Natural history of Niemann-Pick disease type C in a multicentre observational retrospective cohort study

Differently increased volumes of multiple brain areas in Npc1 mutant mice following various drug treatments

Background

Niemann-Pick disease type C1 (NPC1, MIM 257220) is a heritable lysosomal storage disease characterized by a progressive neurological degeneration that causes disability and premature death. A murine model of Npc1-/- displays a rapidly progressing form of Npc1 disease, which is characterized by weight loss, ataxia, and increased cholesterol storage. Npc1-/- mice receiving a combined therapy (COMBI) of miglustat (MIGLU), the neurosteroid allopregnanolone (ALLO) and the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HPßCD) showed prevention of Purkinje cell loss, improved motor function and reduced intracellular lipid storage. Although therapy of Npc1-/- mice with COMBI, MIGLU or HPßCD resulted in the prevention of body weight loss, reduced total brain weight was not positively influenced.

Methods

In order to evaluate alterations of different brain areas caused by pharmacotherapy, fresh volumes (volumes calculated from the volumes determined from paraffin embedded brain slices) of various brain structures in sham- and drug-treated wild type and mutant mice were measured using stereological methods.

Results

In the wild type mice, the volumes of investigated brain areas were not significantly altered by either therapy. Compared with the respective wild types, fresh volumes of specific brain areas, which were significantly reduced in sham-treated Npc1-/- mice, partly increased after the pharmacotherapies in all treatment strategies; most pronounced differences were found in the CA1 area of the hippocampus and in olfactory structures.

Discussion

Volumes of brain areas of Npc1-/- mice were not specifically changed in terms of functionality after administering COMBI, MIGLU, or HPßCD. Measurements of fresh volumes of brain areas in Npc1-/- mice could monitor region-specific changes and response to drug treatment that correlated, in part, with behavioral improvements in this mouse model.

Swallowing characterization of adult-onset Niemann-Pick, type C1 patients

BACKGROUND

Niemann-Pick disease, type C1 (NPC1) is a rare lysosomal disorder with progressive neurological manifestations, historically recognized as a pediatric disease. However, awareness of the adult-onset (AO) subtype is increasing, often with non-specific symptoms leading to delayed and misdiagnosis. Dysphagia, commonly recognized as a clinical morbidity in NPC1, raises concerns for swallowing safety and aspiration risk. This study aims to characterize swallowing function in AO NPC1, addressing the gap in understanding and clinical management.

METHODS

Fourteen AO NPC1 individuals in a prospective natural history study (NCT00344331) underwent comprehensive assessments, including history and physical examinations utilizing the NPC1 severity rating scale, videofluoroscopic swallowing studies with summary interpretive analysis, and cerebrospinal fluid (CSF) collection for biomarker evaluation at baseline visit. Descriptive statistics and multivariate statistical modeling were employed to analyze NPC1 disease covariates, along with the American Speech-Language-Hearing Association National Outcome Measure (ASHA-NOMS) and the NIH Penetration Aspiration Scale (NIH-PAS).

RESULTS

Our cohort, comprised of 14 predominately female (n = 11, 78.6%) individuals, had an average age of 43.1 ± 16.7 years at the initial visit. Overall, our AO patients were able to swallow independently with no/minimal cueing, with 6 (43%) avoiding specific food items or requiring more time. Upon risk analysis of aspiration, the cohort demonstrated no obvious aspiration risk or laryngeal aspiration in 8 (57%), minimal risk with intermittent laryngeal penetration and retrograde excursion in 5(36%), and moderate risk (7%) in only one. Dietary modifications were recommended in 7 (50%), particularly for liquid viscosities (n = 6, 43%) rather than solids (n = 3, 21%). No significant correlations were identified between swallowing outcomes and NPC1-related parameters or CSF biomarkers.

CONCLUSION

Despite the heterogeneity in NPC1 presentation, the AO cohort displayed functional swallowing abilities with low aspiration risk with some participants still requiring some level of dietary modifications. This study emphasizes the importance of regular swallowing evaluations and management in AO NPC1 to address potential morbidities associated with dysphagia such as aspiration. These findings provide clinical recommendations for the assessment and management of the AO cohort, contributing to improved care for these individuals.

Effects of miglustat therapy on neurological disorder and survival in early-infantile Niemann-Pick disease type C: a national French retrospective study

BACKGROUND

Niemann-Pick disease type C (NP-C) is a rare neurovisceral lysosomal lipid storage disease characterized by progressive neurodegeneration and premature death. While miglustat can stabilize neurological manifestations in later onset forms of NP-C, its efficacy in the early-infantile neurological form has not been demonstrated. In this observational retrospective study, we compared long-term neurodevelopmental outcome and survival between an untreated and a treated group of early infantile NP-C patients.

METHODS

Data available on all NP-C patients with early infantile neurological onset diagnosed in France between 1990 and 2013 were compiled. Patients with incomplete data or who had died from a systemic perinatal, rapidly fatal form were excluded.

RESULTS

Ten patients were included in the treated group (year of birth: 2006-2012), and 16 patients in the untreated group [born 1987-2005 (n = 15), 2012 (n = 1)]. The median age at neurological onset was 9 months (5-18) in the treated group, and 12 months (3-18) in the untreated group (p = 0.22). Miglustat therapy was started at a median age of 24.5 months (9-29) and median duration was 30 months (11-56). Gastrointestinal adverse events were reported in 7/10 patients on miglustat. All patients developed loss of psychomotor acquisitions or additional neurological symptoms despite miglustat therapy. The ages of developmental milestones and neurological involvement did not significantly differ between the two groups. Four patients in the untreated group were lost to follow up. The 22 remaining patients had died by the end of the study and no patient survived beyond the age of 7.4 years. The median survival age was 4.42 years in the untreated group and 5.56 years in the treated group; the Kaplan-Meier survival curves were not significantly different (log-rank test: p = 0.11).

CONCLUSIONS

Miglustat allowed no significant long-term neurodevelopmental improvement nor significant increase of survival in patients with early infantile NP-C.

Experimental pharmacology: Targeting metabolic pathways

Since the discovery of the treatment for Wilson disease a growing number of treatable inherited dystonias have been identified and their search and treatment have progressively been implemented in the clinics of patients with dystonia. While waiting for gene therapy to be more widely and adequately translated into the clinical setting, the efforts to divert the natural course of dystonia reside in unveiling its pathogenesis. Specific metabolic treatments can rewrite the natural history of the disease by preventing neurotoxic metabolite accumulation or interfering with the cell accumulation of damaging metabolites, restoring energetic cell fuel, supplementing defective metabolites, and supplementing the defective enzyme. A metabolic derangement of cell homeostasis is part of the progression of many non-metabolic genetic lesions and could be the target for possible metabolic approaches. In this chapter, we provided an update on treatment strategies for treatable inherited dystonias and an overview of genetic dystonias with new experimental therapeutic approaches available or close to clinical translation.

The Niemann-Pick type diseases – A synopsis of inborn errors in sphingolipid and cholesterol metabolism

Disturbances of lipid homeostasis in cells provoke human diseases. The elucidation of the underlying mechanisms and the development of efficient therapies represent formidable challenges for biomedical research. Exemplary cases are two rare, autosomal recessive, and ultimately fatal lysosomal diseases historically named "Niemann-Pick" honoring the physicians, whose pioneering observations led to their discovery. Acid sphingomyelinase deficiency (ASMD) and Niemann-Pick type C disease (NPCD) are caused by specific variants of the sphingomyelin phosphodiesterase 1 (SMPD1) and NPC intracellular cholesterol transporter 1 (NPC1) or NPC intracellular cholesterol transporter 2 (NPC2) genes that perturb homeostasis of two key membrane components, sphingomyelin and cholesterol, respectively. Patients with severe forms of these diseases present visceral and neurologic symptoms and succumb to premature death. This synopsis traces the tortuous discovery of the Niemann-Pick diseases, highlights important advances with respect to genetic culprits and cellular mechanisms, and exposes efforts to improve diagnosis and to explore new therapeutic approaches.

