Skip navigation
MedlinePlus Trusted Health Information for You U.S. National Library of MedicineNational Institutes of Health
Contact Us FAQs Site Map About MedlinePlus
español Home Health Topics Drugs & Supplements Medical Encyclopedia Dictionary News Directories Other Resources

 

Medical Encyclopedia

Other encyclopedia topics:  A-Ag  Ah-Ap  Aq-Az  B-Bk  Bl-Bz  C-Cg  Ch-Co  Cp-Cz  D-Di  Dj-Dz  E-Ep  Eq-Ez  F  G  H-Hf  Hg-Hz  I-In  Io-Iz  J  K  L-Ln  Lo-Lz  M-Mf  Mg-Mz  N  O  P-Pl  Pm-Pz  Q  R  S-Sh  Si-Sp  Sq-Sz  T-Tn  To-Tz  U  V  W  X  Y  Z  0-9 

Alpha-1 antitrypsin deficiency

Printer-friendly versionEmail this page to a friend
Contents of this page:

Illustrations

Lungs
Lungs
Liver anatomy
Liver anatomy

Alternative Names    Return to top

AAT deficiency

Definition    Return to top

Alpha-1 antitrypsin deficiency is a lack of a liver protein that blocks the destructive effects of certain enzymes. The condition may lead to emphysema and liver disease, and in rare cases, skin disease.

Causes    Return to top

Alpha-1 antitrypsin deficiency results from a genetic defect. The mechanism that causes associated liver disease and emphysema in some people with this deficiency is not known. However, some evidence suggests that it may be related to inflammation.

Studies now show that Alpha-1 antitrypsin deficiency may be more common than once thought. Approximately 75% of adults with severe deficiency will develop emphysema, which often begins before 40 years of age. Smoking can increase the risk.

Symptoms    Return to top

Additional symptoms that may be associated with emphysema or cirrhosis include the following:

Exams and Tests    Return to top

A physical examination may reveal a barrel-shaped chest. Listening to the chest with a stethoscope may reveal wheezing, crackles, or decreased breath sounds. The following tests may also help with diagnosis:

Treatment    Return to top

Replacement (augmentation) therapy with the missing AAT protein is available. However, it is not known how effective this is once disease has developed or which people would benefit most. Quitting smoking is crucial.

Other treatments include bronchodilators and prompt antibiotics for upper respiratory tract infections. Lung transplantation may be an option for those who develop end-stage lung disease. In addition, genetic testing of relatives may be recommended.

Outlook (Prognosis)    Return to top

Some people with this deficiency will not develop liver or lung disease. Emphysema and cirrhosis, however, are both progressive diseases that can kill.

Possible Complications    Return to top

When to Contact a Medical Professional    Return to top

Call your health care provider if you develop symptoms of alpha-1 antitrypsin deficiency.

References    Return to top

Perlmutter, DH. Alpha-1-antitrypsin deficiency: diagnosis and treatment. Clin Liver Dis. November 2004;8:839-859.

Stoller JK, Tomashefski J, Crystal RG, et al. Mortality in individuals with severe deficiency of alpha-1-antitrypsin: Findings from the National Heart, Lung, and Blood Institute Registry. Chest. April 2005;127:1196-1204.

Update Date: 3/1/2007

Updated by: David A. Kaufman, M.D., Assistant Professor, Division of Pulmonary Medicine, Mount Sinai School of Medicine, New York, NY. Review provided by VeriMed Healthcare Network.

A.D.A.M. Logo

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2008, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.