C3d Elicits Neutrophil Degranulation and Decreases Endothelial Cell Migration, with Implications for Patients with Alpha-1 Antitrypsin Deficiency.

Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by increased risk for emphysema, chronic obstructive pulmonary disease (COPD), vasculitis, and wound-healing impairment. Neutrophils play a central role in the pathogenesis of AATD. Dysregulated complement activation in AATD results in increased plasma levels of C3d. The current study investigated the impact of C3d on circulating neutrophils. Blood was collected from AATD (n = 88) or non-AATD COPD patients (n = 10) and healthy controls (HC) (n = 40). Neutrophils were challenged with C3d, and degranulation was assessed by Western blotting, ELISA, or fluorescence resonance energy transfer (FRET) substrate assays. Ex vivo, C3d levels were increased in plasma (p < 0.0001) and on neutrophil plasma membranes (p = 0.038) in AATD compared to HC. C3d binding to CR3 receptors triggered primary (p = 0.01), secondary (p = 0.004), and tertiary (p = 0.018) granule release and increased CXCL8 secretion (p = 0.02). Ex vivo plasma levels of bactericidal-permeability-increasing-protein (p = 0.02), myeloperoxidase (p < 0.0001), and lactoferrin (p < 0.0001) were significantly increased in AATD patients. In endothelial cell scratch wound assays, C3d significantly decreased cell migration (p < 0.0001), an effect potentiated by neutrophil degranulated proteins (p < 0.0001). In summary, AATD patients had increased C3d in plasma and on neutrophil membranes and, together with neutrophil-released granule enzymes, reduced endothelial cell migration and wound healing, with potential implications for AATD-related vasculitis.

Alpha-1 Antitrypsin Deficiency and Tobacco Smoking: Exploring Risk Factors and Smoking Cessation in a Registry Population.

The ZZ genotype of alpha-1 antitrypsin deficiency (AATD) is strongly associated with COPD, even in never-smokers. Moderate AATD genotypes (MZ and SZ) have been shown to increase the severity of COPD in smokers. In this comparative study, we examine the association between AATD, genotypes, and smoking cessation. Two hundred and ninety-three Irish people with AATD [MZ (n = 91), SZ (n = 72), and ZZ/rare (n = 130)] completed a custom questionnaire assessing their social and smoking histories. The primary outcomes analyzed were the predictors of ever-smoking and effect of genotype on awareness of AATD and maintained smoking cessation, using logistic regression analyses. Parental smoking exposure was associated with ever-smoking status (OR 1.84 vs. no parental smoking, p = 0.018), higher cumulative tobacco consumption (23.47 vs. 14.87 pack-years, p = 0.005) and more quit attempts required to achieve cessation among former-smokers (2.97 vs. 5.60, p = 0.007). Awareness of genotype was 67.7% versus 56.3% versus 33% for ZZ, SZ, and MZ, respectively (p < 0.001). Among ever-smokers, current-smoking was uncommon (2.5% vs. 17% vs. 16% for ZZ, SZ, and MZ, respectively, p = 0.009) with ZZs significantly less likely to be current-smokers (OR 0.15 relative to MZ, p = 0.025). These results suggest that the genetic risk of COPD in AATD families is compounded by transmission of social risk factors (via parental smoking). Increasing severity of genotype is associated with lower current-smoking rates among ever-smokers. Whether this is attributable to greater awareness of risk is an area of interest. Achieving a change in smoking habits may also result in positive health behavior in subsequent generations.

Activation of complement component 3 is associated with airways disease and pulmonary emphysema in alpha-1 antitrypsin deficiency.

INTRODUCTION: Alpha-1 antitrypsin (AAT) deficiency (AATD) is associated with early onset emphysema. The aim of this study was to investigate whether AAT binding to plasma constituents could regulate their activation, and in AATD, exploit this binding event to better understand the condition and uncover novel biomarkers of therapeutic efficacy. METHODS: To isolate AAT linker proteins, plasma samples were separated by size exclusion chromatography, followed by co-immunoprecipitation. AAT binding proteins were identified by mass spectrometry. Complement turnover and activation was determined by ELISA measurement of C3, C3a and C3d levels in plasma of healthy controls (n=15), AATD (n=51), non-AATD patients with obstructive airway disease (n=10) and AATD patients post AAT augmentation therapy (n=5). RESULTS: Direct binding of complement C3 to AAT was identified in vivo and in vitro. Compared with healthy controls, a breakdown product of C3, C3d, was increased in AATD (0.04 µg/mL vs 1.96 µg/mL, p=0.0002), with a significant correlation between radiographic pulmonary emphysema and plasma levels of C3d (R2=0.37, p=0.001). In vivo, AAT augmentation therapy significantly reduced plasma levels of C3d in comparison to patients not receiving AAT therapy (0.15 µg/mL vs 2.18 µg/mL, respectively, p=0.001). DISCUSSION: Results highlight the immune-modulatory impact of AAT on the complement system, involving an important potential role for complement activation in disease pathogenesis in AATD. The association between plasma C3d levels and pulmonary disease severity, that decrease in response to AAT augmentation therapy, supports the exploration of C3d as a candidate biomarker of therapeutic efficacy in AATD.

