Mortality trend from sporadic Creutzfeldt-Jakob disease (CJD) in Italy, 1993-2000

Genetic Creutzfeldt-Jakob disease in Turkish Jews-demographic and clinical features

BACKGROUND

The largest cluster of genetic Creutzfeldt- Jakob Disease (CJD) exists in Libyan Jews carrying the E200K mutation in the PRNP gene. However, there is another cluster of genetic CJD with E200K mutation in families of Turkish-Jewish origin.

AIMS

In this retrospective study, we aim to describe the demographic and clinical features of this population of patients.

MATERIAL AND METHODS

The Israeli National CJD database was searched for demographic, clinical, imaging, and laboratory data of genetic CJD patients of Libyan and Turkish ancestry with the E200K mutation. The data of Libyan and Turkish patients were compared with notice similar or different demographic or clinical courses.

RESULTS

Four hundred and twenty-three patients with CJD of Libyan (L) ancestry and 27 patients with CJD of Turkish (T) ancestry were identified. There were no significant differences in demographic and clinical data between the two populations (age of onset: T = 62 ± 8.8, L = 60 ± 9.7; age of death: T = 63 ± 8.6, L = 61 ± 9.7; and disease duration: T = 7.8 ± 8.4 months, L = 9.6 ± 13.6 months). Rapidly progressive dementia was the most common presentation in both groups, followed by pure cerebellar onset. The levels of tau protein in CSF did not differ between groups (T = 1290 ± 397.6 pg/ml, L = 1276 ± 594.2 pg/ml). MRI and EEG showed classical CJD features in most patients in both groups.

DISCUSSION

The E200K mutation is the most common mutation among gCJD patients and was reported in different ethnical populations, suggesting several independent haplotypes of the mutation. The Turkish-Jew cluster, first described in this study, shares similar demographic and clinical features with the bigger cluster of Libyan-Jews CJD patients.

CONCLUSION

E200K gCJD patients of Turkish ancestry share similar demographic and clinical features to patients of Libyan descent, suggesting a common origin of both populations.

Survival Patterns of Human Prion Diseases in Spain, 1998–2018: Clinical Phenotypes and Etiological Clues

Background

Human transmissible spongiform encephalopathies (TSEs) are a group of fatal neurodegenerative disorders of short duration. There are few studies on TSE survival. This study sought to analyze the survival and related factors of a TSE patient cohort, based on a nationwide surveillance system in Spain.

Methods

Survival analyses were performed on 1,530 cases diagnosed across the period 1998–2018 in Spain. We calculated median survival times and plotted survival curves using the Kaplan–Meier method for all cases and for sporadic TSE (sTSE) and genetic TSE (gTSE). Crude and adjusted Cox proportional hazard models were used to identify variables associated with shorter survival.

Findings

Median age at onset decreased from the sporadic forms to gTSE and, lastly, to acquired TSE. Overall median and interquartile range (IQR) survival time was 5.2 (IQR, 3.0–11.7) months and 4.9 (IQR, 2.8–10.8) months in sporadic cases and 9 (IQR, 4.9 to over 12) months in genetic cases, p < 0.001. Male sex, older age at onset, presence of 14-3-3 protein, typical MRI, and MM and VV polymorphisms at codon 129 were associated with shorter survival. gTSE showed higher survival in crude comparisons but not after adjustment.

Interpretation

TSE survival in Spain replicates both the magnitude of that shown and the TSE entity-specific population patterns observed in Western countries but differs from features described in Asian populations, such as the Japanese. The reduction in differences in survival between gTSE and sTSE on adjusting for covariates and international patterns might support the view that gTSE and sTSE share causal and pathophysiological features.

