The clinical characteristics and treatment outcomes of patients with systemic polyarteritis nodosa: a single-centre...

To describe the clinical profile and compare the long-term outcomes of patients with systemic polyarteritis nodosa (S-PAN) treated with various treatment regimens at our centre in the last two decades.

Data regarding clinical presentation, treatment allocation, relapses and outcomes of patients fulfilling American College of Rheumatology (ACR) 1990 criteria for PAN in the last two decades were recorded from electronic medical records. Relapse-free survival and predictors were analysed using Kaplan-Meier survival statistics and regression analysis.

Altogether, 53 patients, including two with hepatitis B infection, were included. Cutaneous lesions and peripheral neuropathy were the commonest manifestations. Most patients (64.2%) presented with a five-factor score (FFS) of 0. Disease-attributable hypertension and peripheral gangrene were the most common manifestations of severe disease. During a median follow-up period of 53.5 months in 49 patients who had a follow up, 43 (87.8%) attained complete response while 3 (6.1%) had a partial response. Among 46 patients who had follow up of more than 3 months, 19 (41.3%) patients relapsed at a median duration of 82 (interquartile range 36.3-127.7) months. The relapse-free survival in patients who received induction with mycophenolate (n = 26) was comparable to that with cyclophosphamide (n = 21) [adjusted hazard ratio (HR): 0.68]. Smoking history was an independent predictor of relapse (HR = 6.28, P = 0.013) while age was protective (HR = 0.94, P = 0.015). Overall, fatality was observed in 5 (10%) patients. FFS and BVAS at 3 months were among the predictors of mortality.

In our cohort of S-PAN, relapses were observed in 41.3% of patients. Mycophenolate was similar to cyclophosphamide in maintaining relapse-free survival. Only 10% fatality was recorded. FFS and BVAS at 3 months were predictors of mortality.