Eine Kinderkrankheit wird erwachsen

Zusammenfassung: Die Untersuchung von seltenen Erkrankungen ist aufgrund der geringen Anzahl an Patient_innen sowie einem häufig heterogenen, multisymptomatischen Erscheinungsbild deutlich erschwert. Als Beispiel für eine solche seltene Krankheit dient im Folgenden die progrediente, neurodegenerative Erbkrankheit Niemann-Pick Typ C (NPC), die lange Zeit als „Kinderkrankheit“ galt. Im Verlauf des letzten Jahrzehnts wurde jedoch auch ein substanzieller Anteil an erwachsenen NPC-Patient_innen diagnostiziert. Da zum klinischen Erscheinungsbild von erwachsenen NPC-Patient_innen wenig Umfassendes bekannt ist, widmet sich der Artikel diesem Thema und zeigt, inwieweit die Erkenntnisse zu Manifestationen sowie zur Krankheitsentwicklung von pädiatrischen auf erwachsene NPC-Patient_innen übertragbar sind. Die Darstellung von Erkrankungsmerkmalen der Subpopulationen pädiatrischer gegenüber jugendlicher bzw. erwachsener NPC-Patient_innen basiert auf der verfügbaren Literatur sowie Expertenmeinungen hinsichtlich der Epidemiologie, des genetischen Mutationsmusters, des klinischen Bildes einschließlich der Prodromalsymptome, der Progressionsrate, dem allgemeinen Behandlungsregime und den Therapieeffekten. Insgesamt erweist sich NPC als ein Krankheitskontinuum, basierend auf weitestgehend ähnlichen genetischen Mutationsmustern sowie einer sich in den Altersgruppen entsprechenden Pathophysiologie. Pädiatrische und jugendliche bzw. erwachsene Patient_innen sind durch diverse Facetten fortschreitender neuropsychologischer Manifestationen wie bspw. kognitive Defizite und deutliche Einschränkungen ihrer motorischen Fähigkeiten (einschließlich der Berücksichtigung von prodromalen Symptomen) gekennzeichnet. NPC verläuft bei Kindern sowie bei jugendlichen bzw. erwachsenen Patient_innen auf die ähnliche Weise – jedoch mit einer beschleunigten Progressionsrate und einer somit verkürzten Lebenserwartung, je jünger die Patient_innen bei erstmaligem Auftreten neurologischer Symptome sind. Jedoch weist die hohe Krankheitslast aller NPC-Patient_innen auf die Schwere dieser seltenen Stoffwechselkrankheit hin. Die Behandlung von NPC erfolgt altersunabhängig interdisziplinär. Es besteht bisher keine kausale Therapieoption.

The Antifungal Antibiotic Filipin as a Diagnostic Tool of Cholesterol Alterations in Lysosomal Storage Diseases and Neurodegenerative Disorders

Cholesterol is the most considerable member of a family of polycyclic compounds understood as sterols, and represents an amphipathic molecule, such as phospholipids, with the polar hydroxyl group located in position 3 and the rest of the molecule is completely hydrophobic. In cells, it is usually present as free, unesterified cholesterol, or as esterified cholesterol, in which the hydroxyl group binds to a carboxylic acid and thus generates an apolar molecule. Filipin is a naturally fluorescent antibiotic that exerts a primary antifungal effect with low antibacterial activity, interfering with the sterol stabilization of the phospholipid layers and favoring membrane leakage. This polyene macrolide antibiotic does not bind to esterified sterols, but only to non-esterified cholesterol, and it is commonly used as a marker to label and quantify free cholesterol in cells and tissues. Several lines of evidence have indicated that filipin staining could be a good diagnostic tool for the cholesterol alterations present in neurodegenerative (e.g., Alzheimer's Disease and Huntington Disease) and lysosomal storage diseases (e.g., Niemann Pick type C Disease and GM1 gangliosidosis). Here, we have discussed the uses and applications of this fluorescent molecule in lipid storage diseases and neurodegenerative disorders, exploring not only the diagnostic strength of filipin staining, but also its limitations, which over the years have led to the development of new diagnostic tools to combine with filipin approach.

Diagnostic value of plasma lysosphingolipids levels in a Niemann-Pick disease type C patient with transient neonatal cholestasis

OBJECTIVES

Niemann-Pick disease type C (NPC) is a lysosomal storage disease due to impaired intracellular lipid trafficking caused by biallelic pathogenic variants in NPC1 or NPC2 genes. NPC is classified according to the age of onset of neurological manifestations. Cholestatic liver disease can be transient or lead to liver failure. Accompanying neurological findings can be observed at any age. In this report, an infant with a homozygous pathogenic variant in NPC1 gene whose diagnosis was eventually confirmed by specific biomarkers is described.

CASE PRESENTATION

A sixteen-day-old male was admitted to hospital with prolonged jaundice. He had mild hepatosplenomegaly, conjugated hyperbilirubinemia, elevated liver transaminases, and mild hypoalbuminemia. Cholestasis resolved spontaneously and patient was readmitted due to progressive hepatosplenomegaly without any neurologic findings when he was 8 months old. Molecular investigations detected homozygous c.1123A > C (p.Thr375Pro) pathogenic variant in NPC1 gene. NPC-specific lysosomal biomarkers such as Lysosphingomyelin and Lysosphingomyelin-509 were elevated, confirming the diagnosis.

CONCLUSIONS

The clinical features of NPC are highly heterogeneous, from disease severity or age of onset to disease progression. Patients presenting with transient neonatal cholestasis and should be regularly followed for neurodevelopmental status and visceromegaly. In the case of variants of unknown significance in NPC1 gene, lysosomal biomarkers play an important role when genetic analyses are inconclusive.

Genetic and phenotypic variability in adult patients with Niemann Pick type C from Serbia: single-center experience

BACKGROUND

Niemann Pick type C is an autosomal recessive lysosomal storage disorder caused by mutations in NPC1 and NPC2 genes. It is a neuro-visceral disease with a heterogeneous phenotype. Clinical features depend on the age at onset. Visceral manifestations are more prominent in the early onset (infantile) form, while neuro-psychiatric symptoms are more prominent in the late disease onset (juvenile and adult forms).

METHODS

A total number of 150 patients have been screened for changes in NPC1 and NPC2 gene at the Neurology Clinic, University Clinical Centre of Serbia in the period 2012-2020. Clinical data were extracted for patients with biallelic mutations.

RESULTS

Fifteen patients carried biallelic mutations in the NPC1. Out of eight different reported NPC1 variants, four are novel (c.1204_1205TT>GC, p.F402A; c.2486T>G, p.L829R; c.2795+5 G>C; c.3722T>A, p.L1241*). The mean age at the disease onset was 20.3 ± 11.9 years with the average diagnostic delay of 7.7 ± 4.3 years. Movement disorders and psychiatric or cognitive disturbances were the most common initial symptoms (in 33% and 28% patients, respectively). The average age at the first neurological manifestation was 21 ± 12.0 years. At the last examination, eye movement abnormalities (vertical slow saccades or vertical supranuclear gaze palsy), and ataxia were present in all patients, while dystonia was common (in 78.6% of patients). Presence of c.2861C>T, p.S954L mutation in homozygous state was associated with older age at the neurological symptom onset.

CONCLUSIONS

Clinical findings were in line with the expected, but the diagnostic delay was common. We hypothesize that the presence of c.2861C>T, p.S954L mutation may contribute to the phenotype attenuation.

Advancing Diagnosis and Treatment of Niemann-Pick C disease through Biomarker Discovery

Niemann-Pick C is a rare neurodegenerative, lysosomal storage disease caused by accumulation of unesterified cholesterol. Diagnosis of the disease is often delayed due to its rarity, the heterogeneous presentation and the early non-specific symptoms. The discovery of disease-specific biomarkers - cholestane-3β,5α,6β-triol (C-triol), trihydroxycholanic acid glycinate (TCG) and N-palmitoyl-O-phosphocholineserine (PPCS, initially referred to as lysoSM-509) - has led to development of non-invasive, blood-based diagnostics. Dissemination of these rapid, sensitive, and specific clinical assays has accelerated diagnosis. Moreover, the superior receiver operating characteristic of the TCG bile acid biomarker and its detection in dried blood spots has also facilitated development of a newborn screen for NPC, which is currently being piloted in New York state. The C-triol, TCG and PPCS biomarkers have also proven useful for monitoring treatment response in peripheral tissues, but are uninformative with respect to treatment efficacy in the central nervous system (CNS). A major gap for the field is the lack of a validated, non-invasive biomarker to monitor the course of disease and CNS response to therapy.

Psychosis symptoms associated with Niemann-Pick disease type C

Niemann-Pick disease type C (NP-C) is a severe neurovisceral lipid storage disease that results in the accumulation of unesterified cholesterol in lysosomes or endosomes. The clinical presentations of NP-C are variable which include visceral symptoms, neurologic symptoms and psychiatric symptoms. Psychosis is the most common psychiatric manifestation of NP-C and is indistinguishable from a typical psychosis presentation of schizophrenia. The common psychotic presentations in NP-C include visual hallucinations, delusions, auditory hallucinations and thought disorders. Psychosis symptoms are more common in adult or adolescent-onset forms compared with pediatric-onset forms. The underlying pathophysiology of psychosis in NP-C is most probably due to dysconnectivity particularly between frontotemporal connectivity and subcortical structures. NP-C sometimes is mistaken for schizophrenia which causes delay in treatment due to lack of awareness and literature review. This review aims to summarize the relevant case reports on psychosis symptoms in NP-C and discuss the genetics and pathophysiology underlying the condition.