Variant CJD: Reflections a Quarter of a Century on

Twenty-five years has now passed since variant Creutzfeldt-Jakob disease (vCJD) was first described in the United Kingdom (UK). Early epidemiological, neuropathological and biochemical investigations suggested that vCJD represented a new zoonotic form of human prion disease resulting from dietary exposure to the bovine spongiform encephalopathy (BSE) agent. This hypothesis has since been confirmed though a large body of experimental evidence, predominantly using animal models of the disease. Today, the clinical, pathological and biochemical phenotype of vCJD is well characterized and demonstrates a unique and remarkably consistent pattern between individual cases when compared to other human prion diseases. While the numbers of vCJD cases remain reassuringly low, with 178 primary vCJD cases reported in the UK and a further 54 reported worldwide, concerns remain over the possible appearance of new vCJD cases in other genetic cohorts and the numbers of asymptomatic individuals in the population harboring vCJD infectivity. This review will provide a historical perspective on vCJD, examining the origins of this acquired prion disease and its association with BSE. We will investigate the epidemiology of the disease along with the unique clinicopathological and biochemical phenotype associated with vCJD cases. Additionally, this review will examine the impact vCJD has had on public health in the UK and the ongoing concerns raised by this rare group of disorders.

Prognostic Features of Sporadic Creutzfeldt-Jakob Disease: An Analysis of Taiwan's Nationwide Surveillance

OBJECTIVES

To study the prognostic features of Creutzfeldt-Jakob disease (CJD) and shed light on its future therapy.

DESIGN

Retrospective cohort study of a longitudinal national cohort of the Taiwan Centers for Disease Control.

SETTING AND PARTICIPANTS

All patients with suspected CJD are reported to the CJD surveillance unit of the Taiwan Centers for Disease Control. An expert committee discussed the reported cases and designated a consensus-based diagnosis. From 1996 to 2020, a total of 809 cases were referred to the CJD surveillance unit for confirmation; of these, 441 cases (women, n = 230) were determined to be sporadic CJD.

METHODS

We investigated the clinical manifestations and laboratory findings for 400 patients diagnosed with definite or probable sporadic CJD. We used Kaplan-Meier analyses and Cox proportional hazards model to identify prognostic factors.

RESULTS

The mean age of onset was 67 ± 9.9 years. The mean survival duration was 13.3 ± 14.2 (median 10) months. The leading clinical symptoms were myoclonus (73%) and akinetic mutism (54%). For PRNP polymorphism, 99% of patients (195/197) showed a methionine homozygous genotype at codon 129 (M129M). The sensitivity of periodic sharp wave complexes (PSWCs) on electroencephalograms (EEGs) was 59.7%. The sensitivity of cerebrospinal fluid 14-3-3 protein and total tau protein (>1200 pg/mL) were 69.7% and 75.6%, respectively. Younger patients lived longer than those aged ≥65 years [hazard ratio (HR) 0.466, P < .001]. Women had a better survival probability in the first 3 years than their male counterparts (HR 0.712, P = .005). PSWCs had a persistent negative effect on survival (HR 0.788, P < .05). Although uncommon, epileptic seizures were the only clinical prognostic factor for survival time (HR 0.768, P < .05). PSWCs can be used as an EEG biomarker for prognosis. Epileptic seizures, though not common, are the only clinical prognostic factor for a short survival.

CONCLUSIONS AND IMPLICATIONS

We found that a lower age of onset and female gender favor the survival of patients with sCJD. PSWCs are EEG biomarkers unfavorable for survival, and so are epileptic seizures.

The importance of ongoing international surveillance for Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease (CJD) is a rapidly progressive, fatal and transmissible neurodegenerative disease associated with the accumulation of misfolded prion protein in the CNS. International CJD surveillance programmes have been active since the emergence, in the mid-1990s, of variant CJD (vCJD), a disease linked to bovine spongiform encephalopathy. Control measures have now successfully contained bovine spongiform encephalopathy and the incidence of vCJD has declined, leading to questions about the requirement for ongoing surveillance. However, several lines of evidence have raised concerns that further cases of vCJD could emerge as a result of prolonged incubation and/or secondary transmission. Emerging evidence from peripheral tissue distribution studies employing high-sensitivity assays suggests that all forms of human prion disease carry a theoretical risk of iatrogenic transmission. Finally, emerging diseases, such as chronic wasting disease and camel prion disease, pose further risks to public health. In this Review, we provide an up-to-date overview of the transmission of prion diseases in human populations and argue that CJD surveillance remains vital both from a public health perspective and to support essential research into disease pathophysiology, enhanced diagnostic tests and much-needed treatments.

