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From: TSS ()
Title: ABNORMAL PRION ACCUMULATION ASSOCIATED WITH RETINAL PATHOLOGY IN EXPERIMENTALLY INOCULATED SCRAPIE-AFFECTED SHEEP Greenlee, Justin Interpretive Summary: Scrapie is a naturally occurring fatal disease of sheep and goats affecting the nervous system. After infection, the scrapie agent is known to accumulate in the brain, lymph nodes, and retina, the specialized sensory structure lining the inside of the eye. All current methods of diagnosis for scrapie and related diseases require collection of brain tissue after death of the animal. This study uses special staining techniques to show that accumulation of the agent causing scrapie in sheep is associated with pathology in the retina. When small amounts of the agent causing scrapie were present in multiple, small areas of the retina, there was moderate positive staining to indicate cell injury. In eyes (retinae) with large amounts of agent present, staining to indicate damage to retinal cells was very abundant and spread throughout the entire retina. The inoculated animals were not examined for vision deficits, but the extent of special staining of damaged cells suggests that there may be functional deficits that could be measured possibly leading to new methods of disease diagnosis in live animals. Results of this study will have a possible impact on directing future research on live animal diagnostic methods for transmissible spongiform encephalopathies. http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=180675 Vet Pathol 43:733-739 (2006) Abnormal Prion Accumulation Associated with Retinal Pathology in Experimentally Inoculated Scrapie-Affected Sheep The purpose of this study was to characterize the patterns of PrPSc immunoreactivity in the retinae of scrapie-affected sheep and to determine the extent of retinal pathology as indicated by glial fibrillary acidic protein immunoreactivity (GFAP-IR) of Müller glia. Sections from the retina of 13 experimentally inoculated scrapie-affected and 2 negative control sheep were examined with immunohistochemical staining for PrPSc, GFAP, and PrPSc/GFAP double staining. GFAP-IR of Müller glia is suggestive of retinal pathology in the absence of morphologic abnormality detected by light microscopy. Sheep with the least amount of PrPSc in the retina have multifocal punctate aggregates of prion staining in the outer half of the inner plexiform layer and rarely in the outer plexiform layer. In these retinae, GFAP-IR is not localized with prion accumulation, but rather is present in moderate numbers of Müller glia throughout the sections of retina examined. The majority of sheep with retinal accumulation of PrPSc have intense, diffuse PrPSc staining in both plexiform layers, with immunoreactivity in the cytoplasm of multiple ganglion cells and lesser amounts in the optic fiber layer and between nuclei in nuclear layers. This intense PrPSc immunoreactivity is associated with diffuse, intense GFAP-IR that extends from the inner limiting membrane to the outer limiting membrane. This is the first report of a prion disease in a natural host that describes the accumulation of PrPSc in retina associated with retinal pathology in the absence of overt morphologic changes indicative of retinal degeneration. -------------------------------------------------------------------------------- Key words: Glial fibrillary acidic protein; immunohistochemistry; prion diseases; retina; scrapie; sheep; spongiform encephalopathy. Request reprints from Dr. J J Greenlee, National Animal Disease Center, 2300 Dayton Ave., Ames, IA 50010 http://www.vetpathology.org/cgi/content/abstract/43/5/733 Subject: CJD SURGICAL INCIDENT REPORTING FORM UPDATE NOVEMBER 2006 snip... Please tick Please circle or underline where appropriate CNS / Spinal cord 8. How many instruments were used, and what were they? (Please continue overleaf or attach details if necessary) (e.g. all / some / none / disposable / don?t know) (e.g. all are quarantined / some are quarantined / none are quarantined / not applicable/ don?t know) http://www.hpa.org.uk/infections/topics_az/cjd/SI_formNov06.doc http://brain.hastypastry.net/forums/showthread.php?t=4807 USA CJD QUESTIONNAIRE http://brain.hastypastry.net/forums/showthread.php?referrerid=38487&t=2408 4 May 2004 Creutzfeldt-Jakob Disease (CJD) and Ophthalmology* snip... Patients with classical (sporadic) CJD are predominantly in their 60s and as such may come into contact with ophthalmologists because of cataract, glaucoma and macular degeneration, or because of visual symptoms caused by their condition5. Although there is no clear evidence of the transmission of spongiform encephalopathy from one patient to another by ophthalmic surgery other than through corneal transplantation6, it has been accepted for many years that instruments used on patients with known or suspected CJD undergoing any surgical procedure, should be destroyed7. snip... 5. Action if exposure to risk of CJD occurs The CJD Incidents Panel (established November 2000) is aware of over 140 separate incidents in which patients may have been put at risk because of instruments or devices previously used on patients who