Clinical and differential diagnosis of Creutzfeldt-Jakob disease

Overview and evaluation of 15 years of Creutzfeldt-Jakob disease surveillance in Belgium, 1998-2012

Background

In 1998, following the detection of variant Creutzfeldt-Jakob disease (vCJD) in the UK, Belgium installed a surveillance system for Creutzfeldt-Jakob disease (CJD). The objectives of this system were to identify vCJD cases and detect increases in CJD incidence. Diagnostic confirmation of CJD is based on autopsy after referral by neurologists. Reference centres perform autopsies and report to the surveillance system. The aim of this study was to assess whether the system met its objectives and to assess its acceptability.

Methods

For 1999–2010, we linked surveillance data with hospital discharge data. We calculated the proportion of CJD suspected patients who died in hospitals and were captured by the surveillance system. We surveyed stakeholders on knowledge of the surveillance system, referral practices and acceptability. We compared proportions using the chi-square test and investigated variables associated with capture using a multivariable logistic regression model.

Results

On average 60 % of hospitalised patients who died with suspected CJD were captured by the surveillance system. This proportion did not significantly differ over the years (p = 0.1). The odds of capture significantly decreased with every 1 year increase in age (OR = 0.95, 95 % CI 0.92–0.98, p = 0.001). Eleven percent of surveyed neurologists would not refer suspect vCJD cases for autopsy, nor contact a reference centre for diagnostic support. Sixty-one percent of surveyed neurologists were not familiar with the surveillance system. Awareness of the existence of the system did not impact referral behaviour (p = 0.18). CJD and vCJD surveillance were considered important by the majority of stakeholders.

Conclusions

Although 40 % of the suspect CJD cases were not referred for autopsy, our data suggest that the Belgian CJD surveillance system meets one of its main objectives: it can detect changes in CJD incidence. However, we do not have sufficient evidence to conclude that the system meets its second objective of detecting vCJD cases arising in Belgium. Although not well known, the system was considered acceptable by its stakeholders.

The Levels of Tau Isoforms Containing Exon-2 and Exon-10 Segments Increased in the Cerebrospinal Fluids of the Patients with Sporadic Creutzfeldt-Jakob Disease

The alteration of protein tau in the cerebrospinal fluid (CSF) of Creutzfeldt-Jakob disease (CJD) has been widely evaluated, possessing a significant diagnostic value for CJD. With the biotin-labeled tau-exon-specific mAbs, direct ELISA methods were established and the levels of tau isoforms containing exon-2 and exon-10 segments in CSF of the patients with various human prion diseases and in brain tissues of scrapie-infected animals were evaluated. The results showed that the levels of tau, especially containing four repeats in microtubule binding domain, were increased in the CSF samples of the patients with sporadic CJD (sCJD). Using the unlabeled (cold) mixed exon-specific mAbs, a competitive tau ELISA was conducted based on a commercial tau kit. It revealed that the majority of the increased tau in the CSF of sCJD cases was derived from the tau isoforms with exon-2 and exon-10 segments. Increases of CSF tau isoforms with exon-2 and exon-10 segments were also observed in the patients of E200K and T188K genetic CJD (gCJD), but not in the cases of fatal familiar insomnia (FFI). The increasing levels of tau isoforms with exon-2 and exon-10 segments in the group of sCJD correlated well with the positive 14-3-3 in CSF. Additionally, the similar alterative profiles of tau isoforms with exon-2 and exon-10 segments were also observed in the brain tissues of scrapie-infected rodents and a sCJD patient. Our data here propose the tau isoforms with exon-2 and exon-10 segments increase in CSF of sCJD and some types of gCJD, which may help to understand the physiological metabolism and pathological significance of various tau isoforms in the pathogenesis of prion diseases.

Surveillance for Creutzfeldt-Jakob disease in China from 2006 to 2007

Background

Human transmissible spongiform encephalopathies (HTSE), or Creutzfeldt-Jakob disease (CJD), is a group of rare and fatal diseases in central nervous system. Since outbreak of bovine spongiform encephalopathy (BSE) and variant CJD, a worldwide CJD surveillance network has been established under the proposition of WHO. In China, a national CJD surveillance system has started since 2002. The data of CJD surveillance from 2006 to 2007 was analyzed.

Methods

Total 12 provinces are included in CJD surveillance system. The surveillance unit in each province consists of one or two sentinel hospitals and the provincial CDC. All suspected CJD cases reported from CJD surveillance were diagnosed and subtyped based on the diagnostic criteria for CJD issued by WHO.

Results

Total 192 suspected CJD cases were reported and 5 genetic CJD, 51 probable and 30 possible sporadic CJD (sCJD) cases were diagnosed. The collected sCJD cases distribute sporadically without geographical clustering and seasonal relativity and the highest incidences in both probable and possible sCJD cases appeared in the group of 60–69 year. The most common three foremost symptoms were progressive dementia, cerebellum and mental-related symptoms. The probable sCJD patients owning both typical EEG alteration and CSF protein 14-3-3 positive have more characteristic clinical syndromes than the ones having only one positive. The polymorphisms of codon 129 of all tested reported cases shows typical patterns of Han Chinese as previous reports, that M129M are predominant whereas M129V are seldom.

Conclusion

Chinese CJD patients possessed similar epidemiological and clinical characteristics as worldwide.