Potential Disease-Modifying Effects of Lithium Carbonate in Niemann-Pick Disease, Type C1

Background: Niemann-Pick disease type C1 (NP-C1) is a rare, autosomal-recessive neurodegenerative disorder with no United States Food and Drug Administration (FDA)-approved drug. Lithium has been shown to have considerable neuroprotective effects for neurological disorders such as bipolar disorder, Alzheimer's disease and stroke and has been tested in many clinical trials. However, the pharmacological effect of lithium on NP-C1 neurodegenerative processes has not been investigated. The aim of this study was to provide an initial evaluation of the safety and feasibility of lithium carbonate in patients with NP-C1. Methods: A total of 13 patients diagnosed with NP-C1 who met the inclusion criteria received lithium orally at doses of 300, 600, 900, or 1,200 mg daily. The dose was reduced based on tolerance or safety observations. Plasma 7-ketocholesterol (7-KC), an emerging biomarker of NP-C1, was the primary endpoint. Secondary endpoints included NPC Neurological Severity Scores (NNSS) and safety. Results: Of the 13 patients with NP-C1 (12-33 years) enrolled, three withdrew (discontinuation of follow-up outpatient visits). The last observed post-treatment values of 7-KC concentrations (128 ng/ml, SEM 20) were significantly lower than pretreatment baselines values (185 ng/ml, SEM 29; p = 0.001). The mean NNSS was improved after lithium treatment at 12 months (p = 0.005). Improvement in swallowing capacity was observed in treated patients (p = 0.014). No serious adverse events were recorded in the patients receiving lithium. Conclusion: Lithium is a potential therapeutic option for NP-C1 patients. Larger randomized and double-blind clinical trials are needed to further support this finding. Clinical Trial Registration: ClinicalTrials.gov, NCT03201627.

Inhibition of Histone Deacetylases 1, 2, and 3 Enhances Clearance of Cholesterol Accumulation in Niemann-Pick C1 Fibroblasts

Niemann-Pick disease type C1 (NPC1) is a rare genetic cholesterol storage disorder caused by mutations in the NPC1 gene. Mutations in this transmembrane late endosome protein lead to loss of normal cholesterol efflux from late endosomes and lysosomes. It has been shown that broad spectrum histone deacetylase inhibitors (HDACi's) such as Vorinostat correct the cholesterol accumulation phenotype in the majority of NPC1 mutants tested in cultured cells. In order to determine the optimal specificity for HDACi correction of the mutant NPC1s, we screened 76 HDACi's of varying specificity. We tested the ability of these HDACi's to correct the excess accumulation of cholesterol in patient fibroblast cells that homozygously express NPC1^I1061T, the most common mutation. We determined that inhibition of HDACs 1, 2, and 3 is important for correcting the defect, and combined inhibition of all three is needed to achieve the greatest effect, suggesting a need for multiple effects of the HDACi treatments. Identifying the specific HDACs involved in the process of regulating cholesterol trafficking in NPC1 will help to focus the search for more specific druggable targets.

Long-term survival outcomes of patients with Niemann-Pick disease type C receiving miglustat treatment: A large retrospective observational study

Miglustat has been indicated for the treatment of Niemann-Pick disease type C (NP-C) since 2009. The aim of this observational study was to assess the effect of miglustat on long-term survival of patients with NP-C. Data for 789 patients from five large national cohorts and from the NPC Registry were collected and combined. Miglustat-treated and untreated patients overall and within sub-groups according to age-at-neurological-onset, that is, early infantile-onset (<2 years), late infantile-onset (2 to <6 years), juvenile-onset (6 to <15 years), and adolescent/adult-onset (≥15 years) were analysed and compared. Survival was analysed from the time of first neurological manifestation (Neurological onset group, comprising 669 patients) and from diagnosis (Diagnosis group, comprising 590 patients) using a Cox proportional hazard model adjusted for various covariates. Overall, 384 (57.4%) patients in the Neurological onset group and 329 (55.8%) in the Diagnosis group were treated with miglustat. Miglustat treatment was associated with a significant reduction in risk of mortality in both groups (entire Neurological onset group, Hazard ratio [HR] = 0.51; entire Diagnosis group, HR = 0.44; both P < .001). The effect was observed consistently in all age-at-neurological-onset sub-groups (HRs = 0.3 to 0.7) and was statistically significant for late infantile-onset patients in both groups (Neurological onset group, HR = 0.36, P < .05; Diagnosis group, HR = 0.32, P < .01), and juvenile-onset patients in the Diagnosis group only (HR = 0.30, P < .05). Despite the limitations of the data that urge cautious interpretation, the findings are consistent with a beneficial effect of miglustat on survival in patients with NP-C.

Clinical and Molecular Features of Early Infantile Niemann Pick Type C Disease

Niemann Pick disease type C (NPC) is a neurovisceral disorder due to mutations in NPC1 or NPC2. This review focuses on poorly characterized clinical and molecular features of early infantile form of NPC (EIF) and identified 89 cases caused by NPC1 (NPC1) and 16 by NPC2 (NPC2) mutations. Extra-neuronal features were common; visceromegaly reported in 80/89 NPC1 and in 15/16 NPC2, prolonged jaundice in 30/89 NPC1 and 7/16 NPC2. Early lung involvement was present in 12/16 NPC2 cases. Median age of neurological onset was 12 (0-24) and 7.5 (0-24) months in NPC1 and NPC2 groups, respectively. Developmental delay and hypotonia were the commonest first detected neurological symptoms reported in 39/89 and 18/89 NPC1, and in 8/16 and 10/16 NPC2, respectively. Additional neurological symptoms included vertical supranuclear gaze palsy, dysarthria, cataplexy, dysphagia, seizures, dystonia, and spasticity. The following mutations in homozygous state conferred EIF: deletion of exon 1+promoter, c.3578_3591 + 9del, c.385delT, p.C63fsX75, IVS21-2delATGC, c. 2740T>A (p.C914S), c.3584G>T (p.G1195V), c.3478-6T>A, c.960_961dup (p.A321Gfs*16) in NPC1 and c.434T>A (p.V145E), c.199T>C (p.S67P), c.133C>T (p.Q45X), c.141C>A (p.C47X) in NPC2. This comprehensive analysis of the EIF type of NPC will benefit clinical patient management, genetic counselling, and assist design of novel therapy trials.

Characterization of Dysphagia and Longitudinal Changes in Swallowing Function in Adults with Niemann-Pick Disease Type C Treated with Miglustat

Niemann-Pick disease type C (NPC) is a rare, autosomal recessive neurodegenerative disease, characterized by progressive psychiatric and neurological deficits. Neurological symptoms include cognitive decline and dysphagia. Aspiration pneumonia secondary to dysphagia is a leading cause of death in NPC. Miglustat is currently the only approved disease-specific treatment shown to be effective in stabilizing neurological symptoms. Miglustat has previously been reported to halt or improve early dysphagia and cognitive symptoms. Here we examine the characteristics of dysphagia, the relationship between dysphagia and the presence of cognitive impairment, and longitudinal changes in swallowing function during miglustat treatment in adult-and-adolescent-onset NPC. Retrospective analysis of videofluoroscopic swallow studies (VFSS) was completed for ten adults with NPC (mean age 28.44 years ± 9.34 years). Participants were recruited through the Royal Melbourne Hospital in Australia between 2008 and 2015. The Bethlehem Swallowing Scale and the Penetration-Aspiration Scale were used to quantify VFSS data. Dysphagia was present in 90% of participants at baseline with reduced lingual function and a delayed swallowing reflex as the most common symptoms. Swallow impairment appeared to stabilize during miglustat therapy for periods up to 66 months, with no significant changes in scores (p > 0.05). Data were in accordance with the literature and support the use of miglustat as an efficacious treatment for reducing swallowing impairment and stabilizing cognitive function. Findings provide detailed information on the impairments experienced by patients, give context to events leading to aspiration in NPC and, importantly, inform how management of dysphagia can complement pharmaceutical treatment.

