Long-term outcome of 251 patients with Takayasu arteritis on combination immunosuppressant therapy:: Single centre experience from a large tertiary care teaching hospital in Southern India

Abstract Introductio Long term outcome studies in Takayasu arteritis (TA) are few and limited by small sample size. In this study, we analysed the outcome of treatment in a large series of TA patients with a minimum follow up period of ≥ 12 months by objective instruments. Materials and Methods Patients with TA satisfying the 1990 ACR, Ishikawa's, Sharma's or EULAR/PRESS criteria were recruited from our clinics between 1998 and 2016. Only patients with a minimum follow up of 12 months were studied. Data related to clinical presentation, disease extent [DEI.Tak score], activity [Indian Takayasu arteritis clinical activity score i.e. ITAS-A (CRP)] and damage score [Takayasu Arteritis Damage Score i.e. (TADS)], angiography and treatment were collected for all patients. Response to treatment was categorised as complete response (CR), partial response (PR) or refractory disease. Patients with sustained CR on prednisolone dose of ≤ 5mg/day were classified as having sustained inactive disease. Appropriate statistical tests were used for parametric and non-parametric data. Relapse free survival was projected by Kaplan Meir curve. Cox proportional hazards regression plot was used to compare the efficacy of medications. Predictors of sustained response were identified by logistic regression and a prediction model was constructed. Results Among 503 TA patients examined during study period, 251 had follow-up of ≥ 12 months and were included in this study. Median follow up duration was 42 months (IQR: 24-81, maximum 240 months). Patients (81.7% females, mean age of 29.2 ± 11.8 years, symptom duration of 24 (6-70) months) were treated by a uniform protocol that included high dose steroids (n=239) plus concurrent steroid-sparing immunosuppressant (n=235) with mycophenolate in majority. Biological agents (n= 44 patients) and revascularisation procedures were used in symptomatic patients after control of disease activity. At 1 st follow up, CR (ITAS2010 =0, CRP 87 (49.4%) of them achieved sustained inactive disease . Disease activity relapsed at a median duration of 37 (29.9- 44.1) months in 56 patients. Cumulative relapse free survival was 93%, 73%, 66% and 52% at 1, 3, 5 and 10 years respectively. Baseline CRP 1) was arrested in 68% of patients and was lower in patients with sustained inactive disease [0 (0-1)] as compared to the rest [1 (0-2.75)], p=0.000. Both early response as well as cumulative hazard for relapse was similar between patients initiated on 0.5mg/kg/d and 1mg/kg/d steroids. Conclusions Our strategy of upfront combination immunosuppressant therapy stabilised disease activity in 92.8% of patients while 7.2% had true refractory disease. Relapse free survival was 66% at 5 years and 52% at 10 years. Damage progression was arrested in 68% and only 2 fatalities were observed. Initial steroid dose of 0.5mg/kg/day had similar efficacy as 1mg/kg/day dose.