AB0368 TREATMENT OF SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITH BELIMUMAB – PROSPECTIVE OBSERVATION OVER 2 YEARS

Background:Systemic lupus erythematosus (SLE) is autoimmune connective tissue disorder of unclear etiology. It is characterized by autoantibody production and a variety of clinical manifestations. The introduction of biological treatment over the past few years provided an opportunity for a disease control.Objectives:The aim was to assess the effectiveness and safety profile of Belimumab in the treatment programs of SLE patients during a 2 year period.Methods:We initiated a prospective observational study of SLE patients in the Rheumatology Department in University Hospital St Marina – Bulgaria. The study comprises data from 26 patients at baseline before Belimumab treatment initiation and data after 6, 12, 18 and 24 months of treatment. All patients were with moderate disease activity according to SELENA – SLEDAI index and were on treatment with immunosuppressive drug (azathioprine) and glucocorticoids (GCs). We observed the change in the dosage of glucocorticoids over the observed period, the number of flares of SLE, as well the SELENA – SLEDAI index change. Safety profile of Belimumab was also registered.Results:We included 26 patients with SLE over a period of 4 years – between 2015 and 2019. The mean age was 45.8 + 11.4 years and 94% were Caucasian females. All patients were on a stable dosage of GCs at least 3 months before the first infusion of Belimumab and azathioprine 100 mg daily. Ninety percent of patients were diagnosed with SLE for more than 6 years according to ACR – SLE criteria. All of SLE patients were with moderate disease activity. Main reasons for biological treatment decision were persistent mucocutaneous manifestations (20%), polyarthritis (15%), haematological disturbances (35%) and persistent immunological markers (30%). One patient was excluded from the study due to infusion- related flush and severe hypotension reaction while the rest 25 completed the observation. We investigated and analyzed haematological results, ANA, anti – ds DNA, anti – Sm autoantibodies and complement fractions at baseline as well on the 12th and 24th month of treatment. The mean SELENA – SLEDAI index changed from 8.9 to 4.5 after 12 months of treatment and remained unchanged until the end of the study. We observed a mean reduction of GCs daily dosage from 12 mg to 6 mg after 18 months.Conclusion:Biological treatment with Belimumab added to the standard treatment with GCs and AZA in patients with non-lupus nephritis SLE patients adds additional benefits. Our results show that there is a reduction in SLEDAI index as well as reduction in daily GCs intake. Safety profile is not different from the one reported previously.Disclosure of Interests:None declared