Predictive Factors for Early Initiation of Artificial Feeding in Patients With Sporadic Creutzfeldt-Jakob Disease

Background: Akinetic mutism has often been used as the predictor of sporadic Creutzfeldt-Jacob disease (sCJD) endpoints, but it may be difficult for general physcians to assess. Nasogastric (NG) tube insertion is indicated for many neurodegenerative diseases with a clinical course of swallowing failure, and can be more easily identified than akinetic mutism by general physicians. Therefore, the aim of this study was to identify whether there are predictive factors for early initiation of artificial feeding in patients with sCJD who require enteral nutrition due to swallowing failure.

Methods: We retrospectively reviewed the medical records of all patients diagnosed with probable sCJD who were admitted to the neurology ward at a medical center in Taiwan from January 2002 to July 2017. We used Pearson's chi-squared test to detect the correlation of initial symptoms, neurological signs, brain magnetic resonance imaging (MRI), electroencephalography (EEG), and increased levels of 14-3-3 protein in cerebrospinal fluid (CSF) analysis. The Cox proportional hazards model was used to detect prognostic factors for early initiation of NG tube insertion in sCJD patients.

Results: The onset age ranged from 51 to 83 years, and mostly ranged from 60 to 79 years. Akinetic mutism was correlated with pyramidal tract signs, myoclonus, and extrapyramidal signs. Furthermore, myoclonus was revealed to be associated with pyramidal tract signs. Multivariate Cox regression analysis showed that myoclonus and elevated CSF levels of 14-3-3 protein are predictive of early NG insertion.

Conclusions: Increased levels of 14-3-3 protein in CSF and the presence of myoclonus at diagnosis are predictive of early swallowing difficulty and indicate rapid deterioration in probable sCJD. In addition to akinetic mutism, early initiation of artificial feeding can be used to predict early deterioration in sCJD.

Quantifying prion disease penetrance using large population control cohorts

More than 100,000 genetic variants are reported to cause Mendelian disease in humans, but the penetrance-the probability that a carrier of the purported disease-causing genotype will indeed develop the disease-is generally unknown. We assess the impact of variants in the prion protein gene (PRNP) on the risk of prion disease by analyzing 16,025 prion disease cases, 60,706 population control exomes, and 531,575 individuals genotyped by 23andMe Inc. We show that missense variants in PRNP previously reported to be pathogenic are at least 30 times more common in the population than expected on the basis of genetic prion disease prevalence. Although some of this excess can be attributed to benign variants falsely assigned as pathogenic, other variants have genuine effects on disease susceptibility but confer lifetime risks ranging from <0.1 to ~100%. We also show that truncating variants in PRNP have position-dependent effects, with true loss-of-function alleles found in healthy older individuals, a finding that supports the safety of therapeutic suppression of prion protein expression.

Specific clinical signs and symptoms are predictive of clinical course in sporadic Creutzfeldt-Jakob disease

Background and purpose

Akinetic mutism is thought to be an appropriate therapeutic end‐point in patients with sporadic Creutzfeldt−Jakob disease (sCJD). However, prognostic factors for akinetic mutism are unclear and clinical signs or symptoms that precede this condition have not been defined. The goal of this study was to identify prognostic factors for akinetic mutism and to clarify the order of clinical sign and symptom development prior to its onset.

Methods

The cumulative incidence of akinetic mutism and other clinical signs and symptoms was estimated based on Japanese CJD surveillance data (455 cases) collected from 2003 to 2008. A proportional hazards model was used to identify prognostic factors for the time to onset of akinetic mutism and other clinical signs and symptoms.

Results

Periodic synchronous discharges on electroencephalography were present in the majority of cases (93.5%). The presence of psychiatric symptoms or cerebellar disturbance at sCJD diagnosis was associated with the development of akinetic mutism [hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.14–1.99, and HR 2.15, 95% CI1.61–2.87, respectively]. The clinical course from cerebellar disturbance to myoclonus or akinetic mutism was classified into three types: (i) direct path, (ii) path via pyramidal or extrapyramidal dysfunction and (iii) path via psychiatric symptoms or visual disturbance.

