Oculomotor analysis to assess brain health: preliminary findings from a longitudinal study of multiple sclerosis using novel tablet-based eye-tracking software.

A growing body of evidence supports the link between eye movement anomalies and brain health. Indeed, the oculomotor system is composed of a diverse network of cortical and subcortical structures and circuits that are susceptible to a variety of degenerative processes. Here we show preliminary findings from the baseline measurements of an ongoing longitudinal cohort study in MS participants, designed to determine if disease and cognitive status can be estimated and tracked with high accuracy based on eye movement parameters alone. Using a novel gaze-tracking technology that can reliably and accurately track eye movements with good precision without the need for infrared cameras, using only an iPad Pro embedded camera, we show in this cross-sectional study that several eye movement parameters significantly correlated with clinical outcome measures of interest. Eye movement parameters were extracted from fixation, pro-saccade, anti-saccade, and smooth pursuit visual tasks, whereas the clinical outcome measures were the scores of several disease assessment tools and standard cognitive tests such as the Expanded Disability Status Scale (EDSS), Brief International Cognitive Assessment for MS (BICAMS), the Multiple Sclerosis Functional Composite (MSFC) and the Symbol Digit Modalities Test (SDMT). Furthermore, partial least squares regression analyses show that a small set of oculomotor parameters can explain up to 84% of the variance of the clinical outcome measures. Taken together, these findings not only replicate previously known associations between eye movement parameters and clinical scores, this time using a novel mobile-based technology, but also the notion that interrogating the oculomotor system with a novel eye-tracking technology can inform us of disease severity, as well as the cognitive status of MS participants.

Real-World Retention and Clinical Effectiveness of Secukinumab for Axial Spondyloarthritis: Results From the Canadian Spondyloarthritis Research Network.

OBJECTIVE: Axial spondyloarthritis (axSpA) is a chronic, immune-mediated, inflammatory condition consisting of 2 clinical subsets: nonradiographic axSpA and ankylosing spondylitis, the latter having an estimated prevalence of 0.2% to 1% in Canada. Secukinumab (SEC) received Health Canada approval in 2016 for the treatment of adults with axSpA who have responded inadequately to conventional treatment, and has demonstrated efficacy and safety through extensive clinical trials. However, there is limited evidence on its real-world use in Canada. The objective of this study was to use the Canadian Spondyloarthritis (CanSpA) Research Network to describe real-world retention and effectiveness of SEC in the Canadian axSpA population. METHODS: This was an observational cohort study of Canadian patients with axSpA aged 18 to 65 years within the CanSpA network who had received treatment with SEC. Patients were indexed on the first date of SEC initiation. Retention and clinical effectiveness were assessed at 12 months postindex. Clinical effectiveness was measured as the proportion in remission and change in disease activity using multiple clinical indices. RESULTS: A total of 146 patients were included. Overall retention was estimated at 62.9%. Low disease activity (ie, Bath Ankylosing Spondylitis Disease Activity Index < 4) was achieved in 29.2% of patients, and 2% had achieved remission based on the Ankylosing Spondylitis Disease Activity Score. Bath Ankylosing Spondylitis Metrology Index scores improved by more than 60% from baseline to 12 months. CONCLUSION: The results of this real-world study of Canadian patients with axSpA, one of the first of its kind, support the effectiveness of SEC for treatment of axSpA. The CanSpA network presents an opportunity to continue building and improving the real-world evidence base for treatment of Canadian patients with spondyloarthritis.

Real-World Retention and Clinical Effectiveness of Secukinumab for Psoriatic Arthritis: Results From the Canadian Spondyloarthritis Research Network.

