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Alpha-1 is estimated to affect up to 100,000 Americans, but up to 95percent are undiagnosed or have been misdiagnosed as having another form ofchronic obstructive pulmonary disorder (COPD). Details of the study werepresented at CHEST, the annual meeting of the American College of ChestPhysicians held in Chicago from October 20 to 25. Study results are beingannounced today on World COPD Day to focus attention on the need for widertesting for AAT deficiency.
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"Findings from this study suggest that simply all patients with moderateor severe persistent asthma and/or COPD with chronic pulmonary symptoms shouldbe tested for AAT deficiency," said Gary Rachelefsky, MD, Professor of Allergyand Immunology and Director of the Executive Care Center for Asthma, Allergyand Respiratory Diseases at UCLA School of Medicine and study investigator."It is imperative that clinicians become more vigilant about Alpha-1 testingas many patients are going undiagnosed or misdiagnosed due to screeningcriteria and practices."
The study, conducted by the Respiratory & Allergic Disease Foundation,recruited 40 office-based pulmonologists across the United States who tested454 adult patients using the following simple screening criteria: persistentasthma and/or COPD patients with loss of lung function defined by either aFEV1 (forced expiratory volume at 1 second) or a ratio of FEV1 to forced vitalcapacity (FEV1/FVC) of less than 70 percent. Blood tests were taken to assesslevels of AAT, and additional lab results and patient histories were noted andtabulated.
Of the 454 patients studied, 3.3 percent showed deficient levels of AAT.Low blood levels of AAT are commonly associated with progressive severeemphysema that becomes clinically evident by the third to fourth decade oflife; a recent registry showed that 54 percent of AAT deficient patients hademphysema. Less commonly, low levels of AAT are associated with liver diseaseand cirrhosis.
Interestingly, patients who tested with low AAT did not significantlydiffer from the COPD/persistent asthma patients with normal levels of AAT inseveral key pulmonary function criteria, including levels of FEV1, ratios ofFEV1 to forced vital capacity (FEV1/FVC), or the number of bronchialinfections within the past 12 months. This lack of differentiatingcharacteristics in deficient subjects indicates that if pulmonologists rely onstandard screening criteria for Alpha-1 testing, the result will be incorrectand missed diagnoses.
"Our surveillance study found that physicians cannot depend on typicalpatient profiles to assess whether AAT deficiency screening is necessary.There is no 'face' to AAT deficiency," said D. Kyle Hogarth, MD, FCCP,Assistant Professor of Medicine, University Chicago Medical Center, Directorof the Alpha-1 Antitrypsin Deficiency Clinical Resource Center at theUniversity of Chicago and lead author of the study. "A number of patients whowould not normally be screened based on suggested guidelines turned out infact to be positive for AAT deficiency. In the real-world setting, thissuggests that thousands of patients who have been diagnosed with COPD orsevere asthma may actually have Alpha-1."
The RAD study was supported by an unrestricted educational grant from CSLBehring, maker of the Alpha1 Proteinase Inhibitor (Human), Zemaira(R).
About Alpha-1 Antitrypsin Deficiency (Alpha-1)
Alpha-1 antitrypsin is an anti-inflammatory protein that protects thetissue of the body. One of its most important roles is to shield the
