PURULENT-NECROTIC COMPLICATIONS OF THE MAXILLOFACIAL REGION IN ANCA-ASSOCIATED SYSTEMIC VASCULITIS: CLINICAL, IMMUNOMORPHOLOGICAL CHARACTERISTICS AND A DIFFERENTIATED TREATMENT ALGORITHM

Background: Oral and maxillofacial lesions may be the presenting manifestation of ANCA-associated vasculitis (AAV), yet data comparing their clinical, serological and morphological profile across disease phenotypes, and the outcomes of structured treatment, are scarce. Methods: In this hospital-based observational cohort (2023–2026), 104 patients with AAV and purulent-necrotic maxillofacial lesions (GPA n = 46, MPA n = 32, EGPA n = 26) were assessed clinically, serologically (ANCA, IL-6, TNF-α), morphologically (histology, immunohistochemistry) and by MSCT; 20 healthy individuals served as a reference group. Patients were stratified by lesion severity (mild n = 42, moderate n = 32, severe n = 30) and treated with necrectomy, rituximab-based immunosuppression and microcirculation-targeted therapy, with local platelet-rich plasma added in moderate and severe disease and a rheological agent in severe disease. Follow-up was 12 months. Because enrolment required a maxillofacial lesion, the study describes the profile of lesion-positive patients and does not estimate lesion frequency in AAV; comparisons are descriptive. Results: GPA was characterised by PR3-ANCA (82.6%), granulomatous inflammation (78.3%) and CD68+ macrophage infiltration (80.4%); MPA by MPO-ANCA (75.0%); EGPA by eosinophilic infiltration (80.8%), elevated IgE (80.8%) and a more chronic course. Complete epithelialisation at short-term control was documented in 73.8%, 62.5% and 56.7% of the mild, moderate and severe groups, with IL-6 and TNF-α reductions of 52.6–60.0%. At 12 months, complete remission was seen in 65.4% and recurrence in 11.5%; recurrence did not differ significantly between phenotypes (p = 0.567). Conclusions: Among patients with established maxillofacial lesions, AAV phenotypes differ in clinical, serological and morphological profile. Treatment outcomes, obtained without a control group, require confirmation in prospective, multicentre studies of unselected AAV cohorts.