Rare variants and HLA haplotypes associated in patients with neuromyelitis optica spectrum disorders.

Neuromyelitis optica spectrum disorders (NMOSD) are rare, debilitating autoimmune diseases of the central nervous system. Many NMOSD patients have antibodies to Aquaporin-4 (AQP4). Prior studies show associations of NMOSD with individual Human Leukocyte Antigen (HLA) alleles and with mutations in the complement pathway and potassium channels. HLA allele associations with NMOSD are inconsistent between populations, suggesting complex relationships between the identified alleles and risk of disease. We used a retrospective case-control approach to identify contributing genetic variants in patients who met the diagnostic criteria for NMOSD and their unaffected family members. Potentially deleterious variants identified in NMOSD patients were compared to members of their families who do not have the disease and to existing databases of human genetic variation. HLA sequences from patients from Belgrade, Serbia, were compared to the frequency of HLA haplotypes in the general population in Belgrade. We analyzed exome sequencing on 40 NMOSD patients and identified rare inherited variants in the complement pathway and potassium channel genes. Haplotype analysis further detected two haplotypes, HLA-A*01, B*08, DRB1*03 and HLA-A*01, B*08, C*07, DRB1*03, DQB1*02, which were more prevalent in NMOSD patients than in unaffected individuals. In silico modeling indicates that HLA molecules within these haplotypes are predicted to bind AQP4 at several sites, potentially contributing to the development of autoimmunity. Our results point to possible autoimmune and neurodegenerative mechanisms that cause NMOSD, and can be used to investigate potential NMOSD drug targets.

Correction to: Improvement in Cognitive Function as Measured by NeuroTrax in Patients with Relapsing Multiple Sclerosis Treated with Natalizumab: A 2-Year Retrospective Analysis.

An Online First version of this article was made available online at http://link.springer.com/journal/40263/onlineFirst/page/1 on 24 August 2018. An error was subsequently identified in the article, and the following correction should be noted.

Improvement in Cognitive Function as Measured by NeuroTrax in Patients with Relapsing Multiple Sclerosis Treated with Natalizumab: A 2-Year Retrospective Analysis.

BACKGROUND: Cognitive impairment affects many patients with multiple sclerosis (MS). NeuroTrax, a computerized cognitive screen that can be administered during routine clinical care, provides a consistent, validated, objective cognitive profile measure with a global cognitive score (GCS) and seven individual domain scores. Natalizumab is an efficacious therapy for relapsing MS, demonstrating reductions in disability worsening and MS disease activity measured by magnetic resonance imaging. OBJECTIVE: The aim of this study was to assess cognitive function as measured by NeuroTrax in MS patients treated with natalizumab for ≥ 2 years. METHODS: This retrospective observational study included adult MS patients in the United States who received 300 mg intravenous natalizumab every 4 weeks for ≥ 2 years. NeuroTrax data were evaluated at baseline and yearly thereafter. Changes in GCS and the seven individual cognitive domain scores from baseline to after 24 infusions of natalizumab were analyzed. RESULTS: In the study population at baseline (N = 52), 22 patients (42.3%) had disease duration of 0-5 years; 12 patients (23.1%) were treatment naive. GCS score improved significantly from baseline [mean 95.5, standard deviation (SD) 12.9] to year 2 (mean 98.9, SD 13.2; change from baseline 3.4; p = 0.003). After 2 years on natalizumab, 17 patients (32.7%) demonstrated clinically significant improvement (increase from baseline > 1 SD) in GCS. Results were similar regardless of whether patients had previously received MS therapy. CONCLUSIONS: Patients treated with natalizumab demonstrated significant improvement in cognitive function, measured by NeuroTrax GCS, over 2 years of treatment.