microscopy to perform a 3D analysis of the synapses in the neuropil of medial EC in layers II and III from human brain autopsies. Specifically, we studied synaptic structural parameters of 3561 synapses, which were fully reconstructed in 3D. We analyzed the synaptic density, 3D spatial distribution, and type (excitatory and inhibitory), as well as the shape and size of each synaptic junction. Moreover, the postsynaptic targets of synapses could be clearly determined. The present work constitutes a detailed description of the synaptic organization of the human EC, which is a necessary step to better understand the functional organization of this region in both health and disease.

Subregional Density of Neurons, Neurofibrillary Tangles and Amyloid Plaques in the Hippocampus of Patients With Alzheimer's Disease

A variety of anatomical alterations have been reported in the hippocampal formation of patients with Alzheimer's Disease (AD) and these alterations have been correlated with cognitive symptoms in the early stages of the disease. Major hallmarks in AD are the presence of paired helical filaments of tau protein (PHF_Tau) within neurons, also known as neurofibrillary tangles (NFTs), and aggregates of amyloid-β protein (Aβ) which form plaques in the extracellular space. Nevertheless, how the density of plaques and NFTs relate to the severity of cell loss and cognitive decline is not yet clear. The aim of the present study was to further examine the possible relationship of both Aβ plaques and NFTs with neuronal loss in several hippocampal fields (DG, CA3, CA1, and subiculum) of 11 demented AD patients. For this purpose, using stereological techniques, we compared neuronal densities (Nissl-stained, and immunoreactive neurons for NeuN) with: (i) numbers of neurons immunostained for two isoforms of PHF_Tau (PHF_Tau-AT8 and PHF_Tau-pS396); and (ii) number of Aβ plaques. We found that CA1 showed the highest number of NFTs and Aβ plaques, whereas DG and CA3 displayed the lowest number of these markers. Furthermore, AD patients showed a variable neuronal loss in CA1 due to tangle-related cell death, which seems to correlate with the presence of extracellular tangles.

Three-dimensional analysis of synapses in the transentorhinal cortex of Alzheimer's disease patients

Synaptic dysfunction or loss in early stages of Alzheimer’s disease (AD) is thought to be a major structural correlate of cognitive dysfunction. Early loss of episodic memory, which occurs at the early stage of AD, is closely associated with the progressive degeneration of medial temporal lobe (MTL) structures of which the transentorhinal cortex (TEC) is the first affected area. However, no ultrastructural studies have been performed in this region in human brain samples from AD patients.

In the present study, we have performed a detailed three-dimensional (3D) ultrastructural analysis using focused ion beam/scanning electron microscopy (FIB/SEM) to investigate possible synaptic alterations in the TEC of patients with AD. Surprisingly, the analysis of the density, morphological features and spatial distribution of synapses in the neuropil showed no significant differences between AD and control samples. However, light microscopy studies showed that cortical thickness of the TEC was severely reduced in AD samples, but there were no changes in the volume occupied by neuronal and glial cell bodies, blood vessels, and neuropil. Thus, the present results indicate that there is a dramatic loss of absolute number of synapses, while the morphology of synaptic junctions and synaptic spatial distribution are maintained. How these changes affect cognitive impairment in AD remains to be elucidated.