PT  - JOURNAL ARTICLE
AU  - Shumpei Yokota
AU  - Yasuhiko Itoh
AU  - Tomohiro Morio
AU  - Naokata Sumitomo
AU  - Kaori Daimaru
AU  - Seiji Minota
TI  - Macrophage Activation Syndrome in Patients with Systemic Juvenile Idiopathic Arthritis under Treatment with Tocilizumab
AID  - 10.3899/jrheum.140288
DP  - 2015 Apr 01
TA  - The Journal of Rheumatology
PG  - 712--722
VI  - 42
IP  - 4
4099  - http://www.jrheum.org/content/42/4/712.short
4100  - http://www.jrheum.org/content/42/4/712.full
SO  - J Rheumatol2015 Apr 01; 42
AB  - Objective. To identify macrophage activation syndrome (MAS) in patients with systemic juvenile idiopathic arthritis (sJIA) undergoing tocilizumab (TCZ) treatment, and to confirm laboratory marker changes and responses to treatment in patients with MAS receiving TCZ. Methods. In Japan, 394 patients with sJIA were registered in an all-patient registry surveillance of TCZ as of January 15, 2012. TCZ (8 mg/kg) was administered every 2 weeks to patients with sJIA. MAS, hemophagocytic lymphohistiocytosis, or Epstein-Barr virus–associated hemophagocytic syndrome (EB-VAHS) was reported in 23 of these patients (25 events). The Safety Evaluation Committee of Tocilizumab for JIA reviewed these cases and clinically evaluated the data and laboratory findings using their own therapeutic experience. Events were categorized into 4 groups: definitive MAS, probable MAS, EB-VAHS, and non-MAS. Results. The committee’s review revealed 3 events of definitive MAS in 3 patients, 12 events of probable MAS in 11 patients, 2 events of EB-VAHS in 2 patients, and 8 events of non-MAS in 8 patients. There were 2 patients who developed 2 events: 2 events in 1 patient were classified into definitive MAS and probable MAS, and 2 events in another patient were classified into probable MAS. In patients with definitive or probable MAS, common clinical manifestations and laboratory findings of MAS were observed. Changes in laboratory data observed in patients with EB-VAHS were similar to those observed in patients with MAS. Conclusion. These results suggest that the clinical/laboratory features in the course of MAS appear to be similar among patients regardless of whether TCZ is administered. Similarities in the pathophysiological background of MAS and EB-VAHS were also suggested.