Ultrastructure of spinal anterior horn cells in human Niemann-Pick type C (NPC) patient and mouse model of NPC with retroposon insertion in NPC1 genes

Niemann-Pick disease type C (NPC) is a neurovisceral lipid-storage disease. Although NPC patients show lipid storage in anterior horn cells of the spinal cord, little information is available regarding the electron microscopic analyses of the morphologies of intra-endosomal lipid like-materials in the anterior horn cells of NPC patients. In this study, we elucidated the intra-endosomal ultrastructures in spinal anterior horn cells in an NPC patient, as well as in mutant BALB/c NPC1^-/- mice with a retroposon insertion in the NPC1 gene. These morphologies were classified into four types: vesicle, multiple concentric sphere (MCS), membrane, and rose flower. The percentages of the composition in the NPC patient and NPC1^-/- mice were: vesicle (55.5% and 14.9%), MCS (15.7% and 3.4%), membrane (23.6% and 57.1%), and rose flower (5.2% and 24.6%), respectively. Formation of the intra-endosomal structures could proceed as follows: (i) a vesicle or MCS buds off the endosome into the lumen; (ii) when a vesicle breaks down, a membrane is formed; and (iii) after an MCS breaks down, a rose flower structure is formed. Our new finding in this study is that ultrastructural morphology is the same between the NPC patient and NPC1^-/- mice, although there are differences in the composition.

Treatment outcomes following continuous miglustat therapy in patients with Niemann-Pick disease Type C: a final report of the NPC Registry

BACKGROUND

Niemann-Pick disease Type C (NP-C) is a rare, progressive neurodegenerative disorder characterized by progressive neurodegeneration and premature death. We report data at closure of the NPC Registry that describes the natural history, disease course and treatment experience of NP-C patients in a real-world setting.

METHODS

The NPC Registry was a prospective observational cohort study that ran between September 2009 and October 2017. Patients with a confirmed diagnosis of NP-C were enrolled regardless of treatment status. All patients underwent clinical assessments and medical care as determined by their physicians; data were collected through a secure internet-based portal.

RESULTS

At closure on October 19, 2017, 472 patients from 22 countries were enrolled in the NPC Registry. Mean (standard deviation) age at enrollment was 21.2 (15.0) years, and 51.9% of patients were male. First neurological symptom onset occurred during the early-infantile (< 2 years), late-infantile (2 to < 6 years), juvenile (6 to < 15 years), or adolescent/adult (≥ 15 years) periods in 13.5, 25.6, 31.8, and 29.1% of cases, respectively. The most frequent neurological manifestations prior to enrollment included ataxia (67.9%), vertical supranuclear gaze palsy (67.4%), dysarthria (64.7%), cognitive impairment (62.7%), dysphagia (49.1%), and dystonia (40.2%). During infancy, splenomegaly and hepatomegaly were frequent (n = 199/398 [50%] and n = 147/397 [37.0%], respectively) and persisted in most affected patients. Of the 472 enrolled patients, 241 were continuously treated with miglustat during the NPC Registry observation period, of whom 172 of these 241 patients were treated continuously for ≥12 months. A composite disability score that assesses impairment of ambulation, manipulation, language, and swallowing was highest in the early-infantile population and lowest in the adolescent/adult population. Among the continuous miglustat therapy population, 70.5% of patients had improved or had stable disease (at least 3 of the 4 domains having a decreased or unchanged score between enrollment and last follow-up). The NPC Registry did not identify any new safety signals associated with miglustat therapy.

CONCLUSIONS

The profiles of clinical manifestations in the final NPC Registry dataset agreed with previous clinical descriptions. Miglustat therapy was associated with a stabilization of neurological manifestations in most patients. The safety and tolerability of miglustat therapy was consistent with previous reports.

Expanded access with intravenous hydroxypropyl-β-cyclodextrin to treat children and young adults with Niemann-Pick disease type C1: a case report analysis

Background

Niemann-Pick Disease Type C (NPC) is an inherited, often fatal neurovisceral lysosomal storage disease characterized by cholesterol accumulation in every cell with few known treatments. Defects in cholesterol transport cause sequestration of unesterified cholesterol within the endolysosomal system. The discovery that systemic administration of hydroxypropyl-beta cyclodextrin (HPβPD) to NPC mice could release trapped cholesterol from lysosomes, normalize cholesterol levels in the liver, and prolong life, led to expanded access use in NPC patients. HPβCD has been administered to NPC patients with approved INDs globally since 2009.

Results

Here we present safety, tolerability and efficacy data from 12 patients treated intravenously (IV) for over 7 years with HPβCD in the US and Brazil. Some patients subsequently received intrathecal (IT) treatment with HPβCD following on average 13 months of IV HPβCD. Several patients transitioned to an alternate HPβCD. Moderately affected NPC patients treated with HPβCD showed slowing of disease progression. Severely affected patients demonstrated periods of stability but eventually showed progression of disease. Neurologic and neurocognitive benefits were seen in most patients with IV alone, independent of the addition of IT administration. Physicians and caregivers reported improvements in quality of life for the patients on IV therapy. There were no safety issues, and the drug was well tolerated and easy to administer.

Conclusions

These expanded access data support the safety and potential benefit of systemic IV administration of HPβCD and provide a platform for two clinical trials to study the effect of intravenous administration of HPβCD in NPC patients.

Systematic review of psychiatric signs in Niemann-Pick disease type C

Objectives: We conducted the first systematic literature review and analysis of psychiatric manifestations in Niemann-Pick disease type C (NPC) to describe: (1) time of occurrence of psychiatric manifestations relative to other disease manifestations; and (2) frequent combinations of psychiatric, neurological and visceral disease manifestations. Methods: A systematic EMBase literature search was conducted to identify, collate and analyze published data from patients with NPC associated with psychiatric symptoms, published between January 1967 and November 2015. Results: Of 152 identified publications 40 were included after screening that contained useable data from 58 NPC patients (mean [SD] age at diagnosis of NPC 27.8 [15.1] years). Among patients with available data, cognitive, memory and instrumental impairments were most frequent (90% of patients), followed by psychosis (62%), altered behavior (52%) and mood disorders (38%). Psychiatric manifestations were reported before or at neurological disease onset in 41 (76%) patients; organic signs (e.g., hepatosplenomegaly, hearing problems) were reported before psychiatric manifestations in 12 (22%). Substantial delays to diagnosis were observed (5-6 years between psychiatric presentation and NPC diagnosis). Conclusions: NPC should be considered as a possible cause of psychiatric manifestations in patients with an atypical disease course, acute-onset psychosis, treatment failure, and/or certain combinations of psychiatric/neurological/visceral symptoms.

Hepatic and neuronal phenotype of NPC1-/- mice

Niemann-Pick type C disease (NPC) is a fatal autosomal recessive disorder characterized by a defect in the intracellular transport of lipoproteins leading to the accumulation of lipids in diverse tissues. A visceral and neuronal phenotype mimicking human NPC1 disease has been described in NPC1 mutant mice. These mice are by now the most widely used NPC1 rodent model to study NPC and developmental compounds against this devastating disease. Here we characterized NPC1-/- mice for their hepatic and neuronal phenotype to confirm the stability of the phenotype, provide a characterization of disease progression and pinpoint the age of robust phenotype onset. Animals of 4-10 weeks of age were analyzed for general health, motor deficits as well as hepatic and neuronal alterations with a special focus on cerebellar pathology. Our results show that NPC1-/- mice have a reduced general health at the age of 9-10 weeks. Robust motor deficits can be observed even earlier at 8 weeks of age. Hepatic changes included increased organ weight and cholesterol levels at 6 weeks of age accompanied by severely increased liver enzyme levels. Analysis of NPC1-/- brain pathology showed decreased cholesterol and increased Aβ levels in the hippocampus at the age of 6 weeks. Further analysis revealed a decrease of the cytokine IL-12p70 in the cerebellum along with a very early increase of astrocytosis. Hippocampal IL-12p70 levels were increased at the age of 6 weeks followed by increased activated microglia levels. By the age of 10 weeks, also cerebellar Aβ levels were increased along with strongly reduced Calbindin D-28k levels. Our results validate and summarize the progressive development of the hepatic and neuronal phenotype of NPC1-/- mice that starts with cerebellar astrocytosis, making this mouse model a valuable tool for the development of new compounds against NPC.

Lysosomal storage disease overview

The lysosomal storage diseases (LSDs) are a group of inherited metabolic disorders that are caused for the most part by enzyme deficiencies within the lysosome resulting in accumulation of undegraded substrate. This storage process leads to a broad spectrum of clinical manifestations depending on the specific substrate and site of accumulation. Examples of LSDs include the mucopolysaccharidoses, mucolipidoses, oligosaccharidoses, Pompe disease, Gaucher disease, Fabry disease, the Niemann-Pick disorders, and neuronal ceroid lipofuscinoses. This review summarizes the main clinical features, diagnosis, and management of LSDs with an emphasis on those for which treatment is available.

