The complex phenotype of spinocerebellar ataxia type 48 in eight unrelated Italian families

BACKGROUND AND PURPOSE

Heterozygous mutations in the STUB1 gene have recently been associated with an autosomal dominant form of spinocerebellar ataxia (SCA) associated with cerebellar cognitive-affective syndrome (CCAS), named SCA48.

METHODS

Molecular screening was performed in a cohort of 235 unrelated patients with adult-onset, autosomal dominant (17) or sporadic (218) cerebellar ataxia, negative for pathological trinucleotide expansions in the common SCAs, FRDA and FXTAS loci, by using targeted multigene panels or whole-exome sequencing. Bioinformatics analyses, detailed neurological phenotyping and family segregation studies corroborated the pathogenicity of the novel STUB1 mutations. Clinico-diagnostic findings were reviewed to define the phenotypic spectrum.

RESULTS

Eight heterozygous STUB1 mutations were identified, six of which were novel in 11 patients from eight index families, giving an estimated overall frequency of 3.4% (8/235) for SCA48 in our study cohort, rising to 23.5% (4/17) when considering only familial cases. All our SCA48 patients had cerebellar ataxia and dysarthria associated with cerebellar atrophy on brain magnetic resonance imaging; of note, many cases were also associated with parkinsonism, chorea and dystonia. CCAS also occurred frequently, whereas definite signs of pyramidal tract dysfunction and peripheral nervous system involvement were absent. One SCA48 patient presented with hypogonadism, associated with other autoimmune endocrine dysfunctions.

CONCLUSIONS

Our results support SCA48 as a significant cause of adult-onset SCA. Besides CCAS, our SCA48 patients often showed movement disorders and other clinical manifestations previously described in SCAR16, linked to biallelic variants in the same gene, thus suggesting a continuous clinical spectrum and significant overlap amongst recessive and dominantly inherited mutations in STUB1.

Progression of microstructural damage in spinocerebellar ataxia type 2: a longitudinal DTI study

BACKGROUND AND PURPOSE

The ability of DTI to track the progression of microstructural damage in patients with inherited ataxias has not been explored so far. We performed a longitudinal DTI study in patients with spinocerebellar ataxia type 2.

MATERIALS AND METHODS

Ten patients with spinocerebellar ataxia type 2 and 16 healthy age-matched controls were examined twice with DTI (mean time between scans, 3.6 years [patients] and 3.3 years [controls]) on the same 1.5T MR scanner. Using tract-based spatial statistics, we analyzed changes in DTI-derived indices: mean diffusivity, axial diffusivity, radial diffusivity, fractional anisotropy, and mode of anisotropy.

RESULTS

At baseline, the patients with spinocerebellar ataxia type 2, as compared with controls, showed numerous WM tracts with significantly increased mean diffusivity, axial diffusivity, and radial diffusivity and decreased fractional anisotropy and mode of anisotropy in the brain stem, cerebellar peduncles, cerebellum, cerebral hemisphere WM, corpus callosum, and thalami. Longitudinal analysis revealed changes in axial diffusivity and mode of anisotropy in patients with spinocerebellar ataxia type 2 that were significantly different than those in the controls. In patients with spinocerebellar ataxia type 2, axial diffusivity was increased in WM tracts of the right cerebral hemisphere and the corpus callosum, and the mode of anisotropy was extensively decreased in hemispheric cerebral WM, corpus callosum, internal capsules, cerebral peduncles, pons and left cerebellar peduncles, and WM of the left paramedian vermis. There was no correlation between the progression of changes in DTI-derived indices and clinical deterioration.

CONCLUSIONS

DTI can reveal the progression of microstructural damage of WM fibers in the brains of patients with spinocerebellar ataxia type 2, and mode of anisotropy seems particularly sensitive to such changes. These results support the potential of DTI-derived indices as biomarkers of disease progression.

