Adult-onset still's disease and treatment results with tocilizumab

Adult-onset Still's disease (AOSD) is a rare and non-familial auto-inflammatory disorder. Increased levels of IL-6 and other pro-inflammatory cytokines have been shown in AOSD. To evaluate the efficacy and safety profile of tocilizumab (TCZ), an IL-6 receptor antagonist monoclonal antibody, in AOSD.

Thirty-nine patients followed up with the diagnosis of AOSD between 2013 and 2019 were retrospectively evaluated and the 16 patients (10 Female/6 Male) treated with TCZ for refractory AOSD were included in the study group. Among the remaining 23 patients 16 had non-biological treatments and had no important complications at the presentation. TCZ was given to patients at a dose of 4-8 mg/kg every 4 weeks. Patients were evaluated after 3-6 months of TCZ treatment for side effects, inflammatory and clinical response and concomitant treatments.

In TCZ (+) patients, the majority were female (62.5%), the mean age at disease onset was 38.5 ± 17.9 (20-81) years, and the most common symptoms and signs were myalgia (81.3%), fever (81.3%) and skin eruptions (75%). There was no difference between TCZ (+) and TCZ (-) groups for age, sex and clinical presentations. There was a significant decrease in dose of prednisolone, sedimentation rate, leucocyte count, C-reactive protein and ferritin levels and improvement in all clinical complaints after TCZ treatment. There were no relapses during the treatment. Three patients are in remission and under follow-up without any treatment after cessation of TCZ (4 months-3 years). No exacerbation of disease yet seen in those patients.

TCZ is an effective and well-tolerated treatment option for treatment resistant AOSD and contributes to the glucocorticoid-sparing. Since TCZ is a new drug in the treatment of AOSD, further studies are needed to assess whether the complications reported during the treatment are because of TCZ or natural course of the disease or coincidental findings.