Pneumococcal Immunization Reduces Neurological and Hepatic Symptoms in a Mouse Model for Niemann-Pick Type C1 Disease

Niemann-Pick type C1 (NPC1) disease is caused by a deleterious mutation in the Npc1 gene, causing lysosomal accumulation of unesterified cholesterol and sphingolipids. Consequently, NPC1 disease patients suffer from severe neurovisceral symptoms which, in the absence of effective treatments, result in premature death. NPC1 disease patients display increased plasma levels of cholesterol oxidation products such as those enriched in oxidized low-density lipoprotein (oxLDL), a pro-inflammatory mediator. While it has been shown that inflammation precedes and exacerbates symptom severity in NPC1 disease, it is unclear whether oxLDL contributes to NPC1 disease progression. In this study, we investigated the effects of increasing anti-oxLDL IgM autoantibodies on systemic and neurological symptoms in an NPC1 disease mouse model. For this purpose, Npc1^nih mice were immunized with heat-inactivated S. pneumoniae, an immunogen which elicits an IgM autoantibody-mediated immune response against oxLDL. Npc1^nih mice injected with heat-inactivated pneumococci displayed an improved hepatic phenotype, including liver lipid accumulation and inflammation. In addition, regression of motor skills was delayed in immunized Npc1^nih. In line with these results, brain analyses showed an improved cerebellar phenotype and neuroinflammation in comparison with control-treated subjects. This study highlights the potential of the pneumococcal immunization as a novel therapeutical approach in NPC1 disease. Future research should investigate whether implementation of this therapy can improve life span and quality of life of NPC1 disease patients.

Lysosomal storage disease overview

The lysosomal storage diseases (LSDs) are a group of inherited metabolic disorders that are caused for the most part by enzyme deficiencies within the lysosome resulting in accumulation of undegraded substrate. This storage process leads to a broad spectrum of clinical manifestations depending on the specific substrate and site of accumulation. Examples of LSDs include the mucopolysaccharidoses, mucolipidoses, oligosaccharidoses, Pompe disease, Gaucher disease, Fabry disease, the Niemann-Pick disorders, and neuronal ceroid lipofuscinoses. This review summarizes the main clinical features, diagnosis, and management of LSDs with an emphasis on those for which treatment is available.

Adult Niemann-Pick disease type C in France: clinical phenotypes and long-term miglustat treatment effect

Background

Niemann-Pick disease type C (NP-C) is a neurodegenerative lysosomal lipid storage disease caused by autosomal recessive mutations in the NPC1 or NPC2 genes. The clinical presentation and evolution of NP-C and the effect of miglustat treatment are described in the largest cohort of patients with adolescent/adult-onset NP-C studied to date.

Methods

Observational study based on clinical chart data from adult patients with NP-C (> 18 year old) diagnosed in France between 1990 and 2015. Retrospective data from patients at diagnosis, onset of miglustat therapy (if applicable), and last follow up were analysed.

Results

In France, patients with an adolescent-adult neurological form constituted approximately 25% of all NP-C cases diagnosed during the study period. Forty-seven patients (46 with NP-C1 and one with NP-C2; 53% female) were included. Mean ± SD (range) ages at neurological onset and diagnosis were 23.9 ± 12.5 (8–56) years and 34 ± 13.5 (15–65) years, respectively. At presentation, patients mainly had 1) impaired gait due to cerebellar ataxia and/or dystonia, 2) and/or cognitive/behavioural manifestations, 3) and/or psychotic signs. Initially, almost half of patients had only one of the above three neuro-psychiatric manifestations. Vertical supranuclear gaze palsy, usually occurring without patient complaint, was only detected on careful clinical examination and was recorded in most patients (93%) at the time of diagnosis, several years after neurological onset. Thirty-seven patients (79%) received miglustat, among whom seventeen (46%) continued beyond 2 years (at last follow up) to a maximum of 9.8 years. Eight patients (22%) discontinued treatment early due to side effects (n = 3) or perceived lack of efficacy (n = 5).Miglustat treatment duration correlated significantly with reduced neurological worsening (p < 0.001). Treatment for≥2 years was associated with improved patient survival (p = 0.029). Good responses to miglustat were associated with less severe neurological disability at the start of miglustat treatment (p = 0.02).

Conclusion

The proportion of adolescent/adult-onset NP-C cases diagnosed in France increased 2.5-fold since 2009 compared with the 2000–2008 period due to improved awareness. Adolescent/adult-onset NP-C frequently presented initially with a non-specific isolated neuro-psychiatric manifestation (motor, cognitive or psychotic). Patients with less severe neurological disability responded better to miglustat therapy.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0913-4) contains supplementary material, which is available to authorized users.

Miglustat in Niemann-Pick disease type C patients: a review

OBJECTIVE

Niemann-Pick disease type C (NP-C) is a rare, autosomal recessive, neurodegenerative disease associated with a wide variety of progressive neurological manifestations. Miglustat is indicated for the treatment of progressive neurological manifestations in both adults and children. Since approval in 2009 there has been a vast growth in clinical experience with miglustat. The effectiveness of miglustat has been assessed using a range of measures.

METHODS

Comprehensive review of published data from studies of cellular neuropathological markers and structural neurological indices in the brain, clinical impairment/disability, specific clinical neurological manifestations, and patient survival.

RESULTS

Cranial diffusion tensor imaging and magnetic resonance spectroscopy studies have shown reduced levels of choline (a neurodegeneration marker), and choline/N-acetyl aspartate ratio (indicating increased neuronal viability) in the brain during up to 5 years of miglustat therapy, as well as a slowing of reductions in fractional anisotropy (an axonal/myelin integrity marker). A 2-year immunoassay study showed significant reductions in CSF-calbindin during treatment, indicating reduced cerebellar Purkinje cell loss. Magnetic resonance imaging studies have demonstrated a protective effect of miglustat on cerebellar and subcortical structure that correlated with clinical symptom severity. Numerous cohort studies assessing core neurological manifestations (impaired ambulation, manipulation, speech, swallowing, other) using NP-C disability scales indicate neurological stabilization over 2-8 years, with a trend for greater benefits in patients with older (non-infantile) age at neurological onset. A randomized controlled trial and several cohort studies have reported improvements or stabilization of saccadic eye movements during 1-5 years of therapy. Swallowing was also shown to improve/remain stable during the randomized trial (up to 2 years), as well as in long-term observational cohorts (up to 6 years). A meta-analysis of dysphagia - a potent risk factor for aspiration pneumonia and premature death in NP-C - demonstrated a survival benefit with miglustat due to improved/stabilized swallowing function.

CONCLUSIONS

The effects of miglustat on neurological NP-C manifestations has been assessed using a range of approaches, with benefits ranging from cellular changes in the brain through to visible clinical improvements and improved survival.

Linear Cyclodextrin Polymer Prodrugs as Novel Therapeutics for Niemann-Pick Type C1 Disorder

Niemann-Pick Type C1 disorder (NPC) is a rare lysosomal storage disease characterized by the accumulation of cholesterol in lysosomes. NPC has no FDA approved treatments yet, however 2-hydroxypropyl-β-cyclodextrin (HPβCD) has shown efficacy for treating the disease in both mouse and feline NPC models and is currently being investigated in late stage clinical trials. Despite promising results, therapeutic use of HPβCD is limited by the need for high doses, ototoxicity and intrathecal administration. These limitations can be attributed to its poor pharmacokinetic profile. In the attempt to overcome these limitations, we have designed a β-cyclodextrin (βCD) based polymer prodrugs (ORX-301) for an enhanced pharmacokinetic and biodistribution profile, which in turn can potentially provide an improved efficacy at lower doses. We demonstrated that subcutaneously injected ORX-301 extended the mean lifespan of NPC mice at a dosage 5-fold lower (800 mg/kg, body weight) the HPβCD dose proven efficacious (4000 mg/kg). We also show that ORX-301 penetrates the blood brain barrier and counteracts neurological impairment. These properties represent a substantial improvement and appear to overcome major limitations of presently available βCD-based therapy, demonstrating that this novel prodrug is a valuable alternative/complement for existing therapies.

Consensus clinical management guidelines for Niemann-Pick disease type C

Niemann-Pick Type C (NPC) is a progressive and life limiting autosomal recessive disorder caused by mutations in either the NPC1 or NPC2 gene. Mutations in these genes are associated with abnormal endosomal-lysosomal trafficking, resulting in the accumulation of multiple tissue specific lipids in the lysosomes. The clinical spectrum of NPC disease ranges from a neonatal rapidly progressive fatal disorder to an adult-onset chronic neurodegenerative disease. The age of onset of the first (beyond 3 months of life) neurological symptom may predict the severity of the disease and determines life expectancy.