Effect of whey concentration on protein recovery in fresh ovine ricotta cheese

Ricotta cheese, particularly the ovine type, is a typical Italian dairy product obtained by heat-coagulation of the proteins in whey. The aim of this work was to investigate the influence of whey protein concentration, obtained by ultrafiltration, on yield of fresh ovine ricotta cheese. Ricotta cheeses were obtained by thermocoagulation of mixtures with protein content of 1.56, 3.10, 4.16, and 7.09g/100g from the mixing of skim whey and ultrafiltered skim whey. A fat-to-protein ratio of 1.1 (wt/wt) was obtained for all mixtures by adding fresh cream. The initial mixtures, as well as the final ricotta cheeses, were analyzed for their composition and by SDS-PAGE. Protein bands were quantified by QuantityOne software (Bio-Rad, Hercules, CA) and identified by liquid chromatography-tandem mass spectrometry. Significant differences in the composition of the ricotta cheese were observed depending on protein concentration. Particularly, ricotta cheese resulting from the mixture containing 7.09g/100g of protein presented higher moisture (72.88±1.50g/100g) and protein (10.18±0.45g/100g) contents than that prepared from the mixture with 1.56g/100g of protein (69.52±1.75 and 6.70±0.85g/100g, respectively), and fat content was lower in this sample (12.20±1.60g/100g) compared with the other treatments, with mean values between 15.72 and 20.50g/100g. Each protein fraction presented a different behavior during thermocoagulation. In particular, the recovery of β-lactoglobulin and α-lactalbumin in the cheese increased as their content increased in the mixtures. It was concluded that concentrating ovine rennet whey improved the extent of heat-induced protein aggregation during the thermal coagulation process. This resulted in a better recovery of each protein fraction in the product, and in a consequent increase of ricotta cheese yield.

Whole body cholesterol metabolism is impaired in Huntington's disease

We previously reported impaired cholesterol biosynthesis in rodent Huntington Disease (HD) models and HD patients' fibroblasts and post mortem brains. We also found that plasma levels of 24S-hydroxycholesterol (24OHC), the brain specific elimination product of cholesterol considered a marker of brain cholesterol turnover, were significantly reduced in HD patients at any disease stage. In the present study we analysed by mass spectrometry the fasting plasma levels of cholesterol, its biosynthetic precursors lanosterol and lathosterol, of the whole-body elimination products 27-hydroxycholesterol and of brain 24OHC in a cohort of premanifest and HD patients at different disease stages. We found that the cholesterol precursors lanosterol and lathosterol (both index of whole body cholesterol synthesis), the levels of the bile acid precursor 27-hydroxycholesterol, and of the brain specific 24OHC, were all significantly reduced in manifest HD patients, suggesting that whole-body and brain cholesterol homeostasis are both impaired in HD.

Responsiveness of different rating instruments in spinocerebellar ataxia patients

OBJECTIVE

To determine the longitudinal metric properties of recently developed clinical assessment tools in spinocerebellar ataxia (SCA).

METHODS

A subset of 171 patients from the EUROSCA natural history study cohort (43 SCA1, 61 SCA2, 37 SCA3, and 30 SCA6) were examined after 1 year of follow-up. Score changes and effect size indices were calculated for clinical scales (Scale for the Assessment and Rating of Ataxia [SARA], Inventory of Non-Ataxia Symptoms [INAS]), functional tests (SCA Functional Index [SCAFI] and components), and a patient-based scale for subjective health status (EQ-5D visual analogue scale [EQVAS]). Responsiveness was determined in relation to the patient's global impression (PGI) of change and reproducibility described as retest reliability for the stable groups and smallest detectable change.

RESULTS

Within the 1-year follow-up period, SARA, INAS, and SCAFI but not EQVAS indicated worsening in the whole group and in the groups with subjective (PGI) worsening. SCAFI and its 9-hole pegboard (9HPT) component also deteriorated in the stable groups. Standardized response means were highest for 9HPT (-0.67), SARA (0.50), and SCAFI (-0.48) with accordingly lower sample size estimates of 143, 250, or 275 per group for a 2-arm interventional trial that aims to reduce disease progression by 50%. SARA and EQVAS performed best to distinguish groups classified as worse by PGI. All scales except EQVAS reached the criterion for retest reliability.

CONCLUSION

While both the Scale for the Assessment and Rating of Ataxia and the SCA Functional Index (SCAFI) (and its 9-hole pegboard component) had favorable measurement precision, the clinical relevance of SCAFI and 9-hole pegboard score changes warrants further exploration. The EQ-5D visual analogue scale proved insufficient for longitudinal assessment, but validly reflected patients' impression of change.

