Cutoff level to detect heterozygous alpha 1 antitrypsin deficiency in Turkish population

Optimal alpha-1 antitrypsin level cutoffs for genotype identification in patients with chronic liver disease

BACKGROUND

Controversy exists whether alpha-1 antitrypsin (A1AT) genotype testing should be performed as a first-line screening for A1AT heterozygous variants.

METHODS

We calculated the median and interquartile range of A1AT level for each genotype in 4378 patients with chronic liver disease and "miss rate" of MZ genotype identification at various cutoff levels.

FINDINGS

Significant overlap in A1AT level noted with Pi*MM, MZ, and MS variants. Miss rate of Pi*MZ at a cutoff level <100 was 29%, <110 was 18%, <120 was 8%, and <130 was 4%. We suggest simultaneous measurement of A1AT level and genotype in patients with chronic liver disease.

Alpha-1 Antitrypsin Levels and Polymorphisms in Interstitial Lung Diseases

BACKGROUND/AIM

Alpha-1 antitrypsin deficiency may be a potential predisposing factor for interstitial lung fibrosis. We investigated alpha-1 antitrypsin levels and its polymorphisms in patients with interstitial lung disease.

MATERIALS AND METHODS

A total of 103 interstitial lung disease patients were compared.

RESULTS

The mean alpha-1 antitrypsin level in idiopathic interstitial pneumonia patients was 1.67 ± 0.33 g/L, and it was 1.54 ± 0.37 g/L in patients with nonidiopathic interstitial pneumonia (P = 0.13). Low alpha-1 antitrypsin levels were more frequently observed in nonidiopathic interstitial pneumonia patients compared with idiopathic interstitial pneumonia, but the difference was not statistically significant (8.9% vs. 0%, respectively, P = 0.4). In 100 patients, the normal PiMM genotype was detected, while abnormal ones (PiMZ, n = 2, 1.9%; PiMS, n = 1, 0.97%) were determined in three cases. When the frequency of alpha-1 antitrypsin polymorphism in interstitial lung disease patients was compared with the data of the healthy population, no significant difference was detected for the PiMZ and PiMS variants (P = 0.15 and P = 0.44, respectively).

CONCLUSION

Lower levels of serum alpha-1 antitrypsin were more frequent in nonidiopathic interstitial pneumonia patients than idiopathic interstitial pneumonia without an increase in genetic polymorphism. The difference was not statistically significant.

Alpha-1-antitrypsin deficiency: increasing awareness and improving diagnosis

Alpha-1-antitrypsin deficiency (AATD) is a hereditary disorder that is characterized by a low serum level of alpha-1-antitrypsin (AAT). The loss of anti-inflammatory and antiproteolytic functions, together with pro-inflammatory effects of polymerized AAT contribute to protein degradation and increased inflammation resulting in an increased risk of developing chronic obstructive pulmonary disease (COPD) and emphysema, especially in smokers. AATD is a rare disease that is significantly underdiagnosed. According to recent data that are based on extrapolations, in many countries only 5-15% of homozygous individuals have been identified. Furthermore, the diagnostic delay typically exceeds 5 years, resulting in an average age at diagnosis of about 45 years. Although the American Thoracic Society/European Respiratory Society recommendations state that all symptomatic adults with persistent airway obstruction should be screened, these recommendations are not being followed. Potential reasons for that include missing knowledge about the disease and the appropriate tests, and the low awareness of physicians with regard to the disorder. Once the decision to initiate testing has been made, a screening test (AAT serum level or other) should be performed. Further diagnostic evaluation is based on the following techniques: polymerase chain reaction (PCR) for frequent and clinically important mutations, isoelectric focusing (IEF) with or without immunoblotting, and sequencing of the gene locus coding for AAT. Various diagnostic algorithms have been published for AATD detection (severe deficiency or carrier status). Modern laboratory approaches like the use of serum separator cards, a lateral flow assay to detect the Z-protein, and a broader availability of next-generation sequencing are recent advances, likely to alter existing algorithms.

Alpha-1 antitrypsin deficiency in Iranian patients with chronic obstructive pulmonary disease

Background

Alpha-1 antitrypsin deficiency is a genetic disease which affects both lung and liver. This disease is a recognized factor for chronic obstructive pulmonary disease (COPD). However its importance as the cause of COPD in a country such as Iran is unclear.

Objectives

This study was conducted to find out the role of α-1 antitrypsin deficiency as a cause of COPD in Iranian patients.

Materials and Methods

The serum concentration of α-1 antitrypsin was determined and the genotype of α-1 antitrypsin was also evaluated by PCR-RFLP in 130 patients with COPD and 50 normal healthy blood donors.

Results

No α-1 antitrypsin deficient case was found in normal healthy people and COPD patients.

Conclusions

Our results clarify that deficiency of α-antitrypsin is not a major cause of COPD in Iranian patients.