had or have gone on to develop either form of CJD. There have been 13 ophthalmological incidents mostly involving patients destined to develop sporadic CJD who have had cataract surgery. If a patient undergoing ophthalmic surgery subsequently develops any form of CJD, it is essential that all instruments and devices involved should be traceable and taken out of circulation, and that subsequent patients who may have inadvertently been put at risk can be identified. For further advice in such an event contact Dr Nicky Connor, CJD Panel Secretariat, HPA, CDSC, 61 Colindale Avenue, London NW9 5EQ, tel: 0208 200 6868 ext.3411, e-mail: nicky.connor@hpa.org.uk NB: Advice from the CJD Panel is accessible on www.doh.gov.uk/cjd/consultation http://www.rcophth.ac.uk/docs/publications/CollegeCJDNov2003.pdf CJD the eyes have it, and it could be transplanted to you 28 Nov 99 Surgical & Endoscopic http://www.rense.com/general73/screened.htm ADDITIONAL DEBATES OVER THE YEARS ON THIS ISSUE ON CJD VOICE, you'll have to log in...tss some history on the topic of sporadic CJDs and Endoscopy Equipment ??? JULY 2006 ANNEX J ASSESSMENT TO BE CARRIED OUT BEFORE SURGERY AND ENDOSCOPY TO IDENTIFY PATIENTS WITH, OR AT RISK OF, CJD Categorisation of patients by CJD risk and infection control guidance J1. There are special infection control precautions that should be taken in healthcare for patients with or at risk of CJD and Part 4 of this Guidance provides advice on this. This includes the risk categorisation of patients, given in paragraphs 4.16 – 4.17 and Table 4A of Part 4. J2. In brief, when considering measures to prevent transmission to patients or staff in the healthcare setting, it is useful to make a distinction between symptomatic patients and asymptomatic patients as below: Symptomatic i.e. Asymptomatic patients i.e. those with no clinical symptoms, but who are identified as potentially at risk of CJD because of either: The need to ask CJD risk questions as part of pre-surgery assessment J3. It is essential that clinicians ask CJD risk questions to all patients about to undergo a surgical or endoscopic procedure that may involve contact with tissues with high or medium level infectivity, such as brain, spinal cord, eye, olfactory epithelium, spleen, tonsil, gastrointestinal lymphoid tissue and other fixed lymphoid tissue, as part of the pre-surgery assessment. Please refer to Part 4 and Annex A1 for further advice on surgical procedures and CJD tissue infectivity and Annex F for advice on endoscopic procedures. If effective pre-surgery assessment is not carried out, there is a danger that the CJD status of a patient will not be determined and this may result in failure to take the appropriate infection control precautions. If this is the case, there is the potential for a CJD incident to occur and this may result in exposing subsequent patients to CJD infectivity. Recommended CJD risk questions J4. A local level policy should be put in place to ensure that patients with or at risk of CJD are identified before surgery and therefore to allow the appropriate infection controls to be followed. To facilitate this, a list of recommended questions based on the information given in Table 4A is given in Table J1 below. It is recommended that patients are asked these questions prior to elective or emergency surgical procedures likely to involve contact with tissues of potentially high or medium level infectivity. Published: 31 July 2006 Table J1 – CJD Risk Questions for patients about to undergo elective or emergency surgical procedures likely to involve contact with tissues of potentially high or medium level infectivity (please refer to Part 4 and Annex A1 for further advice on surgical procedures and CJD tissue infectivity): Question to Patient i) Genetic testing, which has indicated that they are at significant risk of developing CJD or other prion disease; ii) A blood relative known to have a genetic mutation indicative of familial CJD; iii) 2 or more blood relatives affected by CJD or other prion disease. J5. In addition to asking the patient CJD risk questions, the following actions should also be carried out before any surgical procedure involving tissues with high or medium level infectivity to ensure that a comprehensive pre-surgery assessment is carried out. The clinician undertaking the pre-surgery assessment should: Published: 31 July 2006 These actions, in conjunction with the CJD risk questions, will minimise the chance of a CJD incident occurring and therefore greatly reduce the risk of transmission of CJD to subsequent patients. Emergency Surgery J6. In the event that a patient about to undergo emergency surgery is physically unable to answer questions, the next of kin should be asked the CJD risk questions before surgery takes place. If this is also not a viable option, the questions must be answered as soon as possible after the operation by either the patient or next of kin. Training J7. Trusts should ensure that the healthcare workers conducting the pre-surgery assessment receive the instruction and/or training necessary to understand the underlying reasons for asking these questions. It is crucial that the questions are asked in a