Brain structural damage in Friedreich's ataxia

OBJECTIVE

Neuropathological descriptions of the brain in Friedreich's ataxia (FRDA) were obtained before availability of the current molecular genetic tests for this disease. Voxel-based morphometry (VBM) enables an unbiased whole-brain quantitative analysis of differences in gray matter (GM) and white matter (WM) volume.

METHODS

Using VBM, we assessed the brain structural damage in 22 patients with genetically confirmed FRDA and 25 healthy controls. The results were correlated with the disease duration and the severity of the patients' clinical deficits--evaluated using the International Cerebellar Ataxia Rating Scale and Inherited Ataxia Clinical Rating Scale.

RESULTS

In patients with FRDA, VBM showed a symmetrical volume loss in dorsal medulla, infero-medial portions of the cerebellar hemispheres, the rostral vermis and in the dentate region. No volume loss in cerebral hemispheres was observed. The atrophy of the cerebellum and medulla correlated with the severity of the clinical deficit and disease duration.

CONCLUSIONS

In patients with FRDA, significant GM and WM loss was observed only in the cerebellum and dorsal medulla. These structural changes correlate with the severity of the clinical deficit and disease duration.

Grey matter loss in relapsing–remitting multiple sclerosis: A voxel-based morphometry study

Global grey matter (GM) loss has been reported in multiple sclerosis (MS). We addressed the question of if and where GM loss is localized by means of optimized voxel-based morphometry, applied to MRI studies of 51 patients with clinically defined relapsing-remitting MS and 34 age-matched normal subjects, segmented into normal and abnormal brain tissues using a multiparametric approach. Segmented GM volumes were subsequently compared on a voxel-by-voxel basis to highlight regions of relative GM loss (P < 0.05, corrected for multiple comparisons at AnCova). Additionally, localized differences in brain asymmetry between the MS and the control groups were assessed by comparing on a voxel-by-voxel basis maps of GM differences between the two hemispheres (P < 0.05 corrected for multiple comparisons). In MS patients, GM volume was significantly decreased at the level of the left fronto-temporal cortex and precuneus, as well as of anterior cingulate gyrus and of caudate nuclei bilaterally. The only cortical region of significant GM loss in the right hemisphere was located in the postcentral area. Furthermore, GM loss regions were colocalized with increased GM asymmetries (Left < Right) in MS, confirming a preferential left-sided GM loss. Caudate atrophy correlated with lesion load, while no correlation between cortical regional GM loss and disease duration, clinical status or lesion load emerged. Our findings suggest that in RR-MS cortical GM reduction preferentially involves left fronto-temporal structures and deep GM, the latter correlating preferentially to global lesion load.

Imaging of dopaminergic dysfunction with [123I]FP-CIT SPECT in early-onset parkin disease

OBJECTIVE

To investigate whether the presence of parkin gene mutations is associated with different nigrostriatal impairment than other early-onset parkinsonism.

METHODS

Eighteen consecutive early-onset Parkinson disease (PD) patients (nine parkin and nine nonparkin patients) and six controls were studied with [123I]FP-CIT SPECT.

RESULTS

Parkin patients had longer disease duration (15 +/- 9 vs 6 +/- 2 years, p = 0.008) and higher Unified Parkinson's Disease Rating Scale (UPDRS) motor score (35.8 +/- 13.7 vs 22.8 +/- 7.9, p = 0.025) than nonparkin patients. Caudate and putamen DAT density were reduced by 60% and 79% in parkin and by 43% and 70% in nonparkin patients. Multiple regression analysis showed that the UPDRS and the presence of parkin gene mutations, but not the disease duration, were significantly correlated with the striatal DAT density. Parkin patients showed a more symmetric DAT loss in both caudate and putamen as compared with nonparkin patients.

CONCLUSIONS

Parkin-related disease may be associated with a higher degree of nigrostriatal impairment, independently of the clinical severity of the disease, and a more symmetric involvement as compared with non-parkin early-onset disease.

