# Granulomatosis with Polyangiitis (GPA) in a Polish Tertiary Centre (2010–2025): Sex-Stratified Phenotypes, Serology, and Evolving Treatment Patterns

## TL;DR

This study examines GPA in Poland, highlighting common symptoms, treatment changes, and sex-based differences over 15 years.

## Contribution

The paper provides real-world, sex-stratified insights into GPA management and evolving treatment trends in a Polish tertiary center.

## Key findings

- ENT disease was the most common manifestation, with rhinosinusitis affecting 76% of patients.
- Kidney involvement was frequent but variable, with 22% experiencing rapidly progressive kidney disease.
- Treatment shifted toward rituximab and steroid minimisation, with tofacitinib emerging as a potential maintenance therapy.

## Abstract

Background/Objectives: GPA is a PR3-ANCA–predominant small vessel vasculitis with organ involvement. Real-world, single-centre data are needed to interpret evolving therapies and phenotype patterns in national conditions. Material and Methods: Retrospective cohort study of consecutive GPA patients managed at the National Institute of Geriatrics, Rheumatology and Rehabilitation (Warsaw, Poland) from 1 September 2010 to 1 September 2025. Data included demographics, phenotype, BVAS, organ involvement, PR3/MPO-ANCA serology, and induction/maintenance therapies. Results: Fifty patients were included (54.0% men). Mean age was 52.5 years; mean BMI was 26.15 kg/m2. Ear-nose-throat (ENT) disease was frequent: rhinosinusitis 76.0%, nasal cartilage destruction 64.0%, subglottic stenosis 34.0%. Pulmonary nodules occurred in 52.0%, cavitation in 28.0%, and diffuse alveolar haemorrhage in 34.0%. Renal involvement included haematuria in 42.0%, chronic kidney disease (CKD) in 32.0%, and rapidly progressive kidney disease in 22.0%. Orbital inflammation was 36.0%, and PR3-ANCA was positive in 70.0%. All patients received glucocorticoids for induction; cyclophosphamide 28/50 (56.0%), rituximab 6/50 (12.0%), and mycophenolate with methotrexate 6/50 (32%). Maintenance therapy included methotrexate (78.0%), mycophenolate (64.0%), rituximab (52.0%), and azathioprine (12.0%). Conclusions: This Polish single-centre cohort shows an ear-nose-throat-lung-kidney (ELK)-dominant, PR3-predominant GPA phenotype and frequent but variable kidney involvement. Over 2010–2025, practice changed toward rituximab-based strategies, steroid minimisation, selective use of plasma exchange, and early avacopan uptake, with tofacitinib for maintenance therapy as a possible new therapeutic option.