A deficiency in alpha-1-antitrypsin (AAT), a serine protease inhibitor encoded by the SERPINA1 gene, does not appear to increase the risk of vasculitis associated with anti-neutrophil cytoplasmic antibodies (ANCA) in patients with chronic obstructive pulmonary disease (COPD), according to study findings published in CHEST.
In the study, a cohort of 185 patients with AAT deficiency-related COPD were enrolled from a larger study conducted in France. Indirect immunofluorescence staining of ethanol-fixed human peripheral blood neutrophils was performed to test all sera for ANCAs. Additionally, researchers tested for anti-PR3 and anti-MPO antibodies using enzyme-linked immunosorbent assay. Symptoms suggestive of ANCA-associated vasculitis were examined using a clinical database.
Approximately 87% (n=157) of the patients had the PI*ZZ phenotype and 8% (n=14) had the PI*SZ phenotype. None of the patients tested positive for anti-MPO antibodies, but 1 patient was positive for anti-PR3 antibodies. The patient with a positive anti-PR3 antibody test did not have signs suggestive of ANCA-associated vasculitis, according to medical history and 1-year follow-up data. Based on these data, the prevalence of ANCA-associated vasculitis was 0%, which the investigators suggested was not significantly different from the estimated 0.006% prevalence rate of ANCA-associated vasculitis in the general population.
Study limitations included the small sample size as well as the inclusion of patients from a single restricted geographical location in Europe.
In spite of these limitations, the researchers argued that “because of the low prevalence of ANCAs and ANCA-associated vasculitis symptoms in severe AAT-deficient patients with COPD, systematic screening appears not to be appropriate.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Deshayes S, Silva NM, Khoy K, et al. Prevalence of anti-neutrophil cytoplasmic antibodies and associated vasculitis in chronic obstructive pulmonary disease associated with alpha-1-antitrypsin deficiency: an ancillary study to a prospective study on 180 French patients [published online May 14, 2020]. CHEST. doi:10.1016/j.chest.2020.04.054