Stimulation of growth hormone release in multiple system atrophy, Parkinson's disease and idiopathic cerebellar ataxia

Clonidine has been proposed to differentiate multiple system atrophy (MSA) from idiopathic Parkinson's disease (IPD), as it does not increase growth hormone (GH) release in MSA. We studied GH release in response to clonidine in 7 IPD patients, 6 MSA patients, 4 patients affected by idiopathic late-onset cerebellar ataxia (ILOCA) and 8 healthy controls. In addition, we investigated the effects of GH releasing hormone plus arginine (GHRH-Arg) on GH release in the same patients. Both clonidine and GHRH-Arg raised serum GH levels in all groups examined. Clonidine failed to differentiate MSA from IPD and ILOCA. GHRH-Arg showed a lower increase of serum GH in MSA patients than in other groups, even if such difference was not statistically significant. We suggest that stimulation of GH release with GHRH-Arg rather than clonidine could differentiate MSA from IPD and ILOCA, but this hypothesis would need to be confirmed by further investigations.

Further support for a role for Th2-like cytokines in blister formation of pemphigus

Pemphigus vulgaris and pemphigus foliaceus are commonly known as antibody-mediated bullous diseases. However, recently a role for infiltrating cells as contributors to the pathogenesis of these diseases has been suggested. The aims of our study were to characterize the immunophenotype of the cellular infiltrate of pemphigus lesional skin and to study the cytokines secreted. We have therefore performed an immunohistochemical study with a large panel of monoclonal antibodies (to CD3, CD4, CD8, CD25, CD30, myeloperoxidase, eosinophil cationic protein EG2, tryptase, human interleukin (IL)-2, human IL-4, human IL-5, human IL-6, human IL-8, and interferon (IFN)-gamma using the alkaline phosphatase-antialkaline phosphatase procedure on lesional and uninvolved skin of six patients with clinical, histological, and immunofluorescent proven pemphigus. We also performed RT-PCR in order to demonstrate mRNA expression of the cytokines of interest. Our results suggest the presence of a T cell population with a prevalent Th2-like cytokine pattern in lesional skin. In addition, we demonstrate a consistent number of granulocytes and mast cells that show clear signs of activation. These data suggest the involvement of an inflammatory infiltrate in the production of pemphigus lesions. In particular, we assume that Th2 cells may be implicated in the very early stages of autoimmune response, concluding that they exert broad activity in blister formation.

Relative frequencies of CAG expansions in spinocerebellar ataxia and dentatorubropallidoluysian atrophy in 116 Italian families

Two hundred and forty-eight patients from 116 Italian families with dominant ataxia were studied for CAG expansion within SCA1, 2, 3, 6, 7 (spinocerebellar ataxia) and DRPLA (dentatorubropallidoluysian atrophy) genes. Fifty-six percent of the families originated from Southern, 19% from Central and 25% from Northern Italy. SCA2 was the commonest mutation, accounting for 47% of the families, followed by SCA1 (24%), SCA6 (2%), SCA7 (2%) and DRPLA (1%). No SCA3 family was found. Twenty-four percent of the families carried a still unidentified mutation. When occurrence of mutations was evaluated according to the geographic origin, SCA1 was the commonest in Northern (72%), whereas SCA2 was prevalent (63%) in Southern Italy. The number of CAG repeats in SCA1 normal alleles was higher in Northern than in Central-Southern Italy.

Soluble CD30 and cyclosporine in severe atopic dermatitis

BACKGROUND

Allergen-reactive Th2-like cells expressing membrane CD30 are present in the circulation of atopic dermatitis (AD) patients during seasonal allergen exposure. Moreover, CD30+ T cells are present in the lesional skin of AD patients and high levels of soluble CD30 (sCD30) are found in the serum of the same atopic patients. To investigate the immunosuppressive capacity of cyclosporin A (CsA) in AD patients, the sCD30 serum level was determined before and after CsA treatment (5 mg/kg/day) in 10 patients with severe, refractory AD. The sCD30 serum levels before and after CsA therapy together with other serum parameters were correlated with disease activity.

METHODS

sCD30 serum levels were detected using a commercial sandwich ELISA; serum eosinophil cationic protein (ECP) levels were determined using a radioimmunoassay (RIA).

