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| Patient Support Group |
| Wednesday, 30 July 2008 09:43 |
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Since April 2008 the Patient Support Group has organised five meetings, all members receive minutes and agenda of these meetings. These were held in the Alpha One Foundation’s office located in the RCSI Building at Beaumont Hospital. This venue can be changed at any time as organised by the group. Items discussed range from awareness to feedback of delegates to international patient meetings e.g. Prague in May 2008. Attendance has been low recently but we hope to improve this with an awareness campaign in October 2008. We would encourage patients to keep in contact with other patients and we hope to develop a newsletter updating members of news events and patient stories. Fundraising European Alpha-1 Conference, Rome 2007 Josephine McGuirk, October 2007. Abstracts from Rome Conference 2007ALPHA-1 ANTITRYPSIN DEFICIENCY: WHERE WE ARE, WHERE WE ARE GOING TO Maurizio Luisetti, Center for Diagnosis of Inherited Alpha-1 antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute of Respiratory Disease, University of Pavia, Fondazione IRCCS, Policlinico San Matteo, Pavia, Italy Liver pathology is a major manifestation of Alpha-1-antitrypsin deficiency (AAT), restricted to the AAT mutations causing misfolding of the protein and accumulation in the Endoplasmic Reticulum (ER) of hepatocytes. So far three such mutations have been identified, Z, Mmalton, Siiyama, the Z variant being the most frequent. The spectrum of the associated liver pathology comprises neonatal cholestasis, chronic hepatitis, cirrhosis and HCC. The mechanism of the liver damage is not fully understood. There are two major lines of thinking: 1) the storage is toxic per se, 2) additional factors are required for the development of the liver damage. The main argument favouring the second opinion is mainly based upon the observation that only a minority of AAT deficient individuals develop liver disease. I would like to emphasize the point that the accumulation of the mutant AAT represents per se the elementary lesion of the disease and that is an unavoidable process. In this context I will be reviewing the patho-morphogenesis of the storage phenomenon and the main morphological alterations with special regard to new electron microscopic findings. The epidemiological and clinical relevance of the morphological alterations are discussed also in view of the new experimental data on the pathways for degradation of the mutant proteins that accumulate in the ER. PATHOGENESIS OF LUNG DISEASE Alpha-1 Antitrypsin is produced from the liver and bathes all the tissues of the body. Its role is to protect against tissue damage from enzymes released from neutrophils. The genetic deficiency of alpha-1 antitrypsin that results from the Z mutation causes the protein to form polymers that are retained within the cells of the liver. This retention of protein causes liver disease. The resulting lack of plasma alpha-1 antitrypsin (10-15% of normal levels) leaves the lungs exposed to attack by neutrophil enzymes and so results in emphysema. We have recently shown that some of the alpha-1 antitrypsin that enters the lung can change shape and form chains of polymers. These polymers are unable to function as inhibitors of neutrophil enzymes and so exacerbate the tissues damage. Moreover the polymers are themselves inflammatory and cause further attraction of neutrophils into the lungs. This in turn accelerates the inflammation and emphysema. All these factors are exacerbated by smoking. My laboratory has defined the pathway by which polymers form and is currently developing strategies to block the polymerisation of Z alpha-1 antitrypsin. Such a strategy will prevent the accumulation of Z alpha-1 antitrypsin within hepatocytes thereby treating the associated liver disease. The release of alpha-1 antitrypsin from the liver will increase the circulating levels of alpha-1 antitrypsin and hence provide protection for the lungs against emphysema. THE NEED OF STANDARDIZATION OF DIAGNOSIS AATD is a largely under-recognized condition and one of the most common severe hereditary disorders in the world. To improve the diagnostic yield and to address the discrepancy between expected and diagnosed AATD cases, the recently published ATS/ERS Statement (2003) recommends diagnostic testing for all symptomatic adults with emphysema, COPD or asthma with incomplete reversible airflow obstruction, individuals with unexplained liver disease, asymptomatic individuals with persistent obstruction on pulmonary function tests with identifiable risk factors (cigarette smoking, occupational exposure) and adults with necrotizing panniculitis. The laboratory diagnosis of AATD has evolved from the initial description