Alpha-1 Antitrypsin Deficiency: Dispelling Myths Ronald Reilkoff, MD Staff Physician, HealthEast St.Paul, Mn Assistant Professor (Adjunct) University of Minnesota Disclosures Speakers Bureau for CSL Behring, Grifols and Boehringer Ingleheim Goal Raise awareness regarding the prevalence and diagnosis of Alpha-1 Antitrypsin Deficiency (A1AD) Top Myths - Misconceptions regarding A1AD Myth 1 – A1AD is rare (so why worry) Myth 2 – A1AD has a distinct presentation Myth 3 – A1AD testing is complicated Myth 4 – There is no effective therapy for A1AD 1.Stoller and Aboussouan Arch Int Med 169: 6 2009 A1AD is the Major Genetic Risk Factor for COPD ~15 million individuals have been diagnosed with COPD*1 10M office visits 1.5M ED visits 700K hospital discharges 3rd leading cause of death in United States2 $50 Billion in 2010 direct cost of COPD2 * Self reported diagnosis 1. 2. 3. 4. Ford. Chronic Obstructive Pulmonary Disease Surveillance. 1999-2011 Chest 2013 GOLD 2011 Guidelines Kosacz Morbidity and Mortality Weekly, 2012;61(46) 938 NIH website Alpha-1 Antitrypsin Alpha-1 antitrypsin (A1AT) is a protein predominantly produced by liver cells and released into the bloodstream Broad spectrum anti-protease activity Broad Spectrum antioxidant Modulates inflammation and lymphocyte proliferation Body normally produces 32mg/kg A1AT per day Serum levels 150-350mg/dL Variability in levels as it is an acute phase reactant 1. ATS/ERS Guidelines. Am J Respir Crit Care Med 2003; 168:818-900 Deficiency of Alpha-1 Antitrypsin = Risk of Lung Disease Hereditary condition characterized by low (or dysfunctional) levels of A1AT in plasma. < 11µM/L or <80 mg/dL* PiZZ phenotype *Theoretic protective threshold Alpha-1 Antitrypsin Deficiency A1AT protects the lungs from digestion by neutrophil elastase (NE) (protease) NE is released by white blood cells in response to infection/irritation A1AT accounts for >90% anti-neutrophil elastase Normal Protection Neutrophil elastase burden Antineutrophil protection If left unchecked NE may attack healthy AAT lung tissue A1AT binds NE, neutralizing the elastase and preventing lung damage AAT Deficient Neutrophil elastase burden Antineutrophil protection AAT Molecular Genetics of A1AT1 Two alleles that genetically code for the A1AT protein = “genotype” PI = protease inhibitor “MM” = phenotype >100 alleles for A1AT >30 alleles result in deficiency or dysfunction 98% of human population carries M, S or Z M allele – Normal variant (95% of US) Z allele - Found in 95% with clinically recognized AATD S allele (slightly more common than Z) Variant causing mildly decreased A1AT levels Null allele Interrupted A1AT synthesis due to transcriptional or translational errors 1. ATS/ERS Guidelines. Am J Respir Crit Care Med 2003; 168:818-900 2. Stoller JK & Aboussouan LS. Am J Respir Crit Care Med 2012; 185:246-259 Heterozygous • 2 different alleles • Expressed as: • PI*MZ • PI*SZ Homozygous • 2 same alleles • Expressed as: • PI*ZZ A1AD and Risk of COPD Development Range of serum levels and risk of deficiency by A1AT phenotype 1,2 Units PI*MM PI*MS PI*SS PI*MZ PI*SZ PI*ZZ Null/ null 20-48 18-48 15-33 17-33 8-16 2.5-7 0 150-350 140-350 100-200 90-210 75-120 20-45 0 Normal Low Low Moderate High High High µmol/ L mg/dL Risk Protective Threshold ~ 80mg/dL 1. 2. Rachelefsky G, Hogarth K. J Allergy Clin Immunol 2008;121: 833-838 ATS/ERS A1AD AJRCCM 2003; 168(7):818-900 Myth 1 – A1AD is Rare Studies of the Prevalence of A1AD Two conclusions: Relatively Common disease Under-recognized A1AD thought to comprise 3% of all COPD cases worldwide1 ~ 1in 2500 individuals in US affected2 A1AD can affect multiple ethnicities PIZ most prevalent in Northern Europeans, least in Asian and Hispanic Prevalence of S and Z alleles is worldwide3,4 1. 