NPC has an estimated incidence of ~ 1: 100,000 and the rarity of the disease translate into misdiagnosis, delayed diagnosis and barriers to good care. For these reasons, we have developed clinical guidelines that define standard of care for NPC patients, foster shared care arrangements between expert centres and family physicians, and empower patients. The information contained in these guidelines was obtained through a systematic review of the literature and the experiences of the authors in their care of patients with NPC. We adopted the Appraisal of Guidelines for Research & Evaluation (AGREE II) system as method of choice for the guideline development process. We made a series of conclusive statements and scored them according to level of evidence, strengths of recommendations and expert opinions. These guidelines can inform care providers, care funders, patients and their carers of best practice of care for patients with NPC. In addition, these guidelines have identified gaps in the knowledge that must be filled by future research. It is anticipated that the implementation of these guidelines will lead to a step change in the quality of care for patients with NPC irrespective of their geographical location.

Gait, Balance, and Coordination Impairments in Niemann Pick Disease, Type C1

This is the first study to objectively measure gait, balance, and upper limb coordination in a group of patients with NPC1 and compare the results to age and gender matched controls. This is also the first study to report effect sizes in these measures. Spatiotemporal gait analysis, static and dynamic posturography, and upper limb reaching motion analysis were performed. The findings showed that the NPC1 subjects had statistically significant deficits on 12 out of the 16 parameters investigated compared to controls, and large effect sizes for all but 1 parameter. When ranking the variables in terms of the effect sizes, the top 5 included at least 1 parameter from each of the 3 motor domains investigated. These results can provide insight to clinical researchers on the selection of outcome measures for longitudinal and interventional studies.

Niemann-Pick disease type C in the newborn period: a single-center experience

Niemann-Pick disease type C (NPC) is a neurovisceral lysosomal storage disorder with a great variation in clinical spectrum and age at presentation. Clinical features of 10 NPC patients who presented in the newborn period between 1993 and 2015 at our center were retrospectively analyzed. Males and females were equally distributed; there was a history of parental consanguinity (n = 8) and first-degree relative with NPC (n = 3). Patients were symptomatic between 1 and 10 days (mean 3.6 ± 2.6 days). Age at diagnosis was between 1 and 30 days (mean 14.6 ± 13.3 days). Laboratory work-up included bone marrow aspiration (n = 8) and/or filipin staining (n = 4). Confirmation was done by molecular analysis, indicating NPC1 (n = 8) and NPC2 (n = 2) mutations. All patients had neonatal cholestasis and hepatosplenomegaly. Pulmonary involvement (n = 9) and fetal ascites (n = 2) were additional accompanying features. All but one died due to pulmonary complications (n = 6) and liver insufficiency (n = 3) between 1.5 and 36 months of age (mean 8.1 ± 10.8 months). Currently, one patient is alive at the age of 11 months without any neurological deficit.

CONCLUSIONS

Neonatal presentation is a rare form of NPC with exclusively visceral involvement in the newborn period and poor prognosis leading to premature death due to pulmonary complications and liver failure. What is known: • Neonatal presentation is a rare form of NPC with exclusively visceral involvement in the newborn period and poor prognosis leading to premature death. • Progressive liver disease is the most common cause of death among neonatal-onset NPC patients. What is new: • Natural course of neonatal-onset NPC may show variations. • Pulmonary involvement should be considered as an important cause of death in neonatal-onset cases, and appropriate precautions should be taken to prevent complications of respiratory insufficiency and airway infections.

Alteration of cortical excitability and its modulation by Miglustat in Niemann-Pick disease type C

Niemann-Pick type C (NP-C) is a rare, neurodegenerative, lysosomal storage disease. Cortical excitability using different transcranial magnetic stimulation (TMS) protocols together with clinical and neuropsychological testing was longitudinally assessed in a patient with NP-C. Cerebellar inhibition, a measure for the integrity of the cerebello-thalamo-cortical network, was impaired. Short-latency afferent inhibition, a measure for cholinergic transmission, and cognitive functions were also impaired and improved under Miglustat treatment. Short interval intracortical facilitation, a marker for glutamatergic neurotransmission, was absent initially but increased after treatment with Miglustat. Our results provide new insights into pathophysiological mechanisms of NP-C and the response to Miglustat treatment.

Aberrant activation of Cdc2/cyclin B1 is involved in initiation of cytoskeletal pathology in murine Niemann-Pick disease type C

Niemann-Pick disease type C (NPC) is a fatal, neurovisceral lipid storage disease, neuropathologically characterized by cytoplasmic sequestration of glycolipids in neurons, progressive neuronal loss, neurofibrillary tangles (NFTs) formation, and axonal spheroids (AS). Cytoskeletal pathology including accumulation of hyperphosphorylated cytoskeletal proteins is a neuropathological hallmark of the mouse model of NPC (npc mice). With a goal of elucidating the mechanisms underlying the lesion formation, we investigated the temporal and spatial characteristics of cytoskeletal lesions and the roles of cdc2, cdk4, and cdk5 in lesion formation in young npc mice. Cytoskeletal lesions were detectable in npc mice at three weeks of age. Importantly, concomitant activation of cdc2/cyclin B1 kinase and accumulation of a subsequently generated cohort of phospho-epitopes were detected. The activation of cdk4/cyclin D1 and cdk5/p25 kinases was observed during the fourth week of life in npc mice, and this activation contributed to the lesion formation. We concluded that the progression of cytoskeletal pathology in npc mice older than four weeks is accelerated by the cumulative effect of cdc2, cdk4, and cdk5 activation. Furthermore, cdc2/cyclin B1 may act as a key initial player one week earlier. Targeting cell cycle activation may be beneficial to slow down the NPC pathogenesis.

Pluronic based β-cyclodextrin polyrotaxanes for treatment of Niemann-Pick Type C disease

Niemann-Pick Type C disease (NPC) is a rare metabolic disorder characterized by disruption of normal cholesterol trafficking within the cells of the body. There are no FDA approved treatments available for NPC patients. Recently, the cycloheptaglucoside 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) has shown efficacy as a potential NPC therapeutic by extending lifetime in NPC mice, delaying neurodegeneration, and decreasing visceral and neurological cholesterol burden. Although promising, systemic HP-β-CD treatment is limited by a pharmacokinetic profile characterized by rapid loss through renal filtration. To address these shortcomings, we sought to design a family of HP-β-CD pro-drug delivery vehicles, known as polyrotaxanes (PR), capable of increasing the efficacy of a given injected dose by improving both pharmacokinetic profile and bioavailability of the HP-β-CD agent. PR can effectively diminish the cholesterol pool within the liver, spleen, and kidney at molar concentrations 10-to-100-fold lower than monomeric HP-β-CD. In addition to this proof-of-concept, use of PR scaffolds with differing physiochemical properties reveal structure-activity relationships in which PR characteristics, including hydrophobicity, threading efficiency and surface charge, were found to both decisively and subtly effect therapeutic efficacy. PR scaffolds exhibit absorption, pharmacokinetics, and biodistribution patterns that are significantly altered from monomeric HP-β-CD. In all, PR scaffolds hold great promise as potential treatments for visceral disease in NPC patients.

Impact of miglustat on evolution of atypical presentation of late-infantile-onset Niemann-Pick disease type C with early cognitive impairment, behavioral dysfunction, epilepsy, ophthalmoplegia, and cerebellar involvement: a case report

Background

Niemann–Pick disease type C is a rare inherited neurodegenerative disease involving impaired intracellular lipid trafficking and accumulation of glycolipids in various tissues, including the brain. Miglustat, a reversible inhibitor of glucosylceramide synthase, has been shown to be effective in the treatment of progressive neurological manifestations in pediatric and adult patients with Niemann–Pick disease type C, and has been used in that indication in Europe since 2010.

Case presentation

We describe the case of a 16-year-old white French boy with late-infantile-onset Niemann–Pick disease type C who had the unusual presentation of early-onset behavioral disturbance and learning difficulties (aged 5) alongside epileptic seizures. Over time he developed characteristic, progressive vertical ophthalmoplegia, ataxic gait, and cerebellar syndrome; at age 10 he was diagnosed as having Niemann–Pick disease type C based on filipin staining and genetic analysis (heterozygous I1061T/R934X NPC1 mutations). He was commenced on miglustat therapy aged 11 and over the course of approximately 3 years he showed a global improvement as well as improved cognitive and ambulatory function. During this period he remained seizure free on antiepileptic therapy, using valproate and lamotrigine.

