P58 A Comparison Between The Clinical Features Of Pisz And Pizz Patients With Alpha-1 Antitrypsin Deficiency

Clinical considerations in individuals with α1-antitrypsin PI*SZ genotype

α₁-Antitrypsin deficiency (AATD), characterised by reduced levels or functionality of α₁-antitrypsin (AAT), is a significantly underdiagnosed genetic condition that predisposes individuals to lung and liver disease. Most of the available data on AATD are based on the most common, severe deficiency genotype (PI*ZZ); therefore, treatment and monitoring requirements for individuals with the PI*SZ genotype, which is associated with a less severe AATD, are not as clear. Recent genetic data suggest the PI*SZ genotype may be significantly more prevalent than currently thought, due in part to less frequent identification in the clinic and less frequent reporting in registries. Intravenous AAT therapy, the only specific treatment for patients with AATD, has been shown to slow disease progression in PI*ZZ individuals; however, there is no specific evidence for AAT therapy in PI*SZ individuals, and it remains unclear whether AAT therapy should be considered in these patients. This narrative review evaluates the available data on the PI*SZ genotype, including genetic prevalence, the age of diagnosis and development of respiratory symptoms compared with PI*ZZ individuals, and the impact of factors such as index versus non-index identification and smoking history. In addition, the relevance of the putative 11 µM “protective threshold” for AAT therapy and the risk of liver disease in PI*SZ individuals is explored. The purpose of this review is to identify open research questions in this area, with the aim of optimising the future identification and management of PI*SZ individuals.

Individuals with α₁-antitrypsin (AAT) PI*SZ genotype appear to have an increased risk for lung and liver disease, although definitive evidence is lacking; smoking is a major risk factor for lung disease. The role of AAT therapy requires further study.http://bit.ly/2TxxFD0

Intensive smoking diminishes the differences in quality of life and exacerbation frequency between the alpha-1-antitrypsin deficiency genotypes PiZZ and PiSZ

BACKGROUND

Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder that is associated with low levels of circulating alpha-1-antitrypsin in serum. In comparison to the genotype PiZZ, PiSZ usually leads to lower risk of emphysema, better lung function and better survival. The aim of this study was to analyze the relationship between cigarette smoking (packyears) and the AATD genotypes (PiZZ and PiSZ) concerning quality of life (SGRQ), transfer factor of the lung for carbon monoxide (TLCO), forced expiratory volume in one second (FEV₁) and exacerbation rate.

METHODS

We compared PiZZ and PiSZ individuals from the German registry for individuals with AATD (AATDR) in univariate analysis and multivariate linear regression models. All subjects were stratified into three groups according to their cumulative nicotine consumption (0 py; 0 < py < 30; ?30 py).

RESULTS

868 PiZZ individuals (mean age 52.6 ± 12.8 years (43.5% female)) and 114 PiSZ individuals (mean age 50.3 ± 17.4 years (46.5% female)) were compared. In contrast to never- and intensive (ex-) smokers, moderate (ex-) smoking PiSZ individuals had a significantly better SGRQ total score (B = ?8.148; p = 0.020) and less exacerbations (B = ?0.354; p = 0.037) than individuals with PiZZ in multivariate analysis.

CONCLUSIONS

The differences in quality of life and exacerbation frequency between PiZZ and PiSZ individuals diminish by intensive (ex-) smoking.

Exacerbations and duration of smoking abstinence are associated with the annual loss of FEV1 in individuals with PiZZ alpha-1-antitrypsin deficiency

BACKGROUND

Alpha-1-antitrypsin deficiency (AATD) is a genetic disorder that is associated with a higher risk of chronic obstructive pulmonary disease (COPD) and emphysema. The annual declines in lung function (FEV₁) and transfer factor of the lung for carbon monoxide (TLCO) predict all-cause mortality.

MATERIAL AND METHODS

We investigated the longitudinal follow-up data over 11 years (mean follow-up period of 4.89 years) from the German AATD registry and analyzed the relationship between annual loss of FEV₁ and TLCO and sex, age, body mass index (BMI), nicotine consumption, occupational dust exposure, St. George's Respiratory Questionnaire (SGRQ) score, baseline FEV₁ or TLCO, alpha-1-antitrypsin (AAT) serum level, exacerbation frequency and the duration of smoking abstinence by multiple linear generalized estimating equations models (GEE-models).

RESULTS

We evaluated the data of 100 individuals with post-bronchodilator FEV₁ measurements and from 116 individuals with TLCO measurements. The mean overall decline was -54.06 ± 164.62 ml/year in FEV₁ and -0.17 ± 0.70 mmol/min/kPa/year in TLCO. Accelerated deterioration of FEV₁ was associated with occupational dust exposure (p = 0.026), shorter duration of smoking abstinence (p = 0.008), higher baseline FEV₁ (p = 0.003), higher annual exacerbation frequency (p = 0.003) and higher frequency of glucocorticoids intake (p = 0.004). Furthermore, patients with an elevated decline in TLCO showed significant impaired health-related quality of life at baseline (p = 0.039) and lower AAT serum levels (p < 0.001) in multivariate analysis.

CONCLUSIONS

Annual decline in FEV₁ is related to the exacerbation rate, occupational dust exposure and the duration of smoking abstinence.