OBJECTIVE: Psoriatic arthritis (PsA) is an immune-mediated disease characterized by pain, stiffness, and swelling of peripheral joints, with an estimated prevalence in Canada of 0.45%. Treatment aims to minimize disease activity, reduce progression of damage, and improve quality of life. Secukinumab (SEC) is a biologic disease-modifying antirheumatic drug (bDMARD) that has demonstrated efficacy and safety for PsA in clinical trials; however, there is limited real-world evidence on its use in Canada. The objective of this study was to use the Canadian Spondyloarthritis (CanSpA) Research Network to describe real-world retention and effectiveness of SEC among Canadian patients with PsA. METHODS: This was an observational cohort study of Canadian patients with PsA, 18 to 65 years of age, who attended a clinic of the CanSpA network and received treatment with SEC. Patients were indexed on the date they first initiated SEC. Retention was assessed at 12 months postindex. Clinical effectiveness was measured as the proportion of patients in remission and change in disease activity from baseline to 12 months using several clinical indices. RESULTS: In total, 213 patients were included. Overall retention was estimated at 73.6% at 12 months (81.8% for bDMARD- or targeted synthetic DMARD-naïve patients). Out of 110 patients, 17 (15.5%) were in remission based on the Disease Activity Index in Psoriatic Arthritis in 28 joints, and 10 out of 70 patients (14.3%) were in remission based on the Psoriatic Arthritis Disease Activity Score at 12 months. The Psoriasis Area and Severity Index improved by 65.8%; the tender joint count in 68 joints and the swollen joint count in 66 joints improved by 65.5% and 73.7%, respectively. CONCLUSION: This is the first nationwide study that we know of to describe real-world use of SEC in Canada for PsA, and the results support its effectiveness in a Canadian real-world setting. The CanSpA network represents a unique opportunity to build and improve the real-world evidence base for SpA treatment in Canada.

Rationale, objectives and design of PURE, a prospective registry of patients with moderate to severe chronic plaque psoriasis in Canada and Latin America.

BACKGROUND: Treatment options for the management of moderate to severe plaque psoriasis include phototherapy, oral systemic agents, and biologic therapy. Secukinumab, a fully human monoclonal antibody that selectively targets IL-17A, is the first IL-17 antagonist approved for this patient population. Long-term observational data are required for establishing the true population-based benefit-risk ratio of approved treatments. PURE is a multinational registry that will assess the real-world safety and effectiveness of secukinumab and other approved therapies in the management of patients with moderate to severe psoriasis. METHODS: This is a multinational (Canadian and Latin American), prospective, observational study of adult patients with moderate to severe psoriasis that initiate treatment with secukinumab or other approved therapies as per local standard of care. A total of 2500 patients (1250 per cohort) will be recruited in the practices of hospital and community dermatologists. Decision regarding treatment must have been reached prior to and independent of patient enrollment in the study. The study includes a 5-year follow-up with recommended assessments at Baseline, 3 and 6 months post-Baseline, and every 6 months thereafter. The primary objective of the study is safety. Secondary outcome measures relate to effectiveness (Investigator's Global Assessment -IGA mod 2011-, Psoriasis Areas and Severity Index, Body Surface Area), patient reported outcomes (Dermatology Life Quality Index, Work Productivity and Activity Impairment Questionnaire, Hospital Anxiety and Depression Scale, Psoriasis Epidemiology Screening Tool, Psoriasis Symptom Diary, and Treatment Satisfaction Questionnaire), and healthcare resource utilization. DISCUSSION: This is the first observational study in Canada and Latin America assessing the real-world safety and effectiveness of secukinumab in the management of moderate to severe psoriasis. The extensive clinical, patient-reported and health economic outcomes collected will allow the comprehensive evaluation of this new treatment in comparison to other approved therapies. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02786186 ; date of registration: May 30, 2016.

An interactional network of genes involved in chitin synthesis in Saccharomyces cerevisiae.