RESULTS

In all AD patients sCD30 serum levels were increased ranging from 36 to 300 U/ml, with a mean value equal to 135.7 U/ml. After 6 weeks of CsA treatment, not only was there a significant difference between serum sCD30 levels before (mean 135.7) and after (mean 96.2) treatment but even the serum ECP levels before (mean 57.78) and after (mean 18.69) therapy showed an important reduction. Moreover, no significant difference was found between the mean of serum IgE levels before and after treatment, although the values showed a correlation (p = 0.0003). No significant correlations could be demonstrated between sCD30 levels and serum IgE or between sCD30 and ECP serum levels nor between sCD30 levels and blood eosinophil count after CsA treatment. Moreover, a positive correlation (p = 0.001) was instead documented between sCD30 and the severity of the disease.

CONCLUSIONS

In this study, CsA therapy results in clinical improvement together with a statistically significant reduction in sCD30 and ECP serum levels in AD patients.

Why do some Friedreich's ataxia patients retain tendon reflexes? A clinical, neurophysiological and molecular study

Among 101 patients homozygous for GAA expansion within the X25 gene, 11 from 8 families had Friedreich's ataxia with retained reflexes in the lower limbs (FARR). These patients had a lower occurrence of decreased vibration sense, pes cavus, and echocardiographic signs of left ventricular hypertrophy than the 90 FA patients with areflexia. The mean age at onset was significantly later (26.6+/-11.4 vs. 14.2+/-6.9 years), and the mean size of the smaller allele was significantly less (408+/-252 vs. 719+/-184 GAA triplets) in FARR patients. The neurophysiological findings were consistent with milder peripheral neuropathy and milder impairment of the somatosensory pathways in FARR patients.

Cerebral blood flow in spinocerebellar degenerations: a single photon emission tomography study in 28 patients

We used single photon emission tomography to study regional cerebral perfusion in patients with different forms of spinocerebellar degeneration: 6 patients with Friedreich's ataxia (FA), 6 with early-onset cerebellar ataxia with retained tendon reflexes (EOCA), 5 with autosomal dominant cerebellar ataxia type 1 (ADCA I) and 11 with idiopathic late-onset cerebellar ataxia (ILOCA). The results were related to clinical and magnetic resonance imaging (MRI) findings. Cerebellar hypoperfusion was constant in ADCA I and frequent in patients with other spinocerebellar degenerations. Brain stem hypoperfusion was constant in ADCA I, frequent in ILOCA patients with pontocerebellar atrophy and absent in FA and EOCA. FA and EOCA often showed a reduction in the parietotemporal cortex blood flow, which was not related to cortical atrophy. ILOCA patients had an asymmetric pattern in the temporal areas with decreased blood flow in the right side only. Caudate hypoperfusion was found in ADCA I patients. Cerebral atrophy did not account for changes in regional blood flow, which probably indicate early involvement of cerebral structures.

Th2-like cytokine activity in dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a chronic subepidermal blistering disease, in which a perivascular cellular infiltrate, composed mainly of CD4+ T lymphocytes together with a varying number of neutrophils and eosinophils, is thought to be important in the pathogenesis of blister formation. The aim of this study was to investigate the potential role of cytokines such as the interleukins IL-4 and IL-5 and to quantify the distribution of T cells as well as their state of activation using alkaline phosphatase-antialkaline phosphatase and reverse transcriptase-polymerase chain reaction (RT-PCR) procedures in seven patients with typical clinical and histological features of DH. A strong extracellular staining with anti-IL-4 monoclonal antibody was detected in the upper dermis with a prevalent perivascular pattern in perilesional areas, whereas in the dermal-epidermal separation sites there was an intense, scattered distribution. IL-5 was intensely expressed, mainly at the intracellular level, by eosinophils and lymphocytes. Concerning RT-PCR, five DH patients showed a strong positive signal for both IL-4 and IL-5 cytokines while two patients showed a faint signal for both IL-4 and IL-5; these last two cases were histologically poor in inflammatory cells. In view of these results, it can be hypothesized that the recruitment of eosinophils and neutrophils in DH may be induced not only by granulocyte macrophage colony-stimulating factor and IL-8 as previously demonstrated, but also by Th2 cytokines as well.