Conclusions

The presence of psychiatric symptoms or cerebellar disturbance increased the risk of akinetic mutism of sCJD cases with probable MM/MV subtypes. Also, there appear to be sequential associations in the development of certain clinical signs and symptoms of this disease.

Review: Laboratory diagnosis and surveillance of Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease (CJD) is a representative human transmissible spongiform encephalopathy associated with central nervous system degeneration. Prions, the causative agents of CJD, are composed of misfolded prion proteins and are able to self-replicate. While CJD is a rare disease affecting only 1-1.5 people per million worldwide annually, it has attracted both scientific and public attention as a threatening disease since an epidemic of variant CJD (vCJD) cases appeared in the mid-1990s. Due to its unconventional transmission and invariable fatality, CJD poses a serious risk to public health. The hundreds of sporadic, genetic, and iatrogenic CJD cases as well as potential zoonotic transmission suggest that CJD is an ongoing concern for the field of medicine. Nevertheless, treatment aimed at clinical prevention and treatment that reverses the course of disease does not exist currently. Active surveillance and effective laboratory diagnosis of CJD are, therefore, critical. In this report, the surveillance systems and laboratory tests used currently to diagnose CJD in different countries are reviewed. The current efforts to improve surveillance and diagnosis for CJD using molecular and biochemical findings are also described.

Temporal and regional variations in sporadic Creutzfeldt-Jakob disease in Japan, 2001-2010

The objective of this study was to examine temporal and regional variations of sporadic Creutzfeldt-Jakob disease (sCJD) in a retrospective study using Japanese national surveillance data from 2001 to 2010. We calculated the incidence of sCJD by age and sex, derived the standardized incidence in each of the 47 prefectures, and performed spatial disease clustering analysis. The average annual incidence of sCJD was 1.026 per million in men (637 patients) and 1.132 per million in women (733 patients), a significant sex difference after adjustment for age (P = 0.001). The ratios of familial CJD to sCJD apparently increased between 2001-2005 and 2006-2010, possibly as a result of the nationwide introduction of genetic testing after 2006. Based on the data of 2006-2010, certain geographical clusters of sCJD were identified. The incidence of sCJD was higher in several specific prefectures compared to the national average. Thus, sCJD appears to have regional variations, suggesting the existence of genetic or region-specific factors affecting the incidence of the disease.

Prospective 10-year surveillance of human prion diseases in Japan

We analysed the epidemiological data and clinical features of patients with prion diseases that had been registered by the Creutzfeldt-Jakob Disease Surveillance Committee, Japan, over the past 10 years, since 1999. We obtained information on 1685 Japanese patients suspected as having prion diseases and judged that 1222 patients had prion diseases, consisting of definite (n=180, 14.7%) and probable (n=1029, 84.2%) cases, except for dura mater graft-associated Creutzfeldt-Jakob disease which also included possible cases (n=13, 1.1%). They were classified into 922 (75.5%) with sporadic Creutzfeldt-Jakob disease, 216 (17.7%) with genetic prion diseases, 81 (6.6%) with acquired prion diseases, including 80 cases of dura mater graft-associated Creutzfeldt-Jakob disease and one case of variant Creutzfeldt-Jakob disease, and three cases of unclassified Creutzfeldt-Jakob disease (0.2%). The annual incidence rate of prion disease ranged from 0.65 in 1999 to 1.10 in 2006, with an average of 0.85, similar to European countries. Although methionine homozygosity at codon 129 polymorphism of the prion protein gene was reported to be very common (93%) in the general Japanese population, sporadic Creutzfeldt-Jakob disease in Japan was significantly associated with codon 129 homozygosity (97.5%), as reported in western countries. In sporadic Creutzfeldt-Jakob disease, MM1 type (Parchi's classification) is the most common, as in western countries. Among atypical sporadic Creutzfeldt-Jakob disease cases, the MM2 type appeared most common, probably related to the very high proportion of methionine allele in the Japanese population. As for iatrogenic Creutzfeldt-Jakob disease, only dura mater graft-associated Creutzfeldt-Jakob disease cases were reported in Japan and, combined with the data from previous surveillance systems, the total number of dura mater graft-associated Creutzfeldt-Jakob disease was 138, comprising the majority of worldwide dura mater graft-associated Creutzfeldt-Jakob disease patients. Regarding genetic prion diseases, the most common mutation of prion protein gene was V180I (41.2%), followed by P102L (18.1%), E200K (17.1%) and M232R (15.3%), and this distribution was quite different from that in Europe. In particular, V180I and M232R were quite rare mutations worldwide. Patients with V180I or M232R mutations rarely had a family history of prion diseases, indicating that a genetic test for sporadic cases is necessary to distinguish these from sporadic Creutzfeldt-Jakob disease. In conclusion, our prospective 10-year surveillance revealed a frequent occurrence of dura mater graft-associated Creutzfeldt-Jakob disease, and unique phenotypes of sporadic Creutzfeldt-Jakob disease and genetic prion diseases related to the characteristic distribution of prion protein gene mutations and polymorphisms in Japan, compared with those in western countries.

