Abstract
Background The frequency of proteinase 3 gene (PRTN3) polymorphisms in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is not fully characterised. We hypothesise that the presence of a PRTN3 gene polymorphism (single nucleotide polymorphism (SNP) rs351111) is relevant for clinical outcomes. Methods DNA variant calling for SNP rs351111 (chr.19:844020, c.355G>A) in PRTN3 gene assessed the allelic frequency in patients with PR3-AAV included in the Rituximab in ANCA-Associated Vasculitis trial. This was followed by RNA-seq variant calling to characterise the mRNA expression. We compared clinical outcomes between patients homozygous for PRTN3-Ile 119 or PRTN3-Val 119. Results Whole blood samples for DNA calling were available in 188 patients. 75 patients with PR3-AAV had the allelic variant: 62 heterozygous PRTN3-Val 119 Ile and 13 homozygous for PRTN3-Ile 119. RNA-seq was available for 89 patients and mRNA corresponding to the allelic variant was found in 32 patients with PR3-AAV: 25 heterozygous PRTN3-Val 119 Ile and 7 homozygous for PRTN3-Ile 119. The agreement between the DNA calling results and mRNA expression of the 86 patients analysed by both methods was 100%. We compared the clinical outcomes of 64 patients with PR3-AAV: 51 homozygous for PRTN3-Val 119 and 13 homozygous for PRTN3-Ile 119. The frequency of severe flares at 18 months in homozygous PRTN3-Ile 119 was significantly higher when compared with homozygous PRTN3-Val 119 (46.2% vs 19.6%, p=0.048). Multivariate analysis identified homozygous PR3-Ile 119 as main predictor of severe relapse (HR 4.67, 95% CI 1.16 to 18.86, p=0.030). Conclusion In patients with PR3-AAV, homozygosity for PRTN3-Val 119 Ile polymorphism appears associated with higher frequency of severe relapse. Further studies are necessary to better understand the association of this observation with the risk of severe relapse.
Original language | English (US) |
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Article number | e002935 |
Journal | RMD Open |
Volume | 9 |
Issue number | 1 |
DOIs | |
State | Published - Mar 29 2023 |
Keywords
- Autoantibodies
- Granulomatosis with polyangiitis
- Outcome Assessment, Health Care
- Polymorphism, Genetic
- Systemic vasculitis
ASJC Scopus subject areas
- Rheumatology
- Immunology and Allergy
- Immunology