Prion seeding activity and infectivity in skin samples from patients with sporadic Creutzfeldt-Jakob disease.

Sporadic Creutzfeldt-Jakob disease (sCJD), the most common human prion disease, is transmissible through iatrogenic routes due to abundant infectious prions [misfolded forms of the prion protein (PrPSc)] in the central nervous system (CNS). Some epidemiological studies have associated sCJD risk with non-CNS surgeries. We explored the potential prion seeding activity and infectivity of skin from sCJD patients. Autopsy or biopsy skin samples from 38 patients [21 sCJD, 2 variant CJD (vCJD), and 15 non-CJD] were analyzed by Western blotting and real-time quaking-induced conversion (RT-QuIC) for PrPSc Skin samples from two patients were further examined for prion infectivity by bioassay using two lines of humanized transgenic mice. Western blotting revealed dermal PrPSc in one of five deceased sCJD patients and one of two vCJD patients. However, the more sensitive RT-QuIC assay detected prion seeding activity in skin from all 23 CJD decedents but not in skin from any non-CJD control individuals (with other neurological conditions or other diseases) during blinded testing. Although sCJD patient skin contained ~103- to 105-fold lower prion seeding activity than did sCJD patient brain tissue, all 12 mice from two transgenic mouse lines inoculated with sCJD skin homogenates from two sCJD patients succumbed to prion disease within 564 days after inoculation. Our study demonstrates that the skin of sCJD patients contains both prion seeding activity and infectivity, which raises concerns about the potential for iatrogenic sCJD transmission via skin.

Infectivity in bone marrow from sporadic CJD patients.

Prion infectivity was recently identified in the blood of both sporadic and variant Creutzfeldt-Jakob disease (CJD) patients. In variant CJD (vCJD), the widespread distribution of prions in peripheral tissues of both asymptomatic and symptomatic patients is likely to explain the occurrence of the observed prionaemia. However, in sporadic CJD (sCJD), prion infectivity is described to be located principally in the central nervous system. In this study, we investigated the presence of prion infectivity in bone marrow collected after death in patients affected with different sCJD agents. Bioassays in transgenic mice expressing the human prion protein revealed the presence of unexpectedly high levels of infectivity in the bone marrow from seven out of eight sCJD cases. These findings may explain the presence of blood-borne infectivity in sCJD patients. They also suggest that the distribution of prion infectivity in peripheral tissues in sCJD patients could be wider than currently believed, with potential implications for the iatrogenic transmission risk of this disease. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pathogen reduction/inactivation of products for the treatment of bleeding disorders: what are the processes and what should we say to patients?

Patients with blood disorders (including leukaemia, platelet function disorders and coagulation factor deficiencies) or acute bleeding receive blood-derived products, such as red blood cells, platelet concentrates and plasma-derived products. Although the risk of pathogen contamination of blood products has fallen considerably over the past three decades, contamination is still a topic of concern. In order to counsel patients and obtain informed consent before transfusion, physicians are required to keep up to date with current knowledge on residual risk of pathogen transmission and methods of pathogen removal/inactivation. Here, we describe pathogens relevant to transfusion of blood products and discuss contemporary pathogen removal/inactivation procedures, as well as the potential risks associated with these products: the risk of contamination by infectious agents varies according to blood product/region, and there is a fine line between adequate inactivation and functional impairment of the product. The cost implications of implementing pathogen inactivation technology are also considered.

Distribution and Quantitative Estimates of Variant Creutzfeldt-Jakob Disease Prions in Tissues of Clinical and Asymptomatic Patients.

In the United-Kingdom, ≈1 of 2,000 persons could be infected with variant Creutzfeldt-Jakob disease (vCJD). Therefore, risk of transmission of vCJD by medical procedures remains a major concern for public health authorities. In this study, we used in vitro amplification of prions by protein misfolding cyclic amplification (PMCA) to estimate distribution and level of the vCJD agent in 21 tissues from 4 patients who died of clinical vCJD and from 1 asymptomatic person with vCJD. PMCA identified major levels of vCJD prions in a range of tissues, including liver, salivary gland, kidney, lung, and bone marrow. Bioassays confirmed that the quantitative estimate of levels of vCJD prion accumulation provided by PMCA are indicative of vCJD infectivity levels in tissues. Findings provide critical data for the design of measures to minimize risk for iatrogenic transmission of vCJD.

