To the Editor: The review conducted by Teckman et al (1) on the appropriateness of newborn screening for α-1 antitrypsin (A1AT) deficiency concluded that presently there is insufficient evidence to support expanded newborn screening for this disease, recommending a number of pilot studies to determine the ultimate utility for potential state screening. The largest national newborn screening study of A1AT deficiency was conducted in Sweden and initially published in 1976, with ongoing follow-up, which has addressed some of the concerns raised regarding the appropriateness of newborn screening (2). These studies along with data from North American studies have estimated an incidence of 1 in 1600 to 3500 cases, an incidence comparable with cystic fibrosis (1,2). Follow-up from the original Swedish cohort has shown a positive psychological impact, with the majority of subjects stating they are grateful for their knowledge, recommending neonatal identification of the disease, which can affect parental smoking along with the patient avoidance of smoking and environmental pollution (3). Knowledge of having the disease has been shown to have a positive effect on the avoidance of cigarette smoking (4), with a more recent follow-up study showing normal lung function in 35-year-old ZZ homozygote patients who have avoided smoking similar to normal control subjects, with ZZ homozygote smokers showing early signs of emphysema (5). This long-term follow-up study illustrates the importance of neonatal identification because years of exposure to cigarette smoke can lead to the early development of emphysema.
Furthermore, pilot studies are obviously warranted to determine how to effectively implement neonatal screening of A1AT deficiency in the United States. The follow-up studies in Sweden, however, have clearly demonstrated the positive impact of identifying patients early with A1AT deficiency and the high prevalence of cigarette smoke avoidance, which should provide some sense of urgency in implementing neonatal screening in this not-so-uncommon genetic disease. Given the variation in disease expression of A1AT deficiency, other potential modifiable environmental exposures that could affect liver and lung morbidity are yet to be identified. Presently, what we do know is that the screening test is cheap, the diseased population is prevalent, the diagnosis is often extremely delayed causing increased morbidity, there is present treatment to delay disease progression, and there is great potential for the advancement in present treatment along with a potential cure. Newborn screening for A1AT deficiency seems to be extremely appropriate, and focus should be placed on the logistics of adding this underrecognized disease to state newborn screening.
1. Teckman J, Pardee F, Howell RR, et al. Appropriateness of newborn screening for α1-antitrypsin deficiency. J Pediatr Gastroenterol Nutr
2. Sveger T. Liver disease in alpha-1 antitrypsin deficiency detected by screening of 200,000 infants. N Engl J Med
3. Sveger T, Thelin T, McNeil TF. Young adults with alpha 1-antitrypsin deficiency identified neonatally: their health, knowledge about and adaptation to the high-risk condition. Acta Paediatr
4. Thelin T, Sveger T, McNeil TF. Primary prevention in a high-risk group: smoking habits in adolescents with homozygous alpha-1-antitrypsin deficiency. Acta Paediatr
5. Piitulainen E, Montero LC, Nystedt-Düzakin M, et al. Lung function and CT densitometry in subjects with alpha-1-antitrypsin deficiency and healthy controls at 35 years of age. COPD
2014; [Epub ahead of print].