Anti-α1 Antitrypsin polyclonal antibody, HRP

Severe acute respiratory syndrome virus 2 (SARS-CoV-2) is the cause of the current coronavirus disease 19 (COVID-19) pandemic. Protease inhibitors are under consideration as virus entry inhibitors that prevent the cleavage of the coronavirus spike (S) protein by cellular proteases. Herein, we showed that the protease inhibitor aprotinin (but not the protease inhibitor SERPINA1/alpha-1 antitrypsin) inhibited SARS-CoV-2 replication in therapeutically achievable concentrations. An analysis of proteomics and translatome data indicated that SARS-CoV-2 replication is associated with a downregulation of host cell protease inhibitors. Hence, aprotinin may compensate for downregulated host cell proteases during later virus replication cycles. Aprotinin displayed anti-SARS-CoV-2 activity in different cell types (Caco2, Calu-3, and primary bronchial epithelial cell air-liquid interface cultures) and against four virus isolates. In conclusion, therapeutic aprotinin concentrations exert anti-SARS-CoV-2 activity. An approved aprotinin aerosol may have potential for the early local control of SARS-CoV-2 replication and the prevention of COVID-19 progression to a severe, systemic disease.

Neutrophilic panniculitis associated with alpha-1-antitrypsin deficiency (AATD) is a very rare disease. Its estimated prevalence is 1 in 1000 subjects with severe AATD (usually white individuals with a Pi*ZZ genotype). It is manifested clinically by painful recurrent ulcerating subcutaneous nodules, and characterized histologically by dense infiltrates of neutrophils in the deep dermis and connective-tissue septae, with secondary lobular panniculitis. It may be the only clinical manifestation of AATD, although it can also occur together with the classical pulmonary or hepatic manifestations of the disease. AATD-associated panniculitis is not only very rare but may also be significantly underdiagnosed. The physician managing a case of panniculitis with a clinical presentation suggestive of AATD and a compatible skin biopsy should measure serum AAT concentration and, if low, determine the AAT phenotype by isoelectric focusing. If uncertainty remains, the SERPINA1 gene should be sequenced to identify the genotype. If AATD is diagnosed, AATD testing of first-degree family members should be performed in order to take appropriate preventive and therapeutic measures, including genetic counselling, education on inheritance, risk arising from tobacco smoke, occupational exposure to pollutants and hepatotoxic substances, and the provision of information on clinical management. Cases of panniculitis in which conventional therapy with dapsone has failed may be managed with intravenous augmentative therapy using human AAT. The current manuscript addresses the fundamental concepts of the pathogenesis of AATD-associated panniculitis and describes the clinical presentation and management of cases in order to reduce underdiagnosis and improve outcomes.