Conclusions

Miglustat improved the neurological status of our patient, including seizure control. Based on our findings in this patient and previous published data, we discuss the importance of effective seizure control in neurological improvement in Niemann–Pick disease type C, and the relevance of cerebellar involvement as a possible link between these clinical phenomena. Thus the therapeutic efficacy of miglustat could be hypothesized as a substrate reduction effect on Purkinje cells.

Niemann-Pick disease treatment: a systematic review of clinical trials

The aim of this systematic review was to analyse all the published clinical trials assessing treatments for Niemann-Pick (NP) disease. At present there are only trials investigating the treatment of NP disease type C. Furthermore, there is no uniformity among studies in treatment outcomes or in data analysis and presentation of results. Miglustat is able to delay neurodegeneration, with greater benefits in patients with a late onset of the disease and β-cyclodextrin-hydroxypropyl (HBP-CD) can attenuate clinical symptoms. As for cholesterol-lowering drugs, the combination of lovastatin, cholestyramine and nicotinic acid is the most effective one for lowering cholesterolemia. Further research is much needed, and ongoing trials using enzyme replacement therapy might hopefully show promising results in the foreseeable future.

Otorhinolaryngological, audiovestibular and swallowing manifestations of patients with Niemann-Pick disease Type C

OBJECTIVES

The aim of this study is to evaluate audiovestibular and swallowing impairment of patients with NPC.

METHODS

Audiovestibular and swallowing evaluation were performed on patients with Niemann-Pick disease type C (NPC) at Hacettepe University between 20013 and 2015 prospectively. Pure-tone audiometry (PTA), Auditory Brain stem response (ABR), Flexible endoscopic evaluation of swallowing (FEES) test and posturography were done. Hearing, swallowing and balance states were measured.

RESULTS

There were 16 patients (5 male and 11 female, with a median age of 6.5 years old). The most common ABR abnormalities observed were absent waves I and III (%70 absent I waves, %43.75 absent III waves). Twelve of sixteen patients (%75) had an ABR abnormality in at least one ear, of these, four patients had normal hearing and three of them had periferal hearing loss. 12 (75%) patients had complaint of postural imbalance. 11(69%) of patients had peripheral and one (6%) patient had central impairment. Nine of sixteen patients (56.25%) show some degree of dysphagia (either penetration or aspiration). Two patients (12.5%) showed aspiration both liquid and viscous nutrition. Three patients (18.75%) showed aspiration primarily in liquids and two of them had penetration with viscous nutrition. Three patients (18.75%) had penetration with no aspiration neither liquid nor viscous nutrition (PEN-ASP score was 3, 3, 5, respectively).

CONCLUSION

There is no curative treatment for this devastating and fatal disorder and hearing impairment, balance and swallowing disorders can be seen especially late onset form of disease.

Stable or improved neurological manifestations during miglustat therapy in patients from the international disease registry for Niemann-Pick disease type C: an observational cohort study

Background

Niemann-Pick disease type C (NP-C) is a rare neurovisceral disease characterised by progressive neurological degeneration, where the rate of neurological disease progression varies depending on age at neurological onset. We report longitudinal data on functional disease progression and safety observations in patients in the international NPC Registry who received continuous treatment with miglustat.

Methods

The NPC Registry is a prospective observational cohort of NP-C patients. Enrolled patients who received ≥1 year of continuous miglustat therapy (for ≥90 % of the observation period, with no single treatment interruption >28 days) were included in this analysis. Disability was measured using a scale rating the four domains, ambulation, manipulation, language and swallowing from 0 (normal) to 1 (worst). Neurological disease progression was analysed in all patients based on: 1) annual progression rates between enrolment and last follow up, and; 2) categorical analysis with patients categorised as ‘improved/stable’ if ≥3/4 domain scores were lower/unchanged, and as ‘progressed’ if <3 scores were lower/unchanged between enrolment and last follow-up visit.

Results

In total, 283 patients were enrolled from 28 centers in 13 European countries, Canada and Australia between September 2009 and October 2013; 92 patients received continuous miglustat therapy. The mean (SD) miglustat exposure during the observation period (enrolment to last follow-up) was 2.0 (0.7) years. Among 84 evaluable patients, 9 (11 %) had early-infantile (<2 years), 27 (32 %) had late-infantile (2 to <6 years), 30 (36 %) had juvenile (6 to <15 years) and 18 (21 %) had adolescent/adult (≥15 years) onset of neurological manifestations. The mean (95%CI) composite disability score among all patients was 0.37 (0.32,0.42) at enrolment and 0.44 (0.38,0.50) at last follow-up visit, and the mean annual progression rate was 0.038 (0.018,0.059). Progression of composite disability scores appeared highest among patients with neurological onset during infancy or childhood and lowest in those with adolescent/adult-onset. Overall, 59/86 evaluable patients (69 %) were categorized as improved/stable and the proportion of improved/stable patients increased with age at neurological onset. Safety findings were consistent with previous data.

Conclusions

Disability status was improved/stable in the majority of patients who received continuous miglustat therapy for an average period of 2 years.

Psychiatric signs and symptoms in treatable inborn errors of metabolism

Possible underlying organic causes of psychiatric symptoms can be overlooked in the clinical setting. It is important to increase awareness amongst psychiatric and neurological professionals with regard to certain inborn errors of metabolism as, in some cases, disease-specific therapies are available that can, for instance, treat underlying metabolic causes. The following article describes the basic pathophysiology, clinical and neurological features, and available diagnostic procedures of six treatable metabolic diseases that are associated with neuropsychiatric symptoms: Wilson's disease, cerebrotendinous xanthomatosis, porphyrias, homocysteinemia, urea cycle disorders, and Niemann-Pick disease type C (NP-C). NP-C is taken as a particularly relevant example because, while it is traditionally considered to be a condition that presents with severe neurological and systemic manifestations in children, an increasing number of patients are being detected who have the adolescent- or adult-onset form, which is frequently associated with neuropsychiatric signs. A notable proportion of adult-onset cases have been reported where NP-C has mistakenly been diagnosed and treated as a psychiatric condition, usually based on patients' initial presentation with psychotic or schizophrenia-like symptoms. Underlying organic causes of psychiatric disorders such as psychosis should be considered among patients with atypical symptoms and/or resistance to standard therapy. Alongside improved frameworks for additional multidisciplinary diagnostic work in patients with suspected organic disease, the development of convenient and affordable biochemical screening and/or diagnostic methods has enabled new ways to narrow down differential diagnoses.

Long term follow-up to evaluate the efficacy of miglustat treatment in Italian patients with Niemann-Pick disease type C

Background

Twenty-five patients with Niemann Pick disease type C (age range: 7 months to 44 years) were enrolled in an Italian independent multicenter trial and treated with miglustat for periods from 48 to 96 months.

Methods

Based on the age at onset of neurological manifestations patients’ phenotypes were classified as: adult (n = 6), juvenile (n = 9), late infantile (n = 6), early infantile (n = 2). Two patients had an exclusively visceral phenotype. We clinically evaluated patients’ neurological involvement, giving a score of severity ranging from 0 (best) to 3 (worst) for gait abnormalities, dystonia, dysmetria, dysarthria, and developmental delay/cognitive impairment, and from 0 to 4 for dysphagia. We calculated a mean composite severity score transforming the original scores proportionally to range from 0 to 1 to summarize the clinical picture of patients and monitor their clinical course.

Results

We compared the results after 24 months of treatment in 23 patients showing neurological manifestations. Stabilization or improvement of all parameters was observed in the majority of patients. With the exception of developmental delay/cognitive impairment, these results persisted after 48–96 months in 41 – 55% of the patients (dystonia: 55%, dysarthria: 50%, gait abnormalities: 43%, dysmetria: 41%, respectively). After 24 months of therapy the majority of the evaluable patients (n = 20), demonstrated a stabilization or improvement in the ability to swallow four substances of different consistency (water: 65%, purée: 58%, little pasta: 60%, biscuit: 55%). These results persisted after 48–96 months in 40-50% of patients, with the exception of water swallowing. Stabilization or improvement of the composite severity score was detected in the majority (57%) of 7 patients who were treated early (within 3.5 years from onset) and rarely in patients who received treatment later.

Conclusions

The results of this study suggest that miglustat treatment can improve or stabilize neurological manifestations, at least for a period of time; the severity of clinical conditions at the beginning of treatment can influence the rate of disease progression. This conclusion applies particularly to patients with juvenile or adult onset of the disease.

Trial registration

EudraCT number 2006-005842-35

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-015-0240-y) contains supplementary material, which is available to authorized users.