Endocrine mucin-producing sweat gland carcinoma: report of two cases of an under-recognized malignant neoplasm and review of the literature.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare low-grade sweat gland carcinoma with a strong predilection to the eyelid region. It is histologically analogous to endocrine ductal carcinoma/solid papillary carcinoma of the breast and is characterized by a multinodular solid cystic mucinous tumor with immunoreactivity to neuroendocrine markers. Only 20 cases of this unusual tumor have been reported. We present the clinical and histopathologic findings of 2 new cases of EMPSGC and review the relevant literature. The histological differential diagnosis is discussed and attention drawn to the role of immunohistochemistry in clarifying the nosological position of EMPSGC within the spectrum of cutaneous mucinous neoplasms.

MM2 subtype of sporadic Creutzfeldt-Jakob disease may underlie the clinical presentation of progressive supranuclear palsy.

The classical presentation of sporadic Creutzfeldt-Jakob disease (sCJD) is rapid progressive dementia often associated with myoclonus and ataxia followed by death in less than a year from diagnosis. The few patients in the literature who presented with parkinsonism and who were suspected to have progressive supranuclear palsy (PSP) all ran a malignant course and most of them died within 3 years of diagnosis. We screened the Queen Square Brain Bank database and, among 213 patients with a clinical diagnosis of PSP, we found ten patients with 3 years or less disease duration, including one patient with CJD pathology. We report this patient and review other similar cases from the literature. Ten additional cases with similar presentation were identified in the literature. The mean disease duration was 24.2 months. The classical clinical, radiological and laboratory findings for sCJD were absent in the majority of these cases. Clinical presentation of these patients consists of: early falls, prominent dementia, early vertical supranuclear gaze palsy and symmetric akinetic syndrome. In the patients who were subtyped at post-mortem, all four represented the MM2 subtype of sCJD. A rapidly progressive course of PSP with early falls, cognitive impairments and vertical supranuclear gaze palsy should raise suspicion of underlying sCJD pathology regardless of absence of supportive findings on ancillary tests. This case and the literature support the notion that biochemical properties of the prion protein can influence the clinical presentation of sCJD.

Bilateral non-contiguous atypical papillary glioneuronal tumor: case report.

Papillary glioneuronal tumor (PGNT) was first described as a distinct clinic-pathological entity by Komori et al. in 1998. Since then it has been included as a mixed neuronal-glial tumor in the revised WHO (2007) classification of central nervous system tumors. On brain imaging, it appears as a demarcated, solid to cystic, contrast-enhancing mass usually located in the temporal lobe. Histologically, it is considered a biphasic tumor characterized by small cuboidal GFAP-positive astrocytes around hyalinised blood vessels and synaptophysin-positive interpapillary collections of neurocytes, large neurons and intermediate-sized "ganglioid cells". Although they are generally regarded as benign WHO Grade I tumors, recent reports have described more pathologically aggressive features. To date, these reports have all been single lesions.

Heparin enhances the cell-protein misfolding cyclic amplification efficiency of variant Creutzfeldt-Jakob disease.

Highly sensitive in vitro screening tests are required to prevent the iatrogenic spread of variant Creutzfeldt-Jakob disease (vCJD). Protein misfolding cyclic amplification (PMCA) is a candidate for such a test, but the sensitivity of this method is insufficient. Polyanions were reported to enhance PMCA efficiency, but their effects on vCJD are unclear. We developed a cell-PMCA of vCJD, wherein cell lysate containing exogenously expressed human PrP was used as substrates, to investigate the effects of various sulfated polysaccharides on amplification efficiency. PrP(res) amounts after cell-PMCA were analyzed by western blotting. Heparin, dermatan sulfate, and dextran sulfate (average molecular weight [MW] 1400kDa) enhanced efficiency, but dextran sulfate (average MW 8kDa) and a heparin pentasaccharide analog had no effect. Pentosan polysulfate inhibited cell-PMCA reaction. The amplification efficiency of cell-PMCA of vCJD increased to >100-fold per round with heparin. The enhancing effects of heparin on cell-PMCA were seed dependent: it was high for vCJD, low for sporadic Creutzfeldt-Jakob disease, and low to negligible for hamster-adapted scrapie-derived 263K. In multi-round PMCA, signals were detected at earlier rounds with heparin than without heparin, and PrP(Sc) in 10(-10) diluted vCJD brain was detected by the sixth round. Heparin-assisted cell-PMCA of vCJD represents a significant step toward detecting very minute amounts of PrP(Sc) in the body fluids of asymptomatic vCJD patients.