of the condition in 1963 based on paper electrophoresis – agar-gel electrophoresis – immunoelectrophoresis to the currently used methodology, that is a combination of serum AAT level determination, isoelectric focusing (IEF), genotyping, and sequencing. The availability of matrices such as the dried blood spot have facilitated the implementation of laboratory analyses for alpha-1 antitrypsin deficiency, but have also challenged laboratories to develop more reliable and reproducible techniques starting from dried blood. THE IMPORTANCE OF SCREENING Screening is performed to identify the presence of a disease or a risk factor for a disease, typically among asymptomatic persons. In this way, a disease, or risk factors for a disease, can be detected early, allowing either early treatment or prevention. Screening tests are widely used by clinicians as part of the periodic health examination, as well as by public health officials. Examples of screening tests are as varied as blood tests to detect lead poisoning in young children, mammography to detect breast cancer and questionnaires to identify persons with alcohol or other drug problems. Even if alpha-1 antitrypsin deficiency (AATD) is considered a rare disease, it is probably the most common widespread genetic abnormality. AATD is rarely diagnosed, both because of poor awareness by health workers and lack of implemented screening programs. An underrecognition of AATD diagnosis persists in spite of an effort to enhance clinicians’ awareness. From the clinical point of view the under-recognition might be explained by the facts that most of clinical phenotypes associated with AATD are not exclusive to this condition and that the abnormal genes have an incomplete penetrance (the relationship between genotype and clinical phenotype is not strong). The availability of alpha-1 antitrypsin replacement therapy for individuals with pulmonary emphysema associated with AATD encouraged the scientific community to establish and reinforce AATD screening. Screening for AATD has been recommended by the World Health Organization (WHO) in 1997. The American Thoracic Society (ATS) together with the European Respiratory Society (ERS) in 2003 advise population screening when three main conditions occur: 1) high prevalence of AATD (more than 1/1500), 2) high prevalence of smokers or of people exposed to toxic inhalants 3) availability of adequate genetic “counselling”. A population screening programme might be very innovative making use of new genetic techniques. An adequate screening program and an early diagnosis of AATD may permit to apply primary (i.e. smoking cessation for lung disease or alcohol abstention for liver disorders) or secondary (i.e. treatment of related lung diseases) prevention measures. At the moment there are evidences of neonatal screening, patient oriented detection (case-finding) and so called “targeted screening”. Recently, the Italian Association of “Alphas” coordinated a screening for AATD in the entire population of a small village in a high risk area. ONGOING RESEARCH AND DEVELOPMENT From the first recognition of alpha-1 antitrypsin deficiency in 1963 the research field became very active exploring the deficiency as a cause of all COPD. In the early 1980s augmentation therapy was introduced and with the understanding that this was “a cure” research activity waned. However in recent years a more inquisitive approach to the condition has emerged. Why do some AATD patients remain well? How does the lung disease present? How does it develop? How should patients be treated? What is the effect of chest infections? Can we prevent deterioration? Can we repair the damage? These and many other questions challenge us for the next few years. Of importance clinical trials of old or new treatments will emerge and be delivered through the extensive collaboration of researchers and the developments of the AIR and AOF registries. However it is critical that these are co-ordinated and not replicated merely to appease regulatory bodies. Close collaboration between medical registries, pharmaceutical companies and patient groups will be essential if we are to assess future therapies adequately. 3rd ALFA EUROPE ALLIANCE MEETING SUMMARYPRAGUE 9th – 10th MAY 2008 |
Alpha-1 Antitrypsin is an important protein produced by the liver, which is released into the bloodstream and travels to the lungs. Once inside the lungs it provides protection from the destructive effects of infections and harmful irritants, particularly tobacco smoke.
Alpha-1 antitrypsin deficiency (Alpha-1) is a genetic condition which, along with cystic fibrosis, is the commonest genetic lung disease in Ireland. It severely affects more than 2,000 people nationally, with another 10,000 individuals also at risk of lung and liver disease. It is the only proven genetic risk factor for COPD.