BACKGROUND: In S. cerevisiae the beta-1,4-linked N-acetylglucosamine polymer, chitin, is synthesized by a family of 3 specialized but interacting chitin synthases encoded by CHS1, CHS2 and CHS3. Chs2p makes chitin in the primary septum, while Chs3p makes chitin in the lateral cell wall and in the bud neck, and can partially compensate for the lack of Chs2p. Chs3p requires a pathway of Bni4p, Chs4p, Chs5p, Chs6p and Chs7p for its localization and activity. Chs1p is thought to have a septum repair function after cell separation. To further explore interactions in the chitin synthase family and to find processes buffering chitin synthesis, we compiled a genetic interaction network of genes showing synthetic interactions with CHS1, CHS3 and genes involved in Chs3p localization and function and made a phenotypic analysis of their mutants. RESULTS: Using deletion mutants in CHS1, CHS3, CHS4, CHS5, CHS6, CHS7 and BNI4 in a synthetic genetic array analysis we assembled a network of 316 interactions among 163 genes. The interaction network with CHS3, CHS4, CHS5, CHS6, CHS7 or BNI4 forms a dense neighborhood, with many genes functioning in cell wall assembly or polarized secretion. Chitin levels were altered in 54 of the mutants in individually deleted genes, indicating a functional relationship between them and chitin synthesis. 32 of these mutants triggered the chitin stress response, with elevated chitin levels and a dependence on CHS3. A large fraction of the CHS1-interaction set was distinct from that of the CHS3 network, indicating broad roles for Chs1p in buffering both Chs2p function and more global cell wall robustness. CONCLUSION: Based on their interaction patterns and chitin levels we group interacting mutants into functional categories. Genes interacting with CHS3 are involved in the amelioration of cell wall defects and in septum or bud neck chitin synthesis, and we newly assign a number of genes to these functions. Our genetic analysis of genes not interacting with CHS3 indicate expanded roles for Chs4p, Chs5p and Chs6p in secretory protein trafficking and of Bni4p in bud neck organization.

Analysis of beta-1,3-glucan assembly in Saccharomyces cerevisiae using a synthetic interaction network and altered sensitivity to caspofungin.

Large-scale screening of genetic and chemical-genetic interactions was used to examine the assembly and regulation of beta-1,3-glucan in Saccharomyces cerevisiae. Using the set of deletion mutants in approximately 4600 nonessential genes, we scored synthetic interactions with genes encoding subunits of the beta-1,3-glucan synthase (FKS1, FKS2), the glucan synthesis regulator (SMI1/KNR4), and a beta-1,3-glucanosyltransferase (GAS1). In the resulting network, FKS1, FKS2, GAS1, and SMI1 are connected to 135 genes in 195 interactions, with 26 of these genes also interacting with CHS3 encoding chitin synthase III. A network core of 51 genes is multiply connected with 112 interactions. Thirty-two of these core genes are known to be involved in cell wall assembly and polarized growth, and 8 genes of unknown function are candidates for involvement in these processes. In parallel, we screened the yeast deletion mutant collection for altered sensitivity to the glucan synthase inhibitor, caspofungin. Deletions in 52 genes led to caspofungin hypersensitivity and those in 39 genes to resistance. Integration of the glucan interaction network with the caspofungin data indicates an overlapping set of genes involved in FKS2 regulation, compensatory chitin synthesis, protein mannosylation, and the PKC1-dependent cell integrity pathway.

Global mapping of the yeast genetic interaction network.

A genetic interaction network containing approximately 1000 genes and approximately 4000 interactions was mapped by crossing mutations in 132 different query genes into a set of approximately 4700 viable gene yeast deletion mutants and scoring the double mutant progeny for fitness defects. Network connectivity was predictive of function because interactions often occurred among functionally related genes, and similar patterns of interactions tended to identify components of the same pathway. The genetic network exhibited dense local neighborhoods; therefore, the position of a gene on a partially mapped network is predictive of other genetic interactions. Because digenic interactions are common in yeast, similar networks may underlie the complex genetics associated with inherited phenotypes in other organisms.