Incidence of Creutzfeldt-Jakob disease in Taiwan: a prospective 10-year surveillance

This study was performed to estimate the incidence of Creutzfeldt-Jakob Disease (CJD) in Taiwan from 1998 to 2007. Suspected cases of CJD were reported to the Taiwan Creutzfeldt-Jakob Disease Surveillance Unit, a nationwide, hospital-based case report system initiated since 1996 to prospectively conduct a CJD epidemiological study. Consecutive patients who met the diagnostic criteria recommended by the World Health Organization were enrolled. The clinical information of each suspected case was collected and case ascertainment was performed by an expert committee. A total of 123 sporadic CJD were identified without any iatrogenic or new variant CJD cases. The overall annual incidence rate (95% CI) was 0.55 (0.46-0.65) cases per million person-year. There was no statistically significant difference between the calendar year of disease onset (P = 0.97). The incidence rates were not significantly different between women and men (P = 0.63). Age was the main factor for the risk of CJD (P < 0.0001). Age-specific incidence rate increased after the age of 40 years with the peak being in the 70-79 years age group. Our data showed low annual incidence rate and high frequency of methionine homozygous prion protein genotype of sCJD in Taiwan. This report provided important epidemiological data on ethnic Chinese.

Geographic difference of mortality of Creutzfeldt-Jakob disease in Japan

BACKGROUND

The geographic mortality difference of Creutzfeldt-Jakob disease is still unclear in Japan.

METHODS

Using vital statistics of Japan for 6 year period between 1999 and 2004 officially published by the government, we observed the mortality from Creutzfeldt-Jakob disease (ICD-10th: A81.0 and A81.8) by prefecture. Standardized mortality ratios were calculated for the 47 prefectures.

RESULTS

For the observed 6 years, a total of 792 deaths from Creutzfeldt-Jakob disease were observed whole in Japan. Two prefectures, Akita and Yamanashi, presented significantly high standardized mortality ratios. In addition, Tochigi, Kochi, and Nagasaki showed standardized mortality rates higher than 1.5 without significance. No prefecture had significantly low standardized mortality ratios.

CONCLUSION

Some prefectures with high mortality rate from Creutzfeldt-Jakob disease existed in Japan. Some of them had high incidence rate in a survey conducted in 1996 as well.

Mortality from human transmissible spongiform encephalopathies: a record linkage study

To evaluate the ability of the Italian Creutzfeldt-Jakob (CJD) register to detect human transmissible spongiform encephalopathy (TSE) cases we compared mortality data from the CJD register with those obtained from death certificates collected by the Italian National Census Bureau (ISTAT) between 1993 and 1999. We used the method of record linkage to compare and integrate data from these two sources. The integrated estimate of TSE deaths was 457: 183 deaths recorded by the CJD register and ISTAT, 210 cases only by the CJD register, and 64 cases only by ISTAT. The average integrated estimated mortality rate was 1.58 deaths per million people per year over the study period and peaked in 1999 at 2.13. This figure is similar to that obtained from data from the CJD register alone in the years 2000-2002. The increase in mortality rates is likely due to an improvement in case ascertainment. The misclassification of cases by ISTAT was above 50% from 1996 onward, suggesting that using only death certificates is not a reliable way to monitor TSE cases in Italy.