ORGAN INVOLVEMENT AND PAIN PHENOTYPES IN GRANULOMATOSIS WITH POLYANGIITIS

C. Oprea¹, E. Russu^1|2, L. Rotaru², L. Groppa² | ¹Timofei Mosneaga Republican Clinical Hospital, Chisinau, Republic of Moldova; ²Nicolae Testemitanu State Medical and Pharmaceutical University, Chisinau, Republic of Moldova

Abstract

Background and Aims. Pain in granulomatosis with polyangiitis (GPA) reflects both inflammatory activity and organ-specific damage. Identifying pain patterns related to organ involvement may improve disease monitoring. This study aimed to characterize pain phenotypes in GPA.
Methods. A prospective study included 11 patients with GPA who were followed for 18 months. Pain intensity was assessed using the visual analog scale. Clinical variables included renal and pulmonary involvement, BVAS, and inflammatory markers. Statistical analysis included correlation and cluster analysis.
Results. Three pain phenotypes were identified: 1. Inflammatory pain phenotype (36%)—high BVAS (19.2±3.1), high CRP (24.1±6.2 mg/L), pain score 7.0±1.0; 2. Organ-damage-related pain phenotype (41%) – associated with renal impairment (eGFR < 45 mL/min/1.73 m²), pain 6.5 ± 1.1. Low-burden phenotype (23%)—mild disease activity and lower pain (4.2±1.2). Pulmonary cavitary lesions were associated with higher pain intensity (6.9±1.0 vs 5.2±1.3; p=0.02), while renal involvement significantly increased pain variability (variance ratio=1.8; p=0.03). Pain correlated with CRP (r=0.41; p=0.04) and BVAS (r=0.46; p=0.02). Combined organ involvement increased the probability of high pain burden (OR=4.2; p=0.01).
Conclusions. Pain in GPA is heterogeneous and closely linked to inflammatory and organ-specific mechanisms. Identification of pain phenotypes may support personalized therapeutic strategies.