The BLT1 Inhibitory Function of α-1 Antitrypsin Augmentation Therapy Disrupts Leukotriene B4 Neutrophil Signaling.

Leukotriene B4 (LTB4) contributes to many inflammatory diseases, including genetic and nongenetic forms of chronic obstructive pulmonary disease. α-1 Antitrypsin (AAT) deficiency (AATD) is characterized by destruction of lung parenchyma and development of emphysema, caused by low AAT levels and a high neutrophil burden in the airways of affected individuals. In this study we assessed whether AATD is an LTB4-related disease and investigated the ability of serum AAT to control LTB4 signaling in neutrophils. In vitro studies demonstrate that neutrophil elastase is a key player in the LTB4 inflammatory cycle in AATD, causing increased LTB4 production, and associated BLT1 membrane receptor expression. AATD patients homozygous for the Z allele were characterized by increased neutrophil adhesion and degranulation responses to LTB4. We demonstrate that AAT can bind LTB4 and that AAT/LTB4 complex formation modulates BLT1 engagement and downstream signaling events, including 1,4,5-triphosphate production and Ca(2+) flux. Additionally, treatment of ZZ-AATD individuals with AAT augmentation therapy decreased plasma LTB4 concentrations and reduced levels of membrane-bound neutrophil elastase. Collectively, these results provide a mechanism by which AAT augmentation therapy impacts on LTB4 signaling in vivo, and not only reinforces the utility of this therapy for resolving inflammation in AATD, but supports useful future clinical applications in treatment of other LTB4-related diseases.

Alpha-1 antitrypsin augmentation therapy corrects accelerated neutrophil apoptosis in deficient individuals.

Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by neutrophil-driven lung destruction and early emphysema in a low AAT, and high neutrophil elastase environment in the lungs of affected individuals. In this study, we examined peripheral blood neutrophil apoptosis and showed it to be accelerated in individuals with AATD by a mechanism involving endoplasmic reticulum stress and aberrant TNF-α signaling. We reveal that neutrophil apoptosis in individuals homozygous for the Z allele (PiZZ) is increased nearly 2-fold compared with healthy controls and is associated with activation of the external death pathway. We demonstrate that in AATD, misfolded AAT protein accumulates in the endoplasmic reticulum of neutrophils, leading to endoplasmic reticulum stress and the expression of proapoptotic signals, including TNF-α, resulting in increased apoptosis and defective bacterial killing. In addition, treatment of AATD individuals with AAT augmentation therapy decreased neutrophil ADAM-17 activity and apoptosis in vivo and increased bacterial killing by treated cells. In summary, this study demonstrates that AAT can regulate neutrophil apoptosis by a previously unidentified and novel mechanism and highlights the role of AAT augmentation therapy in ameliorating inflammation in AATD.

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.

Increased outer arm and core fucose residues on the N-glycans of mutated alpha-1 antitrypsin protein from alpha-1 antitrypsin deficient individuals.

Alpha-1 antitrypsin (AAT) is the major physiological inhibitor of a range of serine proteases, and in the lung, it maintains a protease-antiprotease balance. AAT deficiency (AATD) is an autosomal co-dominant condition with the Z mutation being the most common cause. Individuals homozygous for Z (PiZZ) have low levels of circulating mutant Z-AAT protein leading to premature emphysematous lung disease. Extensive glycoanalysis has been performed on normal AAT (M-AAT) from healthy individuals and the importance of glycosylation in affecting the immune modulatory roles of AAT is documented. However, no glycoanalysis has been carried out on Z-AAT from deficient individuals to date. In this study, we investigate whether the glycans present on Z-AAT differ to those found on M-AAT from healthy controls. Plasma AAT was purified from 10 individuals: 5 AATD donors with the PiZZ phenotype and 5 PiMM healthy controls. Glycoanalysis was performed employing N-glycan release, exoglycosidase digestion and UPLC analysis. No difference in branched glycans was identified between AATD and healthy controls. However, a significant increase in both outer arm (α1-3) (p = 0.04) and core (α1-6) fucosylated glycans (p < 0.0001) was found on Z-AAT compared to M-AAT. This study has identified increased fucosylation on N-glycans of Z-AAT indicative of ongoing inflammation in AATD individuals with implications for early therapeutic intervention.

The effect of the decoy molecule PA401 on CXCL8 levels in bronchoalveolar lavage fluid of patients with cystic fibrosis.

BACKGROUND: The chemokine interleukin-8 (CXCL8) is a key mediator of inflammation in airways of patients with cystic fibrosis (CF). Glycosaminoglycans (GAGs) possess the ability to influence the chemokine profile of the CF lung by binding CXCL8 and protecting it from proteolytic degradation. CXCL8 is maintained in an active state by this glycan interaction thus increasing infiltration of immune cells such as neutrophils into the lungs. As the CXCL8-based decoy PA401 displays no chemotactic activity, yet demonstrates glycan binding affinity, the aim of this study was to investigate the anti-inflammatory effect of PA401 on CXCL8 levels, and activity, in CF airway samples in vitro. METHODS: Bronchoalveolar lavage fluid (BALF) was collected from patients with CF homozygous for the ΔF508 mutation (n=13). CXCL8 in CF BALF pre and post exposure to PA401 was quantified by ELISA. Western blot analysis was used to determine PA401 degradation in CF BALF. The ex vivo chemotactic activity of purified neutrophils in response to CF airway secretions was evaluated post exposure to PA401 by use of a Boyden chamber-based motility assay. RESULTS: Exposure of CF BALF to increasing concentrations of PA401 (50-1000pg/ml) over a time course of 2-12h in vitro, significantly reduced the level of detectable CXCL8 (P<0.05). Interestingly, PA401 engendered release of CXCL8 from GAGs exposing the chemokine susceptible to proteolysis. Subsequently, a loss of PA401 was observed (P<0.05) due to proteolytic degradation by elastase like proteases. A 25% decrease in neutrophil chemotactic efficiency towards CF BALF samples incubated with PA401 was also observed (P<0.05). CONCLUSION: PA401 can disrupt CXCL8:GAG complexes, rendering the chemokine susceptible to proteolytic degradation. Clinical application of a CXCL8 decoy, such as PA401, may serve to decrease the inflammatory burden in the CF lung in vivo.

Intracystic papillary carcinoma in a male as a rare presentation of breast cancer: a case report and literature review.

INTRODUCTION: The term "intracystic papillary ductal carcinoma in situ" has recently changed and is now more appropriately referred to "intracystic papillary carcinoma". Intracystic papillary carcinoma in men is an extremely rare disease with only a few case presentations published in the literature so far. CASE PRESENTATION: We discuss a case of a 44-year-old Caucasian man with an intracystic papillary carcinoma treated with simple mastectomy, sentinel lymph-node biopsy and contralateral risk-reducing mastectomy. These were followed by adjuvant radiotherapy of the breast. CONCLUSION: Triple assessment (i.e. clinical examination and radiological and histological assessment) with a high level of clinical suspicion is necessary to diagnose intracystic papillary carcinoma in men due to its rarity. Furthermore, genetic testing and risk-reducing mastectomy should also be considered in cases of a strong family history for male breast cancer.