This study aims to characterize demographically and clinically the population of patients diagnosed with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis with neurological manifestations treated at San Ignacio University Hospital between the years 2005 and 2023.

Few studies in Latin America describe ANCA-associated vasculitis, none supplying neurological characterization of clinical and paraclinical profiles for affected patients

This case-control study examined our institution's patient records for ANCA-associated vasculitis from 2005 to 2023. Inclusion criteria involved patients meeting American College of Rheumatology criteria and presenting neurological symptoms. We compared clinical and laboratory profiles against controls without neurological symptoms from a previously published cohort (Fernandez-Avila et al.) by our research group.

We included forty-nine (n=49) cases and eighty (n=80) controls. Regarding cases with neurological involvement, the median age was 59 (50-69) years, and 63% of patients were female. We diagnosed 65% of cases during hospital stays, and in-hospital mortality was 14.6%. Microscopic polyangiitis accounted for 36.7% of cases, followed by granulomatosis with polyangiitis (30.6%), undetermined ANCA-associated vasculitis (26.5%), and eosinophilic granulomatosis with polyangiitis (6.1%). The most common neurological manifestations were cranial nerve palsy (30.6%), multiple mononeuropathy (26.5%), and headache (24.4%). When compared to the control group, patients with neurological manifestations presented lower levels of creatinine at onset (0.94 vs. 4.37 mg/dL, p<0.001), renal involvement was less frequent (51 vs. 86%, p<0.001), and a five-factor score (FFS) ≥2 was more frequent (44.9 vs 40.2%). Treatment regimens included glucocorticoids 89.8%, cyclophosphamide 46.9%, azathioprine 26.5%, and rituximab 22%.

This study presents a clinical characterization of the neurological profile of patients with ANCA-associated vasculitis in a Latin American third-level hospital. Renal involvement was less frequent among cases; however, a higher FFS was more frequent.