Frontal asymmetry in behavioral variant frontotemporal dementia: clinicoimaging and pathogenetic correlates

We aimed to assess associations between clinical, imaging, pathologic, and genetic features and frontal lobe asymmetry in behavioral variant frontotemporal dementia (bvFTD). Volumes of the left and right dorsolateral, medial, and orbital frontal lobes were measured in 80 bvFTD subjects and subjects were classified into 3 groups according to the degree of asymmetry (asymmetric left, asymmetric right, symmetric) using cluster analysis. The majority of subjects were symmetric (65%), with 20% asymmetric left and 15% asymmetric right. There were no clinical differences across groups, although there was a trend for greater behavioral dyscontrol in right asymmetric compared with left asymmetric subjects. More widespread atrophy involving the parietal lobe was observed in the symmetric group. Genetic features differed across groups with symmetric frontal lobes associated with C9ORF72 and tau mutations, while asymmetric frontal lobes were associated with progranulin mutations. These findings therefore suggest that neuroanatomical patterns of frontal lobe atrophy in bvFTD are influenced by specific gene mutations.     

Molecular signature of disease onset in Granulin mutation carriers: a gene expression analysis study

Mutations within Granulin (GRN) gene are causative of autosomal dominant frontotemporal lobar degeneration (FTLD). Though GRN mutations are inherited at birth, the disease onset usually occurs in the sixth decade of life. The objective of this study was to identify new genetic pathways linked to inherited GRN disease and involved in the shift from asymptomatic to symptomatic stages. Microarray gene expression analysis on leukocytes was carried out on 15 patients carrying GRN T272SfsX10 mutation, and their asymptomatic siblings with (n = 14) or without (n = 11) GRN mutation. The results were then validated by real-time polymerase chain reaction, and compared with those obtained in a cohort of FTLD without GRN mutation (n = 16). The association between candidate genes and damage of specific brain areas was investigated by voxel-based morphometry on magnetic resonance imaging scans (family-wise error-corrected). Leukocytes mRNA levels of TMEM40 and LY6G6F and other genes mainly involved in inflammation were significantly higher in patients carrying GRN mutations compared with asymptomatic carriers and other FTLD. The higher the levels of TMEM40 the greater is the damage of parietal lobule; the higher the LY6G6F gene expression the greater is the atrophy in superior frontal gyrus. Enhanced inflammation associated with the onset of GRN disease might be either related to disease pathogenetic mechanism leading to neurodegeneration or to a compensatory pathway that counteracts disease progression. The identification of specific molecular targets of GRN-FTLD disease is essential when considering future disease-modifying therapies.     

Progressive Anomia Revisited: Focal Degeneration Associated with Progranulin Gene Mutation

In 2003 we reported a case study of a patient, Newton who presented with a progressive circumscribed anomia in association with focal left hemisphere atrophy. Remarkably, he could spell aloud the names of objects that he could not name, indicating dissociated access to phonology and orthography. We now present follow-up clinical data, post-mortem histopathological findings, and results of molecular genetic analysis. Newton showed tau-negative ubiquitin-positive histology consistent with frontotemporal lobar degeneration (FTLD) and a mutation in the progranulin (PGRN) gene. The case exemplifies the heterogeneity of clinical expression of FTLD and contributes to understanding of primary progressive aphasia.     

Progranulin is a potential prognostic biomarker in advanced epithelial ovarian cancers

Objective

There are few validated relapse prediction biomarkers for epithelial ovarian cancer (EOC). We have shown progranulin (PGRN) and secretory leukocyte protease inhibitor (SLPI) are up regulated, overexpressed survival factors in EOC. We hypothesized they would predict presence of occult EOC.

Method

PGRN, SLPI, and the known biomarker HE4 were measured in EOC patient plasma samples, prospectively collected every 3 months from initial remission until relapse. Clinical data and CA125 results were incorporated into statistical analyses. Exploratory Kaplan-Meier estimates, dividing markers at median values, evaluated association with progression-free survival (PFS) and overall survival (OS). Area-under-the-curve (AUC) statistics were computed from receiver operating characteristic (ROC) curves to evaluate discrimination ability. A Cox proportional hazards model assessed the association between PFS, OS, and biomarkers, adjusting for clinical prognostic factors.

Results

Samples from 23 advanced stage EOC patients were evaluated. PGRN at 3 months was the only biomarker independently associated with PFS (P < 0.0001) and OS (P < 0.003). When used to predict progression by 18 months, sensitivity and specificity were 93% and 100%, respectively, with AUC = 0.944. The Cox model hazard ratio for PFS, divided at 59 ng/ml by ROC analysis and adjusted for clinical factors, was 23.5 (95% CI: 2.49-220). Combinations with SLPI, HE4, and/or CA125 did not improve the model.

Conclusions

We report pilot data indicating a potential independent association of PGRN on EOC patient PFS and OS. A validation study will be required to confirm this finding and to inform whether PGRN warrants evaluation as a potential screening biomarker.     

Expansion mutation in C9ORF72 does not influence plasma progranulin levels in frontotemporal dementia

A hexanucleotide repeat expansion in chromosome 9 open reading frame 72 (C9ORF72) gene has recently been described as a cause of familial and sporadic frontotemporal lobar degeneration. The aim of this study was to assess whether plasma progranulin (GRN) levels could be modulated by the presence of this repeat expansion. Sixty-five patients diagnosed with frontotemporal dementia and 10 family members with familial aggregation of disease were screened for the presence of the hexanucleotide repeat expansion in C9ORF72 gene, using a repeat-primed polymerase chain reaction method. Plasma GRN levels were measured in all subjects through enzyme-linked immunosorbent assay. Seven individuals with the repeat expansion were identified. No differences were found between C9ORF72 repeat expansion carriers and noncarriers (116.4 ± 21 ng/mL and 131.7 ± 36 ng/mL, respectively, p = 0.3). Analysis of family members did not disclose any difference in plasma GRN levels between carriers and noncarriers. In conclusion, plasma GRN levels are not influenced by the hexanucleotide repeat expansion in C9ORF72 gene, and therefore, cannot be used as a reliable biomarker to detect mutation carriers.