Effect of fixation on brain and lymphoreticular vCJD prions and bioassay of key positive specimens from a retrospective vCJD prevalence study.

Anonymous screening of lymphoreticular tissues removed during routine surgery has been applied to estimate the UK population prevalence of asymptomatic vCJD prion infection. The retrospective study of Hilton et al (J Pathol 2004; 203: 733-739) found accumulation of abnormal prion protein in three formalin-fixed appendix specimens. This led to an estimated UK prevalence of vCJD infection of ∼1 in 4000, which remains the key evidence supporting current risk reduction measures to reduce iatrogenic transmission of vCJD prions in the UK. Confirmatory testing of these positives has been hampered by the inability to perform immunoblotting of formalin-fixed tissue. Animal transmission studies offer the potential for 'gold standard' confirmatory testing but are limited by both transmission barrier effects and known effects of fixation on scrapie prion titre in experimental models. Here we report the effects of fixation on brain and lymphoreticular human vCJD prions and comparative bioassay of two of the three prevalence study formalin-fixed, paraffin-embedded (FFPE) appendix specimens using transgenic mice expressing human prion protein (PrP). While transgenic mice expressing human PrP 129M readily reported vCJD prion infection after inoculation with frozen vCJD brain or appendix, and also FFPE vCJD brain, no infectivity was detected in FFPE vCJD spleen. No prion transmission was observed from either of the FFPE appendix specimens. The absence of detectable infectivity in fixed, known positive vCJD lymphoreticular tissue precludes interpreting negative transmissions from vCJD prevalence study appendix specimens. In this context, the Hilton et al study should continue to inform risk assessment pending the outcome of larger-scale studies on discarded surgical tissues and autopsy samples.

Biological effects and use of PrPSc- and PrP-specific antibodies generated by immunization with purified full-length native mouse prions.

The prion agent is the infectious particle causing spongiform encephalopathies in animals and humans and is thought to consist of an altered conformation (PrP(Sc)) of the normal and ubiquitous prion protein PrP(C). The interaction of the prion agent with the immune system, particularly the humoral immune response, has remained unresolved. Here we investigated the immunogenicity of full-length native and infectious prions, as well as the specific biological effects of the resulting monoclonal antibodies (MAbs) on the binding and clearance of prions in cell culture and in in vivo therapy. Immunization of prion knockout (Prnp(0/0)) mice with phosphotungstic acid-purified mouse prions resulted in PrP-specific monoclonal antibodies with binding specificities selective for PrP(Sc) or for both PrP(C) and PrP(Sc). PrP(Sc)-specific MAb W261, of the IgG1 isotype, reacted with prions from mice, sheep with scrapie, deer with chronic wasting disease (CWD), and humans with sporadic and variant Creutzfeldt-Jakob disease (CJD) in assays including a capture enzyme-linked immunosorbent assay (ELISA) system. This PrP(Sc)-specific antibody was unable to clear prions from mouse neuroblastoma cells (ScN2a) permanently infected with scrapie, whereas the high-affinity MAb W226, recognizing both isoforms, PrP(Sc) and PrP(C), did clear prions from ScN2a cells, as determined by a bioassay. However, an attempt to treat intraperitoneally prion infected mice with full-length W226 or with a recombinant variable-chain fragment (scFv) from W226 could only slightly delay the incubation time. We conclude that (i) native, full-length PrP(Sc) elicits a prion-specific antibody response in PrP knockout mice, (ii) a PrP(Sc)-specific antibody had no prion-clearing effect, and (iii) even a high-affinity MAb that clears prions in vitro (W226) may not necessarily protect against prion infection, contrary to previous reports using different antibodies.

Glioblastoma-derived spheroid cultures as an experimental model for analysis of EGFR anomalies.

