To estimate the prevalence and describe the etiological distribution of immune-mediated hypertrophic pachymeningitis (HP) in São Paulo, Brazil.
Approach:
Study Design: A retrospective observational study conducted at a dedicated outpatient clinic for HP at Hospital das Clínicas, Universidade de São Paulo, from 2025 to 2026.
Key Findings:
HP is not as rare in Brazil as previously thought, with a spectrum of associated systemic diseases differing from Japan.
IgG4-related disease and ANCA-associated vasculitis were significant contributors to HP cases.
Interpretation:
The study provides insights into the prevalence and causes of HP in a Latin American context, highlighting the need for further research in this area.
Limitations:
HP is not a notifiable disease, making prevalence estimation challenging.
The assumption of comparable referral patterns between HP and multiple sclerosis may not hold true.
Conclusion:
['The findings suggest a higher prevalence of HP in São Paulo, Brazil, with distinct etiological patterns compared to other regions.']
