Augmentation therapy of alpha-1 antitrypsin deficiency associated emphysema

Assessment of Patient Perspectives and Barriers to Self-Infusion of Augmentation Therapy for Alpha-1 Antitrypsin Deficiency During the COVID-19 Pandemic

Introduction

Alpha-1 antitrypsin (AAT) deficiency is an autosomal co-dominant genetic condition that predisposes individuals to pulmonary and hepatic disease, and in severe cases is treated with augmentation by intravenous infusion. Our aim was to assess patient reluctance to transition to self-administered augmentation of alpha-1-antitrypsin, during the pandemic of SARS-CoV-2.

Methods

A phone questionnaire was administered to 22 patients with severe alpha-1-antitrypsin deficiency who were currently receiving AAT augmentation therapy. Inclusion criteria included patients \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 18 years old, diagnosed with AATD, and receiving intravenous AAT protein augmentation therapy. Information was gathered regarding demographics, perspectives on transitioning to self-administered treatment, and anxiety and depression prevalence. Results were collected anonymously using REDCap. Joint and marginal statistical analysis was done to quantify links between participants’ willingness to transition to self-infusion and correlations with sex, age, years of therapy, anxiety, and depression.

Results

Of 22 patients, 14 were male and eight were female. Ages ranged from 36 to 79 years, with an average of 62.5. Genotypes were ZZ (14), MZ (3), and SZ (2) among others. Average length of intravenous augmentation was 9.5 years. The majority, 16 participants, were aware self-infusion was an option. Eight participants were willing to consider transitioning to self-infusion if trained and educated. Eight patients reported that fear of COVID-19 transmission influenced their decision-making. Above-normal anxiety, and depression scores, were found in four, and six patients, respectively. Neither sex, age, years of treatment, anxiety, or depression were found to be associated with willingness to consider self-infusion therapy.

Conclusions

Although there are many reasons AATD patients may benefit from AAT self-infusion, including decreased exposure to SARS-CoV-2, the majority preferred home nurse-infused therapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-022-00182-z.

S-Nitrosylation of α1-Antitrypsin Triggers Macrophages Toward Inflammatory Phenotype and Enhances Intra-Cellular Bacteria Elimination

Background: Human α1-antitrypsin (hAAT) is a circulating anti-inflammatory serine-protease inhibitor that rises during acute phase responses. in vivo, hAAT reduces bacterial load, without directly inhibiting bacterial growth. In conditions of excess nitric-oxide (NO), hAAT undergoes S-nitrosylation (S-NO-hAAT) and gains antibacterial capacity. The impact of S-NO-hAAT on immune cells has yet to be explored.

Aim: Study the effects of S-NO-hAAT on immune cells during bacterial infection.

Methods: Clinical-grade hAAT was S-nitrosylated and then compared to unmodified hAAT, functionally, and structurally. Intracellular bacterial clearance by THP-1 macrophages was assessed using live Salmonella typhi. Murine peritoneal macrophages were examined, and signaling pathways were evaluated. S-NO-hAAT was also investigated after blocking free mambranal cysteine residues on cells.

Results: S-NO-hAAT (27.5 uM) enhances intracellular bacteria elimination by immunocytes (up to 1-log reduction). S-NO-hAAT causes resting macrophages to exhibit a pro-inflammatory and antibacterial phenotype, including release of inflammatory cytokines and induction of inducible nitric oxide synthase (iNOS) and TLR2. These pro-inflammatory effects are dependent upon cell surface thiols and activation of MAPK pathways.

Conclusions: hAAT duality appears to be context-specific, involving S-nitrosylation in a nitric oxide rich environment. Our results suggest that S-nitrosylation facilitates the antibacterial activity of hAAT by promoting its ability to activate innate immune cells. This pro-inflammatory effect may involve transferring of nitric oxide from S-NO-hAAT to a free cysteine residue on cellular targets.

Recombinant Adeno-Associated Virus Vector Genomes Take the Form of Long-Lived, Transcriptionally Competent Episomes in Human Muscle

Gene augmentation therapy as a strategy to treat alpha-1 antitrypsin (AAT) deficiency has reached phase 2 clinical testing in humans. Sustained serum levels of AAT have been observed beyond one year after intramuscular administration of a recombinant adeno-associated virus (rAAV) vector expressing the AAT gene. In this study, sequential muscle biopsies obtained at 3 and 12 months after vector injection were examined for the presence of rAAV vector genomes. Each biopsy sample contained readily detectable vector DNA, the majority of which existed as double-stranded supercoiled and open circular episomes. Episomes persisted through 12 months, although at slightly lower levels than observed at 3 months. There was a clear dose response when comparing the low- and mid-vector-dose groups to the high-dose group. The highest absolute copy numbers were found in a high-dose subject, and serum AAT levels at 12 months confirmed that the high-dose group also had the highest sustained serum AAT levels. Sequence analysis revealed that the vast majority of episomes contained double-D inverted terminal repeats ranging from fully intact to severely deleted. Molecular clones of vector genomes derived directly from the biopsies were transcriptionally active, potentially identifying them as the source of serum AAT in the trial subjects.