Glioblastoma cell cultures in vitro are frequently used for investigations on the biology of tumors or new therapeutic approaches. Recent reports have emphasized the importance of cell culture type for maintenance of tumor original features. Nevertheless, the ability of GBM cells to preserve EGFR overdosage in vitro remains controversial. Our experimental approach was based on quantitative analysis of EGFR gene dosage in vitro both at DNA and mRNA level. Real-time PCR data were verified with a FISH method allowing for a distinction between EGFR amplification and polysomy 7. We demonstrated that EGFR amplification accompanied by EGFRwt overexpression was maintained in spheroids, but these phenomena were gradually lost in adherent culture. We noticed a rapid decrease of EGFR overdosage already at the initial stage of cell culture establishment. In contrast to EGFR amplification, the maintenance of polysomy 7 resulted in EGFR locus gain and stabilization even in long-term adherent culture in serum presence. Surprisingly, the EGFRwt expression pattern did not reflect the latter phenomenon and we observed no overexpression of the tested gene. Moreover, quantitative analysis demonstrated that expression of the truncated variant of receptor-EGFRvIII was preserved in GBM-derived spheroids at a level comparable to the initial tumor tissue. Our findings are especially important in the light of research using glioblastoma culture as the experimental model for testing novel EGFR-targeted therapeutics in vitro, with special emphasis on the most common mutated form of receptor-EGFRvIII.

A multivariate analysis of factors determining tumor progression in childhood low-grade glioma: a population-based cohort study (CCLG CNS9702).

The purpose of this study was to identify risk factors for the progression of low-grade glioma in children from a large population-based cohort. Patient and tumor details of a national cohort of children with low-grade glioma, recruited into an international multidisciplinary clinical strategy, were subjected to univariate and multivariate analyses of progression-free survival and overall survival. From the cohort of 798 patients, 639 patients were eligible, with a median age 6.71 years (0.26-16.75 years); 49% were males; 15.9% had neurofibromatosis type 1, 63.7% pilocytic astrocytoma, 5.9% fibrillary astrocytoma, 4.2% mixed neuronal-glial tumors, and 3.6% others; 21.1% were diagnosed clinically. Anatomically implicated were 31.6% cerebellum, 24.6% chiasma/hypothalamus, 16.0% cerebral hemispheres, 9.9% brain stem, 6.1% other supratentorial midline structures, 5.9% optic nerve only, 4.5% spinal cord, and 1.4% others. The 5-year overall survival and progression-free survival in the whole cohort were 94.6% and 69.4%, respectively. There was a significant association between age and site (P < .001) and extent of tumor resection and site (P < .001). Multivariate analysis identified young age, fibrillary astrocytoma, and extent of surgical resection as significant independent risk factors for progression. Hypothalamic/chiasmatic tumors demonstrated the most sustained tendency to progress. In conclusion, the influence of age and anatomical site upon the risk of tumor progression suggests that these factors strongly influence tumor behavior for the majority of pilocytic tumors. Age <1 year and 1-5 years, fibrillary histology, completeness of resection, and chiasmatic location are candidates for stratification in future studies.

Two cases of recurrent stroke in treated giant cell arteritis: diagnostic and therapeutic dilemmas.

It is not established whether the increased risk of stroke in patients with giant cell arteritis (GCA) is because of atherosclerosis, persistent arterial inflammation, or an iatrogenic effect of corticosteroids. This creates difficulties in choosing the most appropriate treatment. We report 2 patients with GCA who developed repeated strokes involving different arterial territories following initiation of corticosteroid therapy, despite resolution of cranial symptoms and normalization of inflammatory markers. Subsequent investigation suggested persisting arteritis as the cause of these strokes. The cases revealed the limitations of laboratory tests or imaging techniques in determining the cause of stroke in recently diagnosed GCA. There is a need to develop effective means of monitoring GCA activity and to determine the most effective treatment approach in this circumstance.

Validation of diagnostic criteria for variant Creutzfeldt-Jakob disease.