The impact of alpha-1 antitrypsin augmentation therapy on neutrophil-driven respiratory disease in deficient individuals.

Alpha-1 antitrypsin (AAT) is the most abundant serine protease inhibitor circulating in the blood. AAT deficiency (AATD) is an autosomal codominant condition affecting an estimated 3.4 million individuals worldwide. The clinical disease associated with AATD can present in a number of ways including COPD, liver disease, panniculitis and antineutrophil cytoplasmic antibody vasculitis. AATD is the only proven genetic risk factor for the development of COPD, and deficient individuals who smoke are disposed to more aggressive disease. Principally, AAT is a serine protease inhibitor; however, over the past number of years, the assessment of AAT as simply an antiprotease has evolved, and it is now recognized that AAT has significant anti-inflammatory properties affecting a wide range of cells, including the circulating neutrophil.

Brief Report: Genetic Variation of the α1 -Antitrypsin Gene Is Associated With Increased Autoantibody Production in Rheumatoid Arthritis.

OBJECTIVE: To examine the prevalence of α1 -antitrypsin deficiency (AATD) in rheumatoid arthritis (RA), and to determine whether AATD is associated with higher levels of rheumatoid factor (RF), antinuclear antibodies (ANAs), and anti-citrullinated peptide autoantibodies (ACPAs). METHODS: RF, ANAs, and ACPAs were measured by standard immunoturbidimetry, immunofluorescence assay, and enzyme-linked immunosorbent assay, respectively. Characterization of AAT phenotypes was performed by isoelectric focusing and immunofixation. The chi-square test with Yates' correction and the Mann-Whitney U test were used to assess the prevalence of alleles associated with AATD in RA and to compare mean antibody titers, respectively. RESULTS: Of 246 patients with RA, 24 who were heterozygous for AATD were identified, with no statistically significant difference in the prevalence of AATD between RA patients and the general population (P = 0.39). A positive association between heterozygosity for AATD and the production of ACPAs was observed (P < 0.0001), with increased ACPA titers recorded in the AATD RA cohort compared with the general population (P = 0.01). CONCLUSION: AAT heterozygous status in RA is strongly associated with positive ACPAs and may define a distinct subset of patients with increased disease severity.

The path of least resistance in oral surgery.

STATEMENT OF THE PROBLEM: Antibiotic resistance is an imminent threat to worldwide public health. Dental professionals must demonstrate judicious use of antibiotics and educate their patients about the risks associated with their overuse. PURPOSE OF THE PAPER: To encourage the dental profession to prescribe responsibly in order to optimise the use of antibiotics in oral surgery. Antibiotic stewardship programmes are recommended to help reduce the emergence of infections that are multidrug-resistant. Clinical practice audits are encouraged to help dentists ensure conservative prescribing patterns. CONCLUSIONS: The dental profession has a duty of care to prescribe antibiotics in adherence with current best practice oral surgery guidelines. The dental profession must show leadership in slowing antibiotic resistance by pledgina to safeguard their appropriate use.

The impact of smoke exposure on the clinical phenotype of alpha-1 antitrypsin deficiency in Ireland: exploiting a national registry to understand a rare disease.

Individuals with Alpha-1 antitrypsin deficiency (AATD) have mutations in the SERPINA1 gene causing genetic susceptibility to early onset lung and liver disease that may result in premature death. Environmental interactions have a significant impact in determining the disease phenotype and outcome in AATD. The aim of this study was to assess the impact of smoke exposure on the clinical phenotype of AATD in Ireland. Clinical demographics and available thoracic computerised tomography (CT) imaging were detected from 139 PiZZ individuals identified from the Irish National AATD Registry. Clinical information was collected by questionnaire. Data was analysed to assess AATD disease severity and evaluate predictors of clinical phenotype. Questionnaires were collected from 107/139 (77%) and thoracic CT evaluation was available in 72/107 (67.2%). 74% of respondents had severe Chronic Obstructive Pulmonary Disease (COPD) (GOLD stage C or D). Cigarette smoking was the greatest predictor of impairment in FEV1 and DLCO (%predicted) and the extent of emphysema correlated most significantly with DLCO. Interestingly the rate of FEV1 decline was similar in ex-smokers when compared to never-smokers. Passive smoke exposure in childhood resulted in a greater total pack-year smoking history. Radiological evidence of bronchiectasis was a common finding and associated with increasing age. The Irish National AATD Registry facilitates clinical and basic science research of this condition in Ireland. This study illustrates the detrimental effect of smoke exposure on the clinical phenotype of AATD in Ireland and the benefit of immediate smoking cessation at any stage of lung disease.