Plasma Neurofilament Light for Prediction of Disease Progression in Familial Frontotemporal Lobar Degeneration.

OBJECTIVE: We tested the hypothesis that plasma neurofilament light chain (NfL) identifies asymptomatic carriers of familial frontotemporal lobar degeneration (FTLD)-causing mutations at risk of disease progression. METHODS: Baseline plasma NfL concentrations were measured with single-molecule array in original (n = 277) and validation (n = 297) cohorts. C9orf72, GRN, and MAPT mutation carriers and noncarriers from the same families were classified by disease severity (asymptomatic, prodromal, and full phenotype) using the CDR Dementia Staging Instrument plus behavior and language domains from the National Alzheimer's Disease Coordinating Center FTLD module (CDR+NACC-FTLD). Linear mixed-effect models related NfL to clinical variables. RESULTS: In both cohorts, baseline NfL was higher in asymptomatic mutation carriers who showed phenoconversion or disease progression compared to nonprogressors (original: 11.4 ± 7 pg/mL vs 6.7 ± 5 pg/mL, p = 0.002; validation: 14.1 ± 12 pg/mL vs 8.7 ± 6 pg/mL, p = 0.035). Plasma NfL discriminated symptomatic from asymptomatic mutation carriers or those with prodromal disease (original cutoff: 13.6 pg/mL, 87.5% sensitivity, 82.7% specificity; validation cutoff: 19.8 pg/mL, 87.4% sensitivity, 84.3% specificity). Higher baseline NfL correlated with worse longitudinal CDR+NACC-FTLD sum of boxes scores, neuropsychological function, and atrophy, regardless of genotype or disease severity, including asymptomatic mutation carriers. CONCLUSIONS: Plasma NfL identifies asymptomatic carriers of FTLD-causing mutations at short-term risk of disease progression and is a potential tool to select participants for prevention clinical trials. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02372773 and NCT02365922. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in carriers of FTLD-causing mutations, elevation of plasma NfL predicts short-term risk of clinical progression.

NIPT in a clinical setting: an analysis of uptake in the first months of clinical availability.

The objective of our study was to describe the clinical experience in offering noninvasive prenatal testing (NIPT) for aneuploidy to pregnant patients, highlighting the clinical utility, barriers to acceptance and limitations of this novel test. Data were collected from 961 patients offered NIPT from 3/1/12 to 9/30/12. Univariate and multivariate logistic regression analysis was performed. Twenty-eight percent of patients elected NIPT and 72 % declined. Women continue to elect less sensitive and less specific screening through biochemical markers and nuchal translucency. Women considering all options at average risk for aneuploidy were less likely to accept NIPT testing than women who had a risk adjustment from an ultrasound marker or routine screening test. In our multi-ethnic population, Filipina women were significantly less likely to elect NIPT compared to other ethnicities. Five percent of NIPT ordered failed analysis. Several chromosome abnormalities were detected through CVS or amniocentesis that would not have been detected by NIPT. Even though NIPT offers a non-invasive, highly sensitive and specific analysis for aneuploidy, the majority of women in our study declined this option. NIPT should be offered in the context of genetic counseling so that women understand the limitations of the testing and make an educated decision about the testing option best suited to their situation.