OBJECTIVE: Variant Creutzfeldt-Jakob disease (vCJD), a novel form of human prion disease, was recognized in 1996. The disease affected a younger cohort than sporadic CJD, and the early clinical course was dominated by psychiatric and sensory symptoms. In an attempt to aid diagnosis and establish standardization between surveillance networks, diagnostic criteria were established. These were devised from the features of a small number of cases and modified in 2000 as the clinical phenotype was established. Since then, only minor changes have been introduced; revalidation of the criteria in the current format is overdue. METHODS: Included in this study are autopsy/cerebral biopsy-proven cases of vCJD referred to the National CJD Surveillance Unit (NCJDSU) between 1995 and 2004 and suspect cases in which an alternative diagnosis was identified following autopsy/cerebral biopsy. RESULTS: Over the 10-year period, 106 definite cases of vCJD and 45 pathologically confirmed "noncases" were identified from the archives of the NCJDSU. The median age at onset of the cases was significantly younger than that of the noncases (27 years [range, 12-74 years] vs 43 years [range, 10-64 years]), and the median duration of illness was significantly shorter (14 months [range, 6-39 months] vs 22 months [range, 2-139 months]). The most commonly identified core clinical feature in cases was dementia; persistent painful sensory symptoms were the least frequent. Eighty-eight of 106 (83%) vCJD cases were retrospectively classified as probable in life, 6 cases were classified as possible. Most cases were classified as probable on the basis of core clinical features and brain magnetic resonance imaging. To date, the diagnostic criteria remain 100% specific, with no autopsy/cerebral biopsy-proven noncases classified as probable in life. INTERPRETATION: This study confirms that the diagnostic criteria for vCJD are sensitive and specific and provide a useful standard framework for case classification in a surveillance setting.

Application of Atomic Dielectric Resonance Spectroscopy for the screening of blood samples from patients with clinical variant and sporadic CJD.

BACKGROUND: Sub-clinical variant Creutzfeldt-Jakob disease (vCJD) infection and reports of vCJD transmission through blood transfusion emphasise the need for blood screening assays to ensure the safety of blood and transplanted tissues. Most assays aim to detect abnormal prion protein (PrPSc), although achieving required sensitivity is a challenge. METHODS: We have used innovative Atomic Dielectric Resonance Spectroscopy (ADRS), which determines dielectric properties of materials which are established by reflectivity and penetration of radio/micro waves, to analyse blood samples from patients and controls to identify characteristic ADR signatures unique to blood from vCJD and to sCJD patients. Initial sets of blood samples from vCJD, sCJD, non-CJD neurological diseases and normal healthy adults (blood donors) were screened as training samples to determine group-specific ADR characteristics, and provided a basis for classification of blinded sets of samples. RESULTS: Blood sample groups from vCJD, sCJD, non-CJD neurological diseases and normal healthy adults (blood donors) screened by ADRS were classified with 100% specificity and sensitivity, discriminating these by a co-variance expert analysis system. CONCLUSION: ADRS appears capable of recognising and discriminating serum samples from vCJD, sCJD, non-CJD neurological diseases, and normal healthy adults, and might be developed to provide a system for primary screening or confirmatory assay complementary to other screening systems.

Nodule formation and desmoplasia in medulloblastomas-defining the nodular/desmoplastic variant and its biological behavior.

Among the variants of medulloblastoma in the current WHO classification of nervous system tumors, the desmoplastic variant, which has been reported to constitute 5%-25% of pediatric medulloblastomas, is defined by its nodular collections of neurocytic cells bounded by desmoplastic internodular zones. We have studied the frequency, morphological features and biological behavior of medulloblastomas in two contemporaneous SIOP/UKCCSG trial cohorts of children with medulloblastomas, CNS9102 (n = 315) and CNS9204 (n = 35), focusing on tumors with nodular and desmoplastic phenotypes. In children aged 3-16 years (CNS9102), the nodular/desmoplastic medulloblastoma represented 5% of all tumors, while in infants aged <3 years (CNS9204) this variant represented 57% of medulloblastomas. Using iFISH to detect molecular cytogenetic abnormalities in medulloblastomas with a nodular architecture, we demonstrated distinct genetic profiles in desmoplastic and non-desmoplastic (classic and anaplastic) tumors; in particular, abnormalities of chromosome 17 occurred in the latter, but not the former. Significantly different outcomes were demonstrated for classic, nodular/desmoplastic and large cell/anaplastic medulloblastomas in both cohorts. In conclusion, the nodular/desmoplastic medulloblastoma appears to have clinical, genetic and biological characteristics that set it apart from other variants of this tumor.

