CHEST Guidelines-Prevalence-of-Anti-Neutrophil-Cytoplasmic-Antibodi

Prevalence-of-Anti-Neutrophil-Cytoplasmic-Antibodi

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This research letter explores the prevalence of anti-neutrophil cytoplasmic antibodies (ANCAs) and associated vasculitis in patients with chronic obstructive pulmonary disease (COPD) linked to Alpha-1 Antitrypsin Deficiency (AATD). AAT, a serine protease inhibitor, is encoded by the SERPINA1 gene. Mutations in this gene, like the PI*S and PI*Z alleles, can cause AAT proteins to become nonfunctional, contributing to conditions like emphysema and systemic inflammatory disorders such as ANCA-associated vasculitis.<br /><br />The study utilized serum samples from 180 French patients with AATD-related COPD to examine ANCA presence through indirect immunofluorescence and enzyme-linked immunosorbent assay tests for anti-PR3 and anti-MPO antibodies. Surprisingly, none of the patients were diagnosed with ANCA-associated vasculitis, and only one patient tested positive for anti-PR3 antibodies, showing no vasculitis symptoms. The researchers concluded that the prevalence of ANCA-associated vasculitis in this cohort was 0%, aligning with the general population's prevalence of 0.006%.<br /><br />Despite a statistical overrepresentation of AATD in patients with ANCA-associated vasculitis, the study suggests that AAT deficiency is not a sufficient factor in developing vasculitis. The authors acknowledge that AAT may play a role in the disease's pathophysiology but doesn't increase the risk per se. <br /><br />With previous studies mostly showing similar findings, the researchers recommend against systematic screening for ANCA-associated vasculitis among severely AAT-deficient patients with COPD, due to the low prevalence observed. They highlight the need for further research to understand the complex interplay between AAT deficiency and ANCA-associated vasculitis, but caution that results may vary in different demographics outside the French cohort studied.

Keywords

Alpha-1 Antitrypsin Deficiency

COPD

ANCA-associated vasculitis

anti-neutrophil cytoplasmic antibodies

SERPINA1 gene

PI*S allele

PI*Z allele

anti-PR3 antibodies

anti-MPO antibodies

French cohort