manner that does not cause undue anxiety and therefore the questioner should be prepared to reassure the patient and provide further information, if needed. Patients at risk of CJD for public health purposes J8. As outlined in Table 4A in Part 4, a number of patients have been identified as potentially at risk for public health purposes on the recommendations of the CJD Incidents Panel. Paragraphs J9 to J12 provide some further information on these individuals and the steps taken to ensure that medical staff is informed of their risk status. J9. This group of patients includes individuals identified to be at risk of: a) CJD/vCJD due to exposure to certain instruments used on a patient who went on to develop CJD/vCJD, or was at risk of vCJD; b) CJD/vCJD due to receipt of tissues/ organs c) vCJD due to receipt of blood components or plasma derivatives; d) vCJD due to the probability they could have been the source of infection for a patient transfused with their blood who was later found to have vCJD. J10. When someone is notified that they are at risk of CJD, they are asked to take certain precautions to reduce the risk of spreading the infection to others. These include: J11. The individual’s GP is asked to record the patient’s CJD at-risk status in their primary records. The GP should also include this information in any referral letter should the patient require invasive medical procedures. J12. Further information on the work of the CJD Incidents Panel is available on the HPA website, http://www.hpa.org.uk/infections/topics_az/cjd/menu.htm Published: 31 July 2006 http://www.advisorybodies.doh.gov.uk/acdp/tseguidance/tseguidance_annexj.pdf 2006/054 New NICE guidance to reduce the risk of transmission of Creutzfeldt-Jakob disease (CJD) via surgical procedures Issued Wednesday 22 November 2006 71 High Holborn WC1V 6NA Tel: 020 7067 5800 PRESS RELEASE New NICE guidance to reduce the risk of transmission of Creutzfeldt–Jakob disease (CJD) via surgical procedures The National Institute for Health and Clinical Excellence (NICE) has today issued guidance to the NHS on reducing the risk of transmission of Creutzfeldt–Jakob disease (CJD) via surgical procedures. NICE has recommended that: • For certain surgical procedures carried out on the brain or eye (which carry a higher risk of potential transmission than other procedures): �� Steps should be taken urgently to ensure that instruments do not move from one set of instruments to another. Practice should be audited and systems should be put in place to allow these surgical instruments to be tracked �� Supplementary instruments that are used in these procedures should either be single use or should remain with the set to which they have been introduced �� A separate pool of new reusable surgical instruments should be used for children born since 1 January 1997 (who are unlikely to have been exposed to BSE in the food chain or CJD through a blood transfusion) and who have not previously undergone these procedures • For neuroendoscopy, a procedure using a tube inserted into the brain : Page 1 of 3 Page 2 of 3 �� Rigid neuroendoscopes should be used whenever possible. They should be of a kind that can be autoclaved (steam cleaned at a high temperature and pressure) and they should be autoclaved after each use. �� All accessories used through neuroendoscopes should be single use Lester Firkins, lay member of the CJD Advisory Committee says: "As someone whose son died from vCJD, I consider even one preventable death to be one too many. There are so many uncertainties around this disease and whilst the only way to remove all risk is to destroy every single instrument after every single intervention, I understand that in practice this is unachievable. I have been fully involved in the NICE review process throughout and am comfortable that the final guidance fully takes into account the best research evidence as well as the cost implications for the wider NHS." Page 3 of 3 The full guidance, which includes a list of all the surgical procedures covered by the guidance can be found on the NICE website at www.nice.org.uk Ends Notes for editors About NICE 1. The National Institute for Health and Clinical Excellence (NICE) is the independent organisation responsible for providing national guidance on the promotion of good health and the prevention and treatment of ill health. 2. NICE produces guidance in three areas of health • public health – guidance on the promotion of good health and the prevention of ill health for those working in the NHS, local authorities and the wider public and voluntary sector • health technologies – guidance on the use of new and existing medicines, treatments and procedures within the NHS • clinical practice – guidance on the appropriate treatment and care of people with specific diseases and conditions within the NHS. http://www.nice.org.uk/download.aspx?o=387397 Patient safety and reduction of risk of transmission of Creutzfeldt-Jakob disease (CJD) via interventional procedures: Comments and responses on the second consultation http://www.nice.org.uk/download.aspx?o=387378 http://www.nice.org.uk/page.aspx?o=387378 TSS
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