Recent advances in the diagnosis and treatment of niemann-pick disease type C in children: a guide to early diagnosis for the general pediatrician

Niemann-Pick disease (NP-C) is a lysosomal storage disease in which impaired intracellular lipid transport leads to accumulation of cholesterol and glycosphingolipids in various neurovisceral tissues. It is an autosomal recessive disorder, caused by mutations in the NPC1 or NPC2 genes. The clinical spectrum is grouped by the age of onset and onset of neurological manifestation: pre/perinatal; early infantile; late infantile; and juvenile periods. The NP-C Suspicion Index (SI) screening tool was developed to identify suspected patients with this disease. It is especially good at recognizing the disease in patients older than four years of age. Biochemical tests involving genetic markers and Filipin staining of skin fibroblast are being employed to assist diagnosis. Therapy is mostly supportive and since 2009, the first specific therapy approved for use was Miglustat (Zavesca) aimed at stabilizing the rate of progression of neurological manifestation. The prognosis correlates with age at onset of neurological signs; patients with early onset form progress faster. The NP-C disease has heterogeneous neurovisceral manifestations. A SI is a screening tool that helps in diagnostic process. Filipin staining test is a specific biomarker diagnostic test. Miglustat is the first disease-specific therapy.

Miglustat: a review of its use in Niemann-Pick disease type C

Miglustat (Zavesca®, Brazaves®), a small iminosugar molecule that reversibly inhibits glycosphingolipid synthesis, is the only disease-specific drug approved for the treatment of progressive neurological manifestations of Niemann-Pick disease type C (NP-C) in adult and paediatric patients. NP-C is a rare, autosomal-recessive lipid storage disorder characterized by impaired intracellular lipid trafficking and progressive neurological symptoms leading to premature death. In a randomized clinical trial, long-term extension studies and a retrospective observational cohort study, treatment with oral miglustat stabilized key neurological manifestations of NP-C (including horizontal saccadic eye movement peak velocity, ambulation, manipulation, language and swallowing) in paediatric and adult patients with the disease. The therapeutic effects of miglustat in stabilizing or slowing disease progression have been confirmed in other reports in the clinical experience setting. The primary tolerability issues associated with miglustat are mild to moderate gastrointestinal effects (e.g. diarrhoea, flatulence and abdominal pain/discomfort) and weight loss, which usually occur during initial therapy and are generally manageable. In the absence of a cure, miglustat is a valuable agent to reduce the progression of clinically relevant neurological symptoms in paediatric and adult patients with NP-C, which is considered a significant achievement in the treatment of this disease.

Early co-occurrence of a neurologic-psychiatric disease pattern in Niemann-Pick type C disease: a retrospective Swiss cohort study

Background

Niemann-Pick disease type C (NP-C) is a rare autosomal recessive disorder of lysosomal cholesterol transport. The objective of this retrospective cohort study was to critically analyze the onset and time course of symptoms, and the clinical diagnostic work-up in the Swiss NP-C cohort.

Methods

Clinical, biochemical and genetic data were assessed for 14 patients derived from 9 families diagnosed with NP-C between 1994 and 2013. We retrospectively evaluated diagnostic delays and period prevalence rates for neurological, psychiatric and visceral symptoms associated with NP-C disease. The NP-C suspicion index was calculated for the time of neurological disease onset and the time of diagnosis.

Results

The shortest median diagnostic delay was noted for vertical supranuclear gaze palsy (2y). Ataxia, dysarthria, dysphagia, spasticity, cataplexy, seizures and cognitive decline displayed similar median diagnostic delays (4–5y). The longest median diagnostic delay was associated with hepatosplenomegaly (15y). Highest period prevalence rates were noted for ataxia, dysarthria, vertical supranuclear gaze palsy and cognitive decline. The NP-C suspicion index revealed a median score of 81 points in nine patients at the time of neurological disease onset which is highly suspicious for NP-C disease. At the time of diagnosis, the score increased to 206 points.

Conclusion

A neurologic-psychiatric disease pattern represents the most characteristic clinical manifestation of NP-C and occurs early in the disease course. Visceral manifestation such as isolated hepatosplenomegaly often fails recognition and thus highlights the importance of a work-up for lysosomal storage disorders. The NP-C suspicion index emphasizes the importance of a multisystem evaluation, but seems to be weak in monosymptomatic and infantile NP-C patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-014-0176-7) contains supplementary material, which is available to authorized users.

Niemann-Pick disease type C: a case series of Brazilian patients

The aim of the study was to analyze a series of Brazilian patients with Niemann-Pick disease type C (NP-C).

METHOD

Correlations between clinical findings, laboratory data, molecular findings and treatment response are presented.

RESULT

The sample consisted of 5 patients aged 8 to 26 years. Vertical supranuclear gaze palsy, cerebellar ataxia, dementia, dystonia and dysarthria were present in all cases. Filipin staining showed the "classical" pattern in two patients and a "variant" pattern in three patients. Molecular analysis found mutations in the NPC1 gene in all alleles. Miglustat treatment was administered to 4 patients.

CONCLUSION

Although filipin staining should be used to confirm the diagnosis, bone marrow sea-blue histiocytes often help to diagnosis of NP-C. The p.P1007A mutation seems to be correlated with the "variant" pattern in filipin staining. Miglustat treatment response seems to be correlated with the age at disease onset and disability scale score at diagnosis.

Observational, retrospective study of a large cohort of patients with Niemann-Pick disease type C in the Czech Republic: a surprisingly stable diagnostic rate spanning almost 40 years

Background

Niemann-Pick disease type C (NPC) is a rare, fatal neurovisceral disorder with autosomal recessive inheritance, and featuring striking clinical variability dependent on the age at onset of neurological symptoms. We report data from a large cohort of 56 Czech patients with NPC diagnosed over a period of 37 years.

Methods

An observational, retrospective analysis of historic and current clinical and laboratory information was performed among all NPC patients originating from the area of the contemporary Czech Republic and diagnosed between 1975 and 2012. All patients with ≥1 positive diagnostic test and relevant clinical information were included. Data on diagnostic methods (histopathological and/or ultrastructural; biochemical; genetic), clinical status and general information on treatment were collated. Data were examined in accordance with international guidelines for the management of NPC.

Results

Between 1975 and 1985 diagnoses were based exclusively on specific histopathological findings, often at autopsy. Bone marrow smear (BMS) analyses have proved to be a very specific indicator for NPC and have become an important part of our diagnostic algorithm. Filipin staining and cholesterol esterification assays became the definitive diagnostic tests after 1985 and were applied in 24 of our patients. Since 2005, more and more patients have been assessed using NPC1/NPC2 gene sequencing. Twelve patients were diagnosed with neonatal/early-infantile onset NPC, 13 with the late-infantile onset form, 20 with the juvenile onset form, and nine with the adolescent/adult onset form. Two diagnosed patients remained neurologically asymptomatic at study completion. Nineteen patients were siblings. Causal NPC1 mutations were determined in 38 patients; two identical NPC2 mutations were identified in one patient. In total, 30 different mutations were identified, 14 of which have been confirmed as novel. The frequency of individual mutated NPC1 alleles in our cohort differs compared with previous published data: the most frequent mutant NPC1 allele was p.R1186H (n = 13), followed by p.P1007A (n = 8), p.S954L (n = 8) and p.I1061T (n = 4).

Conclusions

These data demonstrate the evolution of the diagnostic process in NPC over the last four decades. We estimate the contemporary birth prevalence of NPC in the Czech Republic at 0.93 per 100,000.

Vitamin E dietary supplementation improves neurological symptoms and decreases c-Abl/p73 activation in Niemann-Pick C mice

Niemann-Pick C (NPC) disease is a fatal neurodegenerative disorder characterized by the accumulation of free cholesterol in lysosomes. We have previously reported that oxidative stress is the main upstream stimulus activating the proapoptotic c-Abl/p73 pathway in NPC neurons. We have also observed accumulation of vitamin E in NPC lysosomes, which could lead to a potential decrease of its bioavailability. Our aim was to determine if dietary vitamin E supplementation could improve NPC disease in mice. NPC mice received an alpha-tocopherol (α-TOH) supplemented diet and neurological symptoms, survival, Purkinje cell loss, α-TOH and nitrotyrosine levels, astrogliosis, and the c-Abl/p73 pathway functions were evaluated. In addition, the effect of α-TOH on the c-Abl/p73 pathway was evaluated in an in vitro NPC neuron model. The α-TOH rich diet delayed loss of weight, improved coordination and locomotor function and increased the survival of NPC mice. We found increased Purkinje neurons and α-TOH levels and reduced astrogliosis, nitrotyrosine and phosphorylated p73 in cerebellum. A decrease of c-Abl/p73 activation was also observed in the in vitro NPC neurons treated with α-TOH. In conclusion, our results show that vitamin E can delay neurodegeneration in NPC mice and suggest that its supplementation in the diet could be useful for the treatment of NPC patients.