Background Biologics offer effective ways to treat autoimmune arthritis avoiding radiological progression. Yet, it has its own risks and hazards, most common - infectious complications.

Objectives To evaluate the incidence of infectious complications in patients with autoimmune arthritis (AA) treated with biological therapy (BT).

Methods Patients with AA (rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), juvenile idiopathic arthritis (JIA)), treated with BT agents (Infliximab (INX), Adalimumab (ADA), Etanercept (ETA) or Rituximab (RTX)) were tested for any infectious events at the start of treatment, after 12, 24 and then every 24 weeks during treatment with BT. The data was collected from 01 Dec 2007 to 01 Jan 2013. Statistical analysis was performed with SPSS 17.0 and Microsoft Excel programs. The study was approved by Lithuanian Bioethics committee.

Results 269 patients treated with BT were evaluated for adverse events (AE). From all (289) AE reported, half (n=145; 52.35%) of them were from infections (female – 89; 61.38%, male – 56; 38.62%). Infections mostly were reported in RA patients (n=82; 56.55%), less so in PsA patients (n=27; 18.62%), AS (n=24; 16.55%) and JIA (n=12; 8.28%). Most of infections were upper respiratory tract (n=44; 30.34%) and urogenital system infections (n=32; 22.07%) for INX, ADA, ETA, RTX users were 60.81, 98.78, 93.96, 30.55; and, 30.40, 89.80, 57.82, 76.37, respectively (per 1000 patient years). Less common were ear-nose-throat infections (n=24; 16.55%) (33.78, 35.92, 65.05 and 15.27), cutaneous infections (n=16; 11.03%) (30.40, 26.94, 28.91 and 0 respectively). There were 11 cases of tuberculosis (TB) (7.59%) (10.13, 53.88, 14.46 and 0 per 1000 patient years respectively for INX, ADA, ETA and RTX), and 3 cases of sepsis (2.07%) (6.76, 8.98, 0 and 0 per 1000 patient years). Two cases of active TB was diagnosed in INX patients, the remaining 9 cases were latent TB, all treated prophylactically before resuming BT.

Nearly half of infections were mild (n=68; 46.9%), severe infections were seen in 9 patients (6.21%) and for one patient (0.69%) was the cause of death. The onset of infectious AE on average were seen after 19,6 [95% CI: 16,68-22,54] months after the start of BT and lasted approximately 22,47 days [95% CI: 13,64-31,3]. Infections were most common among patients treated with ADA - 332.26 per 1000 patient years; least common - with RTX - 152.74; INF - 202.69 and ETA - 274.67, respectively.

No correlation between infection severity and patient's age, gender, diagnosis, BT drug, time of AE occurrence, duration and outcomes were found (p<0,05).

Conclusions Half of AE in patients with AA treated with BT were infections (n=145; 50.23%). Highest rate of infectious complications were seen in patients with RA. Upper respiratory tract and urogenital system infections were most common. They were most often seen in patients treated with ADA and the least - in patients with RTX. Half of infections were mild. Average onset of infections were after 19,6 months after initiation of BT and lasted an average of 22,47 days.

References

1. E.D. Dommasch, K. Abuabara et al. J Am Acad Dermatol 2011;64(6):1035-50.

2. J.B. Galloway, K.L. Hyrich et al. Rheumatology 2011;50:124-31.

3. S.A.A. van Dartel, J. Fransen et al. Ann Rheum Dis 2013;72:895-900.

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.1791