Changes in serum interleukin-6 levels as possible predictor of efficacy of tocilizumab treatment in rheumatoid arthritis.

OBJECTIVES: We aimed to evaluate the association between the change in serum IL-6 during the clinical course of tocilizumab (TCZ) therapy and rheumatoid arthritis (RA) disease activity or occurrence of adverse events. METHODS: General laboratory data including serum IL-6 levels and physical findings were obtained every 4 weeks, and, in addition, at the time when any adverse events occurred. RESULTS: The proportion achieving Clinical Disease Activity Index (CDAI) remission at 52 weeks was significantly lower in 20 patients with serum IL-6 ≥ 30 pg/ml at 12 weeks than 24 patients with serum IL-6 < 30 pg/ml. In 17 patients with serum IL-6 ≥ 30 pg/ml at 24 weeks, the proportion achieving CDAI remission was also significantly lower than 27 patients with serum IL-6 < 30 pg/ml then. In these 17 patients, Disease Activity Score (DAS) 28-ESR and CDAI at 52 weeks were significantly higher than those with serum IL-6 < 30 pg/ml. Age- and sex-adjusted logistic regression analysis showed logIL-6 at 12 weeks to be a predictive factor for DAS28-ESR remission at 52 weeks. CONCLUSION: Serum IL-6 levels from 12 to 24 weeks after TCZ initiation better reflect the efficacy of TCZ at 52 weeks.

A case of sarcoidosis developing as sarcoid myopathy concomitant with systemic sclerosis and review of the literature.

A 65-year-old man was diagnosed with systemic sclerosis on the basis of skin thickening and positivity of anti-Scl-70 antibodies. Because myogenic enzymes, such as creatinine phosphokinase and aldorase, were also elevated, myopathy or myositis associated with systemic sclerosis was considered. Muscle magnetic resonance imaging and gallium scintigraphy did not show abnormalities. Findings of muscle biopsy demonstrated presence of noncaseating granulomas with multinucleated giant cells. In addition, serum angiotensin-converting enzyme and lysozyme were elevated, and therefore a diagnosis of sarcoid myopathy was made. Further, renal sarcoidosis was revealed with renal biopsy. Prednisolone (40 mg/day) improved both the myopathy and nephritis. Sarcoid myopathy is a rare condition, but it should be considered when myogenic enzymes are elevated in the patient with systemic sclerosis. Further, muscle biopsy may be essential to make an accurate diagnosis in such condition.