2. 3. 4. ATS/ERS A1AD AJRCCM 2003; 168(7):818-900 www.alpha1.org/newly-diagnosed de Serres FJ. Environ Health Perspect 2003; 111:1851-1854 de Serres.Ther Adv Resp Disease 2012: 6:5 277-95 Origins of Alpha (S, Z) Gene Frequencies of PiZ in Europe Screening studies show highest prevalence of PiZ in NorthernEuropean populations (founder population) Originated 2000-7000 years ago PiS highest in southern Europe (Iberian pennisula) Originated 10-50000 years ago Vikings/Norse Migration 5th to 10th Centuries Worldwide Indirect Estimates of Predominant PI types1* 1. de Serres.Ther Adv Resp Disease 2012: 6:5 277-95 * Based on epidemiological surveys (indirect) – low estimates Higher Prevalence of Alpha-1 vs US Population: Kentucky Study Observed Genotype Prevalence in KY Cohort Prevalence in Caucasian US Population (N) (%) (%) MM 3948 91.64 94.0 to 96.0 MZ 113 2.62 2.0 MS 174 4.04 5.0 SZ 12 0.28 0.05 ZZ 12 0.28 0.01 SS 5 0.12 0.05 Rare M subtypes 32 0.7 Rare, deficiency-related 12 0.28 4308 100.00 Genotype Total Koura F. Poster presented at: American Thoracic Society International Conference; May 18-23, 2012; San Francisco, CA. Screening for Alpha-1 Population based Screening: PiZZ1,2-5 ~ 1:1600 (Sweden) 1:4500 (US) ~ avg 1:2500 WorldWide estimate: • 116,000,000 PiMZ • 1,100,000 PiZZ In the US 100,000 individuals are affected 4-5 • AATD diagnosed in approximately 7,000 US individuals or <10%4 • ~10 Milliion Americans with deficient alleles (heterozygous) 1. Sveger T. NEJM 1976;294:1316:1321 2. Sveger T. Acta Paediatr Scand 1988; 77:847-851 3. Silverman EK, et al. Am Rev Respir Dis 1989; 140:961-966 4. de Serres FJ. Chest 2002; 122:1818-1829 5. Stoller JK & Aboussouan LS. Am J Respir Crit Care Med 2012; 185:246-259 6. de Serres, Blanco Ther Adv Resp Disease 2012; (6) 5:277-95 Myth 2 – A1AD has a Classic Presentation Myth 2 – A1AD has a Classic Presentation Textbook definition: “early onset emphysema in a nonsmoker with LL predominant emphysema” Original case series in 1963 by Laurel and Erickson with 5 patients1: 3 with obstructive lung disease (chronic bronchitis, emphysema and bronchiectasis) 2 without obvious signs of obstructive lung disease 1. Laurell and Erickson Scand J Clin Lab Invest 1963; 15 : 132-140 A1AD – Clinical Manifestations1 Lung disease Emphysema Chronic Bronchitis Bronchiectasis Childhood and adult liver disease Hepatitis Cirrhosis (37%) Hepatocellularcarcinoma Fulminant liver failure Occasional systemic manifestations Necrotizing panniculitis Inflammation of the subcutaneous fibro-fatty layer that underlies the skin usually over buttocks and thighs Red, painful nodular lesions, with weeping oily discharge C-ANCA Vasculitis (Wegener’s Granulomatosis) 1. Ranes J & Stoller JK. Semin Respir Crit Care Med 2005; 26:154-166 No Unique Presenting Features Majority (72%) of patient with A1AD present with symptoms1 Family member with A1AD (20%) Abnormal imaging (8%) In a survey of patients enrolled in the NHLBI registry of A1AD1, symptoms at enrolment included: Dyspnea (84%) Wheezing: With upper respiratory tract infection (76%) Without upper respiratory tract infection (65%) Cough (42%) Excess sputum production (46%) 1. McElvaney NG et al. Chest 1997; 111:394-403 Variable Imaging in AATD Chest X-rays from 165 ZZ Alpha-1 patients:¹ 15% were normal Only 20% showed classic “emphysema” at bases CTs from 102 ZZ Alpha-1 patients:² 64% showed basal predominance 36% had predominant apical disease Some individuals with A1AD (PiZZ) never develop emphysema Bronchiectasis 1. 