Abnormal prion protein in the pituitary in sporadic and variant Creutzfeldt-Jakob disease.

By using high-sensitivity Western blotting and immunohistochemistry, pituitary glands from patients with sporadic and variant Creutzfeldt-Jakob disease (sCJD and vCJD, respectively) were analysed for the presence of the protease-resistant form of the prion protein (PrPres). PrPres was detected in a greater proportion of vCJD pituitaries than sCJD pituitaries and was localized predominantly in the neurohypophysis. PrPres was also detected in a recurrent pituitary adenoma from an sCJD patient. Immunohistochemical analysis showed sparse positive labelling, predominantly in folliculostellate cells, in vCJD and sCJD adenohypophyses. The PrPres glycosylation pattern in the vCJD neurohypophyses showed a predominance of the unglycosylated band, which differed markedly from patterns found in all other vCJD tissues. The presence of PrPres in the pituitary of CJD patients at autopsy suggests that human growth hormone-related iatrogenic CJD may have indeed resulted from infectivity in collected pituitaries rather than necessarily from contamination of pituitary pools by adjacent brain tissue.

Transplantation of ocular tissue from a donor with sporadic Creutzfeldt-Jakob disease.

BACKGROUND: One definite, one probable and several possible transmissions of sporadic Creutzfeldt-Jakob disease (sCJD) have followed corneal transplantation. We report an incident in the UK in 1997 in which both corneas and scleras from a donor, subsequently confirmed to have had sCJD, were transplanted. The final clinical outcome for two surviving recipients is still not yet known. CASE REPORT: In 1997, a 56-year-old woman died from biopsy-proven carcinoma of the bronchus. Both eyes were donated for transplantation. Shortly before she died, she had developed neurological symptoms thought to be due to brain metastases. However, the final result of a neurological post-mortem examination revealed evidence of sCJD. By this time the corneas had been transplanted, one 3 months previously into a 40-year-old man for keratoconus and the other 4 months previously into an 85-year-old woman for Fuchs' dystrophy. In addition, both scleras had been transplanted into a 36-year-old man undergoing oculoplastic reconstructive surgery. The surgeons and patients were informed and removal of tissue was advised but undertaken in only two of the patients. Immunohistochemistry failed to demonstrate the presence of the abnormal form of the prion protein in explanted tissue. CONCLUSIONS: Eight years after the event, two patients remain free of symptoms suggestive of iatrogenic CJD (http://www.cjd.ed.ac.uk/criteria.htm). The third having died aged 92 years, some 7 years after surgery, showing signs of dementia not considered indicative of iatrogenic CJD. Nevertheless this adverse incident attracted substantial publicity. Coupled with continuing concerns in the UK about person-to-person transmission of variant CJD, this has lead to a number of important consequences in donor eye retrieval, ocular tissue banking and transplantation.

Variant Creutzfeldt-Jakob disease: prion protein genotype analysis of positive appendix tissue samples from a retrospective prevalence study.

OBJECTIVE: To perform prion protein gene (PRNP) codon 129 analysis in DNA extracted from appendix tissue samples that had tested positive for disease associated prion protein. DESIGN: Reanalysis of positive cases identified in a retrospective anonymised unlinked prevalence study of variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom. STUDY SAMPLES: Three positive appendix tissue samples out of 12,674 samples of appendix and tonsil tested for disease associated prion protein. The patients from whom these samples were obtained were aged 20-29 years at the time of surgery, which took place in 1996-9. SETTING: Pathology departments in two tertiary centres in England and Scotland. RESULTS: Adequate DNA was available for analysis in two of the three specimens, both of which were homozygous for valine at codon 129 in the PRNP. CONCLUSIONS: This is the first indication that the valine homozygous subgroup at codon 129 in the PRNP is susceptible to vCJD infection. All tested clinical cases of vCJD have so far occurred in the methionine homozygous subgroup, and a single case of probable iatrogenic vCJD infection has been identified in one patient who was a methionine/valine heterozygote at this genetic locus. People infected with vCJD with a valine homozygous codon 129 PRNP genotype may have a prolonged incubation period, during which horizontal spread of the infection could occur either from blood donations or from contaminated surgical instruments used on these individuals during the asymptomatic phase of the illness.