Background Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis of medium sized visceral vessels. The 2012 Chapel Hill Consensus Conference Nomenclature of vasculitides defined vasculitis affecting any size of vessel in a single organ without systemic manifestations as single organ vasculitis (SOV). However, cutaneous arteritis (CA) and Gastrointestinal (GI) vasculitis are forms of SOV having indistinguishable histopathological findings from PAN.
Objectives In this study, we aimed to evaluate and compare the demographics, clinical characteristics, treatment, and outcomes of patients with systemic PAN, CA and GI vasculitis.
Methods We assembled retrospective cohorts of patients with PAN, CA and GI vasculitis between 1980 and 2014. The demographics, clinical characteristics, treatment and outcomes of patients were abstracted from medical records. Birmingham Vasculitis Activity Score (BVAS), prognostic Five Factor Score (FFS) and vasculitis damage index (VDI) were calculated.
Results The study included 48 patients with PAN, 41 patients with CA, and 19 patients with GI vasculitis. Only 1 patient presenting as CA evolved to systemic PAN during the disease course. Most cases of PAN were idiopathic, while only 7 patients had hepatitis B and 2 patients had hepatitis C positivity. Constitutional and musculoskeletal manifestations were the most common clinical manifestations in the PAN group and were less frequent in CA and GI vasculitis. At diagnosis, 94% of patients with PAN, 93% of patients with CA and 67% of patients with GI vasculitis were treated with glucocorticoids. Additional immune-suppressive agents were used in 67% of PAN, 37% of GI vasculitis and 32% of CA. Twenty-seven patients with PAN, 18 patients with CA and 9 patients with GI vasculitis had mean follow-up of about 6 years. The five year cumulative relapse rate was 45.2% in CA, and only 9.6% in PAN. VDI was comparable in PAN and GI vasculitis, but was lower in CA. While no deaths were observed in the CA group, survival at 10-years was 66% in the PAN and 61% in GI vasculitis group.
Conclusions CA and GI vasculitis appear to be distinct diseases rather than a limited expression of systemic PAN. Progression of CA to systemic PAN is very rare. Relapse risk is very low during follow-up in PAN. Patients with CA have a higher relapse rate compared to those with systemic PAN, possibly due to lower use of immunosuppressive therapy in the former group.
Disclosure of Interest None declared