2. Gishen. Clin Radiol 1982; 33: 371-377 Parr D. Am J Respir Crit Care Med 2004; 170:1172-1178 21 Myth 3 – A1AD testing is Complicated It’s Not. Can be simple as a fingerstick It can be done for free and anonymously. Free testing kits available from Pharma Free testing in state of Florida Alpha-1 Coded Testing Study (ACT) through Medical University of South Carolina 1. Brantley M, Clin Chem. 2006;52 (12):2180-2181 2. Wall. J Pediatr. 1990;116:248-251 3. ATS/ERS Guidelines. Am J Respir Crit Care Med 2003;168:818-900 4. Carpenter MJ, et al. Ann Behav Med. 2007;33(1):22-28 Serologic testing of A1AD A1AT serum level test* Determines A1AT levels in blood or serum May not identify heterozygotes A1AT genotyping* Identifies abnormal A1AT gene Typically performed using polymerase chain reaction Identifies if a patient has S or Z allele(s), but may miss rare alleles A1AT Pi-typing (ie, phenotyping) Determines type of A1AT protein in the blood via isoelectric focusing on polyacrylamide gels Can identify virtually all mutations Requires a high level of expertise to read; more costly; limited number of experts available for reading tests *Free testing via fingerstick kits Diagnosing A1AD To make A1AD diagnosis = Laboratory Diagnosis Positive deficient genotype (PiZZ, PiSZ, null or rare) Clinically compatible disease (COPD, liver disease, panniculitis) Serum levels of A1AT are not sufficient to make diagnosis Acute phase reactant Does not identify heterozygotes Barriers to Testing Misconceptions: Rare disease Easy to detect No effective treatment (“therapeutic nihilism”) Technical barriers: Introduction of A1AD testing in routine hospital laboratories Patient reservations regarding testing Discrimination: Health and Life Insurance Provider remembering to test Testing fatigue 1. Bazzi K & Rahaghi F. US Resp Dis 2010; 6:47-51 Discrimination Concerns Genetic Information Nondiscrimination Act 20081 Bars discrimination of health insurance companies and employers on basis of genetic information Life Insurance A1AD itself is not considered a sole factor in denial of Life Insurance2 1. www.govtrack.us 2.Gomez AJRCCM 185:2012:A4364 Importance of Testing: Delay in Diagnosis Average delay in diagnosis 8.3 +/- 6.9 years between onset of symptoms and diagnosis1 Patients often evaluated by 2-3 providers before diagnosis Average age of 45.5+/- 9.5 ‘Asthma’ is often initial diagnosis 1. Campos, MA et al Chest 2005;128(3) Implications in Delay of A1AD Diagnosis The estimated annual rate of FEV1 decline1 Normal lung function declines at approximately 30 mL/yr PI*ZZ A1AD non-smokers = 4060 mL/yr PI*ZZ A1AD smokers = 113 mL/yr Predictors of greater FEV1 decline Smokers, males, aged 30-44 years, FEV1 35-79% predicted value, decreased serum A1AT levels and bronchodilator response2 1. Piitulainen E & Eriksson S. Eur Respir J 1999; 13:247-251 2. Stoller JK & Aboussouan LS. Lancet 2005; 365:2225-2236 Reasons to Test Early detection of subjects is crucial to apply effective preventive measures and early institution of therapy! Lifestyle implications: Patients who are tested more likely to attempt to quit smoking2,4 Increases potential for family testing and genetic counseling3 Raises awareness to avoid hazards of occupational/environmental respiratory pollutants 1. Brantley M, Clin Chem. 2006;52 (12):2180-2181 2. Wall. J Pediatr. 1990;116:248-251 3. ATS/ERS Guidelines. Am J Respir Crit Care Med 2003;168:818-900 4. Carpenter MJ, et al. Ann Behav Med. 2007;33(1):22-28 ATS Diagnostic Testing Guidelines *No definitive physical conditions that confirm A1AD although certain clinical features should prompt suspicion of A1AT deficiency1 Type A – Recommend • Symptomatic adults with: • • • • -Emphysema -COPD Incompletely reversible asthma Asymptomatic individuals with: -Persistent obstruction on PFT and identifiable risk factors (patients with FEV1< 80% predicted and FEV1/FVC less than 0.70) All individuals with unexplained liver disease Adults with necrotizing panniculitis Type B – Consider • Adults with bronchiectasis of • • • 1. ATS/ERS Guidelines. Am J Respir Crit Care Med 2003;168:818900 unknown source Adolescents with persistent airflow obstruction Asymptomatic individuals with persistent airflow obstruction and no identifiable risk factors Adult C-ANCA-positive vasculitis Myth 4- There are no Effective Therapies for A1AD Treating Alpha-1 Antitrypsin Counseling Family testing Lifestyle modifications Exercise Avoidance of pollutants Vaccinations Influenza/pneumococcus Hepatitis A/B Treating A1AD with Lung Disease COPD Specific therapies: Bronchodilators Inhaled steroids Antibiotics Oxygen COPD Action Plans Pulmonary Rehabilitation Augmentation therapy Lung Transplant Indications for Augmentation Therapy PiZZ, Null or deficient phenotypes Fixed airflow obstruction FEV1 30%-65% Emphysema on CT Nonsmoker, ex-smoker Adherence to medical regimen Rapid decline in FEV1 (>80ml/yr) Necrotizing panniculitis Augmentation Therapeutic Options Purified Preparations: Prolastin-C – Grifols Zeimaira – CSL Behring Aralast – Baxter Glassia - Kamada 60mg/kg weekly infusion Rate 0.08ml/kg as tolerated by patient Augmentation Therapies Original FDA approval to raise blood and lung levels in a genetically deficient population1 Proving clinical efficacy is much harder FEV1 (rate of decline)2 traditional endpoint but poor marker Does not encompass all disease facet Diffusion impairment3 1. 2. 3. 4. 5. 6. CT Densitometry3,6 Symptoms, exacerbations2 Mortality2 Elastin degradation products5 Gadek. J Clin Invest 1981; 68:1158-1165 A1AD NHLBI Registry AJRCCM. 1998;158:49-59 Dirksen. AJRCCM 1999;160:1468-1472 Dirksen ERJ 2009; 33(6):1345-1353 Ma. COPD 2013; 10:1-9 Stockley. Resp Res 2010;11:136 Efficacy of Augmentation Change in FEV1 (mL/yr) Augmentation 100 90 80 70 60 50 40 30 20 10 0 1. Chapman KR et al. COPD 2009; 6:177-184 Control Augmentation Therapy 1. Chapman KR. COPD 2009; 6:177-184 RCT - Change in FEV1 1. Gotzche PC. Cochrane Review. 2010. Issue 7 RCT – CT Densitometry 1. Gotzche PC. Cochrane Review. 2010. Issue 7 Efficacy - Contrasting Recommendations Accumulated data is overwhelming in favor of augmentation Biologic1-2 Observational3-4 Epidemiologic5 ATS/ERS guidelines support6 However: 2 Small RCT No change in FEV17,8 Cochrane Review cannot recommend augmentation9 Several countries do NOT cover on this basis Augmentation Efficacy Controversy “Parachutes reduce the risk of injury after gravitational challenge, but their effectiveness has not been proved with randomized controlled trials” Recommend: moratorium on parachutes until further study Smith G BMJ 2003;327:1459 Summary Fact 1 - A1AD is relatively common and underrecognized by providers Fact 2 – A1AD can predispose to a wide range of lung disease with a variable and non specific clinical presentation Fact 3 – A1AD testing is safe, discrete and important – and only way to rule out or in the diagnosis Fact 4 – There are effective therapies for A1AD; augmentation is efficacious. Thank you! Questions? Contacts/Information: rreilkoff@healtheast.org, rreilkof@umn.edu www.alpha-1foundation.org
© Copyright 2024