Characteristics of Different Types of Prion Diseases - China's Surveillance

A systemic analysis of Creutzfeldt Jakob disease cases in Asia

Creutzfeldt Jakob Disease (CJD) is a rapidly progressive, fatal neurodegenerative disorder, also known as a subacute spongiform encephalopathy. There are three major subtypes of CJD i.e. Sporadic CJD, which occurs for reasons unbeknown to science (85% of known cases), Genetic or Familial CJD which is characterized by the presence of mutations in the human prion protein (PRNP) gene (10-15% cases) and Iatrogenic CJD that occurs via accidental transmission through medical and surgical procedures (1-2% cases). CJD cases occur globally with 1 case per one million population/year. Considerable data is available related to the incidence and prevalence of CJD in Europe and America. However, the global surveillance database is yet to include Asia even though several Asian countries have their own CJD monitoring units. sCJD is the highest among all CJD cases in Asia. China (1957) and Japan (1705) have reported more cases of sCJD than any Asian country and Hong Kong (1) has reported the least. On the other hand, gCJD is highest in Japan (370) and least in India (2). Our analysis establishes the presence of all variants of CJD across Asia. However, in most Asian countries in general and Southeast Asian countries in particular, CJD cases are misdiagnosed and often underreported. Since Asia is the most populated continent in the world, the actual global prevalence of CJD cannot be estimated until and unless these countries are accounted for. Concrete and reliable surveillance networks are needed across Asia to evaluate the prevalence and incidence of CJD in the region. [Figure: see text]The graphical abstract demonstrates the prevalence of CJD cases in the world and systematically analyses the incidence of CJD in Asian countries between the year 1986-2022. Highest number of cases were reported in Japan followed by China. The study emphasizes the need for assimilation of Asian data in global prevalence.

Different reactive profiles of calmodulin in the CSF samples of Chinese patients of four types of genetic prion diseases

Background and purpose

Calmodulin (CaM) levels exhibit significant elevation in the brain tissue of rodent and cell line models infected with prion, as well as in the cerebrospinal fluid (CSF) samples from patients diagnosed with sporadic Creutzfeldt-Jakob disease (sCJD). However, the status of CSF CaM in patients with genetic prion diseases (gPrDs) remains unclear. This study aims to assess the characteristics of CSF CaM in Chinese patients presenting four subtypes of gPrDs.

Methods

A total of 103 CSF samples from patients diagnosed with T188K-gCJD, E200K-gCJD, D178N-FFI, P102L-GSS were included in this study, along with 40 CSF samples from patients with non-prion diseases (non-PrDs). The presence of CSF CaM and 14-3-3 proteins was assessed using Western blots analysis, while levels of CSF 14-3-3 and total tau were measured using enzyme-linked immunosorbent assays (ELISAs). Statistical methods including multivariate logistic regression were employed to evaluate the association between CSF CaM positivity and relevant clinical, laboratory, and genetic factors.

Results

The positive rates of CSF CaM were significantly higher in cases of T188K-gCJD (77.1%), E200K-gCJD (86.0%), and P102-GSS (90.9%) compared to non-PrD cases (22.5%). In contrast, CSF CaM positivity was slightly elevated in D178N-FFI (34.3%). CSF CaM positivity was remarkably high in patients who tested positive for CSF 14-3-3 by Western blot and exhibited high levels of total tau (≥1400 pg/ml) as measures by ELISA. Multivariate logistic regression analysis confirmed a significant association between CSF CaM positivity and specific mutations in PRNP, as well as with CSF 14-3-3 positivity. Furthermore, the diagnostic performance of CaM surpassed that of 14-3-3 and tau when analyzing CSF samples from T188K-gCJD and E200K-gCJD patients.

Conclusion

Western blot analysis reveals significant variations in the positivity of CSF CaM among the four genotypes of gPrD cases, demonstrating a positive correlation with 14-3-3 positivity and elevated tau levels in CSF.

Two Chinese patients of sporadic Creutzfeldt-Jacob disease with a S97N mutation in PRNP gene

Worldwide, 10-15% human prion disease are genetic and inherited, due to the special mutations or insertions in PRNP gene. Herein, we reported two Chinese patients with rapidly progressive dementia who were referred to the national Creutzfeldt-Jacob disease (CJD) surveillance as suspected CJD. Those two patients displayed sporadic CJD (sCJD)-like clinical phenotype, e.g. rapidly progressive dementia, visional and mental problems, sCJD-associated abnormalities in MRI. A missense mutation was identified in one PRNP allele of these two patients, resulting in a change from serine to asparagine at codon 97 (S97N). RT-QuIC of the cerebrospinal fluid samples from those two cases were positive. It indicates that they are very likely to be prion disease.

Geographic Diversity in the Incidence of Human Prion Diseases - China, 2006-2019

Introduction

Human prion diseases (PrDs) are rare, fatal encephalopathies requiring comprehensive diagnostic analysis. This study examines hospital referral patterns to the Chinese National Surveillance for Creutzfeldt-Jakob Disease (CNS-CJD) from 2006 to 2019.

Methods

We assessed 1,970 PrD cases referred by various hospitals to CNS-CJD. Referral distributions were analyzed based on provincial-level administrative divisions (PLADs). Differences in referral numbers and confirmed cases between monitored and non-monitored PLADs were statistically evaluated.

Results

The study included cases from 344 hospitals across 29 Chinese PLADs. Hospital referrals increased over the surveillance years: from 28.2 hospitals annually during 2006-2010, to 64 in 2011-2015, and 107 in 2016-2019. Of these, 12.2% (42/344) of hospitals reported ≥10 PrD cases, accounting for 70.0% (1,379/1,970) of total cases. Referral numbers varied across PLADs, with the top 5 of Beijing (41), Henan (26), Shanghai (21), Guangdong (21), and Jiangsu (21) leading. Additionally, 12 CJD-surveillance PLADs had more referring hospitals and PrD cases than the other 17 non-surveillance PLADs.

Conclusions

Geographical variations in PrD recognition exist across Chinese PLADs